CrookedRacer

Well, I believe I've painted myself into a corner here, but maybe it'll turn out ok... And the reason I say I've painted myself into a corner is that the stock exhaust appears to have been 2 1/4 tubing, but I have now replaced so much of the system with 2.5" components that I feel like there's no going back now. I might as well stick with that all the way through at this point.

From the very beginning, my exhaust has sounded like poo. For a variety of reasons.

First, because the muffler was shot. I replaced it with a 2.5" muffler because that's what was on the outlet side:

https://grassrootsmotorsports.com/fo...3/#post1951471

Still sounded like poo. So that wasn't really the issue. Then I found out I had a broken exhaust valve, and fixing that didn't really make the car quieter. And that's because the test pipe was just about to let go of its connection to the resonator. So I replaced that with a 2.5" pipe and flanges.

https://grassrootsmotorsports.com/fo...4/#post2014572

The car still sounds like doo doo. And I suspect it's either the headers or there is a nasty rattle in the resonator. I'm leaning towards the latter.

So the tailpipe through the resonator to the muffler is 2 1/4" and I am about to replace that with 2.5" all the way through. I can just make it a straight pipe to my new muffler which would be easiest, since I already have the tubing,

or I can buy a 2.5" resonator like this one:


or a bottle-style one like this:


I really don't know the difference between the two styles, or if it makes any difference if I have one at all. I just know that I need to rid myself of the rest of the aged system, and soon.

What says the peanut gallery?

I am also going to perform a close inspection of the headers and really examine their integrity. They're pretty old and rusty looking. I think at least 16 years old, based on the fact that the test pipe was purchased in 2000.

CrookedRacer

TL;DR Version:


What kind of resonator should I put on the car, or should I skip it and just run tailpipe through to the muffler?

Remember, this is a track car, but one that I will be driving to and from the track, ideally.

Thanks!

harveyf

I've always run a single "muffler" device on my track car. I started with an aftermarket muffler, tore that up on the gaiters, then went with a Supertrapp, which is low profile and light, and am currently back to a stockish muffler that I bought from Paragon.

I don't know what your level of track experience is but I have become a proponent of more "quieting" from my track exhaust so I can hear what my tires are trying to tell me. I think the loss in horsepower of an exhaust is not as important as learning how to negotiate the corners at max grip levels.


And please, please, please don't be come "that guy" that thinks straight pipes are an attractive sound option!

CrookedRacer

Thanks,

I am thinking that I will go ahead and pipe it straight back to the muffler, and if it still sounds bad or too loud or raspy, I will get the ultra quiet resonator and put it where the cat was, in the hopes of smoothing it out. If that one won't fit, there is plenty of room for a long bottle-style resonator.

I may be "that guy" now and then; just not in this case!

SloMo228

I have the Vibrant Ultra-Quiet resonator on a shelf in my garage. It will be going in along with a long-tube header, high-flow cat, and a rear high-flow muffler, all 2.5" pipe. My 944 is a street car, so I am hoping for an aggressive but subdued exhaust note with no rasp. I'll report back once I have it all built and installed.

Edit: I did once have a long (like 2 feet or so) glasspack in place of the stock cat/resonator unit, with a stock rear muffler. It sounded pretty good, fairly quiet with no rasp. But the packing blew out pretty quickly, unfortunately. And it wasn't exactly lightweight, either.