I want to know why the 90 mm (throttle body and IM) are better for a 2000 z28 camaro A4. Other than more size means more airflow. Also, I want to knwo what the best place to buy them are. Rightg now i am looking at FAST for the intake Manifold and throttle body.

 

as far as i know...the FAST is the only one out there of that size.

and basically less restictive air in let is the main goal. as well as optimized runner lengths for good volume and flow.

but the FAST 90/90 setup is a waste of money unless you are making some serious power by means of a big h/c setup or forced induction.

for basic boltons and mild h/c an LS6 intake manifold and a ported stock LS1 throttle body will work just fine.

as for price...shop around the vendor list...under the advertisement banner at the top of the page

 

ditto on what teke said, but there a few brands of 90mm tb, fast and nick williams being 2 of them. fast very well may be the only 90mm intake tho

 

What are your current mods on the car?

 

If you're still running a 346c.i. setup, save your money and get an LS6 intake. Only those with bigger cubes and/or wild cams (.600+ lift) will begin to see more than the 5~10 hp difference between the LS6 and the 90/90 setup. At least, that's what I've been noticing on the boards. So, do you think another 5 hp is worth an extra $1000?

 

does anyone have flow numbers on the FAST versus the stock LS1 or LS6?

 

How much flow is only part of it, you need to look at velocity also.