I did a search and found only one post by one man that stated a theoretical value for exhaust gas temps right after a header on a N/A FC. Does 1600-2000 degrees fahrenheight sound about right just after the header? I need someone that knows....so please give informed responses if you can whether it be an educated guess based on trial and error or actual readings from some guage or literature on the RX-7.

I am thinking about grabbing an edelbrock RPM series muffler for right after the header. It is stainless steel 409 externally, and perforated stainless steel internally with two runners, and it is packed with ceramic packing that is stated to accept up to 1800 degrees fahrenheight exhaust gas temps. http://www.jegs.com/cgi-bin/ncommerc...93&prmenbr=361
Hit the "true flow core" link to see a picture of the internals.

My exhaust sounds twice as loud at wide open throttle than any Harley right naw with the exhaust listed in my sig and I NEED to quiet it down. BTW DO NOT USE A MOROSO SPIRAL BAFFLE MUFFLER RIGHT AFTER UR HEADER. They break.....even though they have no packing and are advertised as "unaffected by heat". Chock that one up to another score for the RX-7 .

Thank you guys in advance,
Lee

 

so your using this as a prescilencer?
hmm.. it would be cool to get the dual outlet one and run those to a dual rear.... so the muff would be the Y pipe...

anyway, i dont know how long it would last. I say go for it! your my hero if it works out. and if it doesnt, well, you took one for the team

 

The general consensus has always been that a NA exhaust at the exhaust manifold can be up to 1800F.

With a header I imagine it would be slightly cooler, but I suppose it would depend on actual A/F mixture.

 

That is a good idea with the y-pipe idea OC but I believe that it would take away half of the sounds reduction because it would be making 50 percent less turns through the perforated piping. I would like to stay away from a true baffled chamber muffler being too restrictive IMO but my exhaust is WAY too loud with a straight through design. I am trying to find a happy medium (which I thought I had found in that moroso muffler until it broke).

Thank you Icemark for the general concensus info. I will definitely be testing the limits of this muffler if I get it according to the advertised limit in JEGS catalog. I am runnig a bit rich right now as well....I guess I will wait till tomrrow mornin to see if anyone else has anything to add to this post and if no adverse opinions arise then I suppose that I will be ordering this muffler tomorrow then. Thanks so far guys.

-Lee

 

i think the loudness would be about the same. It should be plenty quite when matched with your "main" mufflers. Are you running dual muffs on your car??

this looks like a good place to burn some cash, i might try this in the future if i do the RE converson. ill need a new exhaust system anyway then.

 

On all the motors I've ever owned, and had the pleasure to have Rob@pineapple tune on; 1850f was the goal. That was 6" away from the header flange, in the top of 3rd gear. 4th gear was best, but 3rd will work. CJ

 

Well my current configuration has a RB header that exits at 2" runners to a 2.25" collector. From there I have 12 inches of 2.25" piping to my moroso sp.iral baffle muffler and then from my moroso back I have 3 inch piping to a straight through dynomax 3" muffler. So it is practically a straight through single design that produces noise in excess of small airplanes... hehehehe but I was informed that autox has limits on dB and so I need to quiet it down as much as I can without true baffling.

-Lee

 

pp13 u talkin 6" from the block? or you talkin 6" from the end of the header?

 

6" from the header flange, at the motor. CJ

 

how about turbo im thinking 1400??

 

FWIW, I'm consisently getting temps, within the range of 700-800 degrees celcius at WOT, usually In 3rd or 4th gear. My sensor Is tapped In an Inch after the O2 Sensor.

 

sooooo any idea on what EGT's the turbos should run!?!?!