boring out crossfire throttle bodies
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (da747)
Contact member, "Lionsden". Dan bores these TBs. If you haven't done anything to your manifold, you'll be wasting your time. I ported my manifold within a .001" of it's life. That was worth over a half second in the 1/4. Subsequently, I installed 2" TBs for NO additional gain. Track tested. Good luck, and...
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Thread Starter
Instructor
Joined: Nov 2001
Posts: 210
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From: Watertown CT
Re: boring out crossfire throttle bodies (CFI-EFI)
im considering an x-ram, but only if i can enlarge the throttle bodies. Im not going to put on a 1400 cfm manifold when the stock throttles flow @550. where is the pressure regulator on a crossfire? is it part of one of the injectors or separate? thanks
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (da747)
I hope you are planning a TON of other modifications to go along with all that. I'm not sure what a 1400 cfm manifold will do for a 500 cfm engine. My manifold flows a lot more than stock, but the stock TBs fed it.
The pressure regulator is in the rear TB.
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The pressure regulator is in the rear TB.
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Thread Starter
Instructor
Joined: Nov 2001
Posts: 210
Likes: 0
From: Watertown CT
Re: boring out crossfire throttle bodies (CFI-EFI)
i got this car with a new 383 crate engine in it, i recently found out why the previous owner didnt try to put tpi on it, too much trouble to convert an 84. i wish he put a superram on but oh well. there is good potential in this engine if the induction could match it.
Drifting
Joined: Aug 2000
Posts: 1,316
Likes: 0
From: Houston, TX
Re: boring out crossfire throttle bodies (da747)
http://www.crossfire.homeip.net/
Register on the Cross Fire Vault, the most info you will find anywhere on Cross Fire cars. You can have a lot of fun with your cross fire car if you take the time to learn how to make it run. Guy around her has a 383 Stroker cross fire car. Says his 17 year old son really enjoys spanking the LT-1's with it at the strip and watching those guys shake their heads.
Register on the Cross Fire Vault, the most info you will find anywhere on Cross Fire cars. You can have a lot of fun with your cross fire car if you take the time to learn how to make it run. Guy around her has a 383 Stroker cross fire car. Says his 17 year old son really enjoys spanking the LT-1's with it at the strip and watching those guys shake their heads.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (HWoods)
Says his 17 year old son really enjoys spanking the LT-1's with it at the strip and watching those guys shake their heads.
A built 383 probably could take advantage of bored TBs. I have seen a ported Crossfire casting on a 400 cid engine. With his cam and headers, I believe he was taking advantage of the bored TBs, he had. I can tell you, they are worth no gain on a stocker.
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Pro
Joined: Apr 2003
Posts: 552
Likes: 13
From: Oz
Re: boring out crossfire throttle bodies (CFI-EFI)
You can bore them to 2" without sleeving, I have done this and used 2" butterflys from Holley, #26-100 is a pack of four for only a few dollars.
Dan has bored'n'sleeved them to 2.25". I am about to bore/sleeve a spare set of mine to 2.20". I really don't know if it will make any difference, but there's only one way to find out! Mine ran 12.8 @ 107 with the 2" bores, X-ram, 383 etc....
Here is Dans 'Boring' page. http://www.swko.net/~lionsden/crossfire.htm
Ben.
Dan has bored'n'sleeved them to 2.25". I am about to bore/sleeve a spare set of mine to 2.20". I really don't know if it will make any difference, but there's only one way to find out! Mine ran 12.8 @ 107 with the 2" bores, X-ram, 383 etc....
Here is Dans 'Boring' page. http://www.swko.net/~lionsden/crossfire.htm
Ben.
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Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (ben73)
I am about to bore/sleeve a spare set of mine to 2.20". I really don't know if it will make any difference, but there's only one way to find out! Mine ran 12.8 @ 107 with the 2" bores, X-ram, 383 etc....
Ben.
Ben.
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Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Re: boring out crossfire throttle bodies (da747)
i got this car with a new 383 crate engine in it, i recently found out why the previous owner didnt try to put tpi on it, too much trouble to convert an 84. i wish he put a superram on but oh well. there is good potential in this engine if the induction could match it.
I would suggest you learn how to tune the ECM.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (da747)
what kind of fuel pump are you guys using?
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Drifting
Joined: Aug 2000
Posts: 1,316
Likes: 0
From: Houston, TX
Re: boring out crossfire throttle bodies (da747)
I would upgrade the pump, it is a simple upgrade and a win-win move. With the stock 84 fuel pump, results are questionable.
Also remember that with bored throttle bodies, you are increaseing air flow so can get into a lean condition, so more fuel may be required as you are flowing more air into your engine
Also remember that with bored throttle bodies, you are increaseing air flow so can get into a lean condition, so more fuel may be required as you are flowing more air into your engine
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: boring out crossfire throttle bodies (da747)
The spec for fuel pressure on a Crossfire is 9-13 psi. I have mine set at 14 psi. To test it, I set the pressure to 17. I taped a fuel pressure gauge to my windshield, and made a 1/4 mile pass. I revved it higher (6300 rpms) than I normally do, like I ran the pressure higher, to put the max stress on the fuel system. The needle on the gauge never fluttered. If you have money you haven't spent, yet, buy a new one. If not... test yours.
The X-Ram and the throttle bores don't determine fuel delivery. The flow rate of the injectors, fuel pressure and the pulse from the ECM, determine the fuel consumed. Your set up will probably require more fuel than mine. I would get everything set up and test to see if the pump is up to the job. Or if you have more money than...
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The X-Ram and the throttle bores don't determine fuel delivery. The flow rate of the injectors, fuel pressure and the pulse from the ECM, determine the fuel consumed. Your set up will probably require more fuel than mine. I would get everything set up and test to see if the pump is up to the job. Or if you have more money than...
RACE ON!!!