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Turbochad
07-27-2017, 10:51 PM
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
07-28-2017, 07:53 AM
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
07-28-2017, 11:01 AM
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
07-29-2017, 10:46 AM
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
07-30-2017, 01:03 AM
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
07-30-2017, 08:42 PM
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
07-30-2017, 11:40 PM
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
07-31-2017, 12:56 AM
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
07-31-2017, 01:16 AM
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
07-31-2017, 03:44 PM
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
07-31-2017, 04:30 PM
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
08-02-2017, 01:51 AM
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
10-26-2017, 11:01 AM
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
10-26-2017, 02:23 PM
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
10-26-2017, 07:06 PM
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
10-26-2017, 08:10 PM
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
12-05-2017, 02:09 PM
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
12-09-2017, 06:01 PM
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
12-09-2017, 06:10 PM
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
12-09-2017, 08:47 PM
PM sent about the alpha package

Turbochad
12-10-2017, 02:48 PM
PM sent about the alpha package

PM replied.

Turbochad
12-10-2017, 03:00 PM
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
12-11-2017, 08:16 PM
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
12-23-2017, 11:27 PM
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
01-16-2018, 12:59 AM
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
01-16-2018, 01:19 PM
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
01-16-2018, 05:42 PM
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
01-18-2018, 11:30 PM
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
01-19-2018, 02:48 PM
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
01-19-2018, 02:50 PM
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
01-19-2018, 03:22 PM
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
01-19-2018, 06:10 PM
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