birdblack

Anyone have any experience changing out an Ls6 intake for a Fast 92? Did you notice a difference either thru the seat of the pants or on a dyno? Did you change out the factory injectors and fuel rails? Will the factory fuel rails and injectors supply enough gas after stepping up to the Fast 92? I already have changed out the stock heads and cam. Running Kooks headers as well. A larger throttle body seems to be the next step.

Injuneer

Injector size is a function of flywheel HP. Do you have dyno numbers on your current setup?

Might want to update your "signature" with head and cam info.

While I understand this question is related to fuel, I think it might get better response on "LS1 Based Engine Tech". We really have a shortage of LS1 owners, but I think it's a better location. I'll move it if you want.

birdblack

Yes that would be OK. The dyno numbers right after the heads and cam was 396 to the ground.

Injuneer

396 HP at the rear wheels would correspond to about 455 HP at the flywheel. Based on that, you are on the ragged edge with the stock injectors (28.8 #/HR). You should be seeing greater than 90% duty cycle.

birdblack

We did increase the injectors to 42 lbs with the head and cam. On the dyno the engine dropped fuel pressure so the new injectors were put in as well as a higher capacity Aeromotive fuel pump. Seems to me the next logical step is the Fast 92 manifold and TB. My hope is to get to 490+ at the flywheel.

BandDirector Blk98ZM6

I've got a '98 Z28 that I swapped an LS6 longblock back in '04 and ran an SLP LS6 intake (modified to accept the EGR on the '98-'99 F-Bodies) until this past summer. I put down 385.9 RWHP on the LS6 intake and then 400.1 RWHP when I swapped over to the FAST 92mm/Nick Williams 92mm TB.

birdblack

Thanks. I was hoping for a little more then 15 hp.

BandDirector Blk98ZM6

My LS6 longblock still has stock LS6 heads and internals. The FAST92mm will let it pickup even more with cam and/or head swap...I wouldn't be surprised if you didn't see a 20-25 RWHP increase with your head/cam swap...