wSc*daywalker

Hey Guys,

I´m looking for the upgrade I will do this year to my Z06. I was thinking about the FAST LSX Manifold in 92mm or 102 incl. the throttle body. My car has a Vararam, Powerduct, Kooks 7/8 Longtubes incl. X-Pipe and B&B Bullet exhaust. The car was on the dyno and has approx 402 RWHP.

What do you guys think this setup could provide to me? Would I have to redyno? I´m somehow scared to put a cam in and to port the heads.

Thanks for your input.

Day.

ctusser

Not a lot, maybe 5-7 hp. Until you get the cam and heads done. The stock intake is not much of a restriction at your power level. You could gain a few just by porting the stock throttle body for $95

wSc*daywalker

Hm that doesn´t sound too good

Do you have an address which is known for porting?

So perhaps then the next option will be looking in a cam and ported heads hm...

ctusser

Lingenfelter will do a good throttle body port for cheap, getting into heads opens up a whole new bunch of options.

c6speedjon

What else do you need to convert to this set up? can you use the same ls1/ls6 fuel rails with the fast 92? from what I understand you need a ls2 tb in order to run the fast 92 set up, anyone chime in on this?

ctusser

If you port the stock throttle body nothing is needed. If you go FAST intake and Ls2 throttle body a wiring adapter harness is needed.

c6speedjon

I understand this, but what else is needed? Do the fuel rails mount and line up with the fast 92?

ctusser

Nothing else is needed.

Although you might want to trim the fuel rail covers with a Dremel tool to fit the contour of the FAST intake.

Milan

I am selling my ported LS6 TB if you need it...

AJPM

The stock fuel rails will work. I just put a FAST 90 on my car. The intake was worth 22hp peak on my car. Are mods are similar with the addition of a cam and some mildly ported heads on my setup. If you buy used, just make sure it comes with the button heads bolts that hold the valley cover down. Thats what I ran into. Other than that, pretty straightforward install.

wSc*daywalker

Guys, sorry for the question but which size does the stock LS6 throttle body has? Base on the setup I run right now, what do you think a ported throttle body would bring HP wise? And would you need to dyno it again to benefit from the porting?

Thank you!

ctusser

Stock TB is 78mm, a good port might net you 3-5 hp on a bolt on car. I had a pro ported LS6 mani and ported stock TB on a head/ cam car and only gained 5 hp when I changed to a FAST 90.

If you just port the stock TB I wouldn't bother with a retune. Even after switching to the Fast 90 a retune didn't gain me any more hp. But my pro ported LS6 setup was flowing pretty well and was actually putting down more power than the Fast 90 below 5000 rpm.

blackdak318

If you upgrade I would recommend the 92mm version. The 102mm version can be hard to tune and some tuners won't even tune a 102. When I called my tuner the first question they asked was what TB size.

I would spend your money elsewhere though to get a better bang for the buck. With stock heads and cam it's not worth the $$ for a FAST setup. Look into suspension or maybe nicer seats even. I have the Pfadt JOC suspension setup and it was a very noticable upgrade. I also have Corbeau A4's and they're SO much better than the stock seats.

wSc*daywalker

Thanks guys for your input I will look into the Lingenfelter throttle body porting!