Outlaw - I am only guessing, but I am most likely somewhere in the low 80's. I will GPS it this spring when I am done with the motor refreshing projects. I think it could use more prop, as I am hitting 5600 rpms.

My boat had 174 blowers on it when I got it, which I probably would never have done, but now I am kind of glad they are there. Incredible acceleration. Plus the blower whine sounds really cool when you get on them! I definitely had a learning curve getting used to the maintenance /setup (had a few probs to work through), but don't be afraid of them like a lot of people are. My blocks are original 1987's, and the blowers have been on for 10 years. I have the motors torn apart currently and am refreshing the heads. The blocks look mint after all this time which surprised me. I only run about 5-6 lbs of boost, so it doesn't beat on the motors too badly.

Since I have these motors torn down, I could have gone back to normally aspirated, and ported the heads, cam change, etc, to get the power back up there, but I didn't. Instead I rebuilt the blowers and heads, and basically keeping everything else the same performance-wise. I just think it's a cool boat the way it is, as there aren't many supercharged boats near me. As I said the acceleration on this is sick... I can be going mid 50's and hit the throttles, and throw people back into their seats!

There is nothing wrong with big power normally aspirated motors, but those aren't impervious to troubles either. My friends with wild cams and aftermarket ignitions sometimes break valve springs, burn pistons, etc, so don't think that they are flawless. Big HP = big $$, and more problems always. My old smallblock boat - I think the most it needed ever was a water pump impeller and a shift cable! Those days are long gone...

I'm just saying another decent (and fun!) route to go is to build or buy a solid motor, and put a smaller supercharger on it with around 5 lbs of boost. This way you don't need to typically change compression ratios, ignitions, etc. Carbs, and fuel system will need to be changed, but just buy a long block then.

Sorry to hijack the thread temporarily!!! If you or anyone has ?'s just PM me!

"Jay", well now you've gone and done it. Just when I thought I'd made my mind up, you've given me more ideas. If I could "freshen" my 454's, add a procharger, it would be much less expensive in the long run. You give a very strong testimony for going that route. What kind of superchargers are you running? Thank you for all the information. It's really got me thinking now. I'm shooting for mid 80's. Russ

Jaybird-

Formula states that 336 weighs 8400 lbs which is 1000 lbs. more than a 311 ( Can that be right?). It is a non-stepped hull so stern lift would be needed. I was thinking bravo 1 props because they seem plentiful used and if I found one that was close I could have it lab finished and be into them for the price of non-labed props new.

If my 336 is really 1000 lbs heavier than I would probably need a 23 hydro or a 24 bravo 1 4 blade.

Powerguy,

As I understand it, Bravo 1 props are NOT stern lifting, they are bow lifting, which most likely wouldn't work out for you with the non-stepped hull, and heavy stern. If you try decide to try a set of Bravo's, make sure you can return them as there is a decent chance they aren't the right ones for the boat. If you want a 4 blade for stern lifting, the only one I know of is the hydromotive Quad-IV. If you buy new from them, they will allow you to try different models for only a $20 restocking fee per prop. This way guarantees that you end up with the right prop, and they get a sale. I'm considering going that route probably around June timeframe.

You could also lab finish your Mirage 23's, and probably be where you want to be RPM-wise too. However, sometimes people don't always get the results they are looking for w/ labbing, and then your stuck with the props too. I'd say get a different set of props that work out of the box, keep the 23's stock, and either sell them or keep them as spares.

I am surprised that the 336 weighs in at 1000 lbs more than the 311! Essentially they are the same boat, except the 336's had the newer platform design on the rear. I wonder why?

The Hydromotives are definitely the way to go for stern lift. Give the guys there a call and they will guide you very well. They nailed it right on the head for me. I think that for your 336 non step, I would try that route.

Are there any other Formula owners who have 4 blade props on their boats? results compared to stock 3 blade mirage or mirage plus?

Yes, I have an 89' 311 SR-1 with your stock 454 mags. The boat came with Mirage 23 inch props. After spending much phone time with Hydromotive, I went with the Quad IV's and got 7 mph more at cruise and 3 mph more at WOT. The props did EXACTLY what the guys at Hydromotive said they would. I could not be more pleased with the results.

See another post of mine on this thread up near the top.

Thanks again formula outlaw. There has to be others out there who have made the switch to 4 blades. Any 303 or 336 owners?

Boating season starts here in a couple of weeks and I will be trying two new sets of props.The first set is 22 hydromotive Q-IV stock props and the second is a set of lab finished 23 Mirage + props. Hopefully with both changes I should be where I want to be. This should be a good comparison to others looking to change props. My 336 has stock 454 mag's.

Dave, Get it dialed in right you don`t want to lose any ground to those cigs on the lake

See you in June hope to see a few more Formulas