Good news, I just got my car registered where there is no gay echeck!! That means I am getting rid of my air pump, and cat and getting a header. Which brings me to my question. Is the pre silencer what replaces the cat? I priced pre silencers and cant believe that it costs $300 for just a piece of straight tubing to connect the header and Y pipe. Is this for real?!? Please tell me there is another way. If this is the only way, that means I would be paying about $500 for just a header and pre silencer. Please give me some advice on this. Thanx guys

 

Racingbeat has header/presilencer for $400, just installed today. Also Victoria British has Monza brand headers for 219 or so ceramic coated, bolts up to stock, so does Rb with silencer. They are really really really loud and high pitched without the presilencer. (It sets off car alarms in parking lots WITH the silencer).

You can probably buy others (Like Pacesetter) but those require modification to work (O2 sensor) or there are others that would fit if you had a muffler shop make you a pipe to connect. Keep in mind the airpump removal requires the 5/6 ports to be wired/removed and headers (usually) replace all cats so you will have no bp to open aux ports, and you will have less torque!

But I love em! 5.0 burned same day inst.

 

But I thought that adding a header and removing the cat ADDS horsepower. I'm really confused now. Can someone please clear up this confusion? Should I go this route or what? Any advice please...

 

Wiring the aux.ports open will cause alittle low end power loss.Most of the gain with the header is in the midrange and top end.The power gain with the headers should be pretty noticable,even with the aux. ports wired open.I don't think you'll be disapointed.

 

So how do you wire the ports open? Is it an easy process? On the RB web site, it says that the pre silencer features the backpressure sensing tube. Will it still be necessary to wire the ports open even with this feature?

Also, do the RB headers have a place for the O2 sensor? Will the car even run right without an O2 sensor?

 

Or do you guys think it would be better to do a header and a Random Technology High Flow Cat setup?

 

To be quiet honest it might be simpler(is this a word?lol) to just run a straight pipe(aka: downpipe to mid(race)pipe). You will receive a good gain and alot better sound. It is cheaper as well. Oh and there are places that sell cat replacement pipes for the main cats. Look here:

www.testpipe.com

 

i say the cheapers ever.... will be goin to a muffler shop and have them custom make you a straight pipe. instead of payin for expensive pipings. which you will pobably gain hp more or less with the custom exhaust. for at least 200 bux you could have a full exhaust. .. good luck

 

The header and presilencer has been the best mod I have done to my car yet. Hella loud, but adds a LOT of power aboue 3k RPM in my 91. The cat will allow for backpressure, which makes it possible to keep some torque, but if you can learn to launch it, the loss in torque is really not that bad. I reccomend the RB header and presilencer to any N/A owner.

 

I am running dual $20 "turbo pack" presilencers and dual $20 glass bombs. Power is good (pulls freely thru 8k) BUT the Wankel fractures the welds out of the presilencers - so they rattle after 3 months. I need to search for some steel packed straight through presilencers. Yeah - I'm a cheapskate..
Bill

 

As far as I'm concerned, the best my car ever sounded was when I had the cats replaced with a straight pipe and was still using the factory mufflers. There was a nice increase in HP(the cats were clogged some) and the noise was very livable. On my daily driver I want to it to be somewhat quite at normal driving rpms but it can get louder at higher rpms. If you don't mind loud then get the header and some earplugs.

As an alternative to your original question you could use a Borla XR-1 series muffler inplace of the pre silencer. Its made of stainless steel and has stainless steel wool packing. Available in many different sizes thru www.summitracing.com

 

I have a presilencer for sale for 115.00 if you want one !!! Im moving to maryland and they have emissions there so I had to put on a cat.

 

If you use the back pressure sensing tube you should be able to keep the ports functional if you want.The header does have a place for the O2 sensor.

 

Very cool.. Thanx for the info guys!

 

RP sells a bonez pre-silencer cat replacement for like $160 or so.

 

what is their web site?

 

www.rx7.com

 

I just ordered that ill let you know how it is its supposed to get to me on the 15th

 

I have the bonez race pipe with N1 duals and I like it, good power, good sound. I run open no 6th ports so there is a little lag below 3G but it's nothing to me. only wishing that damn presilencer wasn't in the middle of the race pipe, its loud, but not loud enough for me.