Ported L98 heads Intake Flow #s
#1
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Car: 92Z28
Engine: L98
Transmission: A4
Ported L98 heads Intake Flow #s
Well I am pretty happy with my flow numbers so far on my L98 cast heads. After 35 hours of grinding and installing 2.02" intake valves the first one went on the superflow 600 bench today.
It became turbulant after .500 lift but peaked at .500" at 245cfm. They flowed within 5cfm of an AFR 180 through .100" to .500" I have not had the valve job done on the exhaust yet so it was not flowed. I had a friend, who ports heads, help me and finish out the ports. He still thinks we can get at least 10 cfm more out of them with chamber work.
It became turbulant after .500 lift but peaked at .500" at 245cfm. They flowed within 5cfm of an AFR 180 through .100" to .500" I have not had the valve job done on the exhaust yet so it was not flowed. I had a friend, who ports heads, help me and finish out the ports. He still thinks we can get at least 10 cfm more out of them with chamber work.
Last edited by Insomniac92z28; 11-26-2003 at 10:14 PM.
#2
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That's impressive.
Any chances of pic's?
I think I'll request a HeadPorting Forum to keep these all in one area.
Any chances of pic's?
I think I'll request a HeadPorting Forum to keep these all in one area.
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Car: 1988 IROC-Z
Engine: L98 (350 TPI)
Transmission: MD8 (700 R4) + 3.42 LS1 Rear
Originally posted by 8Mike9
I think I'll request a HeadPorting Forum to keep these all in one area.
I think I'll request a HeadPorting Forum to keep these all in one area.
BTW Great #'s
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I couldn't help but notice your impressive et's out of a stock motor.
Apparently, steeper gears can help out the tpi to some degree.
I can't wait to see your times with the heads back on, low 13's on a TPI motor with no aftermarket parts, ha ha.
Keep it coming, I'm interested in seeing your pics.
Apparently, steeper gears can help out the tpi to some degree.
I can't wait to see your times with the heads back on, low 13's on a TPI motor with no aftermarket parts, ha ha.
Keep it coming, I'm interested in seeing your pics.
#6
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Car: 92Z28
Engine: L98
Transmission: A4
Originally posted by Hype
I couldn't help but notice your impressive et's out of a stock motor.
Apparently, steeper gears can help out the tpi to some degree.
I can't wait to see your times with the heads back on, low 13's on a TPI motor with no aftermarket parts, ha ha.
Keep it coming, I'm interested in seeing your pics.
I couldn't help but notice your impressive et's out of a stock motor.
Apparently, steeper gears can help out the tpi to some degree.
I can't wait to see your times with the heads back on, low 13's on a TPI motor with no aftermarket parts, ha ha.
Keep it coming, I'm interested in seeing your pics.
Low 13s is the goal. I am also porting the upper, siamese porting the lower plenum, LT1 cam, adding a cutout and long tube headers. The 3.73 gears picked up about 4 tenths and helped my 60ft come down from a 1.97 to a best of 1.81. I just want to surprise some LS1s
Later,
Charlie
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Which gear ratio did you swap from? My brother drives an '88 GTA and its equipped with the 2.73, or 2.77 or whatever rear-end. Even with the long-legged gears, that thing pulls out of the hole like a freight train compared to my carb'd 350. I'm actually trying to sell off the 'ol firebird now, I just can't stand the daily driving during our winters with a carb, plus it just doesn't have that low-end nut of the TPI. I figure I'd get more out of picking up my bro's GTA for peanuts and with some simple mods, I'll be a whole lot quicker with better fuel economy and without the hassle of waiting for the pig to warm up. =) I love the 3rd gens though, definitely one of the best bang for buck platforms out there right now.
BTW: Why are you swapping to an LT1 cam? Isn't the profile of that cam, similar if not tamer than the L98 cam? I could be wrong, I just can't be bothered to look. If you're going with headers, and have free-breathing heads, step 'er up a notch man! Unless you have ****-retentive smog laws...
BTW: Why are you swapping to an LT1 cam? Isn't the profile of that cam, similar if not tamer than the L98 cam? I could be wrong, I just can't be bothered to look. If you're going with headers, and have free-breathing heads, step 'er up a notch man! Unless you have ****-retentive smog laws...
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#8
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Car: 92Z28
Engine: L98
Transmission: A4
Re: Ported L98 heads Intake Flow #s
Originally posted by Insomniac92z28
Well I am pretty happy with my flow numbers so far on my L98 cast heads. After 35 hours of grinding and installing 2.02" intake valves the first one went on the superflow 600 bench today.
It became turbulant after .500 lift but peaked at .500" at 245cfm. They flowed within 5cfm of an AFR 180 through .100" to .500" I have not had the valve job done on the exhaust yet so it was not flowed. I had a friend, who ports heads, help me and finish out the ports. He still thinks we can get at least 10 cfm more out of them with chamber work.
Well I am pretty happy with my flow numbers so far on my L98 cast heads. After 35 hours of grinding and installing 2.02" intake valves the first one went on the superflow 600 bench today.
It became turbulant after .500 lift but peaked at .500" at 245cfm. They flowed within 5cfm of an AFR 180 through .100" to .500" I have not had the valve job done on the exhaust yet so it was not flowed. I had a friend, who ports heads, help me and finish out the ports. He still thinks we can get at least 10 cfm more out of them with chamber work.
Finished heads
Intake peaked @ .480 lift flowing 248cfm (+50cfm improvement from stock)
Exhaust w/EGR port unfilled peaked @.500 flowing 181cfm (+60 improvement from stock)
This was a lot of work, but I am very pleased with the results and can't wait to get them on the car.
Later,
Charlie
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