I went by an import garage today to inquire about the cost to install my rb exhaust in case my buddy can't let me use his garage this weekend...the older gentleman i first talked to first said "let me see if he'll do it" and then continued with "why would you want to do that? back pressure is very important in the rx8 and changing the exhaust will cause your seals to wear worse, I have an rx7." WTF? I was like..."it's made my rb a rotary performance company" and he said "ok" - i was sort of unsure about the place so i left...

any input?

 

Leaving was good......

 

I think you did the right thing by leaving.

edit: darn it dannobre beat me to it!

 

i've always heard of the whole "backpressure" thing when it comes to exhausts in any car.... the only thing I know that is important when it comes to design is in the header to allow proper scavenging... after that, the free-er the flow the better.

but does a rotary even scavenge? i would assume not considering its all exhaust strokes coming out.

 

I get my Vtec fluid changed there all the time.

 

^^^ you should get your wind shield washer fluid changed there. one less trip you have to make and all those HP your going to get out it

 

Yeah mean your oil

 

My limited understanding is that lowering back pressure decreases low end torque but increases high end horse power (at least in conventional engines, I guess I don't know the effect in a rotary).

 

In the older rx-7's (86-92) back pressure was used to operate the 6-port actuators in the non-turbo models. When the actuators are closed the car would have more torque at lower rpm.s. As the rpm's increase the actuators open to allow for more power. Many people would wire the actuators fully open and install exhaust systems that produce no back pressure at the cost of lower power in the lower rpm's.

Racing Beat actually mentions this in their product line.
http://www.racingbeat.com/FCExhaust/HDR%20DP.htm

 

You did the right thing (that you left the place)

 

Actually I've heard many people with RX-7s and a lot of knowledge say that if you just install a full free exhaust on an RX-7 and don't change anything in the engine bay you have a good chance of ******* it up, so he probably thought it's the same with the RX-8. (you only had a catback though?)

 

Yeah good call on leaving. They get paid to do a job, not give their EXPERT opinions on things they obviously dont know **** about. Its a 20 mintue max job with a lift and air tools, take it to the next corner muffler shop and move on.

 

HA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! i LOLED!!!!