Exhaust Flap Module - Help Needed!

[richc63s]

Hey Guys,

I'm looking at buying either a RennTech or ASR module for my 2020 C63S Coupe (One of the plug and play modules which keeps the exhaust valves open all the time, normally they only open past a certain RPM, even with exhaust 'on') Just had a couple of concerns which I'm wondering if someone might know about:

- Is there a reason that the valves only open past a certain speed/rpm normally? Is it just for noise regs or is there a mechanical reason?
- Are there any warranty issues for using it? Would it show up on some kind of diagnostic check at a dealer?

If anyone's got any experience with this, let me know

 

[mioba]

Why do you need the mod, just to have the grunty noise all the time?

As to your questions, Ask RennTech, they seem to know what they do.
It would be a mod so need to inform your insurance co.

 

[changchewsoon]

Hi,

I recently had my CPC changed and flashed to remove the torque limiter and vmax, and at the same time they were able to reprogram the exhaust flap to be open full time.

Because the new stock 45s are quite muted from the factory, opening up the valves does make it sound a lot better.

But I think an aftermarket catback would be a better choice in my opinion.

 

[Ndwgolf]

Hi,

I recently had my CPC changed and flashed to remove the torque limiter and vmax, and at the same time they were able to reprogram the exhaust flap to be open full time.

Because the new stock 45s are quite muted from the factory, opening up the valves does make it sound a lot better.

But I think an aftermarket catback would be a better choice in my opinion.

I bought the ASR module not knowing that there’s work differently from the Renntech. The renntech one is installed in the boot whereas the ASR one connects under the car directly onto the valves.
(i didn’t want the hassle of taking it on and off whenever I take the car into Benz for service)
I was lucky and was able to send the ASR valve back for a refund and will now buy a new titanium cat back after my car is registered with the local vehicle registration department here in Phuket……… takes about 2 to 3 months
It will still be a PITA when the car is due for service at 10 and 20k kilometres (both free services) but have been told that to take the cat back off and stock back on it will take about 2 hours off and 2 hours on
My buddy just put the same cat back on a S500 and it sounds amazing
Neil

 

[SquabzZz]

Hey Guys,

I'm looking at buying either a RennTech or ASR module for my 2020 C63S Coupe (One of the plug and play modules which keeps the exhaust valves open all the time, normally they only open past a certain RPM, even with exhaust 'on') Just had a couple of concerns which I'm wondering if someone might know about:

- Is there a reason that the valves only open past a certain speed/rpm normally? Is it just for noise regs or is there a mechanical reason?
- Are there any warranty issues for using it? Would it show up on some kind of diagnostic check at a dealer?

If anyone's got any experience with this, let me know

Hi Mate

not quite the same but I have exhaust valves simulators. (So the valves are unplugged and keep valves open all the time the simulators fool the ecu to make think they are plugged in and working hence no limp mode)

Its definitely not a mechanical reason why they open up at 3k rpm it’s more for noise pollution. But to be honest it’s a nice noise under 3k not super loud a proper v8 rumble.

mine doesn’t show anything on a diagnostic scan!