Porting Crossfire intake, first attempt, please critique
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine 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.
Here you have many members that not only tell you that you are wrong...but they have put their money where their mouth is an proven you wrong with real results (ya know...dyno charts and ET time slips vs "Feelings" and "opinions")
You've stated "Countless hours" yet you choose to ignore the "hours" it would take to do a Carb swap...then you go for the coup de grâce mentioning that you'd swap out for a TBI system. That would take what....48 minutes?? Sure...
Let's not forget twotonthunder posted earlier that He went from 14.9 seconds to 14.1 with a Carb, while CFI-EFI is running much faster.......(Last time I checked, 13s where actually faster than 14s....I know, I know...facts facts facts)
Don't allow any of those facts to get in your way of posting yet MORE misinformation......but hey!! it's fun to bash on the missfire...
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
It's painfully obvious that your opinion is based on what you've read or been told. Try thinking on your own. Use logic, reason and knowledge of engine opertion. Pick up a tool and do some work on the thing....THEN comment with real world, objective data to back up your postings. Kind of like what I, and others here have done and the OP is actually doing.
Thanks for sharing your OPINION that you're "not a big fan". Noted. But don't state your misguided opinion as fact.
EDIT: You never answered my question in post #39...
Last edited by Tom400CFI; Nov 1, 2009 at 03:43 PM.
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
Why? And why are you on this thread?
But you haven't done the work, so how would you know? What is "countless hours"? I did it. It's time, but it was totally worth it, for me b/c the gains WERE significant, the work wasn't that hard, the gains were "ALL MINE" (not store-bought). Try it some time. The second part of your quote above (in bold), is just not true at all. Not compared to other cars or engines of the same decade. Just wrong, misinformation that you're spewing there.
That would get you ABOUT the same results, except it would cost you the intake and TBI unit in $$'s.
It's painfully obvious that your opinion is based on what you've read or been told. Try thinking on your own. Use logic, reason and knowledge of engine opertion. Pick up a tool and do some work on the thing....THEN comment with real world, objective data to back up your postings. Kind of like what I, and others here have done and the OP is actually doing.
Thanks for sharing your OPINION that you're "not a big fan". Noted. But don't state your misguided opinion as fact.
EDIT: You never answered my question in post #39...
But you haven't done the work, so how would you know? What is "countless hours"? I did it. It's time, but it was totally worth it, for me b/c the gains WERE significant, the work wasn't that hard, the gains were "ALL MINE" (not store-bought). Try it some time. The second part of your quote above (in bold), is just not true at all. Not compared to other cars or engines of the same decade. Just wrong, misinformation that you're spewing there.
That would get you ABOUT the same results, except it would cost you the intake and TBI unit in $$'s.
It's painfully obvious that your opinion is based on what you've read or been told. Try thinking on your own. Use logic, reason and knowledge of engine opertion. Pick up a tool and do some work on the thing....THEN comment with real world, objective data to back up your postings. Kind of like what I, and others here have done and the OP is actually doing.
Thanks for sharing your OPINION that you're "not a big fan". Noted. But don't state your misguided opinion as fact.
EDIT: You never answered my question in post #39...
fact both are 350's both are for the most part stock meaning no performance mods. The 82 trans am is a roller cam 350 with TBI the 82 corvette bone stock as far as I know.
Fact the trans am runs wayyyyyy better and can at will run circles around the vette. It can out accelerate the vette with ease as well. both cars have similiar gearing and weight probably close as well.
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,187
Likes: 1
From: Superior WI
Well, I was going to start a new thread with my new pics, but this one seems to still be going along nicely, quite a lively discussion.
Just to put my own two cents in, I understand that there are other induction methods on newer cars that fit those newer cars. I however have a 1984 Corvette. It has the Crossfire injection. It will stay that way. Period. I can afford to buy a newer model, but chose to buy an '84 and see what I could squeeze out of it. I'm having a great time working on it and planning my next move. The time I've spent grinding away I've used to contemplate many of life's great questions, like should I put a roller cam in here or maybe some new heads, what kind of headers should I get and more importantly, I think that new barmaid down at the saloon digs me!
So on to the newest batch of pics. Note that in one of them you can see where I've gone through, Tom mentioned an epoxy that he's used in a similar situation, I'll try that and see how it works. I'm pretty sure I can get some more material out but I'm taking a little break to watch some football.
Again, thanks to all of you who have contributed to my efforts
Just to put my own two cents in, I understand that there are other induction methods on newer cars that fit those newer cars. I however have a 1984 Corvette. It has the Crossfire injection. It will stay that way. Period. I can afford to buy a newer model, but chose to buy an '84 and see what I could squeeze out of it. I'm having a great time working on it and planning my next move. The time I've spent grinding away I've used to contemplate many of life's great questions, like should I put a roller cam in here or maybe some new heads, what kind of headers should I get and more importantly, I think that new barmaid down at the saloon digs me!
So on to the newest batch of pics. Note that in one of them you can see where I've gone through, Tom mentioned an epoxy that he's used in a similar situation, I'll try that and see how it works. I'm pretty sure I can get some more material out but I'm taking a little break to watch some football.
Again, thanks to all of you who have contributed to my efforts
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
I understand that there are other induction methods on newer cars that fit those newer cars. I however have a 1984 Corvette. It has the Crossfire injection. It will stay that way. Period. I can afford to buy a newer model, but chose to buy an '84 and see what I could squeeze out of it. I'm having a great time working on it and planning my next move.
my opinion is factual. case in point, I have a 82 corvette with cfi and a 82 trans am with a 90 TBI conversion.
fact both are 350's both are for the most part stock meaning no performance mods. The 82 trans am is a roller cam 350 with TBI the 82 corvette bone stock as far as I know.
Fact the trans am runs wayyyyyy better and can at will run circles around the vette. It can out accelerate the vette with ease as well. both cars have similiar gearing and weight probably close as well.
fact both are 350's both are for the most part stock meaning no performance mods. The 82 trans am is a roller cam 350 with TBI the 82 corvette bone stock as far as I know.
Fact the trans am runs wayyyyyy better and can at will run circles around the vette. It can out accelerate the vette with ease as well. both cars have similiar gearing and weight probably close as well.
I fail to see any logic there.
It would be nice if you took your '82 Vette and ported it the way it is being shown in this thread...then you used those results to quantify ANYTHING........
Last edited by jhammons01; Nov 1, 2009 at 11:48 PM.
Instructor
Joined: Jul 2009
Posts: 238
Likes: 0
From: CA
it's just darn cool to try to improve something you own, someone gotta do it and someone's gotta post it, there are always some negativity, this is a free country, i say go for it and, i bet you are eager to see the results...
the op is on a mission, and i encourage him to max out his vision and
HOBBY!!!!
true car guy
the op is on a mission, and i encourage him to max out his vision and
HOBBY!!!!
true car guy
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
As far as Vette owners go, you are a keeper, you have a very healthy attitude and you are probably a generally happy person....it shows
so lemme get this straight, you modified the '82 TA and now it seems to run better than the stock '82 CFI......and somehow that makes your point??
I fail to see any logic there.
It would be nice if you took your '82 Vette and ported it the way it is being shown in this thread...then you used those results to quantify ANYTHING........
so lemme get this straight, you modified the '82 TA and now it seems to run better than the stock '82 CFI......and somehow that makes your point??
I fail to see any logic there.
It would be nice if you took your '82 Vette and ported it the way it is being shown in this thread...then you used those results to quantify ANYTHING........
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Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
^We already know what a stock CFI intake flows. About 180 CFM each runner. It's not good. Hence, the desire to PORT it, and get some reasonable flow out of it.
That's good stuff right there. "My OPINION, is factual". Wow. That must be really convenient at work, w/the wife, etc. Nice job in achieveing that status!
GM never made a '90 F-body TBI 350. Swap from a truck?
Based on what data? Your SOTP meter?? lol. Even if the TA is faster (objectively) there are plenty of other reasons that I can cite as to why, and none of the reasons have anything to do w/"magical" intakes.
Try again...this time, using facts and objective data.
That's good stuff right there. "My OPINION, is factual". Wow. That must be really convenient at work, w/the wife, etc. Nice job in achieveing that status!
Try again...this time, using facts and objective data.
Last edited by Tom400CFI; Nov 2, 2009 at 11:17 AM.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
To the OP; that last pic is looking good. Keep in mind, that you need to do that same thing, all the way through the runner. You need some long cutting bits to be able to reach all teh way through. Looks great so far though! You should feel good about the work you've done so far.
I see where you've cut through and the epoxy will fix that up no problem.
I see where you've cut through and the epoxy will fix that up no problem.
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
GM never made a '90 F-body TBI 350. Swap from a truck?
Based on what data? Your SOTP meter?? lol. Even if the TA is faster (objectively) there are plenty of other reasons that I can cite as to why, and none of the reasons have anything to do w/"magical" intakes.
Try again...this time, using facts and objective data.[/QUOTE]
The trans am has absolutely nothing special. Just a garden variety roller cam 350 with production heads and a LO-3 intake and throttle body. Stock exhaust 3.08 gears & stock 305 prom 305 injectors. So cite your other reasons why it's way faster! I can certainly say why the vette is so much slower LOL.
CFI's true downfall is that intake and electronics & without both issues addressed the other one will be non productive. Get the temperature up to 220ish and I bet that wet fuel system will benefit my 82 vette runs a lot better with elevated temps. Ditch that modem speed ecm Then perhaps CFI will perform.
Based on what data? Your SOTP meter?? lol. Even if the TA is faster (objectively) there are plenty of other reasons that I can cite as to why, and none of the reasons have anything to do w/"magical" intakes.
Try again...this time, using facts and objective data.[/QUOTE]
The trans am has absolutely nothing special. Just a garden variety roller cam 350 with production heads and a LO-3 intake and throttle body. Stock exhaust 3.08 gears & stock 305 prom 305 injectors. So cite your other reasons why it's way faster! I can certainly say why the vette is so much slower LOL.
CFI's true downfall is that intake and electronics & without both issues addressed the other one will be non productive. Get the temperature up to 220ish and I bet that wet fuel system will benefit my 82 vette runs a lot better with elevated temps. Ditch that modem speed ecm Then perhaps CFI will perform.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
The trans am has absolutely nothing special. Just a garden variety roller cam 350 with production heads and a LO-3 intake and throttle body. Stock exhaust 3.08 gears & stock 305 prom 305 injectors. So cite your other reasons why it's way faster! I can certainly say why the vette is so much slower LOL..
What part of that is hard for you to understand??
If you'd like to make a comparison (one that is logical) It would have been cool if you took the TA with a Crossfire and your 92 Vette with the Crossfire and then made both Mods (The one you think is great, and the one being mentioned here) one on each car......and then posted the results.
That is how you "prove" something. Telling us how you put an 8 year newer motor in a car and now that car is faster than your '82 Vette tells us nothing that we didn't already KNOW!!.
How much more clear do I need to be???
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
According to Standard Catalog of Chevrolet Trucks by John Gunnell, 1995, it depends on your VIN code.
5.7L TBI
VIN Code A
190 hp @ 4000 rpm
300 lb.-ft. @ 2400 rpm
Standard in Suburbans, 1 ton Vans, optional in C/K Trucks
5.7L TBI
VIN Code K
210 hp @ 3600 rpm
300 lb.-ft. @ 2800 rpm
Standard in Blazer, optional in Suburbans, Vans, and Pickups
Type ohv V-8
Displacement, liters/cubic inch
5.7/350
Bore X stroke, inches 4.00 X 3.48
Fuel management
Cross-Fire Throttle Body Fuel Injection
Horsepower @ rpm
200 @ 4,200
Torque @ rpm, pound-foot
283 @ 2,800
the corvette with 2.73 gears and the trans am with 3.08 gears.
5.7L TBI
VIN Code A
190 hp @ 4000 rpm
300 lb.-ft. @ 2400 rpm
Standard in Suburbans, 1 ton Vans, optional in C/K Trucks
5.7L TBI
VIN Code K
210 hp @ 3600 rpm
300 lb.-ft. @ 2800 rpm
Standard in Blazer, optional in Suburbans, Vans, and Pickups
Type ohv V-8
Displacement, liters/cubic inch
5.7/350
Bore X stroke, inches 4.00 X 3.48
Fuel management
Cross-Fire Throttle Body Fuel Injection
Horsepower @ rpm
200 @ 4,200
Torque @ rpm, pound-foot
283 @ 2,800
the corvette with 2.73 gears and the trans am with 3.08 gears.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Originally Posted by pr0zac
the corvette with 2.73 gears and the trans am with 3.08 gears
"Runs a lot better"? What does that mean? My car made documented faster passes @ ~170*F than it did at ~200*F.
Last edited by Tom400CFI; Nov 2, 2009 at 01:56 PM.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
If you'd like to make a comparison (one that is logical) It would have been cool if you took the TA with a Crossfire and your 92 Vette with the Crossfire and then made both Mods (The one you think is great, and the one being mentioned here) one on each car......and then posted the results.
Nice post.
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
Misguided information is given way to often. Especially when about the CFI. The only way to know if what you've done has improved your setup is to either go run the track or throw it on a dyno. Those will give you "true" results. Everyone's SOTP meter/dyno is different!
Last edited by qws; Nov 2, 2009 at 12:59 PM.
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Very well said...
Misguided information is given way to often. Especially when about the CFI. The only way to know if what you've done has improved your setup is to either go run the track or throw it on a dyno. Those will give you "true" results. Everyone's SOTP meter/dyno is different!
Misguided information is given way to often. Especially when about the CFI. The only way to know if what you've done has improved your setup is to either go run the track or throw it on a dyno. Those will give you "true" results. Everyone's SOTP meter/dyno is different!
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
To make more power, you need more air (supplied by the intake -according to you) and also fuel. Adding only air, won't get you more power. How, with the stock 305 TBI ECM and 305 injectors (calibrated to make 170hp on a 305) are you making over 200 hp; the amount the 'Vette makes....in order to "walk all over" the 'Vette?
Your claims remind me of a time when I had a similar experience as what you're claiming, so bear with me here:
I installed a SBC400 into an F-body, w/no other changes. When done, the car felt "mad" compared to before. Even my GF said that "It gives me whiplash"...much to my delight. At that time, I would have told anyone, that it would "walk all over" it's previous form. Then I took it to the track. It ran .5 to 1 second SLOWER than it had previously. Why? Not enough fuel. Not dialed in, at all. But it FELT, bad assed, that's for sure. The old SOTP meter, just don't work, buddy. You need to present real, objective data.
Later, I tuned in the engine, and while it didn't FEEL significantly faster, it ran 1.5-2 seconds faster in the 1/4.
Your claims remind me of a time when I had a similar experience as what you're claiming, so bear with me here:
I installed a SBC400 into an F-body, w/no other changes. When done, the car felt "mad" compared to before. Even my GF said that "It gives me whiplash"...much to my delight. At that time, I would have told anyone, that it would "walk all over" it's previous form. Then I took it to the track. It ran .5 to 1 second SLOWER than it had previously. Why? Not enough fuel. Not dialed in, at all. But it FELT, bad assed, that's for sure. The old SOTP meter, just don't work, buddy. You need to present real, objective data.
Later, I tuned in the engine, and while it didn't FEEL significantly faster, it ran 1.5-2 seconds faster in the 1/4.
Last edited by Tom400CFI; Nov 2, 2009 at 01:58 PM.