420 - 430rwhp.. FAST 78 or FAST 90??
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Pro
Joined: Aug 2001
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From: Orlando FL
420 - 430rwhp.. FAST 78 or FAST 90??
I am guessing my rwhp to be around there. a member from this forum with the same mods just dyno'd 426 "and I believe another did 43x" What would be my best intake for my current setup?? SHould I go with the 78 or the 90?
Specs in sig.
Thanks guys.
Specs in sig.
Thanks guys.
Last edited by OMG its Jason; Jun 9, 2007 at 11:13 PM.
Thread Starter
Pro
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From: Orlando FL
Thread Starter
Pro
Joined: Aug 2001
Posts: 714
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From: Orlando FL
Well, The heads are stage 2 patriot. I know there are better flowing heads out there, but these are most likely the ones I am sticking with.
I'd consider doing the swap if I would be able to pull another 15-20 over the LS6. If not, it's hard to justify spending a grand for 10hp.
Thanks though. I am SURE this has been talked about, but has anyone actually compared LS6 vs 78 vs 90 with a modded engine?
I'd consider doing the swap if I would be able to pull another 15-20 over the LS6. If not, it's hard to justify spending a grand for 10hp.
Thanks though. I am SURE this has been talked about, but has anyone actually compared LS6 vs 78 vs 90 with a modded engine?
Melting Slicks
Joined: May 2005
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From: gresham oregon
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Pro
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From: Orlando FL
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Former Vendor
Joined: Mar 2004
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From: Valencia CA
I copied and pasted this response I made in another thread discussing various gains from different intakes and their cost effectiveness. This particular customer was looking at buying an 85 mm TB and planned on opening up the 78 to fit which leaves it very thin. Seems some of what I posted below applies to your question....especially the quick chart of power gains versus cost.
--------------------------------------------------------------------
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 $$...........Typical Gain.........Cost/HP
Stk FAST 78.............700...................... ..8....... ............. $87
Stk FAST 90 (w/ TB)..1200......................13....... .......... ...$92
FAST 78 w/ 85 mm.....900.......................11..... .......... .....$82
Ported FAST 78.........1200......................18. .......... .........$67
Ported FAST 90/90.....1700......................23..... .......... .....$74
The key is to understand that the snout doesn't represent the largest restriction in the FAST hence the smaller gains when messing with it. Reshaping and reconfiguring the ports are where the larger gains in airflow and power can be unlocked....
Tony
--------------------------------------------------------------------
Consider this in your search for "value" (I look at everything on a HP per dollar basis).
If you already have a good epoxied and ported 78 mm TB (like a Mark Shaner piece or something similar) score a FAST 78 unit cheap and just consider having it ported. Even at the prices I charge to do a very neat and thorough job your return on investment is still better than buying a larger 85 mm TB and cutting up the snout which might close the gap in half between an unported 78mm and the 90mm FAST (netting you 2-3 more HP than a 78 FAST). For an extra few hundred you would see an additional gain of 10 RWHP and a similar bump in TQ (my ported FAST 78 set-up went 20 RWHP and 15 RWTQ stronger than my former LS6/78 set-up as I previously mentioned).
For grins I just whipped up this spreadsheet....prices and performance may vary slightly but I think the general point I am making would still be intact.
Manifold.............Avg Retail $$...........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....
Tony
Last edited by Tony Mamo @ AFR; Jun 10, 2007 at 12:01 AM.
Burning Brakes
Joined: Jan 2002
Posts: 885
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From: The Woodlands Texas
Since I do all my own work I decided to install a FAST 90mm intake and an LS2 90mm throttle body when I did my heads / cam install. This was a good decision as it opened up the intake and my Kooks headers and cat system opended up the exhaust allowing the great numbers I have with my Stage 2 setup. As always it's your car and your money but the FAST 90mm and LS2 throttle body are a solid combo that is not a waste of money.
Burning Brakes
Joined: Jan 2002
Posts: 885
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From: The Woodlands Texas
I paid $800 for the FAST 90mm intake and $225 for the LS2 throttle body. Not sure where you are getting the $1700 from but no way these parts cost that much. I purchased my stuff new. You can install both pieces in less than 4 hours with a few beer breaks - piece of cake.
Le Mans Master
Joined: Aug 2000
Posts: 5,294
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From: Suffolk, Long Island NY
$1700 was for a ported 90/90. I know everyone's results are different, but I've seen ported Fast intake dyno the same as a non ported.
As for me, I picked up 13rwhp and 20rwtq though a A4. My heads are Absolute Speed Stage II 5.3's and a 230/236 cam.
If you haven't seen my post yet about the Fast intake, plan on adding another $70 to the cost, it's well worth it. http://forums.corvetteforum.com/show....php?t=1727067
As for me, I picked up 13rwhp and 20rwtq though a A4. My heads are Absolute Speed Stage II 5.3's and a 230/236 cam.
If you haven't seen my post yet about the Fast intake, plan on adding another $70 to the cost, it's well worth it. http://forums.corvetteforum.com/show....php?t=1727067
Thread Starter
Pro
Joined: Aug 2001
Posts: 714
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From: Orlando FL
$1700 was for a ported 90/90. I know everyone's results are different, but I've seen ported Fast intake dyno the same as a non ported.
As for me, I picked up 13rwhp and 20rwtq though a A4. My heads are Absolute Speed Stage II 5.3's and a 230/236 cam.
If you haven't seen my post yet about the Fast intake, plan on adding another $70 to the cost, it's well worth it. http://forums.corvetteforum.com/show....php?t=1727067
As for me, I picked up 13rwhp and 20rwtq though a A4. My heads are Absolute Speed Stage II 5.3's and a 230/236 cam.
If you haven't seen my post yet about the Fast intake, plan on adding another $70 to the cost, it's well worth it. http://forums.corvetteforum.com/show....php?t=1727067
13/20 is nothing to complain about, but 6/12 is a LOT for a large price.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Ported is the way to go. Look at it this way, if you picked up the ported setup and it didn't work out, these and the DTE brace are about the fastest selling item in the for sale section and you will only lose a couple of hundred bucks if it doesn't work out. The difference between ported and non-ported is not so much the peak but the mid-range will be drastically improved.
Pro
Joined: Jul 2003
Posts: 568
Likes: 41
From: xyz VA
I have 415rwhp and 420rwtq 372ci with baby cam. I used the 78 FAST and everyone said the tuning issues with the 90 and new TB didn't warrant the extra 2-5 hp. I assume those issues were worked out. I bought my FAST 78 weeks after they first came out. Make sure you consider upgrading fuel injectors. My stock LS1 injectors were maxed at 385rwhp, so upgraded when the FAST went in. Good luck!