84 crossfire mod help
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From: Indianapolis Indiana
Team Owner
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From: Park City Utah
Cut some holes in the top of the radiator shroud and install weather stripping around them to seal the top of the shroud to the hood. Now your stock CAI actually takes in....cold air.
If you follow your hood ducting from the air filter housing forward to the front of the hood, it terminates here:
See that oval hole in the hood? That should have corresponded w/a hole and weatherstripping on the top of the radiator shroud, so ambient air (air ahead of the radiator) could flow freely up through the hood ducting, and into the air filter housing. GM never put the hole in the shroud though, so now your engine is drawing hot, under-hood air from directly above the radiator shroud.
If you follow your hood ducting from the air filter housing forward to the front of the hood, it terminates here:
See that oval hole in the hood? That should have corresponded w/a hole and weatherstripping on the top of the radiator shroud, so ambient air (air ahead of the radiator) could flow freely up through the hood ducting, and into the air filter housing. GM never put the hole in the shroud though, so now your engine is drawing hot, under-hood air from directly above the radiator shroud.
Burning Brakes
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From: norway
Safety Car
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From: Mission Viejo CA
We all know what a good street cleaner we have with our bottom breather radiator inlet. There are plenty of stories of interesting things ending up in our radiator plenum. By cutting out the top of this plenum, this stuff is ducted to your air cleaner, including water spray from the road, and rain. The '83 proto's had this area open, and after finding these problems, GM closed up this area. The gap between the top of the plenum and the bottom of the hood ducts gets a good supply of cool air from the front of the car.
This may make sense for a dedicated fair weather drag car, but I'm not so sure for a DD. GM did a few things right!
This may make sense for a dedicated fair weather drag car, but I'm not so sure for a DD. GM did a few things right!
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From: Indianapolis Indiana
So should i do this air mod since my car is a daily driver due to it being my very first car? Also after running it kinda hard why does it die out when put in reverse and the headlights flicker if it doesnt die, is this the fuel pump?
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From: Park City Utah
Do the mod.
IDK why your car does that. Some diagnosis is in order. Start w/checking fuel pressure.
While possible, it is extremely unlikely that one would lift water 2+ feet off the ground, suck it into the hood ducting, draw it all the way into the filter housing (velocity through the hood is VERY low), then have that water stay in suspension and make it through the filter. Basically, it's not going to happen. Dust, maybe, but that is what the filter is for.
This is absolutely, 100% untrue. The gap draws air from under hood. The air being drawn into that opening (in stock form) is every bit as "hot" as any air under the hood. It IS, the air that is under hood! Look where it is...then tell us, where, exactly the air path is for this supposed "cool air from the front of the car". It doesn't exist b/c it's not there. It's drawing hot, under hood air.
Not in this case, they didn't. There are 100's if not 1000's of '84 CFI cars running around w/this CAI mod, that have no issues. DD's included. This is worrying about crap that don't need worrying about.
IDK why your car does that. Some diagnosis is in order. Start w/checking fuel pressure.
We all know what a good street cleaner we have with our bottom breather radiator inlet. There are plenty of stories of interesting things ending up in our radiator plenum. By cutting out the top of this plenum, this stuff is ducted to your air cleaner, including water spray from the road, and rain.
Not in this case, they didn't. There are 100's if not 1000's of '84 CFI cars running around w/this CAI mod, that have no issues. DD's included. This is worrying about crap that don't need worrying about.
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From: Indianapolis Indiana
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From: Indianapolis Indiana
Air cleaner lid flaps
You know the flaps on lid that lead into the air cleaner they are open when i shut off the engine then when i turn the engine on one flap closes and the drivers side remains open. Could that be a faulty air cleaner sensor? Seems weird that it does that. Need advice
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Drifting
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From: Upstate NY
air intake mod
I made a pattern to match the hood cutout and then duplicated the cutout on the radiator shroud.
I used a 1/2" foam to seal it up.
I also did;
-K&N filter.
-ported intake.
-1.6 roller tip rockers.
-Magnaflow cat.
-Muffler eliminators.
-Hypertech chip -most say it in not worth it?
No before & after times, but overall it feels faster and sounds way better. The ported intake definitely seemed to make the biggest difference!
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From: Park City Utah
They should BOTH be closed when you start the engine cold. During this period, it should be drawing air up through the "heat stove pipe" -a silver tin pipe that runs from the driver's side exhaust manifold, up to the driver's side intake snorkel. See silver pipe in this pic, under snorkel and bending down to exhaust manifold. This is to speed intake warming and fuel vaporizing.
Once "warm" (no specific engine temp; there is a thermostatic vacuum switch inside the air filter housing),both flaps should open, closing off the hot air intake and opening the "cold air"....which again, is only "cold" if you open the path in front of the radiator.
In reality, I disabled the "Thermac" as it's called by GM, in my CFI car as I always wanted the coldest, most unrestricted air intake that I could get. Doing this never caused any issues...even in the winter.
Last edited by Tom400CFI; May 19, 2014 at 12:21 PM.
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What brand of 1.6 roller tip rockers do you guys recommend? Also do you get the same gain from porting your stock intake or buying an aftermarket intake? I think i do have the magnaflow exhaust not to for sure what brand they are they were on there when i bought it. What can you do with the catalaic(cant spell) converter? My dad bored his out on his old 350 monte carlo that thing was a beast even smoking some vettes
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What brand of 1.6 roller tip rockers do you guys recommend? Also do you get the same gain from porting your stock intake or buying an aftermarket intake? I think i do have the magnaflow exhaust not to for sure what brand they are they were on there when i bought it. What can you do with the catalaic(cant spell) converter? My dad bored his out on his old 350 monte carlo that thing was a beast even smoking some vettes
Intakes porting vs. aftermarket? That question is impossible to answer b/c there are so many aftermarket intakes available, and an infinite number of definitions of "porting" or a "ported intake". Do you have a specific intake in mind? IMO, a FULLY ported CFI intake -meaning you've ported it to the limit of the casting, will out perform many of the popular CFI replacements; the X-Ram, or a Performer dual plane, and any stock TPI intake.
However, when you move into the realm of HSR's, Minirams, or something like an Offenhauser Cross ram (if you're talking about keeping it "Crossfire"), then the stock intake is soundly trumped. Stock intake, fully ported is a good intake up to around 300 hp. Above that, it will make power, but becomes an increasing limiting factor as power increases. Needs bigger runners.
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I don't know. I'd probably have to be there to see/hear/feel the symptoms.
I'd guess it's too rich under those conditions, closing the throttle fast makes it even more rich momentarily, and that could cause it to stumble etc. I'd start by checking fuel pressure, though, while it's doing what you described.
I'd guess it's too rich under those conditions, closing the throttle fast makes it even more rich momentarily, and that could cause it to stumble etc. I'd start by checking fuel pressure, though, while it's doing what you described.
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Fully ported pics
Can you guys post some pics of your FULLY ported crossfire intake so i can have it machined. The guy at the shop wants to see pics of what im talking about hes charging me $50/hr.
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No pics here, unfortunately. I had some years ago...don't know what happened to them though.
Just tell the guy to keep removing metal until there is hardly anything left to remove -from the mouth of the runner, to the flange.
@$50/hr, you're going to end up w/a $500 intake (if he does it right).
Just tell the guy to keep removing metal until there is hardly anything left to remove -from the mouth of the runner, to the flange.
@$50/hr, you're going to end up w/a $500 intake (if he does it right).
Melting Slicks
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There's a picture of a cross sectioned cfi intake in my member album. I'd have a bead welded at the thin spot just before the port enters the head, it'll allow more porting & improve the angle there.
Burning Brakes
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From: norway
