I want to put headers on my 1991 Mazda RX-7 N/a with Apexi intake and N1 exhaust. I was wondering what headers would do for my horsepower and if it will make it loader and what is the best brand to get.

 

Racing Beat. But I don't think the N1's will be tollerable.

 

yea i run the rb headers with the n1 and it's pretty damm loud , even with the tip in..

 

If you have cats on your car, or even if you have a straight pipe right now, it will be louder. How much? alot compared to cats, a little more if you have them off already. Racing Beat is some good stuff. Good quality pipes man

 

I own this setup, RB headers, Presliencer, Single catback N1... I just put it together this week but havn't got the Intake manifolds back on.... i'm waiting for my gaskets to get in. I'll let you know how it sounds.

 

Of all the NA bolt-ons, headers make the most difference in power & loudness.
Silencers (or cats if necessary) are a must.
I have pics & a sound clip linked in my sig below.

 

Even if they are loader, with the N1 exhaust with the RB headers, does the sound still sound real good. Also would you say I would get 10 to 15 HP out of the Headers.

 

Probably more with the intake & exhaust setup you already have.

Trust me, you will wonder why you didn't get them sooner..

 

mine isnt that loud, well considering i have two presilencers, people say now it sounds great, alittle more aggressive, yet it not the most quiet in the world, gets up there around 8200rpm

 

What about the RB Cat replancement and presilencer?

And the RB Header bolts up to the RB cat replancement/presilencer with no probs right? Then i want the Borla catbacks.

 

tell me why we are giving a **** if its too loud again? as long as you have cats and a muffler you are in legal specs anywhere in the country. a rotary is one of the loudess cars in the world. a rotary will a straight pipe will put a chevy 350 to shame. you do not drive a lexus. If you care that your car is too loud for you or your neighbors you might want to get another car. Other than that try to squeeze every last HP out of a NA you can and stop sweating the small stuff.

 

I got one reason for you...your hearing

 

another reason getting pulled over constantly by police for having an exhaust that is too loud. Even if they dont cite you it is annoying and gets you the kind of attention you might not want.

 

What?

I can't hear ya.

 

whats a good guess for headers hp increase with a intake & stock exhaust? catless? Thanks!

 

Mazdatrix says some rediculously high numbers 57% IIRC ....

The stock exhaust manifold has VERY poor flow.... it just dumps the exhaust into a chamber sideways and expects it to find it's own way out :P

I don't have any dyno numbers but i would say 20hp increase at the least especially if you were running stock cats previously and they were clogged *which would be the most common application*

Anyone have before/after dyno?

 

Not true...You can get tickets for super loud exhaust.

 

I've only seen a law for this in california, and it's 95 db is the limit. They compare it to a 5hp lawn tractor with the blades running at full throttle makes 95db. The cops actually have to hear your car running between 3k-5k at 20 inches from the exhaust tip... even if they cite you for it.... the only thing they can do is tell you to go to an inspection station so they can actually check it with a db meter. I got this information from apexi's website under the CHP Reasonable noise document.

 

What if you have all kinds of other illegal mods on your car? Going to a referee station may be suicide.

 

then you move oout of the FACIST state of: The People's Republic of California

 

For the sake of your hearing, and not getting pulled over, you might not want an exuast that loud.

 

I don't think I will have to worry about the noise in Indiana and the cops. I just want it to sound as good or better as it is know with a decent hp increase.

 

A loud exhaust gets unbearable after a while. Even with my highflow cat and dual mufflers, it was way too loud for me. It was cool for about a week, then got real old. real fast. With my Greddy now that has dual silencers before the mufflers, its much better. Theres noting worse than an overly-loud annoying exhaust, makes driving the car not even fun anymore.

 

Is there a dual setup that ISN'T so loud? This isn't a rhetorical question..im actually curious because i wanna know what i can run. I live in toronto and recently the cops around here have been getting reaaaaaaaal cute with us import drivers.

 

Any decent muffler should be fine. RB, Greddy, HKS, etc... If you have the stock manifold, then even a so-so muffler setup should be ok, but with a header you need something of high-quality to muffle, but yet still flow well. A dual setup will be quieter than a single.