Grog

I recently purchased a 1999 271 Fastech. I love the boat but in reading some of the threads, I read of other 271 owners reaching top speeds of 65mph GPS. My Fastech is powered by a stock 502 MPI Mag. I am turning a 26 pitch 4-blade prop at 4900 rpm with a 1.65 gearcase. I keep the fuel tank about 1/4 full and the best I have been able to attain is 60 mph.
Can any of you 65mph guys give me some input? What do you have that is aftermarket, or is my Formula just slower than average. I run on fresh water, elevation 2000 ft, temperature in the 100's.

Boating magazine a few years back tested a 2000 271 with a 496HO on salt water. It's top speed was 63mph at 5000 rpm.

mopower

Grog, There's your answer right there

Try sea level and 75* temps and you'll probably pick up the speed. 2000 ft altitude has less dense air , and the 100* temps only make it worse. I can see a difference in mine when comparing cool spring or fall runs to hot summer runs. Ever notice the difference in your car or truck at altitude...less power , same with a boat.
The only consulation is , the boat that's trying to pass you is at the same disadvantage

Oh yeah, they say salt water is faster too ,since it is more dense than fresh and the boat floats higher , but you couldn't prove that by me

Grog

Mopower and Formulafasttech -

Thanks for the feedback. Now I can't wait for that brisk 60° December day to open it up. In the meantime, I am looking into a set of EMI cast aluminum exhaust manifolds and risers. I am optimistically expecting an extra 2-3 mph. Throwing money away or not....it's something I just gotta' try.

mopower

I went with Imco Power Flows on mine. Saw , maybe 1.5 mph

Magicfloat

"Try me fee" from your dealer?What the heck is that?I'll send you a prop when I get back from the Formula dealer meeting next week,but you will have to remind me,short term memory is gone at my age. Robert

Grog

Does anybody have an idea as to whether I would gain top speed with a higher pitch prop....eventhough it may drop me into the 4600-4700 rpm range? Another concern with a higher pitch prop is that with my current 26p, my hole shot is not the best.

hauling ass-a

I have a 2000 271, switched from a 26 p to a 28 the first day i had it. I was hitting the rev limiter. Also added a vortec flame arrestor(probly the biggest increase in speed) only 1-2 mph but also added stainless marine manifolds, arizona speed ecm, and adjustable fuel reg. all together maybe 3-4mph I have seen a honest 70 on the gps. I'am also hitting 5200 rpm and will try a 30p sometime this summer. All 271 are super slow out of the hole to heavy of a boat. Ialso boat at or near sea level

Grog

Thanks guys. This is a great forum. Appreciating all of the tips.

Formulafasttech - I must not have the membership capability yet to view your pictures. I am going to look at my drive when I get home today and see where I can trim the drive in farther based upon your description in words alone. If I can't figure it out, would it be too much trouble to send the pictures to my e-mail address? Thanks again!

dockrocker

One thing to consider - is the bottom clean? *Any* junk on the bottom can seriously scrub speed. I lost almost 5 mph on our boat after leaving it in the water for only a week or so. Hard to believe it could make that big of a difference, but it did.

Grog

Nothing on the bottom of the hull but smooth gelcoat. The boat is a recent purchase so I still wipe it down after every use. We'll see how long that behavior lasts.