X-Pipes are good, we all know it. I've sold a lot of them.

And headers produce even more HP than X-pipes, but (until now) have had the disadvantage of not having any after-market exhaust products that could connect to them. That meant: if a 928 owner wanted headers, he could count on a trip to a custom tube bender to get his exhaust pipes made from the headers-back.

Imagine if you could have BOTH headers and an X-pipe AT THE SAME TIME.

I've developed a Header-X pipe now that combines the HP of headers with the low-end torque of a good X-pipe, and allows the 928 owner to mix-and-match (cats or no cats) and stock exhaust or our Hi Flow Performance Dual Exhaust.

I have it priced at $429.00 including the stainless steel header-X, the dead soft aluminum flange gaskets and yellow-chromate plated hardware, and two SS HD exhaust strap clamps. It also includes an O2 bung on it on the left bank. (If you need two O2 bungs, use the one on the header collector that is on the right bank).

My first shipment of these will arrive about 5/21. I am also receiving a new shipment of our Hi Flow Dual Exhaust at that same time.

On the Dyno chart below, the test vehicle (a 1991 GT) already had a RMB. The gains we post are over and above the gains already realized with the RMB. It took some doing, but I ended up with a design that gained BOTH at the bottom end (torque) and at the top end (HP). See the dyno chart.

Currently I KNOW that this system fits the 32v 928's with the 3-bolt header flanges, as shown. I think it will also connect to the early 16v headers as well, which would mean that it can be used to put the late-model dual exhaust under an early car. This I have yet to test, however.

 

Hmm...those look like S4 torque curves....wonder if the headers change the torque peak back to the early bump ...interesting..

As always..cool stuff Carl...keep up the good work.

 

My 16v headers meet under the bellhousing parallel to each other like the 32v ones above.

 

So there is no confusion: our Header-X Pipe is designed to fit the headers we sell. MSDS makes our headers for us. You should not expect our Header-X to fit headers manufactured by DEVEK or others.

 

Martin Schneider Design Systems - MSDS

Hammer

 

Ah, yes, Martin. Great guy from when I talked to him.

 

The web page is up now if you would like to see more pictures or information about this product:

http://www.928motorsports.com/parts/headerxpipe.php

 

Hi Carl, this sounds like a wonderful header + x-pipe + exhaust upgrade for my 1986 Euro 16V. However, there is a max tolerated dB even on the tracks...Have you measured how loud this combo is???

 

the headers and x-pipe only effect the db level if you choose to not install the cats. The db level is more controlled by what comes after - the resonators and the rear muffler. And of course, the cats conribute to muffling to.

I can tell you that, during development of thse products, we id have EVERYTHING installed on one car (headers, header-x, no cats, our open resonators and a RMB) and she barks pretty loud on WOT. During cruise, its a steady drone that you can talk over. It was fun for a while, but a little much.

Either keeping the stock resonators or installing cats brought it down to a nice rumble that would not offend.

 

Carl, I'm pretty much a newbie at this, one month into a '91 GT and it's the first car I've ever worked on. Actually, first sports car since an 83 Rx7 that I had in high school. Anyway, I currently have stock muffler system on the car and I have been planning on doing an x-pipe RMB upgrade sometime soon. I thought the main purpose of the x-pipe was to bypass the cats and that was where the hp gain came from. I definitely don't want to increase my dbs too much because my 928 is my daily driver and I would like to be able to talk the wife into taking it to the beach (3.5hr drive) or the mountains (5.5hr drive) when we do those things... What would be the better fit for me--do I do a Header x-pipe with cats and rmb or stick with regular x-pipe, no cats and rmb???
Thanks,
Dan

 

No Euro 16V have cats in Europe (unless aftermarket ones), and I won't install any. Are there any"middle" mufflers (what you call resonators???) that with headers and x-pipe will keep the sound reasonably low (under 95 dB) - and still have a nice flow? I will race my car and need all the power I can find.... And keep the weight down at the same time. Hope I'm not dreaming.

 

The stock cats that were installed on US 928's are quite lossy, but you can now install an X-pipe with new metal matrix high-flow cats that lose 5hp or less. More power and nice to the environment at the same time.

Dan
'91 928GT S/C

 

Thanks, so maybe the header x-pipe with new high-flow cats and rmb is the right combo for me.

 

My car has the stock headers, X-pipe with high-flow cats and stock GT exhaust back (GT resonators and rear muffler). I can feel the power difference, especially the low-end torque increase and it's still almost as quiet as stock. For me it's the best of all worlds.

Dan
'91 928GT S/C

 

Good point maybe the RMB is not a good idea for me.