best way to 'hide' muffler....

[Johndoe]

the muffler shows quite a bit - -looks pretty cheap in a high end car...would spray painting a higher gloss silver do the trick - currently you end up seeing dark yellow welding blotches and a very ugly/ visible muffler under the quad pipes ....!

[M3aHOLIC84]

if it was a dark car liek black or jerez you could paint it the color of the car or simply black and get it done...but first of all sedan owners have to figure out how to hide those ugly rear lights of theirs...ugliest lights ever

[jtown]

Do NOT paint it the color of the car. Ever see those $5 mako paint jobs where they forget to cover up the exhaust when they spray the car? Good lord ... please do not bastardize the M that way.

Best way to hide it is to go aftermarket. Maybe a stock sounding and looking exhaust will come out

[M3Kevin]

1) Do not paint it. Fire hazard.
2) Do not paint it. It will discolor.
3) Do not paint it. It will shorten the life of the muffler due to increased heat.
4) Do not cover it - heat needs to be dissapated. Covers will prevent that and heat up other areas not shielded for the new heat load.

[WCH]

Wouldn't painting it black make it less visible? One would need to use a heat resistant paint...

[Revin9k]

powdercoat the mufflers black. or you can invest in a remus exhaust which has black mufflers.

[Remus]

Our exhaust is blacked out from the rear, you can't see it:
http://www.remusexhaustshop.com/images/M3-4jpg.jpg

[swamp2]

Our exhaust is blacked out from the rear, you can't see it:
http://www.remusexhaustshop.com/images/M3-4jpg.jpg

Looks good. I especially like the flat black solution to further hide and address certain visibility concerns. I am noticing that most aftermarket solutions for the E9X M3 are dual canisters, whereas stock is a single canister. My concerns about all of these dual canister configuraitons is the drastic change in the shape of things right in and around the rear diffuser and differentialm area. The design of the cars underbody, area around the differential and diffuser all seem to be key ingredients in providing proper cooling air for the differential. So here is the key question. Has Remus done any analysis or testing on the air flow or cooling to insure this large design change does not affect either differential cooling or other aerodynamic issues?

[FifthStreetz]

Either get new mufflers or a rear diffuser.

[m3forever]

Either get new mufflers or a rear diffuser.


+1

[MrHarris]

That Remus looks nice, any sound clips?

[gorun]

Remus does not center very well in this pic. Can this be adjusted?

[gorun]

if it was a dark car liek black or jerez you could paint it the color of the car or simply black and get it done...but first of all sedan owners have to figure out how to hide those ugly rear lights of theirs...ugliest lights ever

that is so true. hihi true jap style rear light cluster

[BCMPOWER]

^ I think that was a bad install, a company like remus is going to make sure its products fit correctly. They are manufacturers for some of the top tuners they have to get it right.

[BCMPOWER]

That Remus looks nice, any sound clips?

check out this thread http://www.m3post.com/forums/showthread.php?t=122438

[Remus]

Wow, I had never seen that install picture before, looks awful!
Our exhaust comes with adjustable hangers, that installation shop must have done something wrong.

Swamp2 :
I will contact REMUS Austria about this as it is a very technical question.

[jtown]

Wow, I had never seen that install picture before, looks awful!
Our exhaust comes with adjustable hangers, that installation shop must have done something wrong.

Swamp2 :
I will contact REMUS Austria about this as it is a very technical question.

Maybe they're on backwards. Haha. Hopefully the bumper isn't melted on that one.

[swamp2]

Maybe they're on backwards. Haha. Hopefully the bumper isn't melted on that one.

That will melt the diffuser FOR SURE. Tips get HOT especially when you are pushing it a bit. Terrible...

[lucid]

Has Remus done any analysis or testing on the air flow or cooling to insure this large design change does not affect either differential cooling or other aerodynamic issues?

I seriously doubt any of the aftermarket exhaust manufacturers are testing this thoroughly. They would have to instrument the car with flow and temp sensors and drive it at varying conditions for extended periods of time to collect data. Even if they were to do that, I doubt that they would know how to interpret the data. Say, they noticed a temp increase in the differential cooling fins. How would they go about interpreting if that is significant or not, and if it might result in some kind of damage to the differential in the long run (unless the delta is so high that the issue is blatantly obvious, which is unlikely just for an exhaust mod)? BMW engineers might be able to interpret the data for them, but why would they get involved? I think this is all trial and error engineering (well tinkering really), and that's the risk one takes when installing an aftermarket exhaust system.

On a similar note, I have much more of a concern about lowering the car. I wish BMW would somehow release info on what the flow and cooling implications of that might be. They have obviously studied that carefully before deciding on a ride height. The thing rides higher than a 335 coupe, so clearance and everyday drivability are not the reasons behind that decision.

[Johndoe]

...ie. only spray paint heat-resistant black paint behind the exhaust where muffle is currently visible......that should not lead to overheating ...or is it major NO NO.....

[Remus]

Swamp2:
According to REMUS Austria, the exhaust design allows for more cooling of the differential as tested in their R&D department. The tests results cannot be shown to the public. Furthermore, the canisters are packed with heat resistant insulation wool to prevent overheating the differential.

They did not test aerodynamics because REMUS does not have a wind tunnel.

[chasem3]

get a diffuser

[Epacy]

Swamp2:
According to REMUS Austria, the exhaust design allows for more cooling of the differential as tested in their R&D department. The tests results cannot be shown to the public. Furthermore, the canisters are packed with heat resistant insulation wool to prevent overheating the differential.

They did not test aerodynamics because REMUS does not have a wind tunnel.

How do they know if it allows for more cooling on the differential if they did no aero testing?
Sounds like the response was more of a theory than hard fact.
Perhaps you could get them to elaborate on just what kind of tests they did.

[Remus]

REMUS Austria has the technology to test heat emissions under load from the exhaust systems, here is an example :

Motorcycle example :
http://www.remus-japan.jp/technology/SImage11.jpg
http://www.remus-japan.jp/technology/SImage5.jpg

[Epacy]

Thanks. So that means they were able to take the heat signature from the differential before the removal of the stock exhaust system then again after the installtion of the Remus system?
I assume this is a stationary test and not under load?

[Remus]

This is both stationary and under load on the dyno. The sound chamber has roller type dynos.

They will not release the tests, however they confirmed to us the heat signature was cooler on the differential with the REMUS sport system than OEM.

[Epacy]

This is both stationary and under load on the dyno. The sound chamber has roller type dynos.

They will not release the tests, however they confirmed to us the heat signature was cooler on the differential with the REMUS sport system than OEM.

Very interesting and good to hear. Thanks for clearing that up. I retract my previous statement about theory. :thumbsup:

Did they provide reasoning why they won't release the data from the tests? I think that would be a very nice selling point.

[Remus]

REMUS is one of the if the the one and only company that has properly invested into R&D materials such as the industry first acoustic chamber, heat signature, etc. Releasing those tests to the public leaves REMUS wondering about what other companies could do with those tests, it's all about competition.

[lucid]

Very interesting and good to hear. Thanks for clearing that up. I retract my previous statement about theory. :thumbsup:


Well, actually, you shouldn't retract your statement. What's more relevant is heat transfer during different driving conditions with real flow under the car, not on a dyno. They are inferring that sticking the car on a dyno for a limited time and not seeing increased temperatures means everything will be fine. Not necessarily true. Try instrumenting the car and driving it hard on the track for a couple of hours and see what happens. Yes, one can argue that if temperatures for the aftermarket system are not higher than stock in a static scenario under load for a limited period of time, they are unlikely to be higher in a dynamic scenario since flow can only improve heat transfer, but that doesn't mean a whole lot as it's not that simple. The real question is around air flow for the stock vs. aftermarket exhaust during sustained demanding real-life driving situations and how that affects cooling. Based on what has been shared, Remus has not done anything to address that more relevant question. Having said all this, I really don't think replacing the original muffler with something like what Remus developed will cause any problems because of the geometry. But that's just an opinion, and I wouldn't bet on it. I'd be more concerned with products that have different designs.

Also, this is only about cooling issues. The stock system might indeed result in better air flow (not exhaust flow) from a purely aerodynamics perspective.

[Remus]

We agree with what you said. We cannot test air flow precisely and thus cannot make any statement regarding it, we can only speculate based on our heat emission tests, something that is still unique to REMUS as of yet.

[lucid]

We agree with what you said. We cannot test air flow precisely and thus cannot make any statement regarding it, we can only speculate based on our heat emission tests, something that is still unique to REMUS as of yet.

I am not trying to shoot down your product by the way. I appreciate you taking the time to address these questions. I am considering installing an aftermarket exhaust system on my car, mainly for the sound. I would like to hear how your product sounds in person. Thanks.

[Johndoe]

Am I the only one that notices that your car is not an M3? Sorry...

??? first that is not MY car and secondly, hold your breath, late breaking news: M3 is now being offered in a Sedan version as well.....

[Blip Bavarian]

You can paint it with BBQ grill paint. It sounds ghetto i know. But it leaves a nice matte black finish and is very heat resistant.

If you remove the exhaust, and tape well, it can be a very good and cheap option.

:dance:

[gadget]

You can paint it with BBQ grill paint. It sounds ghetto i know. But it leaves a nice matte black finish and is very heat resistant.

If you remove the exhaust, and tape well, it can be a very good and cheap option.

:dance:


What about heat dissipation issues etc. I agree that in theory this a great cheap fix that doesnt create other issues such a the differential temp as discussed above.

Anyone have technical data to demonstrate this is a bad idea? If not does anyone want to volunteer to do this for thier car:drink:

[GewoW]

I would readily expect there to be a problem at high speeds for the exhaust. The ends of each muffler are so sharp, that I would expect heavy wind deflection and pushing of the muffler up and out at higher speeds. Notice all exhaust choices have rounded mufflers.

I do believe a wind-tunnel check would be best, or else it may seriously cause some problems to people at high speeds. That little edge may make all the difference.

P.S. I am assuming that the edge is sharp towards the middle of the car as it is on the outside. If not, then disregard the post.

[rvacha]

What about heat dissipation issues etc. I agree that in theory this a great cheap fix that doesnt create other issues such a the differential temp as discussed above.

Anyone have technical data to demonstrate this is a bad idea? If not does anyone want to volunteer to do this for thier car:drink:

I have no technical data, but I sorta doubt its an issue. My plan is to paint ONLY the portion you see from the back. There is no need to paint the entire thing. So basicaly I will paint the trailing edge. I will not be painting the top, bottom, front, or sides

[WCH]

I have no technical data, but I sorta doubt its an issue. My plan is to paint ONLY the portion you see from the back. There is no need to paint the entire thing. So basicaly I will paint the trailing edge. I will not be painting the top, bottom, front, or sides

I was thinking about this as well. If you do it, please post pics.

[Sick Speed]

I have a 2004 E46 M3 with the DINAN exhaust and muffler and it WAS as visible as the new M3 muffler.

Solution: grill (as in what you BBQ on) paint which is specifically designed for heat and it will make it invisible. Yes...invisible. I never notice my muffler now. From the rear now all you see are the quad pipes. It has been painted this way now for 4 years with over 60K miles and zero issues ever.

Lift the car...tape off overspray areas and paint. You can pick up a can at any Home Depot. I used flat black and like I said...it is literally invisible. Remember if light cannot reflect off of it you can't see it.

[GewoW]

^^^I still wouldn't do that.

[MDCTFTW]

I have a 2004 E46 M3 with the DINAN exhaust and muffler and it WAS as visible as the new M3 muffler.

Solution: grill (as in what you BBQ on) paint which is specifically designed for heat and it will make it invisible. Yes...invisible. I never notice my muffler now. From the rear now all you see are the quad pipes. It has been painted this way now for 4 years with over 60K miles and zero issues ever.

Lift the car...tape off overspray areas and paint. You can pick up a can at any Home Depot. I used flat black and like I said...it is literally invisible. Remember if light cannot reflect off of it you can't see it.

Pics?

[swamp2]

Great thread guys. I posted a decent question/concern and lost track of all the good responses. To the Remus guy: There are a lot of engineers and scientists folks here on this forum, you should not try to BS us! Although a wind tunnel would be the ideal configuration for testing, you could do almost as well on a track with some thermocouples and a simple data acquisition system. Really a few hundred dollars! Tell the boys in Austria to invest and "step it up". It does sound like Remus is more of a real engineering based company as opposed to most exhaust companies that are as lucid described "tinker-ers". However, when the exhaust, diff. and diffuser are all so intimately intertwined care must be given to thermal issues. Most designs simply do not have these components so intertwined

Last but not least on the steel wool issue: You can't fool us in to believing that this material in your (or any )muffler product is to keep the unit from heating nearby components. -1 on that, a big -1.

[Blip Bavarian]

Holding my breath. Seeing as my company is located in Ismaning, I get to see all the duck tape and plastic bag cars nipping about. (drop in with Google Earth to the interesting looking track next door) I can spot a new model simply because it has non-standard lines, and I love to see it when they graduate to the models with only the BMW circle covered.

I have only a handfull of posts, but check the location of your comment target.

Whatever the hell that thing is it is in the USA not sporting Munich tags.

Likely it is a poser who Frankensteined some sporty pipes onto his 3. The cheaper version are the folks that stick M3 onto their cars. Fools girls I suppose. Go speed racer go.

:thumbdown

[Johndoe]

I have a 2004 E46 M3 with the DINAN exhaust and muffler and it WAS as visible as the new M3 muffler.

Solution: grill (as in what you BBQ on) paint which is specifically designed for heat and it will make it invisible. Yes...invisible. I never notice my muffler now. From the rear now all you see are the quad pipes. It has been painted this way now for 4 years with over 60K miles and zero issues ever.

Lift the car...tape off overspray areas and paint. You can pick up a can at any Home Depot. I used flat black and like I said...it is literally invisible. Remember if light cannot reflect off of it you can't see it.

can you provide more info/ pics on this....also did you paint the whole muffler or just the front part that is visible

[gadget]

can you provide more info/ pics on this....also did you paint the whole muffler or just the front part that is visible


Regarding post using Grill / BBQ paint.

I know this is not ideal, bit i think it is a good cheap fix. I, like John Doe above, would like some additional data on this subject. Who else has done this. etc.....

[Johndoe]

it is VHT- heat resistant exhaust spray paint- has a black matte finish and is used for painting exhausts/ manifolds - -a lot of people have used them on mufflers with no long term impact based on discussion in other car forums....definitely better than BBQ paint and should hide the ugly muffler....you can Google / or should be able to get a can at your local auto parts store...

Exhaust Manifold, Catalytic Converter and Headers


VHT Flameproof Coatings are a matte finish, ceramic base silicone designed specifically for automotive headers and exhaust systems. They allow heat and moisture to pass through the metal and coating to prevent rust from forming. No primer is required before applying. Rated to 1500ºF (815ºC).
Recommended products:
VHT Flameproof Coating Range

[gadget]

I think I might give VHT- heat resistant exhaust spray a try. Anyone with their M3 planning on doing this?

[yahtzee]

lets see some pics....

[gadget]

Does anyone know the temp of the exhaust that would be painted- how hot does it get. I assume 1500 is more than enough. My only concern is that this car when pushed hard for a while will probably generate a lot more heat than your average civic driver...

[badfish]

I hid my exhaust by switching to a Remus. I run a diffuser which I had to remove to take these pictures. The Remus exhaust will clear the diffuser no problem and the angled tips blend perfectly. However, the diffuser doesn't quite cover the OEM exhaust all up. I can show pictures with the diffuser after Bimmerfest. But switching to the Remus exhaust gave me better sound and hidden mufflers. Regarding the centering of the exhaust, I recommend you have it professionally installed. Any competent exhaust shop should know how to manipulate the hangers and tabs. Mine is on center, angles in pictures might suggest otherwise, but it's centered, trust me.

http://farm3.static.flickr.com/2038/2434880373_9e0550226b.jpg?v=0
http://farm3.static.flickr.com/2034/2435700138_22420dcc00.jpg?v=0

[Johndoe]

I think I might give VHT- heat resistant exhaust spray a try. Anyone with their M3 planning on doing this?

I'm going to try it based on all the info and the fact that the spray is meant for mufflers (which i believe go up to 500F but one can check that easily by googling). I did call VHT customer service as well (... if you do not like the flat black look, simply remove with a paint stripping agent). I went to check out a M3 sedan over the weekend again at the dealer and the muffler is too visible a eyesore from various angles.....

I do not have any pics but again a Google search may help - -Worst case I spray it on, don't like it and remove it but FLAT BLACK is far better than the raw metal crap currently showing underneath the rear bumper AND you get to keep the original muffler.

[WCH]

Please post pics if you do this. I'm interested in doing the same.

[Too Many Toys]

I was thinking blue painter's tape? ;)

I'll have to ask the BlueTape Man what its temp. rating is.

[bills742]

I was thinking blue painter's tape? ;)

I'll have to ask the BlueTape Man what its temp. rating is.

With the painter's tape alone, it won't cut it. But with black duct tape overlayed on the painter's tape :thumbsup:

[gadget]

:bump::bump:Please post pics if you do this. I'm interested in doing the same.

I know someone posted pics of an IB with a painted muffler, can anyone find it. Did a search but came empty handed.

[ersin]

Just get an asbestos jock strap for it. Oh wait, asbestos is bad. Try titanium; they make them for pro football players. But they usually have a run on them this time of year. On second thought, the blue and black tape is probably the best solution.

Of course, if you're willing to pay, the only real solutions are either a diffuser or new mufflers. I'd go for the AA system. :)