Bates Prototype Valvetronic Exhaust - Custom OEM Exhaust with Valves

[Singletrack]

Sounds awesome.

[Subw00er]

Originally Posted by swamp2

I'm a bit confused about how you qualitatively compare the sounds to both a Vette and to a CGT/European exotic. IMO these characteristics couldn't be more different.

This is the really interesting part of this exhaust and I was astonished when I realized this for the first time. When you are in the car and driving along, the exhaust has sort of a hollow, wallowing, technical-sounding tone. Go to the last in-car footage video I posted above and listen closely for a few seconds right at one minute (1:00:00) - this is the only place in all of my recording that I was able to capture a hint of what the car sounds like inside. Its very strange, but for whatever reason, the mic doesn't pick up the tone well. You can hear overtones of the sound in other parts of the video, but its most clear at 1:00. It sounds a bit like a Carrera GT might sound if it was a V8 (to use the words of my friend). It has none of the super raspiness and gargantuan rumble that occurs when you're outside the car and listening. Everyone I've shown the car to agrees that the difference in sound inside and out of the car is big. The really great part is that both sounds are really, really fun to hear and play with. Its sort of like having two exhausts. Ok, well 3, if you count the valves in stock mode

Originally Posted by swamp2

I think the valves turned out to be way to visible/visibly obtrusive in this design. It sounds good for you though as you like the look. This is one area where the other bypass project posted here in the forum has yours beat - looks. Of course that is all completely subjective.

Its funny I thought that might bother me a bit in the beginning when we started, but the concept and design led to this exact position. But now that they are on the car, they are not really that visible. I took pictures at low angles with good lighting so people could see, but its not like when you look at the car, you see then right away. If you're next to the car, you have to get on your knee to see them. You know, the other part is that I think its pretty cool to open or close them and be able to see them working. Its a pretty good "wow" factor. It probably confuses the hell out of people at stoplights if they notice them moving. I'm sure others will disagree, but for me, I think being able to see the valves is a plus, and I actually love the look. BTW, its also sort of nice to know that when opening them partially, I can visibly check just how far open they are. This would be hard to do if they were hidden elsewhere, and to be honest, I don't know how I feel about all that heat and exhaust gas dumping in the middle of the car. Anyway, I guess the reality as far as looks are concerned is that 95% of people wont notice them (or if they do see them, just think its part of the normal exhaust), and those who do are probably car enthusiasts and may figure out there's something cool going on under there.

Originally Posted by elp_jc

I have to say the system sounds incredible with the valves closed; didn't know a stock M3 sounds that nice, or does your car sound different than stock??? Wish you had done one flyby with the valves closed. You should also have put 'Bates Exhaust' on your plate, no?

My car is mechanically stock except for air scoops behind the grill.

I just realized I did have a pass with them closed. Well, I cant be sure that they are fully closed because I personally didn't shut them and the car does still sound a little aftermarket to me in the video. Either way, I know they were mostly closed because most or all of the raspiness is gone. Enjoy!

http://www.youtube-nocookie.com/v/MG...l=en&fs=1&hd=1

Originally Posted by askiles

It would be cool to do some sort of vacuum actuated system like the C6 Corvette has, where the calves open more at higher RPM's when more vacuum is introduced.

I could build a RPM-activated switch. We would need to maybe find a shift light that would do the RPM conversion for us, then build a logic board so that it makes sense. I think I wouldn't bother though until I saw the Dyno graph though. If its not loosing power below 3K RPMs then there is no need for an active valve. I have a feeling its not loosing anything, but of course, its really hard to tell.

Originally Posted by askiles

If you were to do this work for people @ $2k a pop if they provide their exhaust, I am sure people will be jumping on it. It really does put the few other valved exhaust to shame!

I think we could do it for near $2K if people supplied the shipping, OEM exhaust and valves (I guess it would just make sense for people to buy and put the valves on themselves - then there is no warranty issue with RRP. But if someone wanted us to do the valve flip and install them, they could just buy the valves and ship them to us instead). If we get a few orders together, maybe RRP would even do a little discount there.

Sam and I chatted a little about making these for people and we have some idea of how this might work. I feel that it is a shame to go through all of this R&D and not share it with others. Several people have PM'ed me already throughout this process about making one for them, and now that we know it works and works well, we ARE considering doing this.

It would be useful for us to get a count of people that are SERIOUSLY interested, and would leave a deposit so we can order the initial parts and get that stage going. We think it might work something like this for a small batch:

1. Get a list of people sorted and to leave a deposit so we can order the initial parts (J Bends, flanges, sanding disks, stainless welding rod, etc) and get that stage going.
2. People send us either their exhaust, one from a junkyard, or one from the forum that is for sale (seems like there are a few out there, especially if you don't mind a "cut" one). If people order these, they can ship directly to us. You can of course go to BMW and order a new exhaust, but I just looked it up and its $1600.
3. In the meantime, we fab up the connecting pipes, flanges and generally get organized.
4. Once we have them all, we would then work in an assembly line on several a time. This should save some work/effort.
5. As they're done, we can ship them out to people, or if local to NY, we can meet/pickup.

Also, I could build the headlight switches for people. I think there is a group buy on the newer '09 version going on now for the fog light mod guys, so old ones can be had, or just get a new one. You can of course just take yours off and send it. BTW, you could always use the switch that comes with the valves, or buy their wireless module and just use the keyfob. The headlight switch mod for the valves is really slick though. I love that part, the button even feels nice and squishy; very tactile.

We are guesstimating that we can turn them around in 2-3 weeks. 90% of the work is in Sam's hands so we'd have to work around his busy schedule.

So, there you have it. Let me know via PM the interest level. Thanks for the compliments!

[tightie]

wow.. now that sounded really good..

good job on the project.

[BK]

+1 Sounds great! Thanks for shooting so much video. This was a fun thread to follow.

[Subw00er]

A few people PM'ed me about cost. It would look something like this:
-Welding work $2200
-2 RRP exhaust valves $480 (If you want the wireless module, its $100. If you want me to mod your headlight switch like mine, add $50)
-1 OEM rear muffler (its all just one piece) $150ish seems to be the going rate for a used one, or if you have something else to drive for a couple weeks, just send us yours. We could also obviously mod one thats been cut for a aftermarket exhaust- I'm sure there are a lot of those lying around inexpensively.
-Return shipping (Varies but at least $90 I'd guess). Pickup is also ok.

[335ICoupe]

Great job

[swamp2]

Seems like a very generous price given the work required. I hope you find a couple takers!

[J08M3]

Originally Posted by swamp2

Seems like a very generous price given the work required. I hope you find a couple takers!

+1 and considering the price of it's only competitor.... I think you have some room to raise your price slightly so you actually make a bit of money and still have a great system out for less than the alternative, and with less wait time.

[lucid]

Congrats Subw00er! And, great job with the videos. It does sound great indeed as far as I can tell.

[Subw00er]

Thanks guys. Yes I think that is the least amount we'd want to make them for. Its a solid 5-6 days of Sam's time, then I have to get orders together, coordinate everything, order parts, pack and ship them out, etc. Its a lot of work. I just don't see how you could make these for less, even if you were to tool up somehow. Remember that Sam can make a piece of art in a week and sell it for 5x this amount. The obvious benefit here is that he can make several at a time and have guaranteed buyers at the end. He is also engaged in the project and likes how so many people are interested in it. He was pretty surprised how many people were into the idea when I showed him this thread.

So, as far as I know there are two competitor exhausts, the KKS and Kreissieg. I think the KKS is around $4K and the Kreissieg, 6K?! Last time I checked, both were about a 2 month wait.

I'd like to get into a little history here for those that don't know. I never went into this project thinking that it would be a new sales opportunity. Initially, I was just a guy with a new M3 looking to buy an exhaust. I felt that although the intake noise was to die for, I could barely hear the exhaust and after coming out of a rambunctious C5Z06, I really missed the sound. The M3, for me, was missing something - too refined, too "old man." I previously got hooked on the concept of valve-based exhaust after almost buying a 911s with a factory valve exhaust system installed. What a great concept - to be able to have a nice quiet car for phone calls or long trips, but then when you want to have some fun and be a little obnoxious, you can just hit a button and all hell breaks loose!

When I started to look at the only two options for the M3, I got serious sticker shock and decided to investigate other solutions. I found JML's thread where he paralleled the cutouts to a "ferrari sound" and that peaked my interest http://www.m3post.com/forums/showthr...=valve+exhaust. But I researched further, and found that all of the cutout-based exhausts drone (all of these were pre-muffler), and this was unacceptable to me, I didn't want any compromises like that.

So I started looking at what causes drone, and why stock exhausts don't drone, and read up on the Helmholtz chamber inside - a very interesting concept. I talked to several engineer friends and researched for many weeks online. I drew up some plans (see page 1), and obtained a sacrificial exhaust to play with off of this forum (Thanks Boosted!). Three months later, I have what I think is the best sounding exhausts I've ever heard. I dont mean to be cocky, but you just have to hear this thing in person to understand, and anyone in the NY area is welcome to stop by for a listen. I put a lot of effort into the recordings so I could share, but I just cant capture the right sounds. I may just take some straight WAV or high quality MP3 recordings to bypass the possibility that its my camera thats ruining the sound.

Ok, so there you have it. Thanks for following my little project here and all the positive comments. Its wicked fun to come in each day and see what people write.

[jml]

BMW should have done something like this from the factory. The sounds is pretty intoxicating. EVERYONE who has heard the simple pre-muffler cut-out system raves about it - and I'm talking even AI series racers at NASA (muscle car road racers).

Whomever can productize and sell something like this will win the M3 muffler wars. I'd be surprised if anyone can design an exhaust as quiet as the stock unit with the same flow rate - so I'm interested to see how this goes.

Subw00er - it would be interesting to add a completely removed muffler scenario to your sound clips to demonstrate the reduction in drone.

[STIto335]

where are you located? you can pm me if you don't wanna say it on here

[Subw00er]

JML, I agree, something like this should be on every sports car. What do you mean by removed muffler? Drive around with no muffler!? I wouldnt want to do that. I did take some stationary video of the muffler off. Unfortunately, I had bass reduction on:
http://www.youtube.com/v/VAqfW5k6XcY&hl=en&fs=1

So far, a few people have been interested, but think its too expensive?! I think people are monetarily comparing it to a standard exhaust but what you have to realize is that ya, this might cost a little less than twice that of the cheapest exhaust out there (Remus), but you get twice the muffler, and with no drone or other compromises. This is definitely a niche exhaust though, not everyone is as fascinated by the valves as me. I just loved the concept as soon as I heard it in the 911s.

BTW, after driving around with the exhaust for a week now, I can verify that there is no drone or other issues. Previously I mentioned that I thought there might be the slightest bit at 3K RPMs, but its not drone, there is just a very slight increase in volume, and by very slight, I mean VERY slight; maybe 5%. I think most wouldn't even notice what I'm referring to.

Oh, and my new favorite thing to do.. drive next to buildings, guardrails or pace next to cars. The reflection off of the sides of surfaces is... OMG. I think this is a somewhat unique feature of having the exit pipes to the side, and perhaps this is what causes that intoxicating sound I'm trying to capture. My hypothesis is that normally, with a rear exiting exhaust, even if it had that sound, you wouldn't hear it because of the sound wave projection going only rearward and the car would physically block all instances of the noise. But since mine is tilted slightly sideways and down, I think this is what makes the exhaust sound so unique in the car.

Just thought I'd throw that out there, someone may find it interesting.

[URBAN LEGEND]

Great work.

[Moxie]

I was flying down the auto bahn today & swear I saw valve on guy's exhaust only in the tailpipe - didn't think much of it until I read this thread -

Obviously for me to see them, the valves were behind the muffler, not like cut outs between the headers & muffler -

[Subw00er]

There are two brands of exhaust that have valves, and they both are at the rear, the KKS and Kresissig (probably spelled that wrong). It was likely one of those.

[jerseykid]

Great work!!

I haven't considered an exhaust because none of them truly offer the exotic sound I was always looking for. I've tried to convince myself on some but never could. The stock exhaust has a sound I LOVE but I always wanted a little more. Let me tell you, this is it! You have succeed with exactly that intention with precisely the high pitch note I love. Incredible!

Dam this sounds gooooood! Hands down the best, no doubt about it.

[Subw00er]

If you want to come hear it, let me know. I see you are semi-local.

I'd like others to hear it in person so they can see, and I can get feedback. The videos, although I spent a lot of time trying to get it right, do not do it justice.

[Ca$hOnly]

I love the way it sounds, but I hate the way it looks. If there was a more elegant way to do this I'd be all over it.

[Subw00er]

Maybe there could be flat CF sheets in behind them to block the view? You can buy these at McMaster-Carr. BTw, they really arent that noticeable in person.. The sort of disappear under the car because they match the exhaust color, but I think most enthusiasts would notice them... but then again, what a great conversation piece.

[Periokid]

I have been watching this thread from the beginning and I am still impressed. I was wondering about a few exhaust options for myself. Do think the sound of your exhaust would be acceptable full time in the open position? The reason I ask is I wonder what it would be like if as an alternate the pipes in the absorption chambers were either wrapped with exhaust wrap or replaced with non-perforated piping. Do you think this would yield the same sound you have achieved now, with out the ability to turn it on and off of course.

Basically I want sound and no drone. I wouldn't mind having sound full time, as long as it is not irritating (which usually comes from drone). Thanks.

BTW, once is a blue moon I go upstate to visit friends, maybe I should pay you a visit!

[Subw00er]

Yunno, thats not a bad way to make the stock exhaust not only louder, but quieter. You could open the center section, cover the holes, and remove the packing material. I bet it would be much louder, although I doubt it would be as loud as mine - it still has to go through a couple bends and the tips. Give it a try!

You're definitely welcome to stop by for a listen. PM me for my #.