Stock Headers MAX Power w/ Blower

Seems like almost every car ive seen with a blower north of 680whp or so has LT headers and no cats, anyone make 700whp thru stock headers and cats?

VRP said:

Seems like almost every car ive seen with a blower north of 680whp or so has LT headers and no cats, anyone make 700whp thru stock headers and cats?

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I made 650 on a notoriously low reading dyno on a hot day (over 100F in dyno cell). If it was mid march on a dyno jet I'm sure I was either 680 or 700. Car trapped nearly 130 on a 28" tall tire. Only reason I swapped was due to cats potentially melting or collapsing

I made over 900rwhp with stock headers, mak pipes and magnaflow Catback. ;)

It's never "how much can you make" on stock headers, they flow OK, the question is "how much more could you make swapping to long tubes."

Stock headers and removing the cats is minimum for 700whp, wouldn't want to push that much power and heat through the stock cats for that long.

Im over 700 with arh longtubes and arh cats

804 whp with SW longtubes and high flow cats.

As others have said, I'd hesitate at pushing alot of power through any cats, but especially stock.

Best case scenario is they melt and break apart and blow out your tailpipe, and then you have no way to pass emissions inspection.

Worst case scenario is they melt and collapse, plugging your engine and blowing it.

Not worth the risk IMO. A local shop has told me they've even seen Kooks Green Cats fail, which I believe since they advertise they can handle up to 1500F. With my nGauge I have seen my cats up to 2200F. (I'm going with MAK deletes)

I just put my car on a Dynojet tonight and made 746whp with 613 ftlb torque with Whipple stage 2 gen 3, 11 psi, E85 on stock manifolds with 3 inch make cat deletes. The tuner said the stock manifolds was holding it back from making more power. Would upgrading to long tubes really be worth it?

ahl395 said:

As others have said, I'd hesitate at pushing alot of power through any cats, but especially stock.

Best case scenario is they melt and break apart and blow out your tailpipe, and then you have no way to pass emissions inspection.

Worst case scenario is they melt and collapse, plugging your engine and blowing it.

Not worth the risk IMO. A local shop has told me they've even seen Kooks Green Cats fail, which I believe since they advertise they can handle up to 1500F. With my nGauge I have seen my cats up to 2200F. (I'm going with MAK deletes)

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2200?! Holy smokes. Also with my ngauge, I’ve never seen that value go above 1700.

ahl395 said:

A local shop has told me they've even seen Kooks Green Cats fail, which I believe since they advertise they can handle up to 1500F. With my nGauge I have seen my cats up to 2200F. (I'm going with MAK deletes)

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Not correct. Spoken with the manufacturer of the Green Cats, they can take more but not 2200F. That is f'ing insane. Your car most glow like a modded ricer.

I made 700whp through the stock manifolds and cats, but cats began to fail after about 7,000 miles. (Whipple since day 1)

Since the labor was free, I opted to replace the factory manifolds and cats with Kooks 1 7/8 with their standard high flow cats. After a few hundred miles I started getting the sulfur smell after WOT pulls which is a tell tale sign of cat failure.

We ended up hollowing out the cats and car has never ran better. No more sulfur smell and peace of mind of not having to worry about plugging up the exhaust. Only downside is the exhaust tone got a bit raspy over 3,000 RPMs, but I have been advised swapping out the magnaflow comp mufflers with GT500 mufflers should fix that and restore the deep exhaust note.

If I wasn't emissions exempt, I may have went with the green cats.....maybe

Trying to understand something... why is everyone burning up cats? Are tunes running so lean that it is causing seriously high exhaust temps?

Performance nut said:

Trying to understand something... why is everyone burning up cats? Are tunes running so lean that it is causing seriously high exhaust temps?

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Cats and high performance contradict each other. Pressure and high temps.

SolarFlare said:

Cats and high performance contradict each other. Pressure and high temps.

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Disagree to a certain point. Max performance and cats contradict, yes. High performance and cats contradicting, no.

Just to be clear, my cats failed on the base Whipple tune that comes with their Gen 2, stage 2 kit. Plugs were misgapped from the dealer which I chalked up to contributing to the issue the first time the stock cats failed.

Swapped out to Kooks and their cats failed while still on the Whipple tune. Had replaced 02 sensors and spark plugs after finding out the original NGK plugs were never gapped down from .044 to .028.

93 octane only