I/O set up - Drive Height New 27 Speedster build

[THE Cat Sass]

About to launch a new 27 Speedster build and looking for some opinions based on experience. Motor will be a TCM 1050, drive is going to be a SCX/SC. Based on what I've read it would seem a good starting point would be to go with a -3 upper and space down if needed? I've read posts about a "SCX3" but I don't see anything on the IMCO site about it, sounds like a -3 setup? Anyway I'd love some thoughts along with gear ratios and prop thoughts. Thanks in advance for any feedback.

 

[J.P.]

I think maybe the -3 has the SC lower bolt pattern.

 

[02HoWaRd26]

Would think this would be best answered by Eliminator or Teague as your using their stuff and both have worked together many many a time. Not cheap equipment so best to ask the true pros on something like this I’d think

 

[THE Cat Sass]

Agree and they are working on it but there are a few folks on here who have gone thru the blood sweat and tears of trial and error with similar setups and came up with winning combinations on their own, hoping to tap into some of that experience.

 

[Tinkerer]

I have a 2001 26 with the prop shaft at 2 inches above the lowest point on the bottom of the boat. I am running a -3 IMCO lower.
Unless you do mods to increase negative trim you will not get on plane with a Bravo 4 blade. My boat DID NOT like a stock Maximus 5 blade.
It caused a LOT of transom lift and the boat rode on the front of the sponsons.
With 800+ HP I hit 112 consistently with a labbed Bravo 28 at 6100 RPM and 1.36 drive ratio, roughly 4% slip.

 

[Tinkerer]

IMCO will modify the SCX upper to fit the -3 standard lower. This is what I plan to do when I add the Procharger.

 

[THE Cat Sass]

You guys are running these in a semi-surfacing application (not surfacing) correct? I'm thinking if I start off at -3 I can always add spacers. That sounds like the ticket.

 

[Tinkerer]

Mine IS fully surfaced. The water only hits the bottom of the bullet at speed.
I had to move the water pick up back to just in front of where the skag starts in order to have consistent water pressure at top speed.
I am running a neutral stand off box also.

 

[THE Cat Sass]

Any issues with torque steer at speed? Do you have to adjust the steering wheel to stay straight?

 

[Tinkerer]

Never noticed any torque steer. It is very obvious when the wheel is straight - The boat picks up speed like mad.
Buying a cat with low or basically low stock power will be boring. My cat doesn't start acting like a cat until 80 MPH. Below that it doesn't ride much different than a V.
when it starts packing air the ride is unreal. You can go straight over a wake at 90 MPH and barely feel it.
The least amount of HP in a 26 or 27 that I would do would be 650. My 26 did 90-94 with that HP and an IMCO -2 drive 1.5 ratio and a Bravo 28.
Prop shaft was even with the bottom at that time.
I would also add an extension box or go with the ITS transom assembly.

 

[Tinkerer]

If this is your first cat You will have to learn to drive a boat all over again.
A cat drives and handles totally different from a V.
don't cross big waves or wakes at slow speeds at an angle. You can stuff a sponson and flip the boat.
Cats can bow steer at speed very easily.
Cats ride on air so IF you are going fast and have to stop fast it isn't going to happen. On a V you can drop the drive and wiggle the stern to kill speed.
This doesn't work on my 26.
and even with all of these I don't think I would go back to a V ever.

 

[THE Cat Sass]

I appreciate the feedback! This is actually going to be Daytona #4. I had a 21 with an I/O (119mph), a 25 with a blown 540 (118), my current 26 with an Ilmor 550 (90 and yes, boring)! and trading the 26 in on the 27 with TCM 1050. My hope is to see close to 130 with the speedster but Ive read posts with similar set ups anywhere from 120 t0 137 (El Guapo's DS shootout run). Not that I'm going to spend any time at 130 but like to know its in there.

 

[Tinkerer]

I am at 112 with only 800+ HP, with 1050 HP and the proper setup you should see 125 - 130.

 

[Water rod]

Im in the process of dialing in my 26. I'm running a stand off box and SCX drive. Im approx 1 1/2 " above bottom. I had to use a skeg wedge to keep the boat straight. The boat is much lighter and looser. Ran 90 at 5800 with a 23 pitch 4 blade cleaver!

 

[Tinkerer]

Why are you running an SCX drive. Either you are way down on HP or your set up is way off.
I am running 800 HP with a BRAVO X upper. ( 1.36 ratio )
I am at 2 inches above and a 28 BRAVO 4 blade at 6100 RPM at 112
what is your HP???

 

[Water rod]

The Bravos and SC are the weak link when your running bigger power. Making 980 on dyno. Im doing more prop testing with bigger props. Im sure it will run 115+

 

[boatnam2]

When you guys are talking 1 1/2 or 2 inches above bottom, are you talking prop shaft height or drive plate? Here is my setup, how's it look? 800 hp spinning a labbed 31p 1.36 drive at/ 5700/5800.

 

[El Guapo]

TRIED IT ALL. The Sizzle, our 27’ Speedster:

Fastest set up with the least reliability was XR upper with SC lower, Labbed brovo 4 blade 36P

SCX -3 (one off from IMCO) with-3 SC lower, nutral stand off box was my end point after many $$$ spent testing, and to have a happy medium for speed and reliability. Boat turned and handled really well.
Keep in mind the SC lower will be your weak link. I carried two extra SC lowers in the truck with me on every trip. I rebuilt my lowers every 15 to 30 hours as I rotated them out. I really had to baby the stick coming on plane in fear of the TCM 1050 motor sending the lower unit to the bottom of the lake. Lol

Before I sold the boat, John Teague was helping me game plane pushing the motor HP up with some Teageness, putting the SCX4 on and trying to surface it with #6 props. Momma said no way on a faster single engine boat and throwing $$$ at it. Good call to, because nobody will really talk about/ write about how the single surface drive (#6 prop and prop shaft) single 27’ boats work.

SCX4 with 1 7/8" prop shaft (Brovo Props) 1” to 2” above the bottom with a stand off box is my recommendation, it will be bullet proof.

If you want to get into the 130’s, I would do a TCM XR upper with an SC lower, 1:36 TCM gears and buy a 32P for summer, 34P and test a 36P. Expect to break drives, sorry!

AJ at Barrett Custom Marine set up a 26’ Daytona with the SCX4 and said it worked good with the 1 7/8” prop shaft with 4 & 5 blade brovo props. Said it planned out good too.

Octane Marine set up and rigged my Speedster, they did an outstanding job! They also worked closely with TCM when we put the 1050 in. Charlie and Sunny did the pre-shootout Voodoo set-up for the boats fastest pass at D.S. (as you mentioned.)

Bob and the TCM team can set up your Speedster no problem. It really just comes down to what you want. Crazy top end speed, or a fast ass boat with a reliable drive. Trust me, a broken drive 50 miles up lake does not sit well with the wife.

Dustin at Menace Marine set up a 26’ Daytona with the SCX4 #6 prop surface drive. He told me to save my money.
There was a 26’ Daytona with a #6 drive on it at D.S this year. GT marine did the install I believe, and they have done a few #6’s on single Daytona’s. Teddy Martin is building a 26’ Daytona with a #6 as I type. He is a nice guy and I’m sure he would let me give you his number if you’re interested. He has tested with the SCX4 1 7/8” prop shaft with brovo props too.

130+ in the 27’ Speedster is really fast. I hold no candle to Buck or some of the Other Eliminator 26’ Daytona guys. Nick Stolts and few others have ran these single 27’ Daytona bottoms, same bottom as yours, up in the buck fifty ranges....

Beautiful boat your're building by the way. Keep us posted.

Cheers,

Bo

 

[boatnam2]

Forgot pic

 

[Water rod]

Love this thread its exactly what I'm working on.
I have a 26 daytona with 850 hp. Currently running an extension box with a IMCO SCX with SCX -2 Lower, #6 shaft, 1.34 gears, 30 pitch 16.5" cleaver, 1" above the bottom. Boat lost 15 mph with this set up. Should I swap to a 1 7/16" prop shaft and run a bravo prop or go back to a SCX with SC lower to get the speed back?

 

[zx14]

Love this thread its exactly what I'm working on.
I have a 26 daytona with 850 hp. Currently running an extension box with a IMCO SCX with SCX -2 Lower, #6 shaft, 1.34 gears, 30 pitch 16.5" cleaver, 1" above the bottom. Boat lost 15 mph with this set up. Should I swap to a 1 7/16" prop shaft and run a bravo prop or go back to a SCX with SC lower to get the speed back?

I run a its XR, 1:39 gears 32p bblades
Bravo, even with the bottom of sponsons, with my 540 quadrotor I went north of 125. I have had the drive rebuilt 2 times in 11 years.

 

[BDMar]

Love this thread its exactly what I'm working on.
I have a 26 daytona with 850 hp. Currently running an extension box with a IMCO SCX with SCX -2 Lower, #6 shaft, 1.34 gears, 30 pitch 16.5" cleaver, 1" above the bottom. Boat lost 15 mph with this set up. Should I swap to a 1 7/16" prop shaft and run a bravo prop or go back to a SCX with SC lower to get the speed back?

With an extension box you are too low. With the drive moved back 12" it is similar to the propshaft being 2" lower than you measure. So it will act as if the propshaft is 1" below the bottom. Especially with the 16.5" diameter prop you are running

 

[Water rod]

Pull the box off or go with a smaller prop and drive?