You would think that every question imaginable has been discussed somewhere in OSO regarding supercharging. I have been reading threads on supercharging until I am blue in the face, and still can't find the specific answers I am looking for....the answers that pertain to my specific Formula application. Can you guys enlighten me with your direct experience.... educated guess....or even gut feel on some of this???

I have a 1999 271 Fastech with a 502 EFI, all stock. I am running a 26P 4-blade with 1.65 gears. Top speed with 3/8 tank and 3 adults is 60 mph at 4900 rpm.

Need more speed gentlemen....but not at the expense of reliability. Everything I have been reading will leave out little bits of valuable information like..."when you blew a head gasket or a drive, what boost were you running"? 3lbs...5lbs....7lbs...more?????

Can I Whipple a stock 502 EFI without breaking my stock Bravo 1 if I am careful....or is it inevitable and just a matter of time before I am being towed in by one of my buddies with visions of a new $8000 XR drive looming over my bank account, and total regret that I messed with it.

What sort of performance gain can I expect on my 271 with a modest 3-5lbs boost? Will it be the standard "$1000/mph equation? $5500 for 5.5 mph seems a little steep.

Thanks in advance for any insight.

Your top speed will be more by just changing your prop. Depends on how you run the rig and what kind of water you have available.

IE...
Flat water mostly WOT then a 3 blade will out run a 4 blade.
if you are rough 2-3ft all the time and almost never WOT but running mid-upper RPM's then the 4 or 5 blade will work best.
Since you don't list location then it's your call.

My humble .02 worth........ Forget the wipple/vortech etc.
For the $ spent on the blower you could upgrade in cubic inches and horsepower to a bone stock 500EFI or 540 ...sell your 502 and be money ahead without the headache of a blown headgasket how much boost bullsh++!!!!! and keep your Bravo 1 if you don't get crazy with the throttles.

You have to decide HOW FAST DO I WANT TO RUN.
Then figure the $$$$$$$$$$from there.

Grog,

I have a Whipple on a carbed 454 Mag. I have a friend who I installed a Whipple on a 454 Mag EFI. I have experience with this setup. If you want to do this, here is what it will take.

You will need to remove heads, send out for valve job and replace head gskts and use ARP head bolts or studs. You will need to go to a different higher pitch prop. You will need to install a separate water system for the intercooler. You will need to add some gauges to monitor the boost and oil temp and fuel pressure. You will need to add a drive shower to the Bravo drive. You will need to run synthetic gear oil in the drive. I can tell you where to get all the stuff you'll need to do this.

Now for the fun part. Do all of this and your motor will be making close to 600 hp, it will run and idle like a stocker and when you go full throttle, you will have a smile on your face that will be hard to get rid of. I routinely blow off guys with N/A motors making the same HP. I pull away from twin engine boats with stock engines. NOTHING will accelerate your boat like a Whipple. I have almost 250 hours on my setup and my buddy has over 100 on his. NO PROBLEMS YET. We are smart about driving and when it gets rough we make sure to not over rev the prop when it clears the water.

I picked up 14 mph and my buddy picked up 13 mph over a bone stock setup. I went this way because I still have silent choice exhaust and when I want to I go slow and you would never know I had a blower.

Oh yeah it planes out in about 2 secs and only takes 4 secs to go from 40-60 mph.

It is not cheap to go fast on the water. I don't care which route you choose. Our setups ran around 8,000 for everything. If you ever went for a ride with me you would be hooked.

Good luck with what ever you do !!!!

My buddy Whippled his 271 Formula, beyond the cost of the Whipple install he had to put on hydraulic steering and later he blew a drive and went with a Teaque Platinum XR for a replacement. Later he ended up rebuilding the motor due to improper install on Whipple system.

If everything is done right it can be a great setup. Dustin Whipple usually will respond to inquiries in the Technical Q an A area. I would look for answers there.

Good Luck

Bigwavz -

Sounds like you did it right. What boost are you and your buddy running?

Grog,

I am at 6 psi at around 550 hp and my buddy is at 7 psi at around 590 horse. My boat is faster top end at 75 mph and his goes 74, but he gets me off the line.

Mine is a 24ft Baja and his is a 26 Powerquest

P.S. Both are intercooled setups. I advise against supercharging without an intercooler if you want reliability and longevity.

If you do not want to break your bravo, leave the boat stock. Any time you start building more HP & speed you increase the risk of breaking something.

Read the thread "Can you afford more HP?" Very true statment. If you plan on spending $1000, better be prepared to spend another $1000 for ???

I have had a boat with a blower of some sort since the late 70's. I do not know if I could handle one with out one.

I installed a whipple on my friends 1999 271/ 502 mag.in 2000.
The boat has run without problems for over 3 seasons now and he drives it HARD! Boat ran 66-67 on speedo stock, and now buries the stock gaffrig 80 speedo. We figure 81-83 on the speedo, so maybe 3 less for a gps figure. Had to switch to a 1.5 ratio Bravo drive and turn a 28 Hydromotive at 5000-5100. I routed the intercooler dump so it hits the top of the drive, acting like a drive shower.
Bang for the buck, there is nothing that will come close.