I know someone at a muffler shop can't says they can hook me up with dual flowmasters and straightpipe for under $150.

One of my friends told me that when they took their car to a mechanic, they talked about exhaust and he wanted to straight pipe his T2, but the mechanic say straight pipe wouldn't work because the rotary engine needs backpresure to work corectly. Is this true?

Mine is an n/a and I want a setup that works and doesn't break my wallet.

From reading the forum, I seen that some people said that the exhaust gets hot enough to melt aftermarket exhaust. Is this true?

If all the above fails, would removing that cat have any effect on HP?

 

depends on what series car you have...

taking the cat off the 87 made it so the 6th ports didnt open so we wired them open... which made it a bit of a dog off the line

the 91 didnt care a bit because the 6th ports are electronically actuated...

and as far as the exhaust.. you just have to be sure to get one that is MADE for an RX-7... otherwise the car does run too hot for the exhaust.. my exhaust was under 200.. i think its a dynomax.. but im like half asleep so dont take my word for it.. i loved the exhaust on the car...

 

I have a downpipe, cat replacement pipe and apexi N1 on back from there. No need Cats cept for inspection sticker. Flowmasters would work fine.

 

the thing about flowmasters is that they arent stainless steel, and they are baffled.

 

Posted by: walken

"One of my friends told me that when they took their car to a mechanic, they talked about exhaust and he wanted to straight pipe his T2, but the mechanic say straight pipe wouldn't work because the rotary engine needs backpresure to work corectly. Is this true?"


For any turbo car, the rule of thumb is to eliminate as must back pressure as possible so the turbo can expell the gasses quicker. That's why you see some skylines with 4" tubing. The turbo just won't spool as quick with no back pressure, thus meaning you have to rev it a bit higher if you want to launch quicker. The only bends in my piping is at the very end so that the exhaust doesn't hang on the ground!

As afr as N/A's I'm not to well versed on them, but I will tell you to stay away from aluminized mufflers, and glasspacks, cause they might only last you a couple of weeks if your lucky! Stick to stainless!!!

 

As stated above, with NA's the actual size of piping and style of exhaust system has a huge effect on the power you make, and how your power band will be.
On a turbo car "bigger is better" basically... it won't hurt to choose 1/2" larger than planned really, but on an NA going 1/2" larger than planned will make a HUGE difference on the engine's characteristics and power.

I don't know about NA exhausts in therms of what the system should be built like (diameter of piping, singe-vs-dual) but I do know that you basically want to get the thickest walled exhaust piping available, due to the rotary's high temperature exhaust. Also be sure to get mandrel bends.

Flowmasters are crap. Definitely don't get them. If you are looking for a good comman brand which is near or just as good as the top name brands, but costs a lot less, check into Magnaflow mufflers. They also sell mandrel bends.

 

sorry to jump on this thread - but you paid 200 ( $ ) for an exhaust ???

just checking thats all !!

 

My cheap NA setup:

Mazdatrix header kit - welded up like the RB header (crude but effective.)

2 $20 "turbo pack" presilencers. I tried running without them, but it was WAY TOO LOUD.

2 $20 glasspack bombs with the origonal Mazda tips welded on.
The bombs do OK back at the end of the pipe, where the exhaust is cooler.

 

Here is a short vid.
The bombs are about 1 year old.
idle sound
zoom zoom

 

You don't need backpressure for the engine to work correctly. The engine is basically a pump. The more air you can flow in and out of the better it runs. Why you think porting and no emissions make such a big performance diff. Cause your allowing the motor to "breath".

I have a bud that runs flowmasters on every car he has and has never had problems. A glass pack would last longer though and be less expensive.

To the guy wondering about spending 200 on an exhaust. There are people on this board with close a grand in exhaust. I have about 800 in mine. It will last the life of the car though and the fit and finish are great. Remeber you get what you pay for.

 

my na exhaust,
stock manifold
bonez race pipe (shops around here will NOT take off cats)
as for the mufflers i bought 2 apexi n1 replicas from ebay 55 each, and had a shop put them on for 150.......its louder than ****, but it was resonable cheap. its my recomendation.

 

All this exhaust talk....WHY IN THE HELL FLOWMASTERS?
Your best bet for performance is a straight through design muffler...not an S design and especially not a baffle design...
Dont let a muffler shop that A. doesnt know about a rotary engine and B. Only sells flowmasters talk you into something youll regret. -Gabe

 

What I meant was my friend could get me a deal on exhaust, but if I get exhaust there, it's going to be cheap, but what would you all recommed if I bought shop exhaust, instead of investing $1500 into HKS.