997_rich

Has anyone every tried to put an M97 997s header and cats on an M96? Do they bolt up? I've attached pics of the m96 headers and the m97 headers (with the trapezoid collector welded in).

I've got an M96 997 and i'm wondering if it's worth it to put the m97 headers/cats on it. I've already got them in hand so it's a free upgrade. Any reason for this trapezoid shaped collecter in header? any performance reason or is this just for easy manufactureabilty.

I've also already got the 997s M97 mufflers with the fister mod so it might make sense to match them up.

can anyone offer some advice?

utkinpol

I do not know for sure, but I think it is very wrong idea to put m97 headers on m96 engine. headers intake diameter is calculated from displacement, plus most m97 people change stock headers to X51 ones which look exactly like M96 but are wider.

Mufflers do not matter for exhaust at all, cats do matter a bit but intake of headers is very important as it directly affects pressure in the cylinders and alteration of this parameter may have consequences.

Stock M97 headers are bad anyway, sop real question is what will it do to M96 engine if you put on X51 M97 headers. And I do not know the correct answer but my gut feeling is that it is probably not the best idea otherwise everybody would have done it already and I do not know of a single person who did it.

chsu74

X51 M97 headers is a popular mod for M96 engines. There are plenty of threads on that upgrade because its cheap. I would have done it if I didn't score a used Fabspeed headers for $500.

Not sure about 997 cats and mufflers though..

utkinpol

really? I know people do it on M97, never heard of that done to M96. Can you send a link pls, if you know of any, what does it do to power/torque chart?

chsu74

https://rennlist.com/forums/996-foru...3-4-996-a.html

997_rich

Ahh- should searched the 996 forum.

so it looks like from what I'm reading. 3.4 with stock 997 headers might offer some gains in conjunction with intake/ecu mods

3.6 and 3.8 don't seem to get much better with header upgrades unless you go with x51 headers in conjuction with intake/ecu mods.

utkinpol

same here. i run fabspeed 200 cell x-pipe, had fabspeed mufflers, then got back to stock cans. if I wold see it 2 years ago then may be I would buy x51 m97 headers... now, not sure i want to spend $850 on this.

suncoast has them, may be it would add 5-10hp at its best, but imho it is not very critical. for real power gain one should simply get rid of m96 and get a gt3 drivetrain in a gt3 car - that would be much more cost efficient.

still nice to know it is possible to do.

chsu74

Fabspeed headers and exhaust here. Stayed with stock Cats because of potential droning issue.

The flash is important IMHO. Woke the car up and noticed very little torque loss at low RPMs. More importantly, it gave better sound all around.

Edgy01

It's not simply whether the holes line up and there is no conflict with the space they occupy, but headers are a critical element in the air flow of an engine. When you start to mess with that you will affect things. For example, you can easily lower the torque in the midrange when going to a larger diameter tube (which is what the 3.8 liter engine M97 headers have over the M96 engines).

You should have a dyno handy to check your work before and after you do this sort of thing. And should understand what you are doing. Otherwise, you can actually do more to lower the horsepower of the engine by doing this.