Exhaust system Question

[ismaelae86]

Well question is what exhaust set-up i should go with...my research has come up with mixed answers (on rx7club) so i figured i can just ask u guys...i was wondering if long primaries are better or short? here are the to set-ups i was thinking about. either the isc/mazdaspeed header and have the primaires abour 95" from ports and collected them in to a 3inch outlet inlet borla xr-1 sportmans muffler or dynamax ultra flo ss, and possilbe have a racing beat dual presilencer if its too loud. or have the SDJ header copy from mazdaspeed part# 0000-06-7406 3 inch back to some sort of middle muffler and out a borla xr-1 or dynamax ultraflo ss.. now i know the isc header is cheaper than the sdj but is there a big enough difference in power to offset the price difference?...and from what ive read long primaires have a better wide power band...so pretty much im stuck hahaha
thanks in advance for your help
ismael

[ismaelae86]

here the link where u can find a pic of it by part number
http://www.mazdaspeeddevelopment.com/PartsImages/gallery06.htm

[Scooter]

I think either header should work well. I haven't heard about any real power differences between the two. (I think Chris Ludwig said at one point that the Racing Beat one was close, too.)

Single 3" pipe, muffler in the middle, one at the back. The middle one would be about 14" and the back one is whatever you can fit in there, iirc. (I don't have this setup so I can't check but I think someone posted the info on muffler sizes.)

The mufflers should be straight-through. They do have to have actually muffle the sound, though, or you will end up very LOUD. Most people seem to use the DynoMax or Borlas. The rotary will kill your center muffler quickly. I haven't heard about any good solutions to this.

I'm trying to justify keeping my Mazdatrix full-dual setup because it doesn't break and it's quiet and it's paid for, but I would probably just get the lighter single pipe setup if I did it over again.

[ismaelae86]

what if i were to move the middle muffler further away from the middle and more towards the end where exhaust temps will be lower

[Scooter]

I dunno.

But I would say that I think the muffler is usually in that spot because that's the ideal place to put an expansion chamber for tuning the exhaust.

There is an ideal spot for the chamber along the pipe that you can figure out with science. I suspect that the location of the chamber on the ISC full exhaust is probably pretty close to that spot. Moving the muffler away from that spot is probably not good for power. But I have not done it or tested it. So I dunno.

Also you can't move it too far really. It still has to fit in the area there.

[ismaelae86]

hmmm yeah thats true anybody else have any input on the subject?

[ismaelae86]

ive made up my mind imma go with a collected header i went to the last event this month at willow springs and met some guys from mariah motorsports and gave me some ideas...i update u guys when i get some progress on it