intake port design
Thread Starter
Heel & Toe
Joined: Jun 2011
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intake port design
Hello all, I have an 84 and i took the intake manifold off today and could not believe my eyes. The intake ports are only 2/3 the size of the head intake ports. Is this correct? Who would design such a mismatch? If they wanted low end torque change the cam not the runner proportions.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
Get the grinder out and start grinding. In about 10 hours you will have a reasonably well flowing I.take capable of taking your car into the 13's. Yes, that is how it was designed from the factory, and low RPM ta was not the reason; emissions was the reason.
Safety Car
Joined: Oct 2008
Posts: 4,689
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From: Yucaipa CA
Why complain won't change the dual toilet bowl injection disaster under your hood. Dump the CFI and put a miniram or at least a 4 banger in and feel a instant power increase.
LU-5 or L-83 = complete lack of respect for power and only marginally better then what fred flintstone drove.
LU-5 or L-83 = complete lack of respect for power and only marginally better then what fred flintstone drove.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Why complain won't change the dual toilet bowl injection disaster under your hood. Dump the CFI and put a miniram or at least a 4 banger in and feel a instant power increase.
LU-5 or L-83 = complete lack of respect for power and only marginally better then what fred flintstone drove.
LU-5 or L-83 = complete lack of respect for power and only marginally better then what fred flintstone drove.
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Used to be a member here SHINOBI-X had a stock crossfire with fully ported base would run neck and neck with my 89 TPI on the track
All depended on who got the jump. Car ran well.
Safety Car
Joined: Oct 2008
Posts: 4,689
Likes: 4
From: Yucaipa CA
crossfire has no hope. I own one and they are dogs that can be outrun on foot face it they are a dinosaur of efi. You talk about port a cfi and it will run with a tpi, I call 
.... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.
.... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
crossfire has no hope. I own one and they are dogs that can be outrun on foot face it they are a dinosaur of efi. You talk about port a cfi and it will run with a tpi, I call .... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.
.... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.He has been around for some time & is a very good wrench on all Musclecars including C4's
He has owned & raced many C4's including ZR-1's.
I believe what he said about home porting a 1984 CFI intake & getting to perform nicely for torque an acceptable HP on the street.
Won't make 800 HP with no power adders.
But should make close to 300 flywheel horsepower with a decent combo on a 1984 Vette 350 shortblock/ longblock.
Just my 2 cents.
Brian
Last edited by 87 vette 81 big girl; Jul 5, 2011 at 12:43 AM.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Ron, the guy above your post is an expert cylinder head & intake porter.
He has been around for some time & is a very good wrench on all Musclecars including C4's
He has owned & raced many C4's including ZR-1's.
I believe what he said about home porting a 1984 CFI intake & getting to perform nicely for torque an acceptable HP on the street.
Won't make 800 HP with no power adders.
But should make close to 300 flywheel horsepower with a decent combo on a 1984 Vette 350 shortblock/ longblock.
Just my 2 cents.
Brian
He has been around for some time & is a very good wrench on all Musclecars including C4's
He has owned & raced many C4's including ZR-1's.
I believe what he said about home porting a 1984 CFI intake & getting to perform nicely for torque an acceptable HP on the street.
Won't make 800 HP with no power adders.
But should make close to 300 flywheel horsepower with a decent combo on a 1984 Vette 350 shortblock/ longblock.
Just my 2 cents.
Brian
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Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
crossfire has no hope. I own one and they are dogs that can be outrun on foot face it they are a dinosaur of efi. You talk about port a cfi and it will run with a tpi, I call .... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.
.... port a stock base of a cfi isn't got to make up the the difference of 40hp and what 40ft lbs of tq. face it cfi is good for 2 things .... a boat or a garbage can.Question (for anyone) About how may fwhp does it take to make a 3300 lb car go:
*14.5/95 in the 1/4?
*13.8/102ish in the 1/4?
*13.2's/105ish in the 1/4?
Those are times that I've ran myself, or seen first hand through a ported stock intake. The first time was an UNported, stock intake on stock 305 -rated at 170 hp from the factory. Takes about 220hp to go 14.5/95 in a 3300 lb car.
Point is, a person (obviously not jeffp1167) absolutely CAN make big gains on a CFI car, with little to no costs. The big gains come easy partly b/c the starting point (stock configuration) is so poor. Low hanging fruit, I like to call it.
-Tom
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
x
im not arguing juat saying what ive experienced. Somewhere i still have some timeslips from LACR- you can find him on youtube chieffatnutz maybe he will pipe in. cant remember if he had 307 or 3.54 would just weeze by him towards the tail end run after run unless he got the jump
Edit from post below
You port that intake right you will see night and day gains. Someone didnt do the job correctly if you didnt feel anything.
im not arguing juat saying what ive experienced. Somewhere i still have some timeslips from LACR- you can find him on youtube chieffatnutz maybe he will pipe in. cant remember if he had 307 or 3.54 would just weeze by him towards the tail end run after run unless he got the jump
Edit from post below
You port that intake right you will see night and day gains. Someone didnt do the job correctly if you didnt feel anything.
Last edited by cv67; Jul 5, 2011 at 02:32 PM.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
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"You are in an Elite Wheel Standing Drag Racing League" anyhow.
I was just kidding a few nights ago.
Need to be near 100 % crazy to launch a car down the 1/4 mile and stand it on the rear bumper & drag it for 200 to 300 feet.
Whenever I see your 84 c4 pics of it launching with a wheelstand I have Vivid flashback memories of "Frankie" and his Bright Corvette Red 1969 BBC Camaro.
There are pics out there of him getting all 4 wheels off the ground on launch.
Stood the car up past the rear bumper.
A engine block freeze popped out on launch and spilled water- coolant all over the track and under the rear tires.
I was there..........the adrenaline rush of the crowd & myself was better than any rock concert i had been to in my entire lifetime.
Byron World Wheelie Contest,
Even if you leeve your car at home Will,
You need to attend at least once & watch.
Beyond words some years what you see in person.
Brian
Racer
Joined: Jul 2010
Posts: 261
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From: Spokane WA
I had a fully ported intake on my crossfire, it was a little disapointing. It doesn't work well with a stock setup, you have to charge the convertor, heads exhaust to see any improvement. I switched to a renegade intake now it runs much better.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
CFI-EFI (mentioned above) has also gone down the ported intake road on a box-stock engine, and was generously rewarded by his results, dropping ~.7 seconds off his ET at the track...on the stock "convertor, heads exhaust".
There is absolutely NO "down side" to porting that intake; all you get is gains, with no losses anywhere. It is a win-win "mod".
Last edited by Tom400CFI; Jul 5, 2011 at 03:14 PM.
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Spokane WA
You can go ahead and port your intake. It will be better than stock but be prepared to do a few other mods to help it along. Porting alone will not do much. Advance your timing raise your fuel pressure to 15 psi order a higher stall convertor and be careful not to go through the floor of the ports it is about 3/16 of an inch thick. If you look on this forum you will find some info on porting or google it. You might find a ported intake for sale maybe or you could buy a new intake etc x-ram, renegade. If it is legal where you live you could remove your cat that helps.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Spokane WA
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Right. They were better than most stock or stockish CFI runs, in spite of the elevation.
There were HUNDREDS of "before runs"...many of those ultimately contributing to the earning of two Wally's.
Not me or my car; the late, great, CFI-EFI. You already know that though...didn't you Nelson? I mean, 84L83/85L98 or whatever.
There were HUNDREDS of "before runs"...many of those ultimately contributing to the earning of two Wally's.
Not me or my car; the late, great, CFI-EFI. You already know that though...didn't you Nelson? I mean, 84L83/85L98 or whatever.
Last edited by Tom400CFI; Jul 6, 2011 at 02:32 PM.
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Spokane WA
Right. They were better than most stock or stockish CFI runs, in spite of the elevation.
There were HUNDREDS of "before runs"...many of those ultimately contributing to the earning of two Wally's.
Not me or my car; the late, great, CFI-EFI. You already know that though...didn't you Nelson? I mean, 84L83/85L98 or whatever.
There were HUNDREDS of "before runs"...many of those ultimately contributing to the earning of two Wally's.
Not me or my car; the late, great, CFI-EFI. You already know that though...didn't you Nelson? I mean, 84L83/85L98 or whatever.