C-18 Performance Mods

[Turbochad]

I restored a 16 last year and this year I purchased the boat I plan to keep for a while, a super low hour, pristine 2005 C-18. It came with the Mag 350 MPI/ Alpha package, captains call, transom mufflers. I am in Denver and most of the lakes we run on are above 4,000' elevation. The 18 is nice with the MPI setup for changing altitude, but just not enough power at altitude for serious man fun.

Over the winter I am planning a major performance enhancement of the power unit/drive and i wanted to see if the knowledge base here agrees with my approach to this boat. We travel a lot to different lakes throughout the west and the 18 is the perfect size boat for our use. We do a fair amount of pulling skiers and toys so the boat needs to be pretty versatile. I like everything to be fast so it needs top end. Here are my requirements:

1. 80mph at any altitude. Retain factory fuel injection system and run on pump gas. Retain the single point water drain system.
2. Good hole shot for pulling skiers
3. Nice cruiser for evening wine cruises with the wife and friends. Not too loud from inside the boat, sounds great outside.
4. A performance transom look, but with a swimstep for water/ beach loading.
5. Not concerned about spending money to do it right
6. Good ride, handles great at all speeds
7. Good reliability and room for performance growth
8. Basically, your classic sleeper that delivers surprises and smiles

Here is my plan:

1. Keep the 350 Mag as is (75 hours) and add the whipple supercharger kit for the late model MPI system. Add an oil cooler. I already installed SM exhaust manifolds and the mercuiser Smart Vessel Mobile. The whipple setup nets 450Hp with almost no loss at altitude and loads of torque. From what I have read, 450hp should get me to 80 no problem. I'll add Livorsi fuel pressure guage and boost gauges to the dash.

2. The Alpha should really go because of the whipple, so I am planning on replacing it with a Bravo X 1.5. I'll pull the motor and replace the transom assembly with a new Bravo unit. I am thinking of keeping the Bravo lower because of the pulling and not go with a shortie given that top speed is not the only goal. Either a Mirage + or Hydromotive IV prop, and drive shower. While the engine is out I will probably just remove the through prop exhaust option and run transom only. The stock Corsa mufflers are quiet enough. Add Bravo sea pump and plumb for transom hose hookup.

3. I already purchased a set of Mayfair 12" K planes. I am going to set them up so I can still fit a set of Imco steering rams on the transom and run the Brazil cable setup for the steering. Looks like the outer edge should be right over the outer chine.

4. I want to add a pair of Eddie Marine billet swim platforms (red) under the exhaust mufflers right above the waterline. In the west you are always on a beach, and in the water, so you need to be able to get in and out from the back. I have looked at all the options and this seems to make the most sense to me. There is just barely enough room on the transom to do this along with everything else when planned together.

5. To round things out I already acquired a Hardin marine set of billet controls, new Sony satelite/ USB/ Bluetooth head unit, wet sounds speakers, 10" powered sub, Accon pop up cleats, Accon pop up LED bow light, and steering wheel mounted trim controls.

So here are a couple of questions. Does this plan seem to be the correct approach to achieving my goals? Would a shortie make the boat basically non-skiable? I am really shooting for an epic classic here. Something that really stands out but is good for more than just fast passes.

Thanks for the reactions and input.

Chad

[Greg Guimond]

Hopefullyosur866 will see your post. He has tremendous experience with where you are going. Is that an "open channel" steel trailer? I have been looking for one, who makes that?

[Turbochad]

Yes, osur866 seems to have the most experience here, along with Skilling. I have read most everything he has posted on his development. I am most interested in his opinion on stock Bravo vs shortie lower and effect on pulling skiers/ toys.

It is an open channel trailer. It is a Trail Rite out of Santa Ana, now out of business. Performance trailer in SoCal has taken over most of their business.

It has the folding tongue and surge disk brakes. The boat sits at a nice rake on the trailer and low in it for easy deployment. I added the ratchet tie downs and the F2 winch. I also clear filmed the fenders and forward rails to protect the paint. It tows like a dream.

[smokediver]

Instead of going with a bravo water pump I would go with a crank mounted one.
You won't have to worry about your present serpentine set up and impeller changes will be much easier. Also , I would consider drive ratio. If you were to drop down to a 1.36 that would put a lot more propellers in the mix. Having said that , there very well could be a good reason most use a 1.5 ... Also , Mercury used a 1.68 ratio for altitude so do a little digging on that subject. First and foremost you are going to want to check your bilge for cracking around the stringers where the L brackets are bolted. My 2004 18 had some cracking in the bilge area that needed to be fixed. The old saying safety first applies here. You need a full hydraulic steering setup , not the cable driven kind. As others have said , Steve will be a great resource to you !!

[Turbochad]

Instead of going with a bravo water pump I would go with a crank mounted one.
You won't have to worry about your present serpentine set up and impeller changes will be much easier. Also , I would consider drive ratio. If you were to drop down to a 1.36 that would put a lot more propellers in the mix. Having said that , there very well could be a good reason most use a 1.5 ... Also , Mercury used a 1.68 ratio for altitude so do a little digging on that subject. First and foremost you are going to want to check your bilge for cracking around the stringers where the L brackets are bolted. My 2004 18 had some cracking in the bilge area that needed to be fixed. The old saying safety first applies here. You need a full hydraulic steering setup , not the cable driven kind. As others have said , Steve will be a great resource to you !!


Thanks! I will look into all of the above.

[Turbochad]

What is wrong with using a Brazil Manifold to control the steering rams? Is the main goal to get rid of the cable system altogether?

[Turbochad]

Today I laid out the transom. I confirmed that I can fit the Mayfair K Planes, Dual IMCO Steering Rams (6.35" offset) and Eddie Marine swim steps all on the transom together. The swim steps should be just above the waterline. I am going to have to make adjustments to the brackets because the transom curves and does not have the same vertical angle on the outer bracket. I should be able to just shave off the material and retap the mounting hole. The layout still allows for me to tie the boat down by the rear eyes.

I don't think the swim steps look too bad, at least everything works together. All of my gauges, bezels, controls and speakers are platinum color so I ordered a set of the swim steps in clear anodized to compare. I got these red ones for the 16 and never put them on. So what do you think red or platinum?

[yeller]

The swim steps look good. They're only noticeable because the boat is on the trailer, but I like them. When its in the water they'll be the perfect height and look like they'll sit right on the water line. Good choice. :thumbsup:


The K-planes mounting plate may not fit flush to the transom. At least that's the issue I had with the trim tabs on my 22.
You may have your own plan, but this is what I did to make them fit on mine. (See post #55)
http://www.donzi.net/forums/showthread.php?67302-496HO-to-502/page4

[Turbochad]

The swim steps look good. They're only noticeable because the boat is on the trailer, but I like them. When its in the water they'll be the perfect height and look like they'll sit right on the water line. Good choice. :thumbsup:


The K-planes mounting plate may not fit flush to the transom. At least that's the issue I had with the trim tabs on my 22.
You may have your own plan, but this is what I did to make them fit on mine. (See post #55)
http://www.donzi.net/forums/showthread.php?67302-496HO-to-502/page4


Thanks for sharing the thread. Good solution for the spacer. They aren't flush so I am going to have to do something similar. I have to fit the swim steps too.

[Pat McPherson]

Are you sure you need to ditch the Alpha drive? Lots of guys running 400+HP strokers thru Alpha drives. If yes, I believe the Bravo is longer so you'll need a shorty. Also the Alpha SS runs good on the 18s so a short drive works.
The cable helm has slop but it debatable if just adding the dual external rams is enough.

[Turbochad]

Are you sure you need to ditch the Alpha drive? Lots of guys running 400+HP strokers thru Alpha drives. If yes, I believe the Bravo is longer so you'll need a shorty. Also the Alpha SS runs good on the 18s so a short drive works.
The cable helm has slop but it debatable if just adding the dual external rams is enough.

Pat, I was thinking that with the whipple the torque would likely destroy the Alpha, so it seemed best to just get the Bravo done while I have the motor out. I was going to pull the motor for ease of installing all the stuff on the transom, and at the same time change the gimbal assembly, remove the prop exhaust manifold, do the steering, clean the bilge, and set everything up. It is a real pain working around the motor. It is a bunch of dough to change it but the B1 just gives you more options.

[yeller]

Thanks for sharing the thread. Good solution for the spacer. They aren't flush so I am going to have to do something similar. I have to fit the swim steps too.FYI: If you do try the same thing, don't fully tighten the mounts when setting the putty. Just snug them up. If you fully tighten them, you will flex the mount and/or the transom and defeat the purpose of making a form fitted spacer.
The ones I showed in the thread were my second attempt. :lookaroun:

[Turbochad]

Ok my plan is coming together. I ordered the Whipple kit. I am going to run it on the stock motor until it times out (only has 75 hours) and then rebuild it to a 383. I also acquired a new Bravo transom assembly. I am considering for this winter installing the swim steps, k-planes, whipple kit and all associated detail stuff this year and leave the alpha on for next summer. Then after next season pull the motor, change the transom assembly and do the drive swap. Thinking Bravo X or XR, hydraulic steering and shortie.

Question to the community. The whipple uses a water dump for the intercooler. The alpha water pump is already woefully undersized for the job and does not generate enough pressure to keep the exhaust tips cool because most of the water falls out the bottom of the diverter. I am thinking I need to go to a raw water pump and transom pickup when I install the whipple. A couple of questions.

1. What is the best transom pickup for the 18? I have heard lots about the Stainless Marine unit, but which one, the high speed (tube) or low speed design (square)? I would think the high speed one would be better.
2. Regarding the Alpha pump. I have read that you should just cap the gimbal spigot coming from the drive and that the water will still circulate in the drive. Is there some pressure relief valve in the drive that allows the pumped water to dump somewhere?
3. Has anyone here used a crank driven pump on a SC motor? I can figure this out when I get the kit but it seems to me that there may not be a mounting surface on the SC crank pulley suitable for mounting the pump. I may have to go with a Mercruiser gen 7 type pump.
4. I am considering a sand strainer as apposed to a sea strainer. Most of the lakes we run in the west have more small particles and the intercooler really needs to stay clean. Should it be mounted high or low in relation to the pump?

Thanks,

Chad

[gcarter]

Stainless Marine makes some very nice transom pickups. You can remove the pump impeller out of your
Alpha, along with the hose connecting the drive and gimbal. You also need to block the water passage
inside the gimbal. Merc makes a block off plate and gasket.
A Johnson crank driven raw water pump will deliver all the water you can use.
Look here at the Johnson F6-B9 for $189.00.
http://www.marineexhaustmanifolds.com/raw-water-pumps.htm

Here are some pictures from several years ago during rigging:

[Turbochad]

Stainless Marine makes some very nice transom pickups. You can remove the pump impeller out of your
Alpha, along with the hose connecting the drive and gimbal. You also need to block the water passage
inside the gimbal. Merc makes a block off plate and gasket.
A Johnson crank driven raw water pump will deliver all the water you can use.
Look here at the Johnson F6-B9 for $189.00.
http://www.marineexhaustmanifolds.com/raw-water-pumps.htm

Here are some pictures from several years ago during rigging:

Thanks George. I had not thought of removing the hose between the outdrive and gimbal, very simple. I am assuming that what Stainless Marine calls the low speed pickup works fine on a Donzi at any speed. Good info on the pump.

With all the work to get the accessories in, I am thinking I may be best off to pull the motor. It is almost impossible to get at all this plumbing on an 18 with the motor in. I may just do the Bravo this year......

[gcarter]

Low speed is a relative term. These are good to ,I would guess, at least 100 MPH.
The bottom inlet angle can be ground to a flatter angle if pressure gets too high.
I have a pressure gauge on the dash and have never seen more than 6 PSI @ over
70 MPH. I also have a relief valve w/overboard dump but it's completely redundant.
The pictures are of my 22C Testa Rossa. There's a heat exchanger hiding at the
bottom of the rear seat also w/an electric circulating pump.

Good luck w/your project.

[Turbochad]

First, many thanks to all of the contributions to my project, they are very helpful. Some updates. I am ordering today the hydraulic steering setup. I am going with IMCO because of the low gimbal offsets they offer. I am using the 6.37” offset setup dual ram. I already ordered a Stainless Marine transom pickup and short sea strainer. I will plumb them much as George did with the hard pipe setup before the shut off valve. Once I get the steering system in hand I will begin the project. I already have a new Bravo transom assembly so I will be ready to go. I will get the drive before the end of winter. Plan is for an XR upper and IMCO 2” shortie lower 1:36 ratio. I got the new Corsa 600hp exhaust mufflers, so all set there. I am going to get rid of the captains call system because the mufflers are already quiet enough and I never use it in thru prop mode. That should give me a little more space around the back of the motor for access. I am guessing that the boat will be around 120-140lbs heavier because of all the new stuff.

One more thing. I am having a custom adapter made to run the Johnson crank mounted water pump off the Whipple supercharger pulley adapter. it will be a billet piece. My local race shop is making it for me to match the whipple adapter.

[Turbochad]

Holy Exhaust muffler Bat Man! These 600hp exhaust cans look the part. They have internal flappers so I can run them without exterior flaps. The back of this beast is going to look really cool with k planes, XR Drive with shortie, IMCO Dual steering, Dual water dumps, Livorsi LED lighting, and swim steps. There won’t be an inch of real estate left on the transom. I got the boat apart today and ready to pull the motor, I just need to get lift space so I can get it pulled. I may have to just take the 16’ and move it out of the shop to another garage. I should have the pulley adapter back next week so I will have all the parts needed to get going.

[Turbochad]

FYI, I am going to have some takeoffs for sale. I will price them based on condition once I have time to figure out what they are worth, They include:

Alpha Drive, and transom Gimbal assembly- 80hours, like new.

Corsa Quick and Quiet system complete- wire harness, diverters, 350hp mufflers, hoses, and clamps. Same 80 hours. Like new.

Mag 350 MPI exhaust manifolds and exhaust risers.

Mag 350 MPI intake manifold, throttle body, and fuel rail.

If anyone here wants any of these items let me know.

Chad

[Kirbyvv]

PM sent about the alpha package

[Turbochad]

PM sent about the alpha package

PM replied.

[Turbochad]

Ok, I got the sea strainer and transom pickup. I finished the design of the system and ordered a bunch of SS adapters from McMaster Carr and hose fittings from Hardin. I got a SS garden hose hookup off the strainer for land starts. I am going to put the strainer on the firewall behind the seats on the starboard side. I will move the second battery over to the port side. The strainer, hoses, oil cooler, and trim pump should balance out the two size 24 batteries on the other side. The two new trim pumps for the tabs will fit on the transom on each side now that the steering ram is no longer on the port side. Now I need to find out from George how far down exactly to mount the stainless marine transom pickup. I am guessing that the bottom of the boat should be flush with the leading edge of the pickup and then you can file the back edge down as needed? Also, do I need a bracket to hold the crank pump in place or does the tension of the hoses on the pump enough? Guessing I need a bracket?

[Turbochad]

I got the crank adapter back from my race shop. If anyone else ever needs an adapter between a Whipple crank pulley and a Johnson crank driven sea water pump here is the drawing. If you have to ask what that part cost you shouldn’t be putting a supercharger on your boat. I also got the Livorsi Fuel Pressure guage and Manifold Pressure/ Vacuum guage. It turns out that buying the boat is always the least expensive part for me. I can’t leave anything alone. Getting closer to D day when I will get to installing everything.

Does anyone have a good suggestion on who to deal with to get a new or like new condition Bravo XR upper unit? There is a reman unit on ebay for $4,800. I would love to find someone i could deal with on an reman or new upper and 2” IMCO shortie as a package deal.

[Turbochad]

Ok, before I pull the motor I am getting all the other stuff done outside of the engine compartment and transom. I picked up a wet sound 6 channel amp, (2) 6.5” speakers, (2) 8” speakers, and a 10” sub. I mounted the amp under the deck by installing rivnuts in the inner layer of fiberglass, and using them to mount two aluminum straps to the deck that can be threaded for mounting the amp. I installed the two new 2 5/8” gauges, a fuel pressure guage, and boost/vacuum guage. I also put in the hydraulic helm. I had to get a trim plate from IMCO to cover the factory holes from the old helm. I mounted trim buttons on the steering wheel and got the trim tab panel mounted. I bought new GPS speedo and tach in carbon fiber as an accent on the dash.

Next I will get all of the wires run, remove the old steering cable, and install the four hoses to the helm. Once I get all of that complete I will be ready to pull the motor and get the business done.

Update 1/14- I decided to add LED light rings to the speakers and a LED controller. I also got the new billet stereo cover on and the speaker wiring.

[Turbochad]

Transom is starting to come together. There is not a square inch left unused on this transom, but so far everything fits. I used a laser level to set up all the locations (I did level the boat first). I ordered all my hardware including EM Billet stringer washers for all the through transom bolts so everything is sano. Next I need to get the k-plane holes drilled, and make the resin transom shims for them. Once everything is drilled and all parts dry fitted, with hardware, I will take it all off, pull the motor, install the new Bravo transom assembly, paint the bilge, install all the transom gear, and reinstall the motor. Then I can finally put on the supercharger, which is the whole reason for doing this project, whew....

I did a spreadsheet weight analysis and it appears I am adding close to 170# to the boat including all the stereo gear, supercharger, and drive change. I did my best to move as much of it forward in the engine compartment as possible because a fair amount is on the transom (100# over stock alpha). I also balanced it out laterally so the boat is even side to side with my wife and I both in the boat. Packaging in the 18 is tricky.

I need to start thinking about the drive. I am planning on a Bravo 1 XR upper and either a -2 Sport Master or -2 IMCO SC lower. I am on the fence about whether to go 1:50 or 1.32 ratio. At 1.5 I will be at a 27P M+ and hit 85 at 5400 RPM if all goes to plan. At 1:32 and a 25P M+ I will hit 85 at 5200. That should be top speed with this setup. Looking at the archives it seems that the 18 like 3 blade props the best with the M+ and Turbo 1 as the preferred props.

[yeller]

Looking good.
From what others have said in the past, the Sport Master does not work well on the Classics. Don't know the reason why, but I know they've been tested in the past and the results weren't good.
IMO, unless you're buying a brand new IMCO, I'd just look for a good a deal and not worry too much about gear ratio. Still lots of prop choices available in the 27~29" range. I'd look specifically for a 1:36 if you thought you'd need 30" and up, as the choices get smaller and more expensive.

[craigdskilling]

Looks like a great build doing everything awesome. Drives I would say Blackhawk they love the 18 teens boat the drive and ride like they are on rails I know.😁😁

[Turbochad]

Yeller, I really appreciate all the good advice. I am all set up to make that shim as you outlined in your build. There a ton of curvature in the transom on the 18. I was planning on the IMCO shortie (probably new, they are hard to find used), I will certainly stay away from the sport master.

Craig, I would love a Blackhawk, but I want to be able to tow skiers and I have heard that they don’t pull well. Maybe you have input there. The other issue is now I have steering rams for a B1. I have heard that a -2 shortie works pretty good, not as fast as BH for the same power, but handles well too. By the way, what is your thought on whether or not I should feed the intercooler water before the raw water pump or after? Isn’t yours is on its own separate transom pickup that is force fed with no pump, right? Mine is going to utilize a single transom pickup 1-1/4” for the intercooler and the engine cooling in combination with a sea strainer and crank driven pump. I will call Justin at Whipple to see what he has to say on this but I thought you might have some insight here.

General Comment: The toughest part of this build is all the transom work. I have really loaded up the transom with all manner of gadgets. I am being extremely careful in preparing the layout and drilling the holes. The Mayfair K planes came with templates that they said were good for use in drilling holes. Upon measurement, they were way off, that was disappointing. Luckily I caught it before I drilled the holes. My hull is 2” all the way across the transom because it is a Coosa boat, so all the holes have to be perfectly at the correct angle for the parts to sit flat, or as intended on the surface. The K Planes are a real challenge, but the swimsteps aren’t much better. Both require custom shims and special mounting. The last critical piece once everything is ready will be to get the seal perfect. These through bolt parts concern me. I have added 35 transom hole penetrations......

[yeller]

My intercooler is plumbed after the raw water pump and oil/steering cooler, but before the heat exchanger.
Never had a shortage of water.

I don't know how the BH would act on an 18 for skiing, but it wouldn't pull a skier up very well on my 22.
The increased planing time was one of the things that surprised me with the BH. I had anticipated that the dual props would snap me out of the hole, but that wasn't the case. Much quicker planing time with the stock Bravo.

I swapped drives once with a friend that had a -2 imco. The differences (on my boat) between the Bravo, Imco and BH were, that as the prop went up:
High speed handling improved.
Top speed increased (although some, if not all, was because of the above)
Porpoising increased.
Planing time increased.
Don't take any of this as fact. I stress that this was on my boat. Your boat may react differently

[craigdskilling]

For my set up I put a stainless Marine adjustable pick up on the back lower transom,and when I found the right spot which is not very low below the hull I welded it. Then 1"1/4 line to my see strainer and from there to my cooler and plumes it out beside my pump out hole. I didn't want to take from the motor in case there wasn't enough water flow. Pretty simple just watch for your pressure I put a block pressure have in and boost presure have in.can send you picks just text me. Looks great. And I can still pull skiers and tube rider's no problem if they stay on to long I just bring my drive up a hair and there gone 😁😁

[yeller]

Craigs results with the BH (and planing) are obviously better than mine.....and probably what you can expect.
If you really want to snap a skier up, go with a jet drive. :biggrin.: Pulls super hard! We use to have fun with the tournament ski boat guys (that's pre-wake board boat times...for you youngins). They'd make fun of the jet, so we'd talk them into doing a beach start behind my boat. They'd always take two or three coils of slack....and then I'd hammer it. Often, it would literally pull them right out of their ski.......and their arms were considerably longer after that. :biggrin.:

[Turbochad]

For my set up I put a stainless Marine adjustable pick up on the back lower transom,and when I found the right spot which is not very low below the hull I welded it. Then 1"1/4 line to my see strainer and from there to my cooler and plumes it out beside my pump out hole. I didn't want to take from the motor in case there wasn't enough water flow. Pretty simple just watch for your pressure I put a block pressure have in and boost presure have in.can send you picks just text me. Looks great. And I can still pull skiers and tube rider's no problem if they stay on to long I just bring my drive up a hair and there gone 😁😁

Craig, you always make me laugh! My dad would do that to me with the jetavator on our jet boat when I was a kid. If I didn’t ski the way he thought I should he would pull it up and blast me off the ski!! HA

[Turbochad]

Ok the Swimsteps are done. This was not a simple bolt on operation. I chose the Eddie Marine 24” clear anodized steps with the 12deg transom brackets. If you tape off the waterline on the sides of the hull these sit paralell to the water with the boat at rest just 2 inches above the water. That is true if the inner brackets are mounted flush to the transom. The outer brackets then don’t sit flush because of the transom curvature, so you have to make a wedge shim for each outer bracket. Eddie won’t make custom brackets for one off installations so I made these myself. I got some hard anodized bar stock from McMaster Carr and made two of these shims. All of the exposed surfaces are the anodized finish, the machined surfaces are mating. Then the holes in the transom have to be angled up for the whole thing to sit flush. It all turned out great, but it was a process for sure. I used Eddie Marine billet stringer washers and 316 SS cap screws on the inside of the transom with cut to length 316 SS threaded rod for the hardware. These are not glued on yet.

Also, I spoke with Dennis at Whipple and he says that if the sea water pump can maintain the minimum pressure with the intercooler on the same circuit then it is preferable for it to be after the pump but before any other coolers. So the plan stays as is. I fully expect the Johnson pump to have no problem maintaining good pressure.

[tmdog]

I like it. Neat install and well thought out.:)

[Carl C]

Chad, this looks like a cool project and it's coming along nicely! Where did you get the swim platforms and what will you use for a ladder?

[Turbochad]

Carl,

The platforms are from Eddie Marine, 24” wide with 12deg transom brackets. The bracket spacing works good on the 18. With the kplanes right underneath though, the only type of ladder that might fit would be the slide out Amarine type. I have not verified yet which one will fit. I may not put a ladder on at first and see if I can get away without it. The platforms are templated with holes for an aqua step pull down retractable ladder, but there isn’t room on the 18 for a pull down ladder.

[Carl C]

Thanks for the info. After 13 seasons of climbing the drive I'm ready to install an easier method of boarding. I feel lucky that no one has cut their foot on the propeller yet and heavy people can't even swim because they can't get back in the boat. I think just one swim platform like yours with a built in ladder would work nicely.

[chip w]

Carl, the next thing you know you'll be putting a bimini on your boat! :eek:

[Carl C]

Carl, the next thing you know you'll be putting a bimini on your boat! :eek:

....

[Morgan's Cloud]

....

Bimini ? baah !

I recommend anti-fouling paint ! :biggrin.:

[Ghost]

Bimini ? baah !

I recommend anti-fouling paint ! :biggrin.:

I laughed out loud. :)

[Turbochad]

Thanks for the info. After 13 seasons of climbing the drive I'm ready to install an easier method of boarding. I feel lucky that no one has cut their foot on the propeller yet and heavy people can't even swim because they can't get back in the boat. I think just one swim platform like yours with a built in ladder would work nicely.

Carl, Here is the aqua step ladder that is meant for this swim platform. I got one just to see if it might work with the K planes. It doesn’t on an 18, not sure about a 22. It is a great ladder because it self retracts and is very simple.

[Carl C]

Carl, Here is the aqua step ladder that is meant for this swim platform. I got one just to see if it might work with the K planes. It doesn’t on an 18, not sure about a 22. It is a great ladder because it self retracts and is very simple.

Thanks, I will look into that. Not quite ready for a bimini, bottom paint or cupholders yet! If I can ever teach someone to drive this boat maybe I can ski again.

[Ghost]

FWIW, always thought some of these could also work well and take up less space. Depending on what folks are really wanting.

http://www.perko.com/catalog/deck_hardware/632/fixed_step/

http://www.perko.com/catalog/deck_hardware/660/fixed_step/

http://www.perko.com/catalog/deck_hardware/630/folding_step/

[yeller]

Ghost, I've thought about that 3rd one you posted. Mount it down low as possible, just to get that first step up to the drive.

I've also thought about using one of these:
http://www.garelick.com/Telescoping-Stain-Less-Steel-Sport-Diver-Ladder
along with one of their brackets so the ladder is removable:
http://www.garelick.com/Standard-Transom-Mounting-Bracket

Chad, that type of ladder might work for you if you used their swim platform mount:
http://www.garelick.com/Platform-Ladder-Mount-Bracket

I don't have the guts to cut the required hole in my transom, but take a look at the ladder at 2:45 of this video:
http://www.garelick.com/Boarding-Ladders
I think it's a pretty cool idea.


Of course, with the type of boating I've been doing the last several years, I've been making do with one of these

86384

[Carl C]

Chad, in post #42 you show a ladder. Is that ladder also from Eddie Marine? Do you have a part number? I started a new thread to deal with this and you can answer there if you want so we don't keep cluttering your awesome build thread. Thanks. http://www.donzi.net/forums/showthread.php?71782-Need-22C-Boarding-Ladder-Ideas&p=669330#post669330

[Turbochad]

Ok. I’m working on finishing this project. I need my boat in the water, we have a trip in two weeks to Bear Lake in Utah. Must have a boat. I have been side tracked with my new Can-Am Maverick X3 RC Turbo R buggy. I sold the 16. Toys are a lot of work.

I have been working on getting all this transom hardware installed and glued on the last couple days. What a PITA. I think it was Yeller who pointed to the solution to mounting K planes on a classic transom. Ok, so you need a shim because the transom is curved. I ordered the poly resin, and made them. It also took me two tries to get them right on each side. The whole process of getting K planes on these boats, proper, sealed and done right is simply insane. I can’t imagine anyone other than a crazy hobbyist doing this because of how much work it is. Go with Lenco trim tabs, forget this, don’t do it. Well, they are on and done, and I am the nut job for doing them. I just finished installing all of the transom hardware including the new Bravo transom assembly. This is the most packed Donzi transom I have ever seen, it is crazy. It should look cool with the drive and shortie. Clean boat, crazy transom.

Now I have to get the sea water plumbing done along with the wiring and hydraulic steering hoses done in the compartment. After that I will get to work on the engine, which at this point is just hanging from my hoist. I have to get the Bravo coupler installed and then prep it for installing the supercharger.

I ordered an XR upper and a IMCO 1:50 -2 Shortie with a 1.25” shaft. Overkill like everything else. I am thinking of getting a labbed Mirage + 29P for a prop. I have a call into BBlades to discuss other options. Not a lot of data for 18s with HP and a shortie.

I should have to motor in and whipple on by the end of the weekend. Next week I should have the drive on and ready to get it running on the hose. Two weeks, sea trial on local lake before we head off to Bear lake for a week. We’ll see if this thing will do 85mph at 7000 elevation. If it does, goal achieved, if not, the motor comes apart and I will build a performance 383 for the whipple......

[Turbochad]

Some photos of the process.

[Turbochad]

I need some input. I have a transom pickup for all raw water now and blocked off the back of the transom assembly. I am thinking based on previous feedback from the group that I should remove the hose in the gimbal so that the water pickups on the drive will circulate cool water through the drive. Is this a for sure deal? I don’t want to cut the hose unless that is the best way. I have not heard that the XR drive relies on the water circulation for cooling. I know the alpha does. What say the Donzi mafia, cut the hose?

[yeller]

Love the look of a whipple on top of an engine!



Ok. I’m working on finishing this project. I need my boat in the water, we have a trip in two weeks to Bear Lake in Utah. Must have a boat. Nothing like giving yourself too much work and not enough time to get a project finished. :)

[Turbochad]

I have been hard at work for five days straight. I am close to being finished with the hull rigging. I will get the oil cooler buttoned up and painted tonight and finalize the water hose install. Probably a good time to prime and bleed the trim tab and drive rams, and test all the new electrical. I have a little work yet at the controls.

Then on to the motor. I have to swap out the Alpha drive coupler for a HD Bravo coupler and then get to work on the Whipple install. I will get the manifold on the motor out of the boat, put the block back in the boat and finish the blower install in the boat.

I am ordering a prop today. I am either going to get a Mirage + 27p labbed or a Turbo TXP 27P labbed as my general use prop. 1:50 ratio on the drive that puts me a 85mph at 5400ish. Until I have a built motor that is all she will likely do on the stock block.

I plan to get the boat in the water on the 20th. I should have it on the hose on the 18th.

[smokediver]

I don’t think a 27 at that rpm will get you to 85. And I would guess a 4 or maybe even a p5x is going to be your better option if you are going to run a shorty. My 2 cents

[Turbochad]

Smokediver, although I don’t have facts to back this up, my understanding is that I can expect around 8% slip with the shorty which is the same as I had with the Alpha. If that is the case then I should hit 85 at 5420. My only data on props at this point is what Ours888 has posted and he didn’t leave much detail. I know he tried a 4blade but had concern that it would create too much stern lift on a 18. For now I am going to just use my 25P Mirage+ For our first outing and see how it handles at the top, and what my slip #s are before I order what I need to get the speed.....

[smokediver]

Ok , I hope it works out and my only experience with a shorty is on a 22 so i am sure it will be a different outcome on the 18.

[gcarter]

Sorry I haven't looked at this thread for awhile. The project looks great.
The water from the drive could be used for an intercooler, otherwise, just remove the transom hose. You'll find the drive will supply plenty of water for drive cooling, and then it dumps back into the water.
The strainer can be located a few inches below water line if necessary, if the lid is removed, a "very" small amount of incoming water will help remove any unwanted debris. The important thing is to choose a strainer that isn't self draining. It's better to have the strainer and everything down stream wet all the time. I've been foolish enough to forget to turn the the garden hose on, and havin a full system will give you a few seconds to correct things.
Good luck! I hope everything works well for you.

[Turbochad]

George, thanks for the confirmation. I’ll take the hose out. I already blocked it off inside. Per your recommendation I am using a Johnson pump so I am running the intercooler after the pump but before any other coolers. I got the Stainless Marine strainer that has a pressure relief on it to pre-relief any pressure created at speed from the transom pickup. It has a dump at the back. The water pressure gauge is after the pump. I think the water system is good, and after last night I confirmed everything fits.

The motor is finally in the boat. What a fiasco all the Whipple wiring is. You have to take the whole engine harness apart remove a number of circuits, install some, and move or extend others. Then repackage the whole thing. This is the worst part of the kit install. Otherwise, just an interference exercize making sure everything fits where it goes. Engine install requires a 90deg to port front of engine alignment then rotation once it is under the deck. I used quick connect fittings for fuel and PS hose return. Only had one interference issue, the water hose on the starboard side had to move outward to avoid the fuel filter/separator console. Aligned the engine. Hooked up all the water and oil hoses. At the front of the motor, the long crank snout with the SC pulley and water pump all fit nicely with just enough room to service the pump. The water shutoff valve for the transom pickup just barely fit, and is the only installation alignment that will work on this setup. The SC just misses the hatch strike console. It is like fitting 10# of $h!t into a 5# bag. Anyway, it all looks good and appears to be on the money.

The shortie showed up last night, just in the nick of time. I spoke with Bret at BBlades and he agrees that most likely a 3 blade is going to be best, but he wants me to try a Bravo 1 also. I am going to get him data on the Mirage 25+ for him to look at and make recommendations. I bought a rebuilt XR that needs a refinish to be perfect, so I am going to shoot that in automotive paint. The epoxy base is good so I just need to paint. If I can get exhaust hose in time, I will have this thing in the water this weekend, or Monday at the latest. Still lots of installing and checking to do. The good news is no major problems at this time, hopefully she is all good the first time out.

[Morgan's Cloud]

Looking very nice . You have a good eye for detail . Can't wait to hear how it runs .

(And the next time your car mechanic says he can't fix something for you because he can't reach it ,or whatever , tell him to grow up :kingme: )

[yeller]

Looks good in there. :yes:

[smokediver]

Looking great !

[Bobby D]

Very nice work it’s obvious that you have put considerable time and effort into your project.

FWIW, the angle and location where you installed your ski tow eye will see side load due to angular loading on the eye bolts. An experienced skier will put a large amount of tension on the tow eye that will vary when the load is drifting or moving dramatically over to another location. The thickness of the deck material in the area where the threaded shank and bolt is installed is not very thick as opposed to the amount found in the transom that is much thicker and more robust and will allow for a straight pull as well.
Did you reinforce this area prior to installing the ski tow? Even if the eye comes with a backing plate you may want to add a large block of wood, or an aluminum plate to spread the load over a large area of fiberglass to insure it does not crack or worse yet pull out.

The fiberglass on my boat at that location is not very thick and even with a reinforcing block of wood and or plate of aluminum behind it I would be concerned about its strength.

[Turbochad]

I am almost certain that the existing ski tow was put there by the factory. On this boat the fiberglass is pretty stout there, not that I would put it there if it were me.

The problem pulling skiers on these boats is the rope angle is really low when getting on a plane. I bought, but have not installed, a towing pylon that is designed by Dana for a Hallett Bullet. It would be rigged in the hole where the lifting eye goes, and mounts to the gimbal housing, but I have not decided if I am going to install it or not. It would bring the towing point up about 24” above the transom.

[Donzi Z22]

Ok. I’m working on finishing this project. I need my boat in the water, we have a trip in two weeks to Bear Lake in Utah. Must have a boat. I have been side tracked with my new Can-Am Maverick X3 RC Turbo R buggy. I sold them 16. Toys are a lot of work.

I have been working on getting all this transom hardware installed and glued on the last couple days. What a PITA. I think it was Yeller who pointed to the solution to mounting K planes on a classic transom. Ok, so you need a shim because the transom is curved. I ordered the poly resin, and made them. It also took me two tries to get them right on each side. The whole process of getting K planes on these boats, proper, sealed and done right is simply insane. I can’t imagine anyone other than a crazy hobbyist doing this because of how much work it is. Go with Lenco trim tabs, forget this, don’t do it. Well, they are on and done, and I am the nut job for doing them. I just finished installing all of the transom hardware including the new Bravo transom assembly. This is the most packed Donzi transom I have ever seen, it is crazy. It should look cool with the drive and shortie. Clean boat, crazy transom.

Now I have to get the sea water plumbing done along with the wiring and hydraulic steering hoses done in the compartment. After that I will get to work on the engine, which at this point is just hanging from my hoist. I have to get the Bravo coupler installed and then prep it for installing the supercharger.

I ordered an XR upper and a IMCO 1:50 -2 Shortie with a 1.25” shaft. Overkill like everything else. I am thinking of getting a labbed Mirage + 29P for a prop. I have a call into BBlades to discuss other options. Not a lot of data for 18s with HP and a shortie.

I should have to motor in and whipple on by the end of the weekend. Next week I should have the drive on and ready to get it running on the hose. Two weeks, sea trial on local lake before we head off to Bear lake for a week. We’ll see if this thing will do 85mph at 7000 elevation. If it does, goal achieved, if not, the motor comes apart and I will build a performance 383 for the whipple......

If I'm understanding it right, The whipple kit comes with a new intake that has a throttle body and injection system. Then to cool the charge the cooler uses fresh water supplied to the super charger ?

[Turbochad]

If I'm understanding it right, The whipple kit comes with a new intake that has a throttle body and injection system. Then to cool the charge the cooler uses fresh water supplied to the super charger ?

Yes, it is the whole intake system, manifold, injection, TB, everything.

[Turbochad]

Update for the Archives

Many of you have seen my updates on the DMRS Facebook page but I wanted to do it here for the record. I finished the build. All told it was probably close to 300 hours to plan, gather parts and execute the build. Cost, who knows and I don’t want to add it up. Here is the final build sheet:

Base boat: Stock 2005 C18, Mag 350 MPI Alpha, 80hours, no tabs, captains call, Mirage + 25P (repropped to 21P for 6,000’)

Mods: Switch to Bravo, XR Upper, Imco 1.5 -2 Shorty, Imco Full Hydraulic Dual Ram Steering, Hardin Marine K planes, 24x16 Eddie Marine swim platforms, Shadowcaster underwater LED transom lights, Stainless Marine manifolds, Stainless Marine water pickup, Stainless Marine Sea Strainer, Johnson Crank Driven Sea Pump, Whipple Supercharger Kit, Whipple Oil Cooler kit, Corsa 6.5” internal flapper mufflers, Hardin Billet Controls, GPS silver carbon face Livorsi Speedo, Matching Livorsi Tach, Livorsi Fuel Pressure Guage, Livorsi Boost Guage, Isotta Steering wheel, Steering wheel trim control, Wetsounds Sinister SDX-6 channel Amp, Wetsounds (2) 8”, (2) 6.5”, (1) 10” coaxial speakers with LED rings and controller, and Wetsounds cabling.

Goal: 80mph at any altitude (up to 6000’), able to still pull skiiers and water toys, easy water boarding, and supremely cool

So I finished the build and we took the boat to Bear Lake in Utah for a week. The boat ran great, I only had two things come up that needed to be addressed after our local test run (2hrs). One, a bolt almost fell out of one of the swim platforms (never tightened) and the other was the supercharger belt tensioner wasn’t tight enough and once the belt broke in it jumped two grooves and shredded off one belt groove. I identified both issues before we lost anything and for the remainder of the week it all worked great. The real problem was that I didn’t hit my speed goal. I took a 27P mirage + with me and left my 25P mirage + at home thinking if anything I would be under propped with the 27. Boy was I wrong. I really underestimated the effect of altitude. With a 3/4 tank of fuel, me, and lots of tries I was only able to turn 4200rpm and 65mph GPS. Stock with the Alpha (1.62) and a Solas Titan 3 21P I ran 56 at 5000rpm (less fuel). So I have been out on the inter webs looking at forced induction forums and built a spreadsheet model that calculates MAP (manifold absolute pressure) at set boost levels and supercharger pulley ratios at different altitudes. Man is that interesting. To make a long story short, I am making a little over 380hp at 6000’ with at 7.5psi sea level boost setting (6psi guage pressure at 6000’). The Whipple kit comes set up with 5-6PSI at sea level pulley, and I got a single size smaller top pulley so the setup is 7.5psi at sea level thinking that would be enough to compensate for the altitude loss, wrong! Turns out that 6psi at sea level = 20.7psi MAP, and a 7.5psi at sea level pulley setup = 17.79psi MAP at 6000’. Also you are limited in the ability to speed up the compressor to compensate for air density because the charge air temps go up in relation to the compressor speed and ratio. I am not sure where that boundary lies yet on trade off, but I have a call in to Dustin at Whipple to find out.

So I was way off on propping for this trip. Had I taken the mirage + 25P the spreadsheet says with 380HP I could turn that to 77mph. All slip is 8-9% which was consistent with both the Alpha and shorty. That is hard for me to believe, but I can see getting to 75 on Bear Lake with this setup. So that is that, I have what is likely an 80+ boat at sea level, but not where I run. Options are to leave it as is or build a 600hp sea level whippled 383 with alum heads so I can have a 480Hp boat at 6000’. That will get me into the 80s no problem and still run nice on 91 pump gas. We’ll see.

The shortie: the boat needs tabs for cruising between 30-48mph to stop porpoising with the stock M+ prop. Above 50, tabs up. WOT, and a little trim and the boat sails. Planes easily as long as the boat is not fully loaded. Full load requires finesse to plane or the prop cavitates. I am at 5.5” below the bottom. No problem pulling skiiers, just no sharp turns at low speed or prop cavitates. In water conditions above 3’ waves it is hard to keep the prop from cavitating if you are at speeds that don’t freak out your passengers (30mph). The drive looks amazing, and needs very little trim to air out the boat. Handling is very nice and precise. The stock 27P M+ Has a little chine at WOT and trimmed out, I hear that this is normal on that pitch M+ without labbing.

Other aspects of the build: The swim platforms were a HUGE hit. Everyone loved them, myself included. No more climbing the drive, which is not easy now with the hydraulic steering. The steering is amazing and so precise. The tabs are essential with the shortie, and I love the K planes over basic tabs. The water system worked perfectly and pressures were ideal. Overall, I am really pleased with the whole build. I know I will get the speed sorted out, it is just a matter of physics. I built the whole system to handle a 600hp 383 anyway so I may just go there. Long blocks are relatively cheap and an easy swap. I will do some propping first and get a better sense of where this setup maxes out and whether a 3 or 4 blade setup works best for what I use the boat for. A forum member is lending me a labbed B1 27P to try out. I will do it here at 5000’. The boat should be able to turn it to around 75. All of the other stuff is awesome, the lights, the stereo, and all that. It really gets attention at the dock and on the lake. I am not comfortable yet with letting anyone else drive the boat. It is too complicated and picky without a lot of practice. I hope to make it easier once I get it propped right and tab indicators. My daughter wants to drive. I will keep this boat for a while, it is a ton of fun :)

[Turbochad]

More Pics

[Turbochad]

And more....

[Turbochad]

A few more....

[Turbochad]

And that is it.

[undertaker]

Awesome 18.....good luck with getting it dialed in....:biggrin.:

[Carl C]

Pretty cool! :cool:

[chip w]

Great job on the build. I'm sure that everyone will enjoy it.

Just curious, what's the plan for the 911 in the background?

[Turbochad]

Chip,

That is my '71 Targa. It was my first 911. I basically have all the restoration parts ready for the car. I will probably start working on in when my daughter goes to college in a year. It needed a full repaint and front tank support replacement. The structural work is done, now I need to finish the paint removal, and start prepping it for paint. It is a silver car and will get a 2.7RS motor, All S suspension and trim, and original factory Recaro sport seats. lots of hard to get parts. I have had it on a fixture for about 8 years.

Chad

[Stevo440]

Might I make a suggestion here! Why don't you try a Non M+ Prop and see how the boat characteristics are with stock props and then go from there. My C22 had a M+ Prop stock and it was a really scary prop to go fast with, it Chine walked all over the place at speeds approaching 70mph it porpoised a lot also. I wouldn't let anyone else drive the boat fast because of those traits. I tried a few Turbo props and settled on a Turbo1 (right out of the box) and haven't looked back since. I will never use the M+ prop again. I love the new boat I have with the Turbo 1 prop and it's just as fast. It changed the whole personality of the boat. Chine Walk TOTALLY gone. The boat is safe at any speed now and I don't have any problem letting someone else drive it at speed, it is rock solid steady even hitting some wakes at speed it just feels SAFE. So this my experience and I know you have a C18 and a different lower unit but it's worth a shot trying different type props then a M+, find the one that makes your boat feel safe and works with your boat and still go fast, then Tweak from there. Good luck and you have a great looking boat there.

[Turbochad]

Stevo440, Thanks for that suggestion, it is a good one. I am going to try a Turbo TXP 25P, and a labbed 27P Bravo 1 for starters here at 5000’. I know that lots of Donzi owners love the Turbo 1 and TXP. If the Turbo works out, I will get most likely end up with two different pitches for different altitudes and pulley combinations. I am going to keep working on this setup till I get it maxed out before I go build a 383.

[Stevo440]

@Turbochad, You have more ways of Tweaking your boat then most being it is Supercharged. I think between the Pulley choices, Props and other Tweaks here and there you should be able to hit your mark or come really close. I come from the Turbo Buick world and I had lots of ways to boost my power on my GN's, it was pretty simple, I'm not as familiar with SC'rs but the Theory is pretty much the same. Plus Intercoolers make a world of difference. So have fun Tweaking that's the most fun part, seeing the results of each Tweak. BTW make sure your SC is getting enough Air those little air scoops only flow so much air and your engine wants to breath, Air in and air out!!!!!
I got my Stock 86 GN to go from 14.7s @94 mph to 13.3s @104mph on street tires and less than $300 with out really getting my hands dirty, a Tweak here and a Tweak there Fuel, Timing, Boost and Air flow in (Intake) and out (Exhaust)...Good luck

[chip w]

Chip,

That is my '71 Targa. It was my first 911. I basically have all the restoration parts ready for the car. I will probably start working on in when my daughter goes to college in a year. It needed a full repaint and front tank support replacement. The structural work is done, now I need to finish the paint removal, and start prepping it for paint. It is a silver car and will get a 2.7RS motor, All S suspension and trim, and original factory Recaro sport seats. lots of hard to get parts. I have had it on a fixture for about 8 years.

Chad

Very nice! We're air cooled 911 people here. The '71 is beautiful and will be a work of art when it's done. Good luck on that build. :)

[JParanee]

Great car and boat

Best of times to you and yours

I’m an air cooled fan also

http://i200.photobucket.com/albums/aa302/jparanee/Vehicles/image.jpg1_3.jpg (http://s200.photobucket.com/user/jparanee/media/Vehicles/image.jpg1_3.jpg.html)

[chip w]

Great car and boat

Best of times to you and yours

I’m an air cooled fan also

http://i200.photobucket.com/albums/aa302/jparanee/Vehicles/image.jpg1_3.jpg (http://s200.photobucket.com/user/jparanee/media/Vehicles/image.jpg1_3.jpg.html)

What wheels are those? I'm currently putting a Fabspeed exhaust on my 964. Next is to upgrade the suspension, brakes and then wheels. I like the retro Fuchs look.

[JParanee]

Fifteen 52 Magnus Walker Outlaws

http://i200.photobucket.com/albums/aa302/jparanee/Vehicles/AB9BB0A3-6A05-434E-BE4A-00F9B16AF13C.jpeg (http://s200.photobucket.com/user/jparanee/media/Vehicles/AB9BB0A3-6A05-434E-BE4A-00F9B16AF13C.jpeg.html)

[chip w]

Those are exactly what I was looking at. They look great on your car.

[JParanee]

Those are exactly what I was looking at. They look great on your car.

Thank you


They are pricey but nice and you can get maximum rubber under car because they are built to your off sets

http://i200.photobucket.com/albums/aa302/jparanee/Vehicles/E8EC630F-32BC-491C-8B76-B8168983ACB7.jpeg (http://s200.photobucket.com/user/jparanee/media/Vehicles/E8EC630F-32BC-491C-8B76-B8168983ACB7.jpeg.html)

[chip w]

I'm taking this over to the "Cars & Trucks" forum so that it's in the right place. :)