FAST 78 or 90mm? Which do you recommend?
 

Engine Mods are as follows:

AFR 205 Heads (not milled)
Comp Cam 228/232 .588 .590 113LSA
Catch Can
Vararam Intake
160 T-stat
Intake Catch Can

Exhaust:
B&B PRT catback
Dynatech Longtube headers – jet hot coated (hi-flow cats)

Wondering if spending the extra money on the 90mm is worth it. What's your input? Thanks in advance:crazy:

-Monte

You will notice the power-gains slightly, but the 78 or 90mm Fast intakes won't give you a good dollars-spent to hp-gained ratio.

:iagree: But get the 90mm fast for sure if going to spend the money.

Ls6 or 90mm

FAST90 for sure if you can even find them anymore :thumbs:

I see conflicting reports that the gains are negligible....some say it makes a good bit of difference, others say not worth it.

If you are buying new which they are not making the 90mm no more. Cost to hp gain really not worth it. Get you a ported ls6 are ls2 intake for the money.....:thumbs: If you got money to blow then go for it...

I have a 2001 so I already have an LS6 intake. I suppose porting it is an option however...

If you can find a take off 90/90 setup..get it. You WILL pickup HP commensurate with the cost. It is the next step with you H/C build.

Not worth the money IMO. I nice ported ls6 would be pretty close from what I have seen. Unless you really care about an extra 5-10hp for what 700 plus.

Unless you're building a very high HP NA motor there's not much benefit to doing the FAST90 or 102 relative to the cost difference from just getting an LS6 intake ported. If you're going for a 600RWHP NA motor, get the FAST102, otherwise, save your $$$ for more toys later :thumbs:

I picked up 2 tenths in the 1/4 with a FAST 90 and a nick Williams TB over the original LS6 intake. Well worth the $$ expended. I was conflicted also but I'm glad I did the modification. Get at least the FAST 90.

For most stock cube applications, the throttle body will do just fine when ported. keep in mind your intake is only as good as the weakest link and the throttle body is only sometimes the case.

Also remember that the velocity of moving air is what gives you torque (power you feel). Assuming the throttle body is the "weak link" in your intake, an oversize throttle body will give you great top-end power, but your mid range end may feel sluggish to respond. A undersize throttle body will kill your upper-mid and top end power.

The key is to balance the entire intake flow rates and restrictions to your motor and what part of the power band you're building for.

picked up 2/10 also with the ported fast90/and ported 90 tb. if you want to be near the top in et in a n/a car you have to get all the hp possible and it will cost you some $$$$$$$$$$. like add an electric water pump also. just another $600 for maybe 3 to 5 rwhp. and maybe a underdrive pulley while we're at it. the list goes on.:eek: