Mongo

With an RMB and X-Pipe with no cats, the S4 resonators will make the car sound mellow during a typical cruise until you put your foot in it. Talk to PRC928 on the board. He has this setup. The car sounds so nice at idle and cruising in low RPMs, then once he hammers it it will turn every person's head the car passes by.

Rob Edwards

My GTS had the big resonators on it, so you can't just go by model year as to when they switched over.

PorKen

The big resonator bodies are the same, '86.5-'87/88. The piping is different on one side, however.

You can put big or small (GT) resonators from a later car on a '86.5 by shortening and repositioning the driver's side outlet.

jbrob007

Thanks AGAIN!!! Especially for the pics of both resonators - the inlets / outlets are in relatively the same position which should work. I think we can work around any 1/4" diff in pipe dimensions This site is Grrrrrrrreat!!!!

jbrob007

O.K. Now that all those questions have been answered... I've got one more (of course):

I've found a Magnaflow Tru X-Pipe listed on AutoAnything for $86.00. Its supposed to fit the exhaust pipes on a 1986 928 - increase HP, better sound, etc, etc... with a lifetime warranty. Anybody have any experience with this particular product - good or bad??

Gary Knox

To clarify Ken's comments - I'm pretty sure the passenger side resonator will match up. I think the pipe coming out of the driver's side is a bit too long and will need to be cut shorter, then flared. (I bought and installed a set of '86.5 resonators in an '88 one time. Had to extend the driver's side one).

Gary Knox

jbrob007

Thanks y'all... I'll let ya know how they work out!

hernanca

Used rear mufflers (aka, the pumpkin), for a non-RMB setup, are available from 928 International for $150, currently. The stock setup gives the 928 a very civilized, performance sound, yet with enough coming through that discerning ears inside the party host's house know something "interesting" has just pulled up.

If there is any degradation in performance from the pumpkin, I believe it would be minimal, because of how far back it sits, at the end of the exhaust system.

Many seem to favor the RMB for two reasons:
1. sound (louder at on-throttle)
2. some weight savings at a critical location

An X-pipe will add a more exotic car sound, and give a performance boost to boot.

I have had both 86.5 (larger) and GT (smaller) resonators on my 86.5 5-speed. Between the 86.5 and S4 resonators, both large, PET shows the same part numbers for the Right resonator, but different part numbers for the left resonator. I swapped out the stock 86.5 resonators for a GT resonator setup, by swapping out the entire exhaust piping system going from after the cats, including the resonators, and to the point where it would connect to the pumpkin (or RMB). I had to have minor exhaust mods done (extension, I believe), to hook my RMB back up.

jbrob007

I'm thinkin' I'll go with the X pipe (researching X pipe options now), cats delete, S4 resonators & the RMB (all ready installed). Should be a nice balance between performance, sound and civility...

elgreco

guys dam question here what is rmb?

soupcan

Rear Muffler Bypass

elgreco

thanks brian