I've searched this forum and haven't quite found the answers that I'm looking for. I have a MS Cat Back (which I love) and would like to replace the midpipe, but before I do, I have a couple of questions:

- Is there a hp difference between the two?
- Will the resonator throw CEL?
- Does the resonator smell bad?
- Which is the best brand to go with for each?
- More importantly, would I shoot flames with the resonator

Thanks in advance with the feedback

 

i think instead of resonator you mean race pipe

 

No, I meant resonator http://www.rx7store.net/product_p/rx...%20midpipe.htm

 

The cat is on the same pipe as the resonator, if you take it out and replace with straight pipe, it is very loud.

Most people buy a pipe that incorporates some kind of resonator, and even then, it can be raucous.

S

 

high flow cat = no cel, a little more power, no smell, no flames, louder.
resonator = cel, more hp, smell bad, flames, a lot louder.

 

My high flow cat shoots flames, and it definitely smells alot more than the stock cat.

 

you can shoot flames with the stock cat too.

going without a cat means you can do it a lot easier, since there's nothing soaking it up before it ignites.

midpipe does smell, and it can be quite bad, depending if you're down wind or not. With the stock exhaust, it's not too loud, but any aftermarket exhaust that is louder, will definitely be quite loud.

This question has been asked to death before, so I'm not going to bother posting the links to my videos.

 

Sounds like the hi flow cat is the way to go. Definetly don't want the CEL or the nasty smell. Thanks for the input.

 

accessguru, search on the forum, a lot of people have had the highflow cats fail on them... so take note on what units have failed, and which ones have been more successful before buying.

 

1. there really isn't too much difference in HP with or without it. I believe Racing Beat got 5 or 8 extra HP with their setup. Not too much to really fool with.

2. It will throw a CEL and it will void your ENTIRE warranty. No questions asked.

3. It does smell pretty bad and on top of that, you are breathing in pure carbon monoxide which is not a good thing. Wouldn't let the car idle with you in it for long or in or under anything as this will increase the levels and may kill you.

4. Racing Beat makes a good one. If you do decide to go that route, I would get their midpipe and pair it up with their cat-back (which uses Magnaflow cans btw).

5. Yes, you will get flames as mysql101 said.

In summary, would I go with the resonator? No. Why? Voids warranty is reason one. Sounds like rice is number 2. I've heard it before. Didn't like it but to each his own.

High-flow cat? yes. Why? You keep your warranty. Still may catch a lil hell at the dealership but not much they can say. Allows extra sound but not annoying.

Good luck with your search.

 

i also have this question though ... what is the power difference between the high flo cat and the resonated test pipe, and how significant is the difference in sound and smell?

 

i think racing beat only got 3 or 4 more horsepower without the cat on there. may have been less than that. the high-flow may not give you any.

as far as the smell, read my #3.

Sound, (without cat) IMO is like that of a fart can on a civic. its not something i want my car to be associated with. with the high-flow it will be a lil louder but not much at all.

 

I have gone catless on subaru's in the recent past and the smell was pretty intense while sitting at a stoplight especially!! Noisewise, going catless in a subie with the turbo killing the noise level doesn't really compare to the noise level experienced with an NA RX8 either. Seems like the noise and smell factors combine to make a decent hi-flow cat a better option than a race pipe. The problem seems to be getting a hi-flow cat that lasts on an RX8.

I just spoke to Random Technologies, who IMHO make some of the best high flow cats on the market. Even though Randoms website does not list a part number for the RX8, they do have an RX8 kit that can be made if anyone has interest. Its basically a two piece kit which includes a 5" metal substrate cat pipe, and a second resonator pipe, which sounds like it replaces the pipe between the cat and the back-box section.

Interestingly the Random Tech guy said that the RX8's seem to have a short cat life, even on the stock cats due to the car running too rich. Based on their current sales and support, he said by comparison the RX7 rotary's don't seem to have the same issues as the RX8's. If that is accurate, then that may explain why a lot of the existing hiflow cats seem to die an early death. I talked with a guy the other day that mentioned his stock cat being wasted at low mileage (around 30k if I remember correctly) so perhaps this is something to contend with regardless.

Perhaps going with the Racing Beat ECU re-flash would lean things out a bit, and result in a bit longer life-span for the cat?

 

Not being a pain but I dont agree with this comment...

Federal Law states the dealership must prove the modification performed caused a failure in any other part of the car...I.E. drive train, engine, ETC. To void your warrantee without proof is a violation of that law. My understanding is that they must prove it to you and have it in writing.

This does not mean that it will stop them from claiming you warrantee is void. I am only telling you what I know. If I had a link to the law I would give it to you but I am lazy.

 

Nemesis tested his RP hi-flow cat and got about 6 hp. That is about right. The resonated midpipe will give you maybe 1-2 more hp as RB pointed out (about 8 hp).

 

I've had the RP Cat for over a year now and after about 6 months I got a CEL that won't go away, and a little racepipe smell came as well indicating that the Cat is no longer working.

Oh, and from day one the RP rattled because they didn't put a hanger on it. They insisted it wouldn't need one; but it does and I had to move it from my stock cat.

Whatever you go with make sure it comes with a hanger.

-Mr. Wigggles

 

Yeah, I put a hangar on mine as well.

Mine cooked when my EGT's went to about 2000 degrees after I blew my engine.

 

yes my friend you are correct but it is a crime to take off the converter b/c you are no longer emmissions legal. that's why they can void your warranty when you do that. what are you gonna do about it? nothing cause you are breaking the law to begin with so really they can do what they want.

 

vodoo racing makes a space for under $20.00 that will fix the cel with a race pipe.