500 efi upgrades
 

Has anybody had any luck with HP upgrades on 500s efi ? I have a 02 vyper and thinking of doing something .

It really depends on what kind of power you want to make, if its in the budget, Whipple it, the internals will handle it, as long as you dont go crazy on boost, there's one in the classified's for 6K

I second the whipple idea,,best bang for the buck.

Depending on how far you want to go do forget about drive upgrades

Do the throttle body and ignition upgrade do much?

The million dollar question, do you have to crack into the engine at this time?

not really, that plenum wont flow much more air, heads and cam is where the power is made, if your not going to put a huffer on it.

Hard to gain much power keeping her N/A without dumping as Much money as adding a whipple or procharger. I had 230 trouble free hours with my properly setup procharger......but had drive issues.

Don't forget about your drives! The only upgrade worth throwing money at is a Imco SCX. Now your into your boat for double what its worth.

Might as well sell her and buy something that's already faster.....

The motors have 350 hrs ,the heads were gone through at 300.the boat has xr drives . I'm thinking of opening up the motors at 400 hrs. It currently runs mid to low 80s.

Your running low to mid 80's with stock 500 efi's ??

down hill.

Yep , 83 to 85.6 on two gps . Hits the rev limiters with 30 pitch labs.

Thats rolling for a heavy boat and that power, what are your speed goals?

I know it's hard to believe ,I didn't believe it when we were looking at the boat till I drove it. Upper 80s to 90, I think the hull can handle it.

Has anyone put one on a dyno with the Aetco kit? (Heads,cam,reprogram).

From what I have seen, the 500EFI intake limits motors to just about 600hp.

Thus why Tyler Crocket makes the top mount throttle body conversion....for more power.

Also, why others switch to a more conventional EFI intake (Holley Single Plane and etc) if looking to make more steam.

Brad Smith was able to get right at 600 HP on a pair of 500 EFI's for a buddy. Bored, new pistons, cam, head work, new injectors, PCM remap.

Whats the length and weight of this boat

34 ft 8000 to 8500?

Wow, I scratched my head on that one. Want to trade 500 EFI's?

I've got Smith built 540's with good Chit in em AFR heads, custom cams, custom tuned ECM, CMI headers, 630 HP a side, I don't see how, numbers don't ad up, but good for u, I guess I'll take the 500's out of the Cig put em in the OL and do 90 :grinser010:

Sadly, It won't.

That is pretty light, it is a lot heavier.

Powerboat mag tested the Vyper with 500EFIs and went 85.2 GPS and 86.5 on radar.

I had a 2002 Vyper with 496 HOs and went 79.5 GPS in freshwater. Would run 78 everyday.

Wanted to go faster but the hull was maxed out.

The boat seems pretty calm compared to the last two boat I have had at this speed. Do you think the hull is maxed out ?

I have heard that stock 500 efi's have put up dyno numbers close to 600hp. Completely stock, I spoke to a engine builder that threw one on the dyno before rebuild.

If you love the boat then by all means please enjoy modifying her. But bolt on parts are not going to be enough to satisfy your speed goals. They will just leave you wanting more! I would add a blower and continue to freshen the engines as needed.

Just remember XR drives will prematurely wear out if not break with the added power. Even with every upgrade available your still forced to use the stock junk gears...they WILL pit and come apart. Either have 1 or 2 spare drives laying around and plan on constantly rebuild them almost every season or buy a pair of IMCO SCX for about 30K.

500EFIs usually dyno around 510hp

Nope. You misunderstood. Or he did.

I've always heard they are closer to 470 hp.

We did a 500 EFI package with Bob Madara last year that made 650 HP.

How much is a 500HP or 525HP anyways?

Forget it... I found the price... Thats crazy...

Mine were about 510 and 515

With that plenum different heads and cam will offer very limited results. I spoke with a very irritated individual at a poker run about $20k+ upgrades to his 500efis. Dart Pro1 heads, motors hit a wall at 4500rpm. A well respected builder/tuner built and dynoed them, it was the owners opinion that they should have never made it to the boat as they hit a wall on the dyno as well. Owner also talked with sterling and they had seen similar results.

I like the 34 Viper, considering one for my next ride - whats the word with the Hull?

We like ours,look for a late 2001 or newer. (Faster hull)