LS6 or FAST 78 ?
Drifting
Joined: Apr 2004
Posts: 1,530
Likes: 250
From: CT
Probably not unless you have it ported (or port it yourself).
You prob know they dont make the 78 any more but some suppliers still have them in stock. I picked one up brand new for a good price and porting it. I would expect there's some used ones on eb site.
Un-ported maybe 7-8 hp gain over the LS6. Ported 17-18 or so. Do a search for Tony Mamos (AFR) posts on the FAST Intakes. Here's one of his earlier posts on this subject;
"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 FAST 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 an unported 78mm and the 90mm FAST (netting you 2-3 more HP than a 78 FAST). 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 $$...........Typical Gain.........Cost/HP
Stk FAST 78.............700...................... ..8....... ............. $87
Stk FAST 90 (w/ TB)..1200......................13....... .......... ...$92
FAST 78 w/ 85 mm.....900.......................11..... .......... .....$82
Ported FAST 78.........1200......................18. .......... .........$67
Ported FAST 90/90.....1700......................23..... .......... .....$74
The key is to understand that the snout doesn't represent the largest restriction in the FAST hence the smaller gains when messing with it. Reshaping and reconfiguring the ports are where the larger gains in airflow and power can be unlocked...."
You prob know they dont make the 78 any more but some suppliers still have them in stock. I picked one up brand new for a good price and porting it. I would expect there's some used ones on eb site.
Un-ported maybe 7-8 hp gain over the LS6. Ported 17-18 or so. Do a search for Tony Mamos (AFR) posts on the FAST Intakes. Here's one of his earlier posts on this subject;
"Consider this in your search for "value" (I look at everything on a HP per dollar basis).
If you already have a good epoxied and ported 78 mm TB (like a Mark Shaner piece or something similar) score a FAST 78 unit cheap and just consider having it ported. Even at the prices I charge to do a very neat and thorough job your return on investment is still better than buying a larger 85 mm TB and cutting up the snout which might close the gap in half between an unported 78mm and the 90mm FAST (netting you 2-3 more HP than a 78 FAST). For an extra few hundred you would see an additional gain of 10 RWHP and a similar bump in TQ (my ported FAST 78 set-up went 20 RWHP and 15 RWTQ stronger than my former LS6/78 set-up as I previously mentioned).
For grins I just whipped up this spreadsheet....prices and performance may vary slightly but I think the general point I am making would still be intact.
Manifold.............Avg Retail $$...........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...."
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Here is some good reading on manifolds
http://www.tpis.com/plog/index.php?o...Id=14&blogId=1
Thanks,Matt
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
http://www.tpis.com/plog/index.php?o...Id=14&blogId=1
Thanks,Matt
