T_MaX

Sharkbit, Custom made glasspacks (within the gutted cats), Resonators, RMB

After my prevous R&D I become a true beleiver in the use of a good quality X-over with or without highflow A/M cats or glasspacks. This really should be the first exhuast mod the 928 gets. The stock H-pipe and outdated cats is holding a few ponys back.

Now if you just want to free up a couple of ponys, find a trashed cat setup for a 928 and start cutting

If you go this route, go the extra step and weld in the tubes from a glass pack and than wrap them in fiberglass.

Mongo

Jim expect a deposit into your RMB Revenue account sometime soon! Oh I also wanted to ask; do the catalytic converters on the 928 have an integrated resonator in it too like the 944?

Anyone who is running an x-pipe with RMB, how's your dBs? is your car really loud???

Abby Normal

I have MSDS Headers, no cats, h-pipe, intermediate mufflers and an RMB. From idle to 2500 RPM ,it's a low throaty sound. Put your foot in it and get above 3000 RPM's and your instantly Jeff Gordon...

Red UFO can give some details about how my car sounds. I get a lot of questions from strangers like "what's that got in it?" Most people think it is a Big Block motor.

Jim bailey - 928 International

Andy the big "dual" cat 85> each side has three separate ceramic honey combs which are platinum plated. There is an air gap of a few inches between each of the three honeycombs so it does have a big impact on the sound as pressure waves bounce back and forth. As has been mentioned if the ceramic bits happen to fall out the hollow cat will resonate at certain engine RPMs in a rather annoying fashion.

Garth S

As long as we're talking mufflers, here's one more combo I'd appreciate your input on.
For the S4, I have a GT twin outlet muffler (on), and a pair of GT resonators to replace the stock S4 resonators ( yet to be installed). The good cat is on the bench, with a gutted one installed - it must come off for surgery as there are two 'filler' tubes inside the gutted chambers rattling around:
The question is what to do with the gutted cat. it would be easiest to cut the chambers off, replace with straight pipe - and be left with an 'H' pipe. The next option would be to cut ahead of the 'H', and fab a 'X' - more complicated, but ....
So, any experience as to how one or the other would perform - and sound? Which way to go ....

Mongo

Thanks for explaining that to me Jim. I can see why Abby and RedUFO are talking Nascar when you take those cats off

justin

Nascar sucks

hacker-pschorr

What am I missing here? Jim has had these flowmasters on his car for over 5 years, they are offset on the same side:

http://members.rennlist.com/pageauto/exhaust.htm

drnick

my 86 has the ott-x, stock resonators and rmb which i really like apart from an annoying resonance at around 2000rpm. it sounds just perfect at all other revs especialy 4-5k and i love the volume at WOT.

i see chris L has spintechs in place along with sterling G. i thought the flowmasters were a 'resonator' rather than a 'muffler' ie just metal baffles rather than sound absorbent packing?

Abby Normal

Thanks for your contribution to the thread.

Shane

Ditto Dude!

My '86 has x-pipe with stock everything else and has a nice burble at idle and cruise speeds, but really wakes up the neighbors at WOT.

PS: I hope Kurt Busch takes the cup this year.

BC

Those spintechs are pretty raspy. Thats a good thing sometimes.

T_MaX

Hint: Use a pair of glasspacks (min. 12in. in length) after the X-over if cats are not used

They have low restriction and will take out most if not all of that raspy tone.

Again, JMHO

whall

Curtis
I spoke to my exhaust shop about glasspacks. They said that the car would be "wake the dead" loud. I am looking for a low rumble until I open it up, then more of a roar. The best sound I ever had was a 65 Merc I owned way back when - had headers into sidepipes. This had a amaing rumble sound unitl I opened it up - then.....

Chris Lockhart

Like Sterling said, WOT on my GT is enough to scare folks a block away!!!!!!!!! My set-up is probably louder than most folks appreciate, but I have LOTS of car enthusiasts stop at redlights and such, and compliment the exhaust tone.

The full specs are as follows:
MSDS headers with 3" collectors going into a custom built Dr. Gas X crossover (also 3") then reduced down to 2.5" pipe back to the 2 Spintech Sportsman Series mufflers (resonators mainly, as there is no baffling material) then more 2.5" pipe back to a 928 Specialists RMB.

Before I gutted the rear interior and removed almost all of the sound deadening material, the car had a nice burble at idle, a very reasonable agressive tone at cruise with the windows down, but reserved enough to not drive you crazy with the windows up. WOT is another thing altogether!!!!!!!! It'll scare the sh*t out of most folks if they aren't expecting it. LOL. I scare the Ricer kids all the time. They seem to feel the need to rev their car when they pull up next to me, or even when passing in the opposite direction. I give them a good high rev blast with the GT and they shut up and run home with their tail between their legs. Almost won best sounding exhaust at a local cruise in last summer with it. The DJ asked attendees to point at the car that sounded the best, and I wound up with about 50 people all crowded around my car, pointing like crazy!!!!!!!!! The DJ either wasn't paying attention, or was just a jerk, because he gave the prize to a guy who only had about 15 people around his car. Everybody seemed to be upset over the results, but it didn't bother me. I had too big of a swelled head from the crowds great compliments to let it bother me. LOL.

Mspeigle, I didn't realize that Louie wasn't manufacturing any more x-pipes. He should sell his jig to one of the Big 3 and let them continue. If you can get one made for $200.00, definitely go for it. X is definitely the way to go when compared to an H pipe.

I personally think that the stock exhaust manifolds on the S-4 and up are good, and the MSDS headers are as Jim Bailey has always said "not much of a performance bargain". The best bang for the buck exhaust wise, is Louie's X pipe and an RMB. Great sound, a nice modest power increase, all at a reasonable cost. I personally have around $1200.00 invested in a great sounding exhaust, that only netted me about 5 hp. Not much of a bargain.

Any rate, all you folks exploring the exhaust world, best of luck on price, fitment, sound, and performance. The data will help us all in the future, and thats what it's all about.