Cheburator

Fred, my GT received a set of 928 Intl equal length headers ages ago. We made a custom x-pipe and left the rest of the system stock. Never dynoed it, but we managed to put another 12 to 14 deg of advance on it from 3000 to 6500 rpm. Obviously fuel was adjusted too. No stock GTS could live with it.

My new engine makes a ton more power with the same headers. I doubt I would be there on the stock manifolds...

namasgt

It was said to me that the collector design on these type of headers (MSDS) is not very good and they are actually restrictive. Something like Greg Browns header collector is more ideal....
Does anyone have pics of Greg's collectors for comparison?

17prospective buyer

Lol, some people in this forum...

Everyone can do what they want. But, with that said i'm getting more into the theme that "you get what you pay for" when it comes to OEM or equivalent parts.

Unfortunately some people in this forum seem to have more money than brains, but you do get what you pay for in most cases i do believe.

simos

928 Intl header primary diameter is little too large for 5L engine to give perfect scavenging effect, unless someone is going for big hp and rpm numbers. They will still provide better torque than MSDS because of full merge collector design.

The MSDS works just fine if you plan to install bigger cams and spin the engine above 6000rpm. You need anyways more exhaust breathing capability when trying to reach 400ehp and beyond. Replacing the staright collector to conical collector will give more overall torque as for extra bonus. Also, to get everything out from your exhaust you need to go for 2 x 2,5" tubing to minimize the backpressure. I wouldn't use Flowmaster as they have shown the worst flow numbers in many of the muffler tests, I have seen.

For close stock 5L engine, the best choice would be the famous X-pipe, with stock 32v headers. They work just great there.

Hopefully this explains the situation better.

Cheburator

I love it when people say "White is Black and Black is White"...

"my GT received a set of 928 Intl equal length headers ages ago. We made a custom x-pipe and left the rest of the system stock. Never dynoed it, but we managed to put another 12 to 14 deg of advance on it from 3000 to 6500 rpm. Obviously fuel was adjusted too. No stock GTS could live with it."

There is no way you can put that kind of numbers on a stock GT engine. The person doing the mapping was John Speake. To say he was astounded, is an understatement. The stock manifolds are OK, but nothing more...

Carl Fausett

I'm just the messenger here. Just providing the info Marty gave me. I can see with the current OBX thing he's pissed, and motivated to challenge them.

Try to remember he can't make a living on 928 headers. he (thankfully) makes a lot of headers for a lot of cars or he wouldn't be in business still.
.
You can say all you want, but he has remained the only company still willing to manufacture 928 headers at all. If we loose MSDS we have no-one making headers for this car.

And when I needed larger tube primaries for the Big Motor, he jumped right at it.

Marty is OK with me, and I can understand why he hasn't re-designed before now. I'm just glad he's picked up the gauntlet against OBX, instead of just rolling over. I'm pleased that he still cares enough about the 928 market to fight for his piece of it.

Carl Fausett

+1

Just be glad that some manufacturers are still interested in making performance parts for this out-of-production car.

Take away their profits, and you'll be saying: "why doesn't anybody make interesting after-market parts for the 928?"

FredR

A,

Doubtless well matched headers do wonders and have no doubts about what you report, but what I allude to is which design actually delivers the goods? The x-pipe I have no doubts about [I have one] but before I would consider headers I would want to know if they were going to do what I expect them to do. On the auto s4 suspect they may be pointless. Stick some decent cams on and the right headers another matter altogether, especially if the exhuast pipe diamter is increased to 2.5 inches. That seems to be a potent combination when ST'd. I know the Devek level 2 headers work well on a GT, presumably the other offerings are similar but whether the MSDS design is effective on 32V motors is the question. I understand they are effective on 16V motors.

Not quite sure where I am going at the moment with upgrades but like the idea of more. I have a set of S3 cams awaiting modification and it would be nice to mate them to a faster exhaust. Whether it is worth it on an auto model- not so sure.

Best wishes

Fred

terry gt

I did a back to back dyno with my 91GT.with Colins tri flow cams . stock exhaust with RMB / MSDS headers ,X ,high flow cats, duel 2 1/2 exhaust . Added 32 hp and 40 tq at the rear wheels after sharktuning

Strosek Ultra

Good designed headers by Erkka.

Åke

Ducman82

Very nice

Rob Edwards

Well, if we're going to show some Made in the USA header pride, here goes.

All materials sourced, and all fabrication and finishing performed within 20 miles of Greg's shop. It's the exhaust version of the locavore movement.

Support your local craftsmen, people, or there may not be any more local craftsmen!

oups59

Wow ...

FredR

Rob,

If that motor goes half as well as it looks then that will be one sweet motor and those headers - yum yum.

Regards

Fred

Rob Edwards

That's Hebert's stroker. Currently out there terrorizing the Phoenix metro area.