So I went to the RX-7/8 meet at Fuddruckers in Columbia, MD, and I ran into the other guy in the area with a turbo - he said his magnaflow exhaust was 3" - they told me it was 2.5"

Is it really 3"?

Does anyone make a 3" exhaust? It would be MUCH cheaper than getting mine custom made (the welder quit at my shop which is why it's not on yet).

 

There aren't any big companies making a 3" exhaust yet, at least that I know of. I wish they would though! Altered Atmosphere in Gaithersburg, MD has custom made one for a couple of 8's though.

 

Interesting I was thinking about making one with 3" tube. But with all the story about how the turbo will not work properly with after market cat system. I put it on hold

 

I have the magnaflow exhaust and it is 2.5 in. (measured it myself). However, the tips are 4 in. He may have been thinking of those. Who knows.

 

If a turbo will work with the stock exhaust, it will most certainly work with an aftermarket system. The problem is that alot of people are just relying on the tuning that comes with their turbo kits. It is tuned around using the stock exhaust. If you change it and change how fast the air gets out, you also change how a turbo puts air into the engine. Suddenly the tuning isn't correct anymore. When it comes to turbos, after the turbo no exhaust is the best exhaust. A 3" would be nice but as with any other change, it has to be tuned to work properly. There is no one magic map that will work with every different setup.

 

A) The custom 3" Altered Atmosphere is making is for MY car - they haven't made any for any other cars. The story is as follows - got my turbo installed, asked them to measure for an exhaust - they never bothered. Came back a month later for the custom 3", they got the mufflers wrong - new ones didn't come in before I went to China so I was gone another month - came back, they fucked up the mufflers AGAIN - they finally got the right sized mufflers (or so they say) except their welder quit.

I had a custom tune done when the turbo was installed - the AFR is a sweet 12 flat throughout the band - I'd like to get it leaned out to as lean as possible, then add a little extra fuel or retard timing at those spots for a margin of safety - maybe between 12.5 and 13.0 at points.

I'm waiting to go in to get my recirculating super-sequential BOV, GReddy pressure sensor harness, GReddy injector control harness, the 3" exhaust w/resonators, catless midpipe, and another session tuning on the dyno - I'm currently running 7 psi (5 after 6250 rpm) with no problems whatsoever on the stock exhaust. I have 1-step colder plugs for a little added safety. I'm tossing around the idea of the ignition control harness as well - I've been told that the injector control harness takes over and flat out tells the computer what's up and directly controls the injectors rather than tricking it into adding more fuel like the regular e-manage does. On Celicas, the computer used to override the e-manage/s-afc, but when the injector harness was added the e-manage took over.

Also, on Hondas, running the pressure sensor and tuning for boost seems to get rid of that stumble when switching between maps (I think you guys have been calling it open/closed loop or something like that).

I'll let you all know how it goes when the custom exhaust and the e-manage goodies go on the car.

 

RX8store.net exhaust is 3" http://www.rx7store.net/product_p/rx8storerx8.htm

"RX8 Store stainless catback exhaust system for the RX-8. 3 Inch, Catback system, 3.5 inch tips"