FAST LS Intake
-Joel
-Joel
There is not as much difference between a 78 and a 90 as most think...
Hope you don't mind me quoteing you Tony...
Consider this in your search for "value" (I look at everything on a HP per dollar basis).
If you already have a good epoxied and ported 78 mm TB (like a Mark Shaner piece or something similar) score a 78 unit cheap and just consider having it ported. Even at the prices I charge to do a very neat and thorough job your return on investment is still better than buying a larger 85 mm TB and cutting up the snout which might close the gap in half between the 78 and the 90 netting you 2-3 HP. For an extra few hundred you would see an additional gain of 10 RWHP and a similar bump in TQ (my ported FAST 78 set-up went 20 RWHP and 15 RWTQ stronger than my former LS6/78 set-up as I previously mentioned).
For grins I just whipped up this spreadsheet....prices and performance may vary slightly but I think the general point I am making would still be intact.
Manifold.............Avg Retail $$...........Typical Gain.........Cost/HP
Stk FAST 78.............700........................8....... ............. $87
Stk FAST 90 (w/ TB)..1200......................13................. ...$92
FAST 78 w/ 85 mm.....900.......................11............... .....$82
Ported FAST 78.........1200......................18........... .........$67
Ported FAST 90/90.....1700......................23............... .....$74
The key is to understand that the snout doesn't represent the largest restriction in the FAST hence the smaller gains when messing with it. Reshaping and reconfiguring the ports are where the larger gains in airflow and power can be unlocked....
Tony


