FAST intake upgrade question
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Joined: Apr 2012
Posts: 83
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From: Colonial Beach VA
FAST intake upgrade question
I currently have a 78mm FAST on my LS1 ported with a port matched Throttle body. I am wanting to go with a bigger size FAST like a 90mm or 92mm.
Can I use my existing connections and throttle body or do I have to get a bigger throttle body too?
What all must be done to make it work? Thanks.
Can I use my existing connections and throttle body or do I have to get a bigger throttle body too?
What all must be done to make it work? Thanks.
Drifting
Joined: Feb 2010
Posts: 1,310
Likes: 99
From: Arlington Texas
You will have to upgrade your throttle body also. The 78mm TB has 3 bolts in a triangle. The 90mm + tb have 4 bolts in a square pattern. Also FAST stopped making the 90 and 92 mm intakes. They only sell the 102mm intake new now. So you would have to find a used 90/92 intake and at times they can be hard locate it seems. I personally went with a 102mm intake and tb
Safety Car
Joined: Jul 2004
Posts: 3,904
Likes: 29
From: Vancouver Washington
If you go with the 102 Fast and an LS3 92mm throttle body make sure you use a transition ring behind the throttle body. You'll need the wiring adapter to convert to the 92 and new fuel rails, but your injectors should be fine.
Safety Car
Joined: Aug 2011
Posts: 4,449
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From: Portland OR
Ron
Safety Car
Joined: Jul 2005
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From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
according to Tony Mamo here, a properly ported and tuned FAST 78 will perform with a few HP of a FAST 90. They have the same runner size just a different size opening. Something to think about.
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Le Mans Master
Joined: Jun 2009
Posts: 6,528
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From: South Dakota
That was my question too. I was wondering how much improvement over the FAST 78 to see if it would even be worth the expensive swap. I thought the FAST 78 was a pretty good manifold.