Forgive me if this is in the wrong section wasn't really sure where this post fit.

I just recently bought 2007 rx8 and I was looking to upgrade the exhaust to the borla catback, with a random midpipe haven't really looked at many yet. I've looked at videos of rx8 with the exact setup and everyone says its extremely loud, but video audio doesn't really do it justice. I was wondering if anyone has heard one in person and their feedback about it. I want it to turn heads but I don't want it to be obnoxious. In which case I'd leave the cat and just do the borla kit, I know different midpipes have different results was just looking for a general idea of the sound being catless

Thanks for reading.

 

I've had a midpipe with single resonator and cat back exhaust. Turboxs. It was extremely loud. My ears would ring after 5 minutes of driving. I could set off car alarms with it. I put the stock catalytic converter back on and left the catback on. It's at a good note for me.

I would recommend a double resonated midpipe. BHR and (forgot the other brand) are good quality midpipes. Agency Power is affordable but it tends to drone a bit. BHR does not.

If you're aiming for performance, forget about it. It's purely for sound :-)

 

take a look at BHR, RacingBeat and Mazsports(discontinued) midpipe.

they are slightly over stock sounding.

Get the catback of your choosing and then decide if that sound level is what you want or if you want a little bit louder(bhr,RB,MazSport), a lotta bit louder a the expense of rasp(Agency Power), or you want to rape nature as you drive by (obx straight pipe/raceroots straight pipe), or if you want to proclaim yourself as fire king(open header out the hood)

 

King of fire.

 

the flame might stop at around idle

 

Haha really fun and informative replies, thanks guys!
Probably wont do any of this until spring, but it's just eating me up! All I think about is my 8 haha.

 

i have a quick question since im running a gutted cat with no muffler is it a good idea to get it tuned because i noticed as soon as i gutted the cat i lost some torque and my idle is kinda rough sometimes?

 

What else have you done to the car?

Don't you have a CEL do to Catalytic Inefficiency?

I'm pretty sure that a better flowing exhaust isn't going to lower your torque or cause idle issues

 

Yea i have an intermittent cel that goes on and off i already know its the cat but yea at first i did a muffler delete and everything was fine but as soon as i gutted the cat i immediately felt that lack of low end torque but it picked up fine in the high end. I even did the ecu reset procedure with the 20 brake peddle tap and it felt the same, i was assuming i needed a tune of some sort or it was because of the hollowed out cat having a bigger piping diameter. It's a 2004 Mazda rx8 with aem cai and catless straight pipe thats pretty much it for mods.

 

You shouldn't need a tune.

Flashing cel always means a misfire.

Bad cat efficiency cel would remain on.

AEM Intake is a great intake. But it might be worth checking that the screens are in place (air flow straighteners) as this can play havoc with you idle.

When is the last time you change the coils?
Maybe pick up a HEI Spark Tester

 

I changed the spark plugs, coils and wires last week so they are brand new along with a new battery, I have 103,000 original miles with no rebuild but I feel as if I need it cuz I also noticed I have trouble on hot starts sometimes but I dunno if its a engine problem. Oh and by intermittent I meant the cel will go away for a week then come back on randomly.

 

You need to have the codes scanned to see what they are.

 

I think ill just have a mazda shop check it out and see whats up.Thanks for all the help ill update you guys on what my issue is when i get my rx8 fixed.

 

Get your compression tested. 103k miles on the original engine is starting to push the bounds of the engine life. A cat delete will almost always add power because of reduced back-pressure in the exhaust system. I don't think there is any case where removing the catalyst will result in lost power of any sort.

Also, as an RX-8 owner, it's very useful to have your own wireless OBD-II code reader. You can get an ELM-327 based model that can connect to your phone via Bluetooth or Wi-Fi on Amazon for less than $30.

 

Owning your own OBDII reader FTMFW baby

 

Just as a note.
Next time you are needing/asking for help it would be very beneficial to provide all this detail prior to having someone ask for it.

It can really speed things along. Hahaha no pun intended

Good luck at the dealership and yes please inform us on what is up/needs fixing.

Cheers

Edit: Did you check the flow straighteners (screens) in your intake? This is free and simple to do. Clean Maf while you're at it. Oh and while you're at it, the AEM makes it easy to clean the ESS ... do it

 

So i made an appointment at my local mazda specialists shop for tuesday morning and the guy said it might be compression so they are going to test it. As for the cat delete i realize it adds a bit more power but i also have a muffler delete so thats like zero backpressure am i correct? In the future i might just invest in a actual catback like turboxs but for now i like the sound lol its loud and has terrifying backfires but its not too raspy considering i still have the stock resonator. I might also pick up the obd scanner for future cel lights, and wcs ive made sure everything is ok with the intake, maf sensor and i have cleaned ess sensor as well prior to changing my plugs and ignition system.

 

It's almost a fact of owning an RX-8 that you will get another CEL in your time of ownership. Do yourself a favor and buy a reader now for later.

I'm no tech, but I wouldn't say a muffler delete and cat delete will result in zero backpressure. There might be some, but not nearly as much as with the cat and muffler in.

 

So i just got my car back for the shop and i found out my motor is on its way out, they did a compression test and the first rotor had low compression and the second wasn't as bad but bottom line is i need to replace my engine.Here are the results.

FRONT ROTOR
#1 6.1
#2 6.4
#3 6.2
REAR ROTOR
#1 6.6
#2 6.9
#3 7.0

 

Yeesh, that motor is barely alive. Get it rebuilt before you blow your apex seals and ruin the housings.

 

It's definitely dying, but not in the "barely alive" stage don't over-exaggerate like that. You can't blow a seal from low compression though... That's just silly.

Did they give you the codes Sukhi? That is the only thing that will help us figure out what the problems are (which you absolutely need to do before getting a new engine, whenever that may be).

 

Those values mean nothing without the RPM
Just say'n

THAT SAID! At least they gave you 6 values which means they likely did the compression test correctly.

 

Fair enough, but numbers as low as he got on the front rotor are not very promising at any RPM.

 

Yeah i decided to buy a rebuilt motor with around 40k miles on it which includes the engine itself,6 speed manual tranmission, ecu and wiring harness for $2000 from jdm engine depot. The mazda shop said the new engine from them was gonna be 5k so thats why i went this route,what do you guys think about this. I also talked to the guy selling me the motor and he said all the seals are replaced prior to selling the motor and it has good compression.