Midpipes
 

Well guys my cat went bad and I don't want to get an oem again so I'm asking this question cause I couldn't find an answer in the forums. If there is one then I'm sorry I missed it but here it goes. What mid pipe would best fit with my hks hi power exhaust and which will give it a good sound, no raspy ones. Thanks for the help!

BHR is the best out there if your looking for catless.

Thanks and oh I forgot to mention I have a 200-250 budget. Lol college student problems. And I know the Bhr runs over that

And yes I'm looking for catless

If that is your budget then don't buy one, you need to save up for the BHR. If you want to give it a try on the cheap you could measure your stock cat and see how long it is and find out how long the BHR resonator is and just weld that in. If you really can't spend more than 200-250 then don't expect to get one that will give you what you want.

That would work on my midpipe, I have checked the dimensions I just forget what they were. I have a agency power midpipe and I knew before I bought it that it was lower quality. It definitely has rasp and a resonance at around 4k rpms.

What about gutted OEM cat? They can be had for super cheap

Ah okay but then what you guys think about the racing beat midpipe? And I just need one for now because I use the 8 as my daily driver car.

shagg,

Your criteria is "no raspy" and "good sound". The BHR is the only one that meets this. Period. Even the Racing Beat dual resonated is raspy and drones. It's what happens when every other company uses piston resonators and/or piston exhaust packing. Completely different harmonics, energy flow, etc... They just aren't sufficient.


So, until you are willing to deal with raspy and drone OR bump up your budget, we can't give a recommendation because one doesn't exist. Keep in mind that if you pay $200-$250 now, you will still have to pay $500ish later to get the pipe you want. It would be better to just save up another couple hundred bucks and do it right in the first place. If your cat is shot, just gut it quick and deal with that until you have the money.

Alright seems decent to me then. Bhr it is. Just curious how much they go for used if they ever appear?

$200 is the lowest I've seen, $300-$400 is more common. They don't go for sale often though. Keep an eye on the classifieds.

Cool thank you all of you guys

i paid $370 a month ago for my used one. Again, the dont come up often and when they do they get scooped up quickly. The one I bought had been posted for maybe 2 hours when I made an offer for it and sent him payment.

Gratz :)

You won't be disappointed.

I agree, the BHR midpipe (I have it paired up with a Turbo XS cat-back) is truly the only way to go with midpipes.

I'd sell mine, but only when they release their headers and I am forced to get a new midpipe x_x Though, it seems like you got it, and good job, you will love it.

Good point on the midpipe availability once the header is finally released. Probably a noticeable increase of used pipes will become available, although I expect not a huge increase.

In my experience I had no drone with the RB rev8 exhaust, with a custom made midpipe very similar to the RP supercat. (OBX pipe utilizing a leftover 3" cataltytic conveter)

It wasn't until I installed an OBX header that It got some slight rasp.
Regardless I have very minimal drone if any.

The drone and the rasp comes from the midpipe... a catless midpipe. Any cat in any pipe will eliminate most drone and most rasp.

thanks it will soon be here but I will see how loud it will be paired with the hks hi power. hopefully the local police don't mind since its my summer dd

So keep looking around for a whole new exhaust set up so when I come back home from Afghanistan I already have a good idea what set up I want. I was thinking the RB Headers, BHR midpipe and the RB catback. I wanna get the BHR midpipe cause it seems alot of people are happy with that over the RB one. Also from the website is says that the RB midpipe causes the check engine like to stay on. Does that same issues happen with the BHR one?

Hey curly, my CEL comes on every few days with my BHR midpipe. I clear it with the Android Torque app.
Stay safe bro.:)

Any catless pipe can trigger the CEL, since you are catless.

The broader the generality the broader the fail ... some race cats flow as well as an open pipe, so obviously "any" is not the appropriate word choice

um, so you are saying that these race cats don't eliminate drone or rasp at all?

my comment had no bearing on flow volume, only aspects of noise

Posted From RX8Club.com Android App

So reguardless of the CEL and the fact that you clear it every so often, the BHR midpipe wont cause any other issues, right ?

OMG
If you're that worried don't do it.
Seriously give you're head a shake will yeah.

No issues. I really like the tone of it, especially at WOT.
I have stock exhaust, and to me it sounds good without being loud.
It does have a bit of a hissing sound. It's normal, from the design of the spiral baffle, but it's not bad.
Fit and quality are excellent.

Racing Beat

Catalytic Converter Replacement Pipe for 04-11 RX-8 - Racing Beat

Hard to beat that in terms of value, quality, weight, and sound. I've heard a car running this midpipe, a Racing Beat Header, and an HKS Hi-Power single and it wasn't nearly as raspy as you'd figure. Very nice aggressive sound. Yes it was loud, but in a good way.

Or, if you're baller and want to save even longer than it'd take you to get the BHR...

RE-Amemiya Sports Catalyzer SE3P

Well I'm no "baller" persay but as of right now I'm in Afghanistan and the money Im getting right now is pretty nice. Like I said earlier , I just want a nice free flowing exhaust that with acutally help my Rx8 since from im reading everything it does has to have a whole different type of R&D to actual show better performance since the engine is all rotary and stuff lol. So Im going with the RB header and RB revi catback exhaust but I heard the BHR midpipe is far superior. I wont be back in the states until march so im doing all my own research now so when I get back I have a good blueprint for my car

i have this setup without the headers and yeah its Loud but i dont mind hearing the flames popping out while wot

Hey my cat is going bad and i have been looking into Hi-flow cats (Specifically the rotary performance super cat) and multiple catless midpipes but every mechanic i talk to says not to go catless because ill loose the back pressure from the cat and then loose torque. In a bit of a bind here, thanks

Hi, I'm pretty sure that going catless improves performance.
Headers, midpipes & aftermarket exhausts are a very
popular mod, & guys here wouldn't do it if it hurt performance.
Plenty dyno their 8s, so there is ample evidence of HP gains. The back pressure issue has been used as a sales pitch for cats for years.
I have the BHR, no complaints.

Thanks man helps a lot

Common misconception for piston guys.

The short answer is: Rotaries don't need or use this mythical thing called 'backpressure'. The more open the exhaust the better (when it comes to power)

The longer answer:
"Backpressure" is mis-named. Basically, on piston engines scavenging is used to help pull exhaust gasses from the cylinders. The faster the exhaust velocity in the pipes the better the scavenging is. Now since we know that suddenly expanding gasses makes them cool down (ever use a can of compressed air? CO2 cartridge? It gets REALLY cold as it decompresses) and colder exhaust flows slower, we can see that for any given volume of exhaust gas, there is an optimal pipe size to keep the exhaust flowing fast and hot without creating a bottle neck. Get too big, the exhaust gasses cool down and slow down until there is enough flow (higher RPM) to be at the flow rate that is optimal for that pipe size. Get too small, and you are at the optimal flow rate at low RPM, but it just becomes a bottle neck at higher flow rates (higher RPM).


None of this matters for the rotary simply because we don't use scavenging. Open is better. You don't loose low end power, but gain high end.

"backpressure" if you take the term literally, only really applies to turbocharging, as the turbine will pool based ont he pressure differential between the exhaust manifold pre-turbine and the exhaust system post-turbine. The greater the differential, the faster it will spin up. This is how bolt-on exhaust nets easy gains for turbocharged cars, as it drops the pressure buildup post-turbine, increasing that pressure differential.

I'm about to order a bhr midpipe and thinking about getting one with the extra o2 bung just in case I would need it in the future. Does it anyone know if that comes with a bolt or something to plug the hole until it's needed?

Side note: I noticed reading thru this thread the issues with a CEL. Have y'all tried a spark plug non fouler?

Don't know about the 2nd bung plug. I inquired about if I needed the 2nd, and I believe it's only needed for wide band tuning mods.
Fouler has been discussed, some say it works, others say no. Idk.
A search would get you better results.

just wait Jonathon and buy the full header/midpipe combo :)

Posted From RX8Club.com Android App

Wide band as in air/fuel ratio gauge and Cobb ap?

I think I'm just gonna get the midpipe for now

Yes to the first, but I'm going from memory of a question I asked Charles at BHR. You can PM him and ask.
If you think you you may want to use it later, I think the 2nd bung can be plugged with a standard pipe plug from the hardware store, but I'm not sure.
I don't think mine came with a plug.

Awesome thx

Did it ever occur to you to ask them directly rather than asking everyone else instead?

signed,

Capt. Common Sense

Actually I did and hadn't heard back yet but thank you captain obvious

I sent it via Facebook since I don't get on here very often. I ordered it on Saturday and mentioned it in the notes on paypal. It's not a big deal I was just wondering.

Lol yeah I ordered the ignition with her card cause I was too lazy to get up and get mine. I appreciate it and can't wait to install the pipe. The ignition is awesome.

bhr midpipe cel codes
 

so if i get a bhr midpipe with a second o2 bung, i would still get a cel??

The 2nd O2 bung is just if you want a 3rd O2 sensor in your exhaust. In order to prevent a CEL, you need a cat or an ECU flash that blocks the CEL. Period.

would the cobb accessport be the only way of blocking that cel code, or are there other alternatives i could use, without sending my pcm/ecu somewhere

MazdaEdit is the other option

did they resolve the bricking issue yet?

Neither solution is noob friendly when you take into account who you would be buying an AP from...