I'm getting ready to do my first modification on my 2nd Gen. I drive it to work everyday so each project has to take a weekend at the most. I'm thinking about the Bonez downpipe from Rx7.com.

EX810625 Bönez 2.5" Race Pipe with Presilencer (86-88 5-speed only) $160

Do you guys know if that has everything I need to open the six ports or do I have to do other work? I know the ports open from exhaust pressure but I don't know where that pressure originates.

How much horsepower should I expect from this and what are the cheapest mufflers I could get that wouldn't entirely suck?

 

i was told new cats
where the best way to go for HP

 

The pressure originates from the main cat. If you look under your car on the passenger side, you'll see a tube coming out that goes up to the 6 ports... Any exhaust mod you do should be able to fit that tube to the pipe/cat you buy.

Be aware tho, that going with a race pipe and presilencer, you're going to be much louder.. if that's o.k. for you then fine.. but if you don't like droning on the freeway, get a hi-flo cat and presilencer setup.

Mufflers are not by any means cheap. I went with the RP catback (least expensive and still quality) and love it. Nice growl at idle and moderate noise above 70mph. The increase in power is most noticable with the K&N intake tho.

JB

 

I read on the racing beat website that a downpipe and presilencer will give you an extra 18 HP on the N/A. Is that true?

 

Maybe - maybe not. I'd take that number with a grain of salt if I were you. Every car will be different. You'll gain, but I have my doubts about 18 HP.

Maybe if your old setup was stock and clogged, but then you're regaining what you lost from fucked up stock exhaust, plus gaining maybe 5 - 10 hp.. Dunno...

Only way to know for sure - Dyno before and after.

JB