i was trying to figure out what size to get for my RP supercat? i was searching the threads and i could only come up with the one guy who posted the link to summit racing. but is that the size needed?

ive tried pming other people who had it but they havent gotten back to me...

anyone?

www.summitracing.com

 

3", but the packing in that won't last long in a rotary exhaust

 

I've used Dynomax mufflers on rotaries before and never had an issue. They work fine. Fiberglass packed mufflers are bad to use as presilencers up near the engine. At the back of the car the fiberglass doesn't burn up. I've run nothing but fiberglass packed mufflers on RX-7's for over 10 years now without any issues. If you run one up front as a presilencer, that's where you'll kill one in no time flat. I've seen stainless packed mufflers break up at the back of the car. There's more to it than what it's made out of. Who made it and the quality of their work has a great effect on the longevity. An Edelbrock muffler will abolutely fall apart on a rotary and it's stainless steel.

I wouldn't use the bullet muffler as a presilencer in place of a cat. No way. I'd use a 3" straight through Magnaflow since theirs is stainless steel. Magnaflow and Dynomax are owned by the same company and they have a quality product. Magnaflow is basically the upper line that uses stainless and Dynomax the lower line.

 

can someone explain where its put on the car? i know it has to be welded but where(exactly)? for best productivity of course =/

 

I was assuming you were going to use it in the RP Supercat mid-pipe at the approx. location as OE, which being just downstream of the cat can get extremely hot

you definitely need stainless steel packing there, and even then the fine wool type can get hot enough to mat out, in the case of a resonator you may not notice the difference the same as a main muffler

 

does anyone have any pics of it welded on?

 

Just look at the pictures from Rotary Performance. The first one shows a mid pipe with a cat and no other muffler/resonator after it. The second one shows a resonator but no cat. If you want to envision what an added muffler will look like, jsut imagine what the seond picture's muffler would look like after the cat in the first one. There's nothing that really needs to be explained when it comes to looks. It's under the car where you can't see it anyways.

http://www.rx7.com/store/rx8/rx8exhaust.html

 

edit: my bad

 

Why is that a bad choice? He should take the midpipe that uses the cat and install the new muffler at the rear of the midpipe where there is a nice long straight section and leave the cat alone. If he doesn't want to use a cat then still install the muffler at the same location that I just stated. I merely showed both of those pictures so he could get a visual of what a bullet would probably look like welded up to a pipe as it's dimensions are roughly what the resonator in that pipes is but to install it near the back after the cat.

 

i understand perfectly of what rotarygod is saying, but why is it a bad choice to put it on? it can be put on the straight section of the pipe without problems right?

 

ok, I misunderstood

 

Please let's not get that close. There might be kids watching!

 

lol, I'm not feeling the rotary luv ...

 

i just came back from the shop and they were showing me that the resonator would be rubbing against the heatshield thats protecting it. i was advised that it wasnt a good idea. he said the solution if i wanted it on would have to be removing the plate thats connected with the heatshield to put it on, but that would be exposing the drivetrain to too much heat.

and he is a trustworthy mech id say. any thoughts?

 

bump

 

that doesn't make any sense to me unless he was looking at installing it on the muffler feed pipe that passes by the gas tanks and it was the gas tank heat shielding he's referring too , this is downstream of the cat pipe.

You should be able to weld it it in the rearward straight section of the RP Supercat pipe without any issue. Again, this is exactly where the factory resonator is welded in the OE cat pipe.









if you guys can't figure it out from this then it's hopeless ...


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yes thats what he is pointing at, where the resonator should(would) be.

if anyone can look under there car and take a look lol, theres a metal plate about 1-2 inch away from the cat and muffler which is parrallel running down from the lower half of the cat to the middle of the muffler pipe.

it acts as a cover i guess, from the drivetrain. it also contains a heatshield wrap at the base of the supercat section. if i was to put the bullet in, it would be basically touching the heat shield wrap or at least really damn close to it.

 

i know where to damn put it lol thats not the problem, its the distance from the bullet to the heat shield wrap/ metal cover plate!!!

 

it only has a 4" OD x 12" length, it should fit

eh, WTF do I know ....

https://www.rx8club.com/showpost.php...0&postcount=51




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wow your resonator is MUCH bigger then mine lol. if you put that on im pretty sure that you took off the cover plate with the little heat shield wrap right?