Cross Fire Hop Up
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Joined: Feb 2003
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From: Fort Carson, CO
Car: 83 Z28 camaro **SOLD**
Axle/Gears: stock
Cross Fire Hop Up
Any body have any good recomendations for any good performance mods to do to a cross fire injection setup?
A friend of mine told me that my 1983 305 Cross fire has the same manifold as their old '68 with cross ram on a 302. Could I throw two carburetors on the manifold?? Any help is great...
cherrybombz28
305 crossfire, 700R4
A friend of mine told me that my 1983 305 Cross fire has the same manifold as their old '68 with cross ram on a 302. Could I throw two carburetors on the manifold?? Any help is great...
cherrybombz28
305 crossfire, 700R4
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Joined: Apr 2003
Posts: 267
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From: Houston TX
if you used carbs on the manifold... YOU WOULD NEED to fabricate adaptors... but sure it would work (theoretically)... You can do "ultimate tbi mods" to each injector base unit, and you can upgrade the injectors... If you have the money.. you can find a machine shop pretty easy (some of them will do STOCK manifold boring and porting)
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Joined: Oct 2000
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From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
No, it's not a 69 crossram
First, two carbs on that intake will improve perfomance about....zero. the throttle bodies are not even remotely a restriction. Don't put carbs on that intake. Put that same money (2 carbs, linkage, and fabed intake=$700+) into EXHAUST!!
Second, don't waist your time on the "Ultiamte TBI Mods" until you've done the things I'm about to list below. Our TB's are different than the standard 2bbl units and most of the "Ultimate" mods don't apply to our units. The ones that do won't show you ANY gains until you do the things below, so here goes my spiel....
Your intake shares about as much with the old 69 crossram as a .22 rifle shares w/a 12 gauge shot gun. They're both guns, they look similar, but on is WAY smaller. In this case, it's the CFI intake that's smaller (and more restrictive).
HOWEVER, you can go a LONG way before the intake begins to significantly limit your power. The FIRST THING you need to do is dump the stock exhaust! From the heads to the tail pipes. Headers, newer (bigger) cat, and a good 3" cat back. That, along with a '85 and newer fuel pump, 160 T-stat, AFPR, advanced timing(find out what your engine likes), no smog pump, and good driving should put you right in the upper 14's. I ran a 14.5 @95 with this combo, plus a T-5, 5speed trans years ago.
After that, spend a day with a die grinder, and port the phuk out of the intakes runners. When you remove the intake, you'll see how much porting needs to be done -alot. Actually, buy an intake off ebay, and port that, then swap them one afternoon, and sell your original. This alone will net you another .5 in the quarter. Now you're looking at LOW 14's in the upper 90's. Your knocking on 13's, you havent' opened the motor yet, and you've spent what on the intake system? $40 on gaskets? There's a lot to do in there for little more than some weekend afternooons. Now thorw a modern cam in the mix and your in the thirteens w/a 305 CFI. Have fun!
Second, don't waist your time on the "Ultiamte TBI Mods" until you've done the things I'm about to list below. Our TB's are different than the standard 2bbl units and most of the "Ultimate" mods don't apply to our units. The ones that do won't show you ANY gains until you do the things below, so here goes my spiel....
Your intake shares about as much with the old 69 crossram as a .22 rifle shares w/a 12 gauge shot gun. They're both guns, they look similar, but on is WAY smaller. In this case, it's the CFI intake that's smaller (and more restrictive).
HOWEVER, you can go a LONG way before the intake begins to significantly limit your power. The FIRST THING you need to do is dump the stock exhaust! From the heads to the tail pipes. Headers, newer (bigger) cat, and a good 3" cat back. That, along with a '85 and newer fuel pump, 160 T-stat, AFPR, advanced timing(find out what your engine likes), no smog pump, and good driving should put you right in the upper 14's. I ran a 14.5 @95 with this combo, plus a T-5, 5speed trans years ago.
After that, spend a day with a die grinder, and port the phuk out of the intakes runners. When you remove the intake, you'll see how much porting needs to be done -alot. Actually, buy an intake off ebay, and port that, then swap them one afternoon, and sell your original. This alone will net you another .5 in the quarter. Now you're looking at LOW 14's in the upper 90's. Your knocking on 13's, you havent' opened the motor yet, and you've spent what on the intake system? $40 on gaskets? There's a lot to do in there for little more than some weekend afternooons. Now thorw a modern cam in the mix and your in the thirteens w/a 305 CFI. Have fun!
Last edited by Tom 400 CFI; Apr 28, 2003 at 01:11 PM.
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