OKLACOP

Ok guys. Since I'm definately keeping my car I'm planning my future mods. A Whipple is literally just around the corner, but more on that in another thread. I am most definately going with JBA LT headers, but I can't decide about the midpipe. I'm looking at my stock midpipe and it looks pretty good. The JBA midpipe is 2.5 inches in diameter. Anyone know what the stock one is? I can absolutely see the need for new headers when compared with the stock manifold, but I'm wondering if a new midpipe is really necessary. By the way if I go with the JBA midpipe it will be the off road h-pipe w/out cats. How much difference, if any, will I see by replacing the stock midpipe. Thanks.

thump_rrr

You have no choice.
You must go with the JBA H-Pipe since the Headers are much more spread out than the factory unit.
I would suggest the offroad H-Pipe.
One of my cats had cracked and a big chunk of the cat material made it all the way back to the overaxle hump. A similar failure cost Don_W an engine on a set of Dynatechs.

The replacement set of cats from JBA arrived with the cats welded in upside down (heatshield towards the ground instead of towards the bottom of the car).

They are great headers as far as the quality of the welds, length of headers ,ground clearance, ceramic coating ect.

It's just frustrating when they make stupid mistakes.

BigWorm2005GT

I had the same issue with the mid-pipe cats on my JBA's, a chunk of the substrate came loose. It didn't go down the pipe, just rattled around in the cat. JBA informed me it was amanufacturing defect with that production run of cats and had been corrected. They UPS'ed me a new H-pipe, and I haven't had a problem since, so I tend to take them at their word.

I love mine, really like the sound, and REALLY REALLY like the power gains. You'll enjoy them either way.

If I read your question correctly, you're asking how much power you would gain vis-a-vis the (1) stock midpipe, (2) the JBA catted mid-pipe, and (3) the JBA non-catted mid-pipe. I can't speak authoritatively, since I have no side-by-side comparison, but my guess would be some, but not enough to be very noticeable. The JBA pipes will both flow better than the stocker, since the cats on the JBA are much smaller and freer-flowing than the big mothers on the stock pipe, and of course the cat-less one doesn't even have that restriction.

You will, however, get more drone with the JBA catted pipe, and a LOT more drone with the non-catted. That will probably be the biggest noticeable difference in the three, is the amount and volume of drone.

Just me, I'd get the catted one. The difference between it and the non-cat in power terms will probably be within the margin of error for dyno variation, but the drone would be probably be unbearable to me on the non-catted.

69er-sagittarius

Hello, I bought the 2.5" JBA Long tubes and the catted H-Pipe for my 2007 GT/CS.
Do you know how many cells the catalytic converters have. 100 or 200. I think 200 cells but I am not sure and on the Homepage from JBA I can not find the technucak information.
I am asking, because in Germany at the polution test this might be a problem. 200 cells are postulated for street use.
Did someone here driving with the catted JBA H-pipe had problems at the polution test?

I appologize if my english is not o good, but I hope I could explain what I mean.

Thanks.

Christian

anthony05gt

With the JBA catted mid pipe it will be loud enough. If you go catless with longtubes be prepared for some serious volume. I have JBA longtubes, catted JBA mid pipe and Zoomers axleback and it's plenty loud.

WaltM

Zoomers? Cool. How do you like them? (sorry, don't mean to hijack)