Porting Crossfire intake, first attempt, please critique
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
I new here but in my opinion we should not hijack the OP's thread. I had some questions for Thunder about his carb swap and asked him with a PM. Thunder was very cool about lettin me in on his experience. I have a lot of questions about the CFI. I would like to learn about the CFI. Upgrades. limitations (what can the TBs flow anyways?). But as I said, we should have respect for the OP and keep this thread limited to conversation that is helpfull to the OP's topic.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
The TB's flow flow ~500CFM stock, IIRC. They are not a limiting factor, even on a lightly modified 350 w/a fully ported intake. Perhaps after cam, heads LT's/exhaust the TB's might become a restriction. Boring them is cheap and easy. I did mine, myself.
Fuel system is the second "lowest hanging fruit" after the ported intake, as the stock pump is frequently at or near it's limit in stock form. A pressure test can confirm or deny this on your car. Off the shelf, bolt-in pump and injectors are sufficient for up to ~350hp.
In short, massive intake porting and moderate fuel system upgrades put you in a position to achieve up to 350 hp, with other supporting mods -the same other supporting mods that you'd need w/any induction system; cam, headers, exhaust, heads.
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
CFI-EFI, and TOM400CFI have great experience with the CFI and know there stuff.
Going carb is definetly going backwards in time. If a carb upgrade is whats being done getting a 14.95 out of that upgrade is NOT impressive to me. Not when you can bet better gains from porting. Not only is it cheaper to do but you keep the reliablity of the CFI!
Granted I never ported my intake. I went the Xram route, but with that upgrade alone I ran a 14.2-14.5. Not sure what the ported intake would run but I would think it should run that if not better.
Pro
Joined: Apr 2008
Posts: 694
Likes: 1
From: Spokane WA
Whats the plan on the other end of the runners?
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
I was berated and pestered for months, all over the Internet. Then I was begged and pleaded to for advice and help. Now an expert, here comes the self styled regurgitated advice.
RACE ON!!!
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Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,187
Likes: 1
From: Superior WI
I love this forum. All this experience and the willingness to share it, great stuff guys! I'm a lot closer to completion now, I think I've put in close to 6 hours in since I first posted and I like the way its going. I slapped on a couple of gaskets and found where I needed to remove more material, that was a good tip! I keep on going deeper and deeper, I'm nearing the point where I'm worried about going through on the bottom. I'm probably just having jitters, but its amazing how much material I've removed and how much is still left. I'll start a new thread with some new pics this evening.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
There IS a lot of material there to be removed, Remove it all, from runner mouth to head flange. If you cut through, no big deal; Use a high quality epoxy (I used PC-7 on mine) to fill the breach, then grind it flush and move on. It works great and will give you no problems.
Pro
Joined: Apr 2003
Posts: 552
Likes: 13
From: Oz
Alternatively, in around 2 months the Renegade intake will be available. It is a bolt on replacement with full size runners, better than you could ever do porting a stock intake.
I know its going to make mine faster and I can't wait to get my hands on one.
I know its going to make mine faster and I can't wait to get my hands on one.
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,187
Likes: 1
From: Superior WI
I put another shift in this afternoon. I sat at my bench with the grinder for a couple more hours, and I feel like I made some headway. I took some pics but the angle of the camera really didn't show my new progress, just the opposite, where I need to pick up tomorrow...ugh. Gonna be a long day tomorrow...wish me luck, I'm goin in!
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
Sorry but porting a CFI manifold has serious drawbacks.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Sorry but porting a CFI manifold has serious drawbacks.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
B. Define "minimal". Without guidelines, how would one know?
C. Save your grindings. No weight loss.
RACE ON!!!
Last edited by CFI-EFI; Oct 31, 2009 at 12:12 PM.
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Sorry but porting a CFI manifold has serious drawbacks.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
(a) time could have been spent better at something, I'm not sure what but anything would have been better.
(b) in the end power gains minimal
(c) when you find out it was a waste a time it will be worth less at the recycling center because it weighs less.
But good luck on your venture none the less.
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
well I just hope it is as much as a difference is every one says, not that you are being built up for like 30 hp increase of something and you can't tell in the end.
I never worked on one, but I do know I avoided an 84 for many reasons, but this is the big one. (that is just me) some like them some just have them period.
I guess if worse comes to worse it was fun, and exciting it looks like there is some major room for improvement on them, and if it is not that great you could buy the new setup that might come out.
People are being negative because it is a fact that it is a huge restriction on a 350 unless you mod it, and keep in mind some of the guys here are pretty technical people have skills, and tools(I know we can all buy bits) that the average Joe can't do to make something better, and some of those guys are rooting you on, but you might not have the same out come.
IMO only, GOOD LUCK
I never worked on one, but I do know I avoided an 84 for many reasons, but this is the big one. (that is just me) some like them some just have them period.
I guess if worse comes to worse it was fun, and exciting it looks like there is some major room for improvement on them, and if it is not that great you could buy the new setup that might come out.
People are being negative because it is a fact that it is a huge restriction on a 350 unless you mod it, and keep in mind some of the guys here are pretty technical people have skills, and tools(I know we can all buy bits) that the average Joe can't do to make something better, and some of those guys are rooting you on, but you might not have the same out come.
IMO only, GOOD LUCK
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
well I just hope it is as much as a difference is every one says, not that you are being built up for like 30 hp increase of something and you can't tell in the end.
I never worked on one, but I do know I avoided an 84 for many reasons, but this is the big one. (that is just me) some like them some just have them period.
I guess if worse comes to worse it was fun, and exciting it looks like there is some major room for improvement on them, and if it is not that great you could buy the new setup that might come out.
People are being negative because it is a fact that it is a huge restriction on a 350 unless you mod it, and keep in mind some of the guys here are pretty technical people have skills, and tools(I know we can all buy bits) that the average Joe can't do to make something better, and some of those guys are rooting you on, but you might not have the same out come.
IMO only, GOOD LUCK
I never worked on one, but I do know I avoided an 84 for many reasons, but this is the big one. (that is just me) some like them some just have them period.
I guess if worse comes to worse it was fun, and exciting it looks like there is some major room for improvement on them, and if it is not that great you could buy the new setup that might come out.
People are being negative because it is a fact that it is a huge restriction on a 350 unless you mod it, and keep in mind some of the guys here are pretty technical people have skills, and tools(I know we can all buy bits) that the average Joe can't do to make something better, and some of those guys are rooting you on, but you might not have the same out come.
IMO only, GOOD LUCK
"well I just hope it is as much as a difference is every one says, not that you are being built up for like 30 hp increase of something and you can't tell in the end."
I can't vouch for everyone's claims. In fact, no one's claims, but my own. I may have realized some gains that others haven't. I documented 6 to 7 tenths off my 1/4 mile ET from my intake manifold porting, alone. All in all, I have reduced my ETs by a bit over 2 seconds, with no other changes to the engine. All for no more than $1300.00.
It has been a challenge and a bunch of fun. I agree it isn't for everyone, but it (the Crossfire) doesn't deserve the bad rap it gets. None of the work I've done has been to help reliability or for repairs. The car is a rock.
RACE ON!!!
Last edited by CFI-EFI; Nov 1, 2009 at 01:38 AM.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Speaking from what first hand experience? People here who have actually DONE IT (and done it right) will say otherwise.
Last edited by Tom400CFI; Nov 1, 2009 at 12:25 PM.
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
I'm just not a big fan of dual toilet bowl injection is all. Yes I have one so I can say there is little to no hope for them without countless hours of work and a lot of money sunk into them. It's actually about the only engine I would ever consider doing a carb swap on. I would be more tempted to throw a later model TBI system on and a nice edelbrock manifold then to waste my time trying to get a cfi manifold to breath.