If anyone has any opinions on this, it would be much appreciated. I'm about to buy a resonated midpipe, and I like a somewhat subdued souding car. Anyone have expereince with the two?

FYI, I already have a downpipe and RB dual tip. Which resonated midpipe do you think would sound better/less obnoxious?

Thanks a lot guys,

Ian

 

No real difference that I know of but a better question is who's going to tune the car for open exhaust?

Or are your ready for a new motor

 

I'm running a RX7Store resonated MP, and I'm very happy with the noise reduction. I didn't realize just how quiet my exhaust was until I heard a friend's FD with a straight MP. At idle and low RPM's, there's not a whole lot of difference between it and a cat. It's the higher RPMs that sounds great with the resonated MP.

 

I thought the Pettit pipe actually used a "resonator", while the rx7store pipe uses a Magnaflow straight-through muffler.

I have the rx7store pipe...honestly, in some conditions, it is quieter than my hi-flow cat!

 

I agree. Earlier this year when I swapped the res MP for the hi-flo to pass smog, I couldn't wait to get the MP back on. I found the cat's tone louder, and more obnoxious than the MP. Way to go Magnaflow!

 

At one time I had the Pettit and it has a larger center section with holes inside and it's packed with a steel-wool like material. So it's a straight open 3" pipe (w/holes to the resonator) and worked great as long as you have the supporting mods for an open exhaust but the RB would help a bit sound wise.

I don't know anyone with this setup specifically.

 

Big difference between the two.

The pettit looks like it has a glasspack type muffler welded in, and doesnt quite down the exhaust much. I've also seen one that had 'blown out' and the packing was rattling around inside. It is straight through, but due to the high price and lack of noise suppression I don't think it's the best choice.

The rx7store one has a large rectangular magnaflow muffler welded in, which does a lot to reduce noise. It's also straight through.

I hope like hell they work well to suppress noise, b/c I have a custom made 4 inch diameter turboback exhaust headed my way with a pair of magnaflows welded in

 

Thanks for the input. After speaking with Jeff @ Pettit hesaid theirs is better (surprise!) because it is made wth a ceramic material rather than the magnaflow's steel material. I have a feeling that everything from Pettit is just more expenive & that's about it!

He also said that he would send me "pills" to prevent boost creep...anyone have experence with these?

 

The only thing that will decrease creep is a more restrictive exhaust, to lower the flow.

 

But with a PFC, it'll be covered, right? They're would be no need to port the wastgate with a pfc, correct?

 

ECU? No ECU or controller will stop creep. It's a pure physics issue, too much flow, and not enough wastegate. If it's 100% open already, nothing will magically make it bigger. You could tune the ECU for increased boost but it's a crutch at best, because your creep is highly affected by tempurature. I don't trust the stock wastegate at all with a full free flowing exhaust. Today it was 40F outside, and I had my wastegate set on the spring level (7psi), my controller was off and I was boosting 14psi!!!

Your only options are a less free flowing exhaust, one of those restrictor plates, or getting your WG ported, and a much bigger flapper welded in.

 

The pills are to put in your secondary boost vac line. They are nothing more than a carburetor jet. I think it's a #54 in size and a crutch at best.

As I posted before you need all the supporting mods for an OPEN exhaust. I know, I have a full 4" from the turbo back but it's on a big single with a good boost controller and a 50mm wastgate.

I just sold my spare motor and you seem to be proud of the low miles on your car.

But the low miles won't matter after your first motor it's only money

 

The RX7 Store muffler is the way to go. It's deep, throaty and flows well. The Pettit pipe is a ceramic filled cherry bomb with little muffling ability. Don't make yourself a ricer.

 

I agree on that midpipe. I run it, and it toned my GT spec exhaust down very well. I receive lots of compliments on the sound.

 

I have the pettit resonated mid pipe with an apex'i gt spec exhaust, never had a problem with it and it sounded great. Very deep tone.

The Pettit Resonated mid pipe is now for sale as well as a PFC (no commander, but you can use data logit)

 

Lots of good advice in this thread.

If your FD is that low mileage and you aren't going for monster power (on original motor and twins you really can't anyway) I say keep a cat on it, whether stock or highflow. You can still make over 300 to the ground with a cat.

 

ha

I have the SR resonated midpipe, very nicely made (high quality welds, all stainless), prob similar to the Pettit, basically a cherry bomb: sounds great at low rpm but obnoxiously loud at full throttle

I wonder if there is any difference in high rpm flow? seems like there would have to be some difference

 

not good!

the stock wastegate is too small, send it to Garfinkle to have it hogged out and a new (oversize) stainless flapper door installed....do NOT drive your car like that, you WILL pop, take my word for it

 

Thanks for the advice...after searching for a while, I'm thinking of going with the RX7Store resonated midpipe and the restrictor plates from Jyro. What's your opinion on this setup?

Thanks,

Ian

 

I never really understood buying a midpipe to improve flow, and then putting restrictor plates on it

get the wastegate ported or just run a high flow cat.....save the environment :p

 

+1. Owned them both. Rx7store less droning and overall alot quieter. I made a few more HP on the Dyno w/ the Rx7 Store as well. Although ambient temps were a bit better that day . G

 

I would think that the stock cat is exponentially more restrictive than a simple restricor plate, no? The cat is like a multi-layered filter, whereas the restrictor is just a smaller "hole"

What are your thoughts?

As far as saving the environment goes, this car's a lost cause!

 

I am or you are not understanding. You are not gaining anything using an open 3" pipe and putting a restrictor plate on?

As Rich has stated "I say keep a cat on it, whether stock or highflow" and keep your motor safe.

Most of the older members on the "club" have tried most of the mods as they came out "NEW" from the respective companies and found out that a bad combo will detonate a motor.

We see newer members and try to give advise "that is sometimes ignored" and later see the "I think my motors done" thread.

Do you just want to spend money for the sake of spending more money in the future?

I guess that's what keeps the economy going

 

good question...it's all about pressure drop....a high flow cat may be similar to a mp with restrictor plates

 

It will be interesting to hear the results Rich. I believe it will work for you. Post a thread on your results as I will be researching my own custom 4" pretty soon. G