after PMing lots and lots of ppl in this site and in my local rx-7 clubsite (BCRX7.com) about exhaust set ups, ive come to this conclusion:

custom headers (local shop)
to
down pipe (who makes an aftermarket d/p)
to
bonez high flow cat
to
custom y-pipe (local shop)
to
borla mufflers

please feel free to comments (educated ones please) on this so i know if its the right step to take.

i do have questions tho......my car (91 GXL stock) has 3 cats, correct?
if so, the d/p removes the 1st only or the 1st & 2nd cats?


thanks,
Carlos

 

if your on a budget, i'd go with whats proven to work, people coming up with their own exhausts is just like reinventing the wheel,

RB headers
RB presilencer or random technologies cat from speedmachine peformance (depending on smog laws)
anymuch any catback system from here is acceptable, for sound, I think the RB system sounds best, for performance, an apexi n1.

Men (and women) with far more money and engineering degree's have developed these products. I wouldn't bother hacking together a system when these peices fit so well together.

 

Collected headers are pretty useless for anything but very minor added horsepower unless porting and other major intake mods are made.

Better spend the money on the down pipe and skip the headers unless you plan to do porting.

 

so a down pipe and a high flow cat with stock headers and cat-back should give me good gains?

 

DP = turbo

Header = N/A

 

this falls under scaleability vs short term savings.

400 for the RB setup vs

250 for the bonez pipe....

if you ever plan on having your engine rebuilt and porting done, go with the RB setup, other wise the bonez pipe i suppose... I've got a used one for sale if you'd like. you can PM me for details.

 

just do a large pipe from the header to the cat and then large pipe after. I have 3 inch with no cats to dual 2.25, works great

 

The pipe with the precat connected to the NA manifold is also called a downpipe.

 

I have a cheap pacesetter header which I am going to run to a 2.5in pipe and Magnaflow straight through muffler into a 3in pipe and another 3in magnaflow. should flow nicely.

 

A down pipe replaces the connector and pre-cats on any rotary engine regardless of if it is turbo or not. It bolts between the exhaust manifold and cat (or pre-silencer) on a non-turbo, and the turbo and main cat (or pre-silencer) on a Turbo.

A header only replaces a exhaust manifold, again, regardless of if it is a turbo or not (it simply keeps the exhaust ports apart until the last possible minute). It bolts between the engine and cat (or pre-silencer) on a non turbo, and the engine and turbo on a turbo model.

Do you understand now?

 

then isnt it a midpipe?

its header to (silencer/cat/midpipe) to catback... depending on what kind of setup your running... generally a downpipe is related to turbo cars.

 

many NA cars have a downpipe, some have setups that don't use a seperate pipe that could be called a down pipe, but like icemark said it's still called a downpipe no matter what it's generally related to