Engine Extrude Honed Cobra Upper Flow Data?

WhiteCobra95

Mod Dude
May 2, 2006
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Does anyone have any real flow data for an extrude honed Cobra upper intake?

I’ve searched quite a bit and all I can find is anecdotal comments and speculation. The speculated flow range varies quite a bit, with some stating that “a friend of a friend” got theirs done and it flows 300 CFM/port, while others state that it’s only about a 20 CFM bump from the upper manifold as-cast. Most of the comments are forum posts with no real data sheets to show the flow and port-to-port variation.

Cost aside, this seems like it could be a great stealth performance option for the street when coupled with something like a TMOSS ported lower, but only if the flow comes up in the 260+ CFM range after the process.
 
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Does anyone have any real flow data for an extrude honed Cobra upper intake?

I’ve searched quite a bit and all I can find is anecdotal comments and speculation. The speculated flow range varies quite a bit, with some stating that “a friend of a friend” got theirs done and it flows 300 CFM/port, while others state that it’s only about a 20 CFM bump from the upper manifold as-cast. Most of the comments are forum posts with no real data sheets to show the flow and port-to-port variation.

Cost aside, this seems like it could be a great stealth performance option for the street when coupled with something like a TMOSS ported lower, but only if the flow comes up in the 260+ CFM range after the process.
Cost aside's azz... How much is it? Moss ported my lower and it was $300 after shipping both ways. I have no hard data but for what it'd cost you could have an aftermarket intake that would probably out flow the moss lower/ honed upper combo.
As far as stealthiness goes... Who really cares!? Are you trying to make "the list" in the OKC? Who's popping your hood to decide if they wanna race you or not? Do yall hop out of the car real fast at the red light, run over and see what the other guy has going on and hop back in your car before the light turns green?
I'm guessing the reason you're having trouble finding hard data is that not too many people have done it due to the fact that it's too expensive for too little reward. That and also it's not supported by a brand name and that's what magazines tend to test due advertising and marketing and how many people do you know that have a flow bench at home? Do you have a decent set of cylinder heads on the car? If not than I definatly wouldn't sink a whole bunch of money on an intake manifold.
 
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I posted this question to see if someone had any real flow data, not to perpetuate the conjecture.

Of course there are aftermarket intakes with higher flow numbers, but there's more to choosing an intake manifold than maximum air flow.

The stealth appearance approach boils down to personal preference.
 
All of your "stealth performance" is worthless nowadays.

Some punk 17 year old with a eBay turbo'd civic will blow your doors off.

There is no such thing as a "sleeper" mustang.
 
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Extrude Hone Pricing | Powder Coating, Ceramic Coating and Abrasive Blasting Specialists

I looked for prices or flow data for fun. This site makes Tmoss look very reasonable, and he has flow numbers posted. If the smart, by hand porting does not do it for you, you probably need a different manifold to start with. Too bad, because the EH idea is cool.
Yikes $435 for an ho upper!
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But yeah, the whole idea of having a "sleeper" 302 mustang won't work these days. One has to making the pseudo radical to keep up these days. The days when the 215 horsepower mustang's and 180 hp civics battling it out are over. You have to add 100 horses or so to even be a little competitive these days, and 100 extra horsepower is hard to hide. The porting and extrude honing would be more popular of there wasn't an abundance of aftermarket intakes for the same price or less. I am currently running a t-moss ported ho lower and it gave decent enough gains at 13 hp. The reason I went with the ported lower route is that at the time I was looking at exploder intakes and they were all running around $300. Since I have a '95 I would've had to buy the throttlebbody elbow adapter and that would've been another $50-$100. So I spent about $300 on the ported lower and gained 13 hp. Money well spent? Eh fair enough I guess.
Ps: I didn't do it to be stealthy, I did it because I was broke.
 
Extrude Hone Pricing | Powder Coating, Ceramic Coating and Abrasive Blasting Specialists

I looked for prices or flow data for fun. This site makes Tmoss look very reasonable, and he has flow numbers posted. If the smart, by hand porting does not do it for you, you probably need a different manifold to start with. Too bad, because the EH idea is cool.
One more thing: Say a guy did an ho intake. Wouldn't it still fall on its face around 5k rpm's? If so I don't see where much power could be made.
 
Extrude Hone Pricing | Powder Coating, Ceramic Coating and Abrasive Blasting Specialists

I looked for prices or flow data for fun. This site makes Tmoss look very reasonable, and he has flow numbers posted. If the smart, by hand porting does not do it for you, you probably need a different manifold to start with. Too bad, because the EH idea is cool.
One more one more thing: for giggles I emailed them asking how much hp gain it'd get w my combo if I had them do my upper. We'll see what they say.
 
Common knowledge is modifying the lower is where the power is at, but I still straightened out the throat on the upper a lot when I opened it up for the TB. Let us know what they say.
 
Common knowledge is modifying the lower is where the power is at, but I still straightened out the throat on the upper a lot when I opened it up for the TB. Let us know what they say.
Still no response. I don't think I'd ever go that route, I mean how much more power can be scavenged by smoothing out the HO intake? I doubt $435 worth. I mean you still have the stock heads to contend with. It's not like you'd be revving any higher.