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Discussion Starter #1
Here's the situation I've owned my 90GT since day one. That's 28 years! Other than the stock intake, the only intake that has been on the is a ported cobra intake. In short, as you can see on my signature, the GT sports a 349(.040) and a Paxton Novi2000 pushing 15lbs of boost. Since swapping over to a C4 trans the quickest I've gone is [email protected] That's with a crappy 1.573 60ft. So here's the question. My other fox (in the signature) is a simple 302 with GT40 heads AND an unported Trickflow Street Heat intake. Do you guys think swapping that intake over to the GT would make much difference? My goal is 9.90's. Doing the math the car should be able to do it with it's current setup. Would be cool running 9s with the cobra intake still intact lol.
Thanks,
Rich
 

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Discussion Starter #4

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Going that quick, I am surprised you are looking at a long runner intake at all... I would think there is significant benefit to be had going to something bigger and shorter, but that is just an uneducated guess.

What I am sure of...
On a flow bench, an un-ported cobra intake goes about 205cfm.
An un-ported street heat goes about 245cfm.

You said your Cobra intake was ported. A Cobra intake with a quality street port job (TMoss) will flow 245-250cfm... So in terms of outright flow, I don't think I would expect much. You might gain something due to the increased plenum volume of the street heat but I do not know how to quantify that.
 

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Discussion Starter #6
Going that quick, I am surprised you are looking at a long runner intake at all... I would think there is significant benefit to be had going to something bigger and shorter, but that is just an uneducated guess.

What I am sure of...
On a flow bench, an un-ported cobra intake goes about 205cfm.
An un-ported street heat goes about 245cfm.

You said your Cobra intake was ported. A Cobra intake with a quality street port job (TMoss) will flow 245-250cfm... So in terms of outright flow, I don't think I would expect much. You might gain something due to the increased plenum volume of the street heat but I do not know how to quantify that.
The numbers you posted was exactly what i was wondering. I thought about a boxed upper (ie cartech) for the cobra intake already in the car, but I think it may be not matched well with the comp cam I'm running. The cam card shows a power range good to 6300rpm ?
Thanks for the numbers!
 

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There's a guy on here running a ported cobra intake on a turbo car, stock shortblock in the deep 9's. Can't remember his username. 9.90's may be available in your suspension tune.
 

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The numbers you posted was exactly what i was wondering. I thought about a boxed upper (ie cartech) for the cobra intake already in the car, but I think it may be not matched well with the comp cam I'm running. The cam card shows a power range good to 6300rpm ?
Thanks for the numbers!
No problem.

The *King* of the long runners is pretty much still the Holley Systemax 2. Out of the box, on paper it flows around 265cfm (295+ ported) on average. There are others that are close like the Track Heat, Performer RPM2, and TFS R (not box), but they all screw up on the inside bend of the 180deg turn creating turbulence and hindering flow. Holley actually rounded that bend to fix the problem.

I know you are trying to work with parts on hand but, if I was to swap intakes looking for a gain, the Holley is what I would choose. The stated max rpm of 6500 is also right in the ball park of your cam.
 

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Whats realy more important to figuring improvement is flowing the intake bolted to a cylinder head. In almost all cases calculating hp based on intake flow isnt accurate unless bolted to a head. neither is basing hp on head flow only. a intake flowing 250 cfm bolted to a head flowing 300 cfm might only flow 180 190 CFM. one flowing 250 most likely even less.

2 guys running almost the same against each other forced induction one always against each othe at the strip.one showed up at our shop we ported his heads and intake. next time he hit the strip his adversary cleaned his clock. he lost boost because of improved air flow. He got his boost up to what it was before the changes went back and totally wasted his rival .
 

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Discussion Starter #11
There's a guy on here running a ported cobra intake on a turbo car, stock shortblock in the deep 9's. Can't remember his username. 9.90's may be available in your suspension tune.
I agree... suspension tune in need ?
 

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Discussion Starter #12
Whats realy more important to figuring improvement is flowing the intake bolted to a cylinder head. In almost all cases calculating hp based on intake flow isnt accurate unless bolted to a head. neither is basing hp on head flow only. a intake flowing 250 cfm bolted to a head flowing 300 cfm might only flow 180 190 CFM. one flowing 250 most likely even less.

2 guys running almost the same against each other forced induction one always against each othe at the strip.one showed up at our shop we ported his heads and intake. next time he hit the strip his adversary cleaned his clock. he lost boost because of improved air flow. He got his boost up to what it was before the changes went back and totally wasted his rival .
Great info!
 

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2 guys running almost the same against each other forced induction one always against each othe at the strip.one showed up at our shop we ported his heads and intake. next time he hit the strip his adversary cleaned his clock. he lost boost because of improved air flow. He got his boost up to what it was before the changes went back and totally wasted his rival .
Not trying to start a fight but I am genuinely curious - for the sake of learning. I feel like there are more details missing to this story. What exactly was done to rectify his lost boost? A simple pulley swap?

I ask because I can't think of any situation where more cfm = less power? If anything, the same cfm at less boost should mean cooler IATs and a tick more timing.
 

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Discussion Starter #14
I am no expert by any means. I've been constantly learning about this for almost 30 years lol. From what I have learned, the things that are important is not necessarily CFM but its relationship to velocity. What people also need to take into effect is the type of tumbling effect that goes into a cylinder bore air/fuel mixture. So what I'm seeing 9s are possible. Just gotta dial in that suspension.
 
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