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Discussion Starter #1 (Edited)
JBA headers: dyno results?

Has anybody tried removing the stock exhaust manifold on the '98 Cobra engine and using headers instead? What FMS or aftermarket headers are available? How much do they improve power / torque? Can you still use cats to pass emissions?

Thanks,
 

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You've got several choices:

FRPP - 1-5/8" shorty headers
JBA - 1-5/8" and 1-1/2" shorty headers
BBK - 1-5/8" longtube headers
HOOKER - 1-5/8" longtube headers
SHM - several sizes in longtube headers

I think those are the main ones as far as ready-made bolt-on headers are concerned. There are a couple of other places that can make custom headers like s KOOKS.

I don't really have any data to share with you, but it seems like the FRPP headers are the low performers of the group. Hope this helps.


EDIT: I just noticed that you live in California. You're only CARB-legal choice from the above group is JBA. Bob Cosby uses the 1-5/8" JBAs and has gotten great results! These headers fit the stock h-pipe.
 

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Discussion Starter #3
JBA headers: dyno results?

Nino said:
You've got several choices:

FRPP - 1-5/8" shorty headers
JBA - 1-5/8" and 1-1/2" shorty headers
BBK - 1-5/8" longtube headers
HOOKER - 1-5/8" longtube headers
SHM - several sizes in longtube headers

You're only CARB-legal choice from the above group is JBA. Bob Cosby uses the 1-5/8" JBAs and has gotten great results! These headers fit the stock h-pipe.
Thanks for the info! Has anybody dynoed the JBA headers to compare with the stock exhaust manifold? Don't need exact numbers, just want to know if it's closer to 10 RWHP, or to 30 RWHP?

Also, do they work with the stock catalytic converters and pass smog?

Thanks again,
 

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Michael,
Yes, the headers will work with the stock catalytic converters on the stock h-pipe. They are CARB approved so they will pass the smog test.

Here's a before/after dyno of Bob Cosby's Cobra with the stock and JBA headers.

 

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Discussion Starter #5
Looking at the graph, I'd say the bottom line is about 10-15 RWHP and 10-15 RWTQ throughout the entire RPM range, with slightly more on top than down low. Overall, roughly a 4% improvement.

That's exactly what I wanted to know -- thanks.
 

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One thing that I forgot to mention is that Bob had a non-stock mid-pipe and catback (I believe). Using the JBA headers on a stock exhaust system probably won't net such large gains.
 

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Discussion Starter #7
Nino said:
One thing that I forgot to mention is that Bob had a non-stock mid-pipe and catback (I believe). Using the JBA headers on a stock exhaust system probably won't net such large gains.
That's OK; the Panoz "stock" configuration has dual 3" diameter straight pipes from the cat back -- no mufflers. Not sure what brand the pipes are, but it sounds.... the word AWESOME comes to mind.
 
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