SlickVert

iTrader: (5)

Who has the highest HP 402/408 motor with a Fast intake?
Just trying to compare and see how much the intake is holding back the big numbers.
Bob

JakeFusion

iTrader: (7)

Vince made over 560rwhp when his Futral 408 was in his Camaro and 555rwhp in the Vette.

Mikey at Rapid made 553rwhp out of a 402.

383SS made 540rwhp through 290cfm heads and the FAST 90 on his 408.

ECS had a 418 make over 580rwhp with a FAST. Both Cartek and ECS have made 580rwhp to 600rwhp on 441/447s with the FAST.

MTI ususally does 550s with a 427 and the FAST. LG did 560rwhp with a FAST on a 427 with a G5X4 cam.

The FAST doesn't hold the engine back much in terms of flow (still, the engine can only peak at 6300, so that's where the restriction in power really comes from). Obviously, more intake CFM would make more power. The LS7 can hit upper 500s and lower 600s with 427 and it takes a slightly larger engine to do it with the FAST. But the LS7 has more total flow and the ability to peak higher.

The other restriction is the bore sizing. The 4.125" and larger bores can more easily make 550+ with the FAST 90 and similar heads and cam than the 402/408s out there.

Mike TexaSS

iTrader: (2)

My 402 made 542 RWHp with a FAST intake. In a corvette.

383ss

iTrader: (14)

slight correction on mine, but you are damn close...

made 550rwhp once on the dyno but was consistantly 545. heads flowed 293cfm @ 600 with 2.02 valves. mild 246/250 fms cam also

Nickn20

hehe, im going nuts, ditching the FAST since I nitrous backfired it to peices anyway and going with the LS7, the guys over at ETP are really pushing the LS7 head and intake Should be really interesting to see what my car will make with the combo I am doing next, I think 600 rwhp will be easily acheived.

Mr Powell

iTrader: (1)

I made 500rwhp on motor with my 408ci motor through a 28x10.5W @ 15psi through a Powerglide and a 12-bolt. It went 131mph on motor at 3100lbs.

SlickVert

iTrader: (5)

Thanks for the info, you all are making some awesome power!

I am in the process of building a 383; 3.905 bore and a Callies 4” crank.
I am looking to see what kind of power I can make with the same 4” stroke but with a 3.905 bore instead of the 4.0”.

Tony Mano 383 solid roller set-up made some awesome power 530hp
I am planning to use my ET 215, Fast 90/90 and 4.56 gears.

I am trying to decide on the best cam to get the job done.
Looking to make a max effort 383 Drag/Street set-up, mostly drag.
I would like it to make max average power between 5,600 and 7,200rpm, peak around 6,300 to 6,700 and carry out to 7,200 plus.

After looking at these awesome 402/408 numbers just maybe I can make 520 to 530 hp with the correct cam.

I have had some great advice from some of you, thanks again.
I am sure I can get it none.
Bob

383LQ4SS

iTrader: (33)

With my 385 setup I made 522

with the 415 it made 557rwhp with the only changes being the crank and pistons

this was with 28inch slicks with a large solid nitrous cam that had a ton of overlap killing some tq

I do belive the FAST to be a substantial restiction right around 540-560 rwhp.

SlickVert

iTrader: (5)

Good comparison.
385ci to 415ci = 30 more inch = 35 more HP

What was the Bore and Stroke of your 385 set-up?
Bob

NEVRLIFT

Vette Dcotors has a 402 LS2 making 568rwhp/510rwhp.

383LQ4SS

iTrader: (33)

4.060 bore and 3.72 stroke on the 385
4.062 and 4.00 on the 515

JakeFusion

iTrader: (7)

Bob, I responded to your PM. I hope my clarification, well, is clear.

Although the cam seems small at .050" it is very large at .200" due to LSK lobes. This will make it seem quite a bit bigger than it is, so power should be unreal with it.