Eisenmann Exhaust - Installing Valves & Control Module

[polar993]

I purchased an Eisenmann Race rear muffler system for my 2017 Alpina B6 GC. The Eisenmann Race doesn't come with valves, and Eisenmann wasn't willing to custom fabricate a system with valves for me, so I decided to purchase a set of stainless steel valves myself, along with a control module.

I plan to have the valves welded onto the inner tips of the mufflers. See the photo below.

My question for the forum is....Can I reuse the existing vacuum line that currently goes to the driver's side muffler (only one side on my car is valved), and put a "T" connector off of that line and connect it to both new mufflers once the valves have been welded in place? Will the existing vacuum system be able to control these after market valves? I believe the valves are controlled by the Sport Button in the cabin.

If that doesn't work, I guess I can use the control system that came with my valves. Does anyone here have any experience doing this? The valves and controller didn't come with any instructions, and I'm not entirely sure how to do this. I expect that a regular muffler shop won't know how to do this either....at least based on the ones I've spoken with in my area.

Any help would be greatly appreciated!

[Havy]

First of all you have to know how the muffler works. If the line in question is the one you can use a valve than it could work. If not it is useless to install a valve. See pic of a muffler with valve. The side with the valve is a sort of straight pipe if valve is open. If valve is closed the sound goes through the muffler.

[polar993]

Havy,

You make a good point, and this is something I discussed with Eisenmann directly. They told me that the race muffler that I am buying isn’t designed specifically for use with a valves, but placing a valve on the inner tip of each muffler will help to reduce some of the sound output. It may not reduce as much sound as a muffler that is specifically designed for the use of valves, but if it reduces some of the noise, especially during cold starts, I’ll be happy.

[Havy]

Concerning the vacuum I would measure the vacuum which comes out and than measure the vacuum which is needed to operate the valve. Maybe you have to use a softer spring in the valves. If that doesn’t work go with the electric one. I doubt that you are able reduce much of the sound particular at cold start as the idle is higher to warm up the cats.

[polar993]

How can I measure the vacuum? Are you referring to the vacuum pressure? Not sure how I could measur that.

The spring in the new valve is rather stiff. It’s even difficult to move the valve by hand! Seems like it would require a lot of vacuum pressure to actuate. I suppose I could just try the original vacuum line to see if it moves the new valve. If that doesn’t work, then I would proceed to use the vacuum kit that came with the valve.

You have me concerned that since the Eisenmann Race wasn’t designed to work with a valve, that installing the valve may not so much of anything to reduce sound. Hmmmm....

[Havy]

Yes I am talking about the vacuum pressure. There are specific vacuum gauges available but to connect the new valve to the cvacuum line is probably faster and you know directly if the vacuum is enough.
I think the main purpose of a race muffler is not to reduce the sound.

[polar993]

I’m buying the Race version of the Eisenmann because I want it to be loud, but I also would like to have the ability to tone it down a bit as well.

I have an Eisenmann Race on my E60 M5, and it sounds amazing. It’s super loud, especially on a cold start, but since my M5 isn’t my daily driver, it’s fine to be loud all the time.

Here’s a short video of my M5 with the Eisenmann Race.

[Havy]

Holy cow that is the V10. Yeah Eisenman sounds amazing. By the way I am still on the Akra although you have already an Eisenman. I am not giving up.

[polar993]

Havy, you’re the best! Glad you like the sound of the mighty V10! It’s intoxicating!

Really appreciate all the legwork you’ve done in trying source the Akrapovic exhaust for me. Seemed like a low probability and a costly one too, that’s what led me to the Eisenmann Race.

The Eisenmann is scheduled to arrive this week. You’ve got me wondering if I should bother installing those valves. Knowing that the Eisenmann Race wasn’t specifically designed for a valve system, do you think the valves will make a noticeable difference in reducing the sound of the exhaust?

[Havy]

It is hard to say if the valve will give you a noticable sound decrease. If I just follow the concept of my pic. Both pipes running more or less straight through the muffler. If you close one line all the exhaust gases running through the other one which is also more or less a straight pipe. Therefor no noise reduction. I would install it like it is and at the test run you just cover one side with your Hand. If you notice a different than you can install the valve, if not, just skip that shi....t.

Specially at the cold start all valves are open anyway. After 30sec. the vales are closing and than it is too late anyway as all neighbours are awake.

[kong24680]

I'm running a full eisenmann race with catless downpipes on my m6 right now and the sound is pretty manageable. Cold starts are insanely loud though... If your running stock cats, I think you'll be ok without the valves. If you have catless, I would get the valves or have your cold start coded out.

[polar993]

Originally Posted by Havy

It is hard to say if the valve will give you a noticable sound decrease. If I just follow the concept of my pic. Both pipes running more or less straight through the muffler. If you close one line all the exhaust gases running through the other one which is also more or less a straight pipe. Therefor no noise reduction. I would install it like it is and at the test run you just cover one side with your Hand. If you notice a different than you can install the valve, if not, just skip that shi....t.

Specially at the cold start all valves are open anyway. After 30sec. the vales are closing and than it is too late anyway as all neighbours are awake.

Thanks for the advice Havy....I may just install the exhaust without the valves and see how I like it. Can always retrofit if necessary.

[polar993]

Originally Posted by kong24680

I'm running a full eisenmann race with catless downpipes on my m6 right now and the sound is pretty manageable. Cold starts are insanely loud though... If your running stock cats, I think you'll be ok without the valves. If you have catless, I would get the valves or have your cold start coded out.

Kong, thanks so much for your feedback. catless DPs with the Eisenmann Race must sound insane (in a good way!). Probably way too loud for my everyday use, but would love to hear your setup.

Do you have any videos you can post or PM to me? Gotta hear that setup!!!

As I just posted....I've decided to install the E-Race without the valves for now. I'll see how it goes. I'll cover/stuff the inner pipe as a test and see if it makes a noticeable difference. If it doesn't, I'll know the valves are useless for my setup.

Thanks again guys! Kong, let's hear your beast!

[Havy]

Waiting for your sound file.

[polar993]

Me too Kong!

[Flying Ace]

Originally Posted by polar993

Kong, thanks so much for your feedback. catless DPs with the Eisenmann Race must sound insane (in a good way!). Probably way too loud for my everyday use, but would love to hear your setup.

Do you have any videos you can post or PM to me? Gotta hear that setup!!!

As I just posted....I've decided to install the E-Race without the valves for now. I'll see how it goes. I'll cover/stuff the inner pipe as a test and see if it makes a noticeable difference. If it doesn't, I'll know the valves are useless for my setup.

Thanks again guys! Kong, let's hear your beast!

If you don't think you can live with that level of noise 100% of the time, I would advise against getting straight pipes with the E-Race. Put it this way....I was driving with Kong one day. I have a full Akra system with stock downpipes/cats, and I could hear Kong's car BEHIND me.

IMO, a video of the noise just won't fully capture the db level. It's like watching a racing event on TV. The audio filters the db level to allow it to playback clearly. Plus you're limited by your audio system's output when you play back a sound, otherwise you'll blow your speakers. If you've ever been to an Indy or IMSA race, you'll know the level of noise isn't even remotely the same as what's on TV as those cars will literally shake the bones in your body. I'm talking extremes here comparing a E-race with an actual race car, but I thought about this when I watched the replay of the 12-hours of Sebring over the weekend. I was thinking how the audio production captured the deep rumble of the C7R's V8 perfectly (but filtered out the decibels), but in person, it felt like the 4th dimension of hell just opened up on front of you. The audio also filters out the high frequency pitch of the 911RSR and the Ferrari's high revving motor.

Also if you're an IMSA fan, I personally think the most annoying racecar sound is that of the old AM Vantage V12 GT car from a few years ago. That thing was so high pitched in person I almost threw up...