Single Exhaust Anyone?
 

If anyone can answer this if they make a single exhaust for the 8, like an N/A exhaust, do they not because it not enough back pressure? or because it wont give enough power, im thinking of trying to get a custom one made with like an Apexi N1 muffler let me know what u think and if they make any out there?

Here is one.

http://www.racingbeat.com/resultset....rtnumber=16396

Getting mine on next monday, custom, at a local speed shop. Just a simple magnaflow (#14238, I think). Hope it isnt to loud. Same price as RB too, yet lighter.

Who's making your exhaust? I'll be interested to hear it.

Same place where we met on Dyno day. It should be done next monday night around 6 if you want to stop by. Otherwise we could just meet when you and I are avalible. I will take pics and write it up if it is nice. I installed my header, which is significantly louder. I crossing my fingers that I dont get crazy loud. That would suck...and cost more $.

Bad choice considering that there are dual muffler/tip catbacks out that are lighter than the RB single. RB mufflers are just kinda heavy.

I think a custom route would be much better, like carbonRX8 is doing.

Watch out for hand made exhausts. The insides specs of an exhaust specialized for rotary are very different than piston engines.
In greece we are waiting for single muffler exhaust around May, completely made of titanium. Light as hell and a copycat of jap tuner racing exhaust and the most important, a complete copy of the inside of the exhaust. Thus giving us guaranteed performance over dual muffler setups.

PS.: Trust Japan also has in its catalogues a single muffler exhaust for the RX8, not Greddy USA though. So check out jdm mags for this one.

i thought i was the only one thinking about this,its kinda worthless spending 600 bucks or more on a greddy if your only gonna get so much power and i also think a single apexi n1 slanted to the side would look nice and give as much power also if any one can post pics when they get theres please do i would love to see it

Apexi N1 single slanted to the side? Please don't do that :(

It is not like you could see it. Though, then why do it. Plus in my experience those sound like ass.

Maybe you want to explain in a little more detail what you mean here?

I am curous as to what that RB single sounds like and what it looks like installed. Does anybody have one yet?
________
Bubbler Pipe

well it doesnt have to be an apexi n1 pipe and ur right they do sound like ass , but i just wanted to be different instead of dual try a single but not the racing beat pipe i like the style though, maybe a dif. name brand maybe if u guys have any suggestion let me know

There is a guy in Georgia who did a single exhaust setup with the pipe coming out the rear rotary accent, kinda like a Porsche. I've seen it in person and he posted about it on here a while back. Custom setup.

is the racing beat single exhuast exit good in flow? because i see it maybe exiting on the rear right? if so -- is this the best exit i think maybe a left exit would be better flow wise but im no expert so what does everyone think?

I have one, but took it off.

The Racing Beat exits down behind the rear bumper. It is all 3" and flows like crazy.

custom, 9 lbs complete including the feeder pipe

https://www.rx8club.com/showpost.php...3&postcount=47

building a dual muffler street version

https://www.rx8club.com/showpost.php...4&postcount=24

Very nice. I am impressed. What are you using for the pipe just after the mid/cat but before the exhaust. It is the darker pipe to which you slip clamped the exhaust. Also, did the exhaust come mandrel bent to that odd angle or did you bend and weld it? What is that Burns Stainless clamp attached to? Doesnt look like it has a use. Oh, I bet you some how hung the muffler from that.

It is the factory feed pipe with the muffler cut off, it is very light, I'd guess maybe 18 or 20 Ga tube material with a stamped cat-back flange, which is also the way to keep weight out, but then it also mounts perfectly to the factory cat pipe. The clamp holds a single hanger that goes to the forward LH muffler mount using an OE rubber hanger. I'm welding the two pipes together so that will eliminate the one heavy clamp and the tip was cut to be shorter and welded directly to the muffler eliminating that clamp too. It had that stuff for adjustability since I had to approximate and guess a bit when I ordered the parts the first time through. It's all 2.5" which is more than adequate for a a stock NA engine with factory cat and straight through muffler.

On the street version I'l use two Burns mufflers turned out to the side and then tips out both bumper surrounds just like all the aftermarket stuff. I dropped down to 2" for the mufflers which again is more than adequate for the same situation as above since the flow is split in two, which also helps keep the noise in check. Probably use 4" doublewall polished tips, still haven't finalized those.

For my new race system I'm building a custom 3" midpipe with cat, and exhaust system. My cat was delivered the other day :) it's huge, 5" diameter. Most of the aftermarket midpipes just have the 2-5/8" header inlet on one side of the flange and the 3" tube directly welded on the other side with no transition, same for the exhaust connection, which is not the best for flow. My header flange will transition and I'm using a 3" gasketless ball socket flange connection at the rear midpipe end to have max flow all the way through yet still flex like the OE joint. I intend to have several Burns mufflers on it to abate the noise (probably 3) and just dump it with a turndown near the rear diff. I have an RE Amemiya header to feed it all.

Here's the cat, don't bother asking because I'm not telling except to say that it's rated for 1850 degF continuous and 2100 degF short term peak and can easily handle the flow of a turbo :angel: it costs $$$ but you get what you pay for

https://www.rx8club.com/attachment.p...id=68256&stc=1

there is a forum member.. i don't know how to spell his user name. but his name is gene. with a white 8 with a single exhaust, his user name is something like awwaaqwa or something random like that. should search for it. i would but im too lazi =)

I mean that the diafragms(i don't know the english word for the inside of an exhaust-like the cells of the high flow cat) are completely different than a common let's say sebring exhaust.
We have tried single exhausts that were hand made against dual mufflers made by greddy and we reported a loss rather than gains, except weight.

So in order to get this thing working, because if we take for example my trust ti dual muffler exhaust which has two (again i don't know the english word) thingies before the mufflers, u know two compared with the stock which has one big and two outputs-only JIC and Amemiya make the same setup like stock-and also same diameter pipes with the midpipe(which is bad for backpressure and gas flowing-even if it is a very small amount given that all the flow has already been repressed by the header-it is a loss nevertheless) and a common hand made single exhaust, i have gains not the single, and this is tested. Trust ti is good for up 400 hp but THERE is a loss compared to a full tuned single exhaust.

And a full tuned single exhaust that won't cost as hell (therefore handmade) means that one must take the courage to cut open a single exhaust especially for rotaries(fd, fc's won't matter) and see the insides and fully copycat them. Then i believe you will have a fully working system.

It goes to the right because in USA and Europe we have the steering to the left, so weight and balance wise the pipe should go to the right.
Japanese rx8's with single exhausts(and there are many-believe me) have the output to the left because they drive right.

HEY TeamRX-8.. yreading through your setup... very custom and sounds really interesting.. ...my guess is you want the most free flowing exhaust possible so wont the 3 mufflers and cat just restrict flow??


really interested in the setup.. :)

no, they will be 3" straight-thru style so there really is no restriction, have to run a cat per the rules.

The left/right thing is just preference, it won't make any difference one way or the other, or to not even bother and just dump it somewhere near the back

I disagree about bringing the header outlet down to the smaller outlet size. This is actually a common convergent merge technique, there's nothing wrong with the header outlet throat diameter. The problem is it needs to be followed by a divergent transition to maximize effectiveness and almost nobody is doing this, plus the way the factory gasket has the sleeve tube on the midpipe side doesn't allow it to mate well on the header side. The sleeve pipe should really be on the header side and slip into the midpipe for the best flow transition. I'm contemplating converting my RE Amemiya header to eliminate the factory flange & gasket. This would also allow me to put the primary O2 sensor into the common collector rather than in a single tube as they did it and have a smoother transition.

https://www.rx8club.com/attachment.p...id=68264&stc=1

hey teamrx8 did u feel a power difference with the single? or just more airflow

ditto. I've seen and heard it. It's sweet. Last time I saw him (forget his name/screename), he was selling his 8 though..

the problem with putting it out the center of the bumper cover rotary is that piece is integral to the whole rear bumper, not a separate piece, so once you cut it up that's it, no going back. Plus the exhaust puts out tremendous heat which will easily melt the bumper material, the exhaust system grows quite a bit and moves around when it's at max temp. You're better off either going out the factory exhaust exit points or just dumping it prior to the bumper cover as I, RB, and others have done. It seems like a neat thing to do, but in practice it doesn't really make sense.

Update on the custom single outlet exhaust I alluded to higher up in this thread:

Think Talladega, front row, right after turn three just at the begining of the long straight, and you forgot your ear protection. And I never got it up past 4k rpm. I was actually scared to go faster than 55mph. Thought that the secret service was going to bust me cause they thought a Mig 33 was on the way with the afterburners on! I startled myself going under overpasses (actually ducked.) The quality of the sound is great, but it is like an 8 engine, rotary powered 747 at take-off. The definition of too much of a good thing.

:dragster:

I have a B&B test pipe on now (with the obx header). going to try the two cats I have in the closet (one stock, one SR motorsports.)

I haven't laughed that hard in a long time!!!! thanks carbon

a lot of those oval turbo mufflers aren't going to cut it on a rotary, for starters most of them are designed to be noisy with a piston engine, which means they'll be louder still with a rotary, and then you better have stainless steel scrubble packing in there or the heat alone will fry any other type of sound batting, even at the very end of the exhaust system

We tested a prototype 3" single exhaust on my car and it picked up +10 ft.-lbs. of tq on a Greddy turboed car. Surprised at the results. Still have my JIC Twin Titanium on my car now though, as it was a prototype/custom unit made by "super secret" company, and I like the way the duals look.

DITTO THAT!

I went around the block with the RB single, and drove right back to the shop to remove it. With the RP Supercat midpipe it was way too loud. I have the single in the trunk for now with my old RB connecting pipe. When I went to install the RB Single, I thought it would be nice to get the newer connecting pipe on, but now I wish I'd just left the older RB connecting pipe there. Now I have my older connecting pipe and a brand new RB single exhaust.

I should have recorded the sound for you guys - it was freakin awesome at high RPM, but just not for the street. I might travel with it to the track days and install it on the paddock. It would surely get some attention as I drove by at 8,500 RPM:mdrmed:

So despite being rather ill, I could not help but go out and try to salvage my single outlet exhaust attempt. I put the stock cat back on (it has a large cat and a "glass-pack-like" silencer) and I have to say, the sound is quite reasonable. I dont sound like a 150 db race car anymore. To elaborate, I have the OBX header, stock cat, RB connector (will be replaced with stock soon) then a single magnaflow muffler 3'. I think I am quite pleased. Having to put the weight back on the car with the cat, should be MORE than offset by removing the weight at the rear.

Yes, any weight in front or behind the axles is bad.

You just need to put a good hi-flo cat and appropriate silencer in the midpipe, it will still probably be louder than the OE cat assy though

^^^^Agreed. Now to design.

So here’s the rub.

I have been running around with a catless midpipe. This is probably the only (yes, I said only. Flame me if you want but i dont care) aftermarket exhaust product that produces real, reproducible, feel-able hp gains on a na car. (Please read that twice before you respond) So now I go from RB's well made REV8 to an ok quality, but very small, single silencer to save mega weight in the rear. Problem is, I sound as if I have no silencer at all. So I replace the stock cat which has a large cat and a rather large silencer to get back down to a reasonable sound level (still rather loud. I can imagine some with less tolerance to aural peccadilloes would reject even this level of sound. There is some sympathetic buzzing going on with the plastic panels in the car.)

But now my car is slow!!! I can actually feel it. I would not say that it is slower than stock, just slower than with the midpipe. I can even tell that the car doesn’t rev as quick in neut. as it did with the mid pipe. Feels like I do right now; plugged up (I have a cold.)

On the plus side, the exhaust doesn't stink anymore. I was starting to get annoyed with that constant pig rich exhaust smell.

So what to do? I agree with Team in that I think the only way to go is get a true high-flow cat (all the common aftermarket cats have the same number of cells / unit measured as stock. I checked, Some here appear to have even bench tested the aftermarket cats and found that they did not flow as well as stock. Dynos proved the bench test.) and put this in line with a large straight through silencer (with steel scrubble as Team mentioned) just like the stock set-up. Hopefully this will get me back up to the level that I was getting with the mid pipe, yet allow me to dump weight in the rear.

Ironic ain’t it?

How about the B&B midpipe with a non-RB catback? Something that isn't extremely heavy?

For example, the weight quotes I've gotten from the rx8store catback are the SAME weight as the RB SINGLE. It is a fairly light dual catback, but not super light like titanium would be. I'd go something that route probably. Keep the midpipe, get a dual catback that is light but reasonably priced.

carbonRX8,

When I dynoed my SR Motorsports w/ silencer installed I picked up 4-5 hp across the rev range. Unfortunately I sold it, as it was popping with the Greddy turbo unit. Went back to the stock cat, which helped. But then I swapped out my FMU later & would/should have kept the SR unit. Definitely not as much as the 8-9 hp that the midpipes that were tested but it was also much quieter than the current RP hi-flow cat that I have (which seems to flow a bit better than the SR unit, but is louder).

Someone should have done a search:

This is an old post of my system: https://www.rx8club.com/showthread.p...single+exhaust

Here is a guy that used my setup: https://www.rx8club.com/showthread.p...single+exhaust *pics and video in this one

Single side exhaust...

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I have had a few inquires about my single exhaust so here is the info: Built it myself, borrowed a small portable wire feed welder, cut some bends and went to work. As you look at the pics be nice, I am not a great welder. It is possible that you could do this system with clamps if you do not have a welder, but you would most likely have some leaks as clamps never seal that good.

pics: http://www.cactus.org/~edj/rx8club/muffler/

I cut off the stock muffler about 6" down from the slip fit at the muffler. Then used the U bend to make a large curve, around 110', into the muffler the other end slips over the stock cat-back pipe. I have the muffler tilted up slightly as it goes from the center of the car out. Then cut the J bend at 90' to make your exit. Keep in mind you need to make the exit long enough that it clears the plastic area of the bumper. With the single exhaust there is A LOT of heat coming out of that one pipe and you can melt the plastic if you are not centered in the opening or you make it to short. For a tip I just cut the end of the pipe at about 30' and painted it black with high temp paint. For a hanger I used a piece of 5/16" round bar from Lowes. I bent a 90' on each end, making a squared off U shape, so that it would line up with the factory hangers on the passengers side then welded it to the top of my outlet pipe.
I do not have any HP/Tq info on this system. Due to the lack of credible dyno numbers, damn ECUs, I did not bother with dyno runs. I figured it was not important to worry about a few HP, as most after market systems make 2-3hp, I just look at it as saving 22lbs.
I do not have a DB reading. I can tell you at the San Diego Natl tour they were monitoring Dbs and I was no where near the 93db limit. There is another RX8 in SD with a single side system using the 12" long XR-1 and it has hit 93db once, may have been a fluke as it usually is under, and my car is significantly quieter. I know a few members were in SD and may have heard the system and could comment. Also while in AZ I had a couple of members ride in the car at an autoX and they might have sound/volume feedback as well.

All of my parts came from Summit Racing: All parts are 2 1/2" diameter.

Borla XR-1 16" long: PN# BOR-40942 $132.95
Summit U bend: PN# SUM-622003 $16.95
Summit J bend: PN# SUM-621008 $16.95

all that stuff is way too heavy though :p: but oh so much cheaper :uhh:

I would also personally want a single exhaust, they obviously flow better. Weigh less.

I would be really interested though in a single exhaust unit.

I just had a single exhaust made for me by 3R Racing that weighs a total of 12 # for the whole cat back. I had it dynoed before and after and gained 7 HP and 5 ftlbs and this is at over 5000ft, so results should be much better at lower altitudes. 3R used their extensive racing design experience in creating a very smooth transitioning (from 2.5 to 3") and flowing exhaust. They have been racing in the SCCA World Challenge with Porsches, Vettes and last year, Vipers and this is the type of exhaust they build for those. They were the 2004 GT champs and last year's runnerups, so they have been very successful. Also, the designer was the 2004 EP SCCA Nat'l champion-Chris Dorsey. (Call him for info) You can see and hear the exhaust at:
3rauto.com[/EMAIL]

It sounds deeper in real life than it does on the website, but you can get a good idea.

Not bad. My single is sitting in my basement waiting for track days this summer. :) It's way too loud for a daily driver.

Got any pics Hi Flying 8?

EDIT:
Nevermind, found it on the site http://3rauto.com/gallery_folder/rx8...8_exhaust.html

That is a small ass muffler/resonator you used! No wonder it's so light. I'm surprised it's not louder too.

I just love it when people throw around Solo2 champion names like that makes some kind of difference or something :cwm27: try to remember that 3 months after winning they are officially ex-champions :)

https://www.rx8club.com/rx-8-racing-25/sweet-sounding-new-exhaust-12-a-81562/

Ex-Champ or Champ, they still won and that fact gives them credibility. It also guarantees that they are talking the same language as other autoxers and can more likely get you what you need than some hack shop down the street.

yeah, right .... that's why it weighs 12# instead of 8 or 9# :stickpoke

If the only way you judge the quality of workmanship is by weight, then you would be right. However, this exhaust was engineered to give max flow with the smoothest possible transitions and to avoid the need to be replaced next year. This is the way I want it in order to avoid having to worry about future problems and expenses. I wouldn't disparage someone's work because of three pounds, without knowing a little more info before making that kind of judgement.