Why did they make Crossfire Injection
#101
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Re: Why did they make Crossfire Injection
Hey Tom, good to see you here. After the forum went belly up I lost interest in it and I' completely out o the loop now, I don't own a single CFI car anymore. Only CFI and X ram junk on the shelves LOL
That conspiracy theory was taken straight from the ancient Crossfire FAQ
That conspiracy theory was taken straight from the ancient Crossfire FAQ
#103
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Car: '92 Corvette
Engine: LT1
Transmission: ZF6
Axle/Gears: 3.45
Re: Why did they make Crossfire Injection
I do admit to not checking fuel pressure. I've never done that before, seems fairly straight forward to do. Anything tricky about doing it on a CFI? Idled much better after I tightened up the top plate and TB bolts and cleaned out those gunked up IACs.
That slight roughness BTW, is not so much at idle, you kind of feel some coarseness when you rev the motor. It's not bad, but I can definitely feel the difference between it and my TPI which revs as smooth as a Swiss watch.
That slight roughness BTW, is not so much at idle, you kind of feel some coarseness when you rev the motor. It's not bad, but I can definitely feel the difference between it and my TPI which revs as smooth as a Swiss watch.
Is your "roughness" a misfire issue? Or a internal balance issue? If you get the engine up to the speed of the vibs and cut the ignition, do the vibs remain or instantly dissapear?
#104
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Car: '92 Corvette
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Axle/Gears: 3.45
Re: Why did they make Crossfire Injection
Hey Tom, good to see you here. After the forum went belly up I lost interest in it and I' completely out o the loop now, I don't own a single CFI car anymore. Only CFI and X ram junk on the shelves LOL
That conspiracy theory was taken straight from the ancient Crossfire FAQ
That conspiracy theory was taken straight from the ancient Crossfire FAQ
I don't really want to make a cam recommondation, 'cause it's not MY car. I got lucky when I did my combo, but I don't think that it's extremely critical what cam you use, as long as your in the ball park with duration and lobe separation. Divide your CID by your stock cam duration. Then divide that number, by 383 to give you a ball park cam size that is reletively a similar size. But based on MY experience and results, I'd guess that something in the low 220's range on a 112 split would work pretty good. You can pushing it farther than that, but the farther you push, the more you'd have to be willing to accept for idle/fuel economy/driveability issues. Know that in my 400 with the 224/234, it ran like stock...only way, WAY more so.
#109
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Car: '92 Corvette
Engine: LT1
Transmission: ZF6
Axle/Gears: 3.45
Re: Why did they make Crossfire Injection
Yep, that, or a schrader installed in the tube connecting the TB's is the way to go...for tuning and repeated tests. For a one-time test for diagnosis though, the "T" in the rubber line should suffice.
Maybe. Keep in mind too, that I had a T5. So the gearing and "tq converter factor" was different. I liked the 3.23's too, don't get me wrong. They were WAY better than most of the other F-bod options.
Maybe. Keep in mind too, that I had a T5. So the gearing and "tq converter factor" was different. I liked the 3.23's too, don't get me wrong. They were WAY better than most of the other F-bod options.
#110
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Re: Why did they make Crossfire Injection
#113
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Re: Why did they make Crossfire Injection
*Remove the rubber fuel hose from the fuel filter.
*Insert a "T"
*Add a piece of rubber fuel hose, to another barb on the "T" and connect the opposite end to the fuel filter.
*Attache the rubber fuel hose from your fuel pressure gauge, to the third nipple on the "T"
*Commence pressure testing precedure.
We're talking a spec of 9-13 PSI here. This is no big deal. A agree w/83CrossfireTA, that if you're "tunning" and adjusting pressure all the time, his method is way easier in the long run. But for a one-time diagnostic test, HISTORY has proven that this is the fastest, easiest, cheapest way to get the data that you need. Historically.
Last edited by Tom 400 CFI; 10-03-2011 at 01:50 PM.
#115
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Re: Why did they make Crossfire Injection
I believe that spec is actually 9-12psi, and most people find that they run best at 13-15 (if your stock fuel pump can keep up).
FWIW, I actually started a fire disconnecting the line between the filter and front TB- it runs behind the alternator, and when it was loose it tagged the bat terminal on the back of the alternator, shorted and arced, and I ended up with a jet of buring gas shooting straight up... dumb (bad) luck.
FWIW2, it's not actually the correct way. The factory answer is to disconnect the line between the 2 TB's because the accumulator in the front TB can affect readings. I used to have a shrader valve t-ed in that line but after a while I got concerned about it getting tangled in the throttle linkage (either making it stick or knocking it loose eventually) which is why I plumbed it where I did, just adding a permanent test port where it was solidly mounted and generally out of the way.
FWIW, I actually started a fire disconnecting the line between the filter and front TB- it runs behind the alternator, and when it was loose it tagged the bat terminal on the back of the alternator, shorted and arced, and I ended up with a jet of buring gas shooting straight up... dumb (bad) luck.
FWIW2, it's not actually the correct way. The factory answer is to disconnect the line between the 2 TB's because the accumulator in the front TB can affect readings. I used to have a shrader valve t-ed in that line but after a while I got concerned about it getting tangled in the throttle linkage (either making it stick or knocking it loose eventually) which is why I plumbed it where I did, just adding a permanent test port where it was solidly mounted and generally out of the way.
#116
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Car: 1989 IROC-Z. Original owner
Engine: LB9. Dual Cats. Big Cam
Transmission: World Class T-5
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Re: Why did they make Crossfire Injection
No need to cut anything, and no need to be squeamish.
*Remove the rubber fuel hose from the fuel filter.
*Insert a "T"
*Add a piece of rubber fuel hose, to another barb on the "T" and connect the opposite end to the fuel filter.
*Attache the rubber fuel hose from your fuel pressure gauge, to the third nipple on the "T"
*Commence pressure testing precedure.
We're talking a spec of 9-13 PSI here. This is no big deal. A agree w/83CrossfireTA, that if you're "tunning" and adjusting pressure all the time, his method is way easier in the long run. But for a one-time diagnostic test, HISTORY has proven that this is the fastest, easiest, cheapest way to get the data that you need. Historically.
*Remove the rubber fuel hose from the fuel filter.
*Insert a "T"
*Add a piece of rubber fuel hose, to another barb on the "T" and connect the opposite end to the fuel filter.
*Attache the rubber fuel hose from your fuel pressure gauge, to the third nipple on the "T"
*Commence pressure testing precedure.
We're talking a spec of 9-13 PSI here. This is no big deal. A agree w/83CrossfireTA, that if you're "tunning" and adjusting pressure all the time, his method is way easier in the long run. But for a one-time diagnostic test, HISTORY has proven that this is the fastest, easiest, cheapest way to get the data that you need. Historically.
#117
Re: Why did they make Crossfire Injection
I read in a Camaro book that GM had a trailer full of cross ram carb intake manifolds and told the engineers to make use of them: thus that is where the entire crossram FI came from. and thats why the idea was somewhat flawed in the first place. Because really its just a modified carb setup.
I know that was mentioned, but I think it was kind of a more "make it work" concept . Either way the hoods were awesome. They should of incorporated that into the iroc somehow.
I know that was mentioned, but I think it was kind of a more "make it work" concept . Either way the hoods were awesome. They should of incorporated that into the iroc somehow.
#118
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Car: 1989 IROC-Z. Original owner
Engine: LB9. Dual Cats. Big Cam
Transmission: World Class T-5
Axle/Gears: BW 3.45
Re: Why did they make Crossfire Injection
I read in a Camaro book that GM had a trailer full of cross ram carb intake manifolds and told the engineers to make use of them: thus that is where the entire crossram FI came from. and thats why the idea was somewhat flawed in the first place. Because really its just a modified carb setup.
I know that was mentioned, but I think it was kind of a more "make it work" concept . Either way the hoods were awesome. They should of incorporated that into the iroc somehow.
I know that was mentioned, but I think it was kind of a more "make it work" concept . Either way the hoods were awesome. They should of incorporated that into the iroc somehow.
There was a lot of potential still left in the CFI system, had development continued. But immediately after it's release, all work shifted to TPI. And if you really look at TPI, it's almost a port fuel injected version of CFI with some bugs worked out.
Last edited by chazman; 05-31-2012 at 04:58 PM.
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