well, im having trouble deciding and figure out the difference of which exhaust will be best for me.

the car will be:

1988 gxl, large sp on all 6 ports
pr sleeves
automatic is being swapped to 5speed
emmissions is going to be removed
and cold air intake will be installed

now the exhaust setup....
i have a dynomax catback system that i want to keep now.

i think the best exhaust setup will be headers to presilencer

now racing beat's site is unorganized and has literally confused the hell outta me.....so many different presilencer combinations and 2 headers with a pretty big price difference.

someone please help and advise which headers will work best, which presilencer, and whatever else will work best for me when going from the engine to the catback.

 

For the money, you're better off with a downpipe and a presilencer/midpipe. This is what Racing Beat will tell you. Unless you go carb, you wont see the extra gains that the header provides.

 

or a standalone ems.

 

Buy the Streetable header/collector and the correct precilencer for your series. If you have an S4 you need the pre-silencer with the aux port tube to retain proper aux port functionality.

 

is it true that the header wont help if i keep fuel injection?

 

I beleive that a header will help no matter what your mods. Its impostible for it not to help the engine make power. The theory behind headers has been used like for ever. :-D Just ask every guy on here with a header on their car. Racing Beat would probably not offer headers anymore if they didn't work well for street car's.

 

I have a s.p. 91 with the mazdatrix true duals. it made 11hp more than a down pipe and greedy cat back. i did put a apex afc on also. it was very noticable in mid ,up! Worth the extra money. it was even quiter.

 

Whoa, you guys are missing the point.

If you don't ever plan to carb your 13b, it's better to just go with the DP/PS combo, as it's quieter, cheaper, and provides about the same power gains. I'm talking about the single outlet header and presilencer, not a trueduals system. The true duals offer something likle 30% over stock power.

 

Even a signle outlet header should provide gains. I don't care what they recommend. The header provides power based on the same theory that any other car that has headers available for it. I suggest you read this little peice from our friends at how stuff works dot com. Header Article
Although it talks about piston engines the theory should be quite the same for our dorito machines. And on a further note EFI is far superior to a carb setup. The stock system my be limited and old but any aftermarket EFI system will out perform any carb setup out there because it is much more tuneable.

 

I'm not even going to get into an argument. I'm not denying that a header is good. I know how it all works. I'm just conveying what RB says. And I don't think they'd try to sheister you into spending less anyway.

 

I've seen the article. but I think they are trying to side with the people that have to pass emmissions and it is way easier to keep the stock manifold and just swap in the cats when emmissions come. But A header will make more power.

 

true duals system, $100? hmmmm looks like a header, pipes + mufflers to me...anyone custom made this?

the headers have two holes on them, why not just weld custom piping?

 

Cause it's alot easier to buy a full setup. Cheaper probably to buy a header and mufflers and make your own, though.

 

hella cheaper, $1200 to $1500 for the true duals...less than $500 if you get it done yourself