How did it change the sound? My SE is nearly as quiet as the wife's camry right now, just wondering how much louder it'll be with the cat hollowed out, if any louder at all. Just got a stock header & RB high flow cat.

 

Mine is not that much louder, it just gives more of a rumble at idle. My racing beat exhasut on my last rex was louder. But my muffler is also brand new, that probably has alot to due with it. I do get the odd backfire.

 

mine isn't much louder than before. it is just a little bit deeper. i should give you a couple of hp too.

 

My car came with the stock exhaust and hollowed cats and i didn't even know it, it was very quiet, i was actually going to hollow out my cats, looked through the pipe and they already were... without cats the ACV needs to be removed and blocked off.

 

Anyone running a test pipe with the stock manifold? How does that sound with the stock muffler?

 

Why do you need to remove the acv if you don't have cats?

 

I've got a test pipe and stock manifold and it isn't too loud. Also have a really crappy old muffler

 

It works off the cats... or something, i don't really know... i just read it needs to be done. without cats the 5th and 6th ports need removed or wired open because the actuators won't have enough backpressure to open.

 

mazdatrix's racing beat exausts have the provisions for the 6 port acutation for the GSL-SE's.

 

Yeah, that they do, but i'm talking about just gutting the cats.

 

Blockoff plate, actuators wired open, etc has been done.
https://www.rx7club.com/forum/showth...hreadid=169237

Now Kevin's having at it again, rebuilding my engine and doing a streetport, as well as hollowing out the cats. This car will really be something special in about a week!!

 

you have it backwards, the cat needs the acv, the acv doesnt need the cat.

mike

 

while were om the subject of cats, I have mine out right now, and is there anyway I can tell just by looking at it if its clogged? I dont really know what to look for here. All I can say is that there is that screen on both sides, and some of the holes in the screen are plugged up. I dont know how bad is "bad".

 

So if I get the racingbeat system do I have to remove the acv and air pump or can I just leave them on?

 

So if I gutted the cats on my GS, i'd have to wire the 5/6th ports open? Or is that for GSL-SE's only?

 

only for the GSL-SE buddy. all the other models are 4 port.

 

ive got the acv off and blocked and all emmisions off and a test pipe then midpipe with no muffler it sounds nice loud but nice got a cool murmur to it! well thats when the car is running lol!

 

Hmm, does anyone know if its possible to run a test pipe with the air pump still hooked up, and the air pump 5/6th port mod done?
I'm thinking it might get kind of noisy with the vented pump going all the time...