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The Hedgehog
01-07-2007, 05:17 PM
Brian and I concluded that a non-step 27ZX does not like a shorty. Not enough leverage to generate bow lift. I was told that this might be an issue but had not talked to anyone that has tried it so we did. We were plagued by a couple of mechanical issues but I think that we got a good feel for it:

First of all the boat is running in cold start mode. I discussed this with Mark Boos at Precision Marine. The cold water flowing rapidly through the engine was around 90 degrees. Mark told me I could put in a 120 degree thermostat with holes drilled. He told me I would want to take it back out in the summer. I decided to run rich for now.

Then we had some blower belt slippage. We fixed that.

Tried two props - a 28" Bravo I labbed by Bblades with extra cup + no diffuser ring. It had a hard time getting out of the hole. Took 4 tries till we were able to coax it up with the tabs dropped fully. Lots of slip. Only able to get high 50's. Then went with a 26" Bravo I labbed by Throttle up with extra cup. It liked this prop better but still ran flat as a pancake and had high slip numbers (around 21%)

Bottom line - The boat ran too flat. Trimming generated no bow lift. The slip at cruise speed was around 31%

Oh well. Now we know. You got to try to know. Thanks to Tex I don't have to wonder about it any more. I can go ahead and got those headers!

The Hedgehog
01-07-2007, 05:26 PM
I know. Lots of work there. I have not totally discounted it and there is probably a sweet spot somewhere. I will probably do it again sometime with a 1" spacer to see how it likes that. For now I am going to go for some more hp.

BigGrizzly
01-07-2007, 06:02 PM
Couple of things. Shorties are tough to get up on bigger boats. I have had a lot of problems with bravos on shorties on bigger boats. After the boat show I should have some time. I have a 28 5 blade we should try, works on the big cats. Another thing the shortie is better hydro dynamically and should worl better at std X than bravo anyway. Was the defuser ring removed or was the hub long. I removed one and the prop turned to crap this had no prop exhaust either. Just food for though

The Hedgehog
01-07-2007, 06:43 PM
Couple of things. Shorties are tough to get up on bigger boats. I have had a lot of problems with bravos on shorties on bigger boats. After the boat show I should have some time. I have a 28 5 blade we should try, works on the big cats. Another thing the shortie is better hydro dynamically and should worl better at std X than bravo anyway. Was the defuser ring removed or was the hub long. I removed one and the prop turned to crap this had no prop exhaust either. Just food for though

The diffuser ring has been removed.

I would love to try the 5 blade shorty combo. I am always up for trying different stuff. The worst thing that can happen is that I learn something!

I would ultimately like to migrate to an IMCO lower. Will probably end up with an IMCO lower and beefier upper as well. I learned today that it is not a layup and will require lots of tweaking with props, spacers etc. Just trying to prioritize. I thing the bling factor is cool as well.

BigGrizzly
01-08-2007, 07:07 PM
The defuser was cut off, I am not liking that prop more and more. You will have a hard time with that and a shortie. One of the cats I propped won't even get on plane with bravoIs and a shortie. Now with the Precision five blades it kicks the stuff out of the hydro P5 and P5X on that boat

LKSD
01-09-2007, 09:24 AM
Sorry to hear the shorty didnt go as well as expected.. Possibly a spacer will get a better result along with a 5 blade.. :) Keep us posted.. J

The Hedgehog
01-09-2007, 02:02 PM
What do you guys think would solve the bow lift problem. Would an extra inch make a difference. Boat was driving real flat. Like both planes were down. They were not.

LKSD
01-09-2007, 03:02 PM
What do you guys think would solve the bow lift problem. Would an extra inch make a difference. Boat was driving real flat. Like both planes were down. They were not.

It may, but it's hard for me to say for sure.. I think that a silghtly raised X can help. I do agree that the 2" shorter version sounds like it went too high.. I think that the 5 blade would also help.. For example Reggie sets his stuff up with high x's & I have seen them runnig 5 & 6 blade stuff on it.. The boats may feel a little loose because of it BUT his stuff does run quick because of it. The main thing is knowing how to properly drive a set up like that... I think from the sounds of it you have a good ammount of drive time & it may be worth looking into.. I know it wont plane as fast because of the higher x's, you may also have to feather the throttles & use more tabs to start out with.. Another prop you may want to look into is Julie's (throttle up) new cnc cleavers.. I would say try propping with Big griz first if he has some stuff to try or sell you that works.. The Cnc stuff is very $$$$ but would be worth it if you know the higher X works for you.. I dont have any Imco spacers to try off hand, but if you already have the drive it may be worth the expense to try one, or search the clasifieds for a take off one on OSO.. If ya need me give me a call.. :) Jamie / Lakeside 570-639-2628

One last thing which you may or may not already know is that with higher x you will NOT have the hole shots or low end speed that you were used to... :) Jamie

BigGrizzly
01-09-2007, 06:38 PM
The clevers don't have enough blade area to plane off well, been there done that. This guy had the coin but hated the results. Also remember every boat is different and what works well on one may not work well on others. The 5 blade will get the bow up especially if we use that blade design. You said 31% slip tells me the prop isn't biting so trim is non existence. The rooster posted is about 15 feet lower with our prop biting and pushing instead of spraying water up. Small note the speed was up per rpm too. With these props he could still plane at 16 mph when before (with hydromotives) at 30mph it would fall off a plane. As for CNC props if there done from a billet like Herring, then expect to spend $4000 per prop. CNC is the new buzz word for props. I don't care if there CNC or not. The blade does the talking not the the manufacturing process. There is more to the IMCO then prop height as I am sure you noticed. I just wouldn't give up yet. Remember only one lap counts and that is the last one! The face says it all!

Last Real Texan
01-09-2007, 08:28 PM
Still want to teast some of your props when we get a chance....What does the turbo 4 blade do differently than the Bravo I 4 blade? HAve a 28-30 in the test program?

Bryan

Last Real Texan
01-09-2007, 08:39 PM
What do you guys think would solve the bow lift problem. Would an extra inch make a difference. Boat was driving real flat. Like both planes were down. They were not.
Spacer may have helped a bit but we are not comparing apples to apples...On my testing I tried a 1 inch spacer thinkng it would help once I bought my lab finished prop...OOPS:smash: . The spacer mabe no real difference in the way the boat performed at all. I thought it was going to be the sweet spot, I would have brought it with me if I had not sold it after finding out no joy with it. On your rig it may have helped some with the leverage but then again maybe not...I would have liked to put a bone stock bravo I or one of Big grizz's props to see if the labbing had an affect on the results we got. As you know I am no real fan of a labbed prop on my boat.....it ran better and faster w/ the stock props i tried but I bough into the whole labbing process looking for that last 2 MPH, Don't get me wrong on a lighter rig I think there is some gain but on a heavy single I don't think so...But that is another story in and of itself.

We will do some more testing when the water heats up an we can get the thermal benefit of warmer water to get the BIG GREEN ZX up to temperature where it can make some power.


Bryan

LKSD
01-09-2007, 09:32 PM
The face says it all!

Yes he does look happy.. :D J

BigGrizzly
01-10-2007, 05:33 PM
Stop!!!! A labbed prop doesn't fix anything. It may be a mile an hour faster, but this isn't the issue. First, we have 31% slip, then boat runs too flat like tabs are down. The slipping is the biggest problem (read that ventilation). Common to shorties and high X s. With the boat pictured it was a bear to plain untill we changed the prop. We spent the whole summer with blade designs to stop that problem yet keep the speed up and yet have better manners too. When at a poker run it takes forever for the fast boats to plane, even the 38ZR has a problem with high Xs. We have, I think, accomplished that. Think of it this way. With a shortie yoy need a prop with more bite down under the prop shaft. Testing is easy once we have a base line. to answer the question on what does the precision prop have the others don't that is blade design is different. I would have to have the props side by side to point it oit

Last Real Texan
01-10-2007, 05:54 PM
Stop!!!! A labbed prop doesn't fix anything. It may be a mile an hour faster, but this isn't the issue. First, we have 31% slip, then boat runs too flat like tabs are down. The slipping is the biggest problem (read that ventilation). Common to shorties and high X s. With the boat pictured it was a bear to plain untill we changed the prop. We spent the whole summer with blade designs to stop that problem yet keep the speed up and yet have better manners too. When at a poker run it takes forever for the fast boats to plane, even the 38ZR has a problem with high Xs. We have, I think, accomplished that. Think of it this way. With a shortie yoy need a prop with more bite down under the prop shaft. Testing is easy once we have a base line. to answer the question on what does the precision prop have the others don't that is blade design is different. I would have to have the props side by side to point it oit
I agree with you here Grizzzzzzz. I only found this out ater a $900.00 mistake........Labbed Bravo I ,overall the prop works OK but I know there is better stuff out there and will be selling this 28 inch Labbed bravo once I find the right prop. I am planning on testing the procharger next week and am Having Brett @ B blades send me a stock 28 to baseline with and go from there. I am very interested in trying a prop from Precision ...a 28 inch 4 blade offering from them......What 'cha got Big grizzzzzzz? By the way Big Green ZX you reading this? Hopefully you will be in Macon to help with the testing.....

The Hedgehog
01-10-2007, 06:24 PM
I agree with you here Grizzzzzzz. I only found this out ater a $900.00 mistake........Labbed Bravo I ,overall the prop works OK but I know there is better stuff out there and will be selling this 28 inch Labbed bravo once I find the right prop. I am planning on testing the procharger next week and am Having Brett @ B blades send me a stock 28 to baseline with and go from there. I am very interested in trying a prop from Precision ...a 28 inch 4 blade offering from them......What 'cha got Big grizzzzzzz? By the way Big Green ZX you reading this? Hopefully you will be in Macon to help with the testing.....

Yes, 80% chance or better that I will be there. Will get Larry's mech gauge. Remind me to bring the bassinet. Can't miss the maiden voyage of another Blown 27ZX. We can sample some whine (not wine). Yours should really boogy. Am in the process of booking rooms for the trip to Orlando to check out the X-18. Not enough toys in the toy box. Once we get everything set up we can have our bi-weekly Donzi rallies this summer. We can let Jim follow along in the 16. He can tie it up behind my wife's 18!

BigGrizzly
01-10-2007, 06:24 PM
First of all you sure you want a 4 blade. I feel we need to go both ways a 3 and a four. I have said it before. Honest testing is TRUTH. Lets see what I can pull together. Are sure you can pull a 28? When you get your base line we can work from there. Right now I have a 3, 4 and a 5 blade 28. What I need from you is the speed (GPS only) RPMs and hight of water chop approx. and the prop ypur running preferable not labbed. Be careful your on another playing field now, stay safe.

Last Real Texan
01-10-2007, 08:14 PM
First of all you sure you want a 4 blade. I feel we need to go both ways a 3 and a four. I have said it before. Honest testing is TRUTH. Lets see what I can pull together. Are sure you can pull a 28? When you get your base line we can work from there. Right now I have a 3, 4 and a 5 blade 28. What I need from you is the speed (GPS only) RPMs and hight of water chop approx. and the prop ypur running preferable not labbed. Be careful your on another playing field now, stay safe.
Good base line was done before labbing the prop
All this was with bone stock props and a -2 Shorty 1.5 gears and a stock 500 EFI 470 HP @ the prop
Best GPS speed was the same with the 26 Bravo I and the 28 Bravo I
26 Bravo I = 72.4@5200
28 Bravo I = 72.4@4800
The labbed 28 I bought best has been 71.2@5100....I lost speed.
This was last fall on Lake Tobosofkee ....elevation appx 500ft and a temperature of 60 degrees and water conditions were almost flat ...maybe a 6 inch chop from the wind
so to answer the ? can I pull a 28 inch prop.....I think so and now that I have upped the HP with the Procharger @ 5psi I am guessing this on my 500 EFI will net a solid 700HP

The Hedgehog
01-10-2007, 08:37 PM
First of all you sure you want a 4 blade. I feel we need to go both ways a 3 and a four. I have said it before. Honest testing is TRUTH. Lets see what I can pull together. Are sure you can pull a 28? When you get your base line we can work from there. Right now I have a 3, 4 and a 5 blade 28. What I need from you is the speed (GPS only) RPMs and hight of water chop approx. and the prop ypur running preferable not labbed. Be careful your on another playing field now, stay safe.

I am pretty sure that he will spin the heck out of a 28"

I would like to re-try some 3 blades (and 4 for that matter). My boat started with a 23" Mirage Plus. It liked it. Went to a Procharger so the 23" was not enough. Tried a 25" Mirage and got lots of slip. Cruise speed had tons of slip. Throttle-up told me the the torque of a the blown motor caused the 3 blade to slip too much. Ended up with a 26" Bravo I labbed. It seems ok but does not carry the bow as much as the Mirage Plus. It pulls pretty hard but then seems to hit the wall around 67 (at 5100 rpm) unless I got heavy chop to air it out. I have since learned that all props of the same type are not necessarily created equal. I would like to come up for a day when it warms up.

BigGrizzly
01-11-2007, 07:22 PM
Real tex, doy u still have the shortie on? The data you gave me is good, now try to get a base lin with the procharger, you don't have to go wfo with a small prop give me a 4000 run with gps and which drive your using. the shortie will need mor blade area or a Fusion blade style.
Rember all 4 blades are not created equal. WE have found bravos and shorties don't get along. The only bravo we tried was labbed by the great late dave Cavenaugh of merc racing, but a stock hyfro beat it in all respects. Lets see where are with the pro-C and go from there. Green I use a three blade, I gues I read a different book then throttle up. What they told you is BS.
At that time you had a deep drive so it should not have been an issue. Here is what we need to do, first You are 4 miles slow to begin with, you should be in the 70s unless your boat is water logged or you do what I do(carry everything except a spear engine). If I had known you were that slow when I was there we could have fixed it than. I had a prop that was specifically sent me for a lame 27 foot Donzi Daytona with a hp500 in it. The guy disappeared and I had the prop. Too bad he was going to sell it cheep and I wanted it. He still owes Garry $3000. Maybe good luck it could be $3000 and a prop too. Back to what we need to do. First - how long are you going to keep the shortie on. what works with a shortie won't work with the bravoI. Find out what YOU want to do to your boat, not what others want to do, and We can prop the boat accordingly. I want to look at your boat on the trailer to see if tabs and such are ok. I see no reason we can't prop it to 70+ mph, I could be wrong but I doubt it. The Marage is not a nice prop on big huls with singles. I shure you know this but the bravo tries to lift the stern in turn drops the bow except on cats with twins then it squats the stern. These are reasons that fountains and Eliminator cats have issues with them. Before we go any farther be it known I am not an advocate of labbing, if out of the box doesn't work then we find one that does. I'm pretty booked until after the Miami show. When I get back both you and last tex and I need to chat.

The Hedgehog
01-11-2007, 09:08 PM
Real tex, doy u still have the shortie on? The data you gave me is good, now try to get a base lin with the procharger, you don't have to go wfo with a small prop give me a 4000 run with gps and which drive your using. the shortie will need mor blade area or a Fusion blade style.
Rember all 4 blades are not created equal. WE have found bravos and shorties don't get along. The only bravo we tried was labbed by the great late dave Cavenaugh of merc racing, but a stock hyfro beat it in all respects. Lets see where are with the pro-C and go from there. Green I use a three blade, I gues I read a different book then throttle up. What they told you is BS.
At that time you had a deep drive so it should not have been an issue. Here is what we need to do, first You are 4 miles slow to begin with, you should be in the 70s unless your boat is water logged or you do what I do(carry everything except a spear engine). If I had known you were that slow when I was there we could have fixed it than. I had a prop that was specifically sent me for a lame 27 foot Donzi Daytona with a hp500 in it. The guy disappeared and I had the prop. Too bad he was going to sell it cheep and I wanted it. He still owes Garry $3000. Maybe good luck it could be $3000 and a prop too. Back to what we need to do. First - how long are you going to keep the shortie on. what works with a shortie won't work with the bravoI. Find out what YOU want to do to your boat, not what others want to do, and We can prop the boat accordingly. I want to look at your boat on the trailer to see if tabs and such are ok. I see no reason we can't prop it to 70+ mph, I could be wrong but I doubt it. The Marage is not a nice prop on big huls with singles. I shure you know this but the bravo tries to lift the stern in turn drops the bow except on cats with twins then it squats the stern. These are reasons that fountains and Eliminator cats have issues with them. Before we go any farther be it known I am not an advocate of labbing, if out of the box doesn't work then we find one that does. I'm pretty booked until after the Miami show. When I get back both you and last tex and I need to chat.

I am with you Grizz. I wanted to try props at Eufaula but had a house full and some other issues. I look forward to getting together. I gave the Shortie back to Tex. Thanks for the input.

Last Real Texan
01-12-2007, 06:37 AM
Grizzzzzz
The shorty is back on my ride where it will stay until Bill and I do some more testing on his boat when it warms up over the next few months. As you have stated I have had good luck with it on there so I guess I am married to it. Do not really want to have o go through swapping the gears again .....I had the guidance of a Guy named Ted Fraser of Fraser performance in Cumming teach me how to do it and check and re-check as we went along....did this last year. Youu may know him. I have since sold the Bravo I lower case empy to help re-coup the cost of the shorty case. I am happy with the performance so far and tink it's hydrodynamic benefits will now really come into play now that the boat is capable of the high 70's maybe more.
Thank you for all of the guidance and help through all of this testing.
About Bill's Boat ....I too was surpised it did not fun ovr 70 after the Procharger install. I also think it is in the prop.... it pulls hard to 67 in a hurry then it just hits a wall. I have looked at the bottom on his boat and it is true, and the tabs are 3/4 of an inch abovve the bottom running surface of the boat. One thing I will say Bill is a lot like you are , he carries everything he could possibly need for a day of fun on the water as do I and guess where it all goes......in the cabin up front. I remember e was driving my boat back from lunch and we were cruising @ 55 mph urning about 3800-4000 and I went from standin behind the bolsters ( wife was in the front seat with the kid) down in the cabin to get a few things and we scrubbeb 2-3 mph just by shifting 200 lbs forward by about 4-5 feet....My boat is very sensitive to weight distribution in fron of the drivers feet. I am gueessing Bills non step is as well. I know for sure he will pick up 2-3 mph shedding all of he weekend gear for a testing top speed run.....
Next week I will ave Brett @ BBlades send we a stock 28 inch Bravo I to run against my labbed 28 Bravo I for some baseline testing and I will post resultswhen we have them. I am not really intersted in a five blade until I upgrade the drive upper to an XR......too much bite I think.
What I liked about the 28 was the cruise #'s
3500 netted 50 mph and 4000 netted 60 mph. with a top of 72.4 @ 4800
Thank again Big grizzzzzzzzz
have a nice day!
Bryan

BigGrizzly
01-12-2007, 05:52 PM
I don't really think the 5 blade is for you. We need to try different props. Wh knows maybe the Bravo will work great, there is only one way to find out, and that is to try it. thanks for the replies call if you need something.