$50 C63S Exhaust Valve Mod: Force Valves Open 100% with AWE Simulators
#27
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Thread Starter
Also, in the write-up I talk about still making sure the exhaust button is ON. Even though the button no longer controls the two rear exhaust valves, keeping the exhaust button on allows the valve in the H-Pipe to open more aggressively in Sport+ and Race mode.
Phorte - My ASR module was out for delivery today, but I didn't receive it. It should be here tomorrow so I will test one of the simulators on the H-Pipe when I remove them for the ASR install.
#28
MBWorld Fanatic!
Yeah looking forward to hearing the sim on H-Pipe... To be honest, the module by itself is probably enough for me.. It's pretty loud -- to the point that this is what I imagined the secondary cat delete to sound like... You guys who are cattless must be mental 😂 HAHA
#29
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I turned the car off, opened the bootlid, put the key 20 feet away, left for 5 minutes, and did for install without any ill effects.
#30
Just got them yesterday and installed this afternoon. Took 15 min including time to jack the back end up for easy install. HANDS DOWN BEST MONEY YOU WILL EVER SPEND ON A MB MODIFICAITON.
Also, no need to worry about the H Valve. With the sims hooked up i pressed the exhaust button to see if there was any change in the H valve, there isn’t.
Start up is nice and burrly, very similar to the roar of a cold start.
Low rpm daily driving is nice and growly like when in S+ or R
Also, i noticed a difference in the WOT sound as well. Might just be me or the fact that it starts roaring from the get go but it sounds amazing! Should have done this ages ago!
You can also notice a huge improvement on the in cab noise also. No more CLOSED valves and Prius noise level idle when at a stop light. Keep on purring. In cab sounds great as well. Not to loud but just enough that you can actually hear the exhaust now, even in C mode
Also, no need to worry about the H Valve. With the sims hooked up i pressed the exhaust button to see if there was any change in the H valve, there isn’t.
Start up is nice and burrly, very similar to the roar of a cold start.
Low rpm daily driving is nice and growly like when in S+ or R
Also, i noticed a difference in the WOT sound as well. Might just be me or the fact that it starts roaring from the get go but it sounds amazing! Should have done this ages ago!
You can also notice a huge improvement on the in cab noise also. No more CLOSED valves and Prius noise level idle when at a stop light. Keep on purring. In cab sounds great as well. Not to loud but just enough that you can actually hear the exhaust now, even in C mode
#31
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Quick update. I just installed the sim on the h-pipe valve and gave it a test. Unfortunately, I don’t think it made any difference. Any increased volume I hear is more than likely placebo, and unfortunately (and most importantly), the annoying issue with the idle sound getting quieter as you press harder on the brake when in gear is still present.
I’m honestly at a loss as to what causes the idle to get quieter since the two rear valves are forced open with the ASR and the h-pipe valve connector is physically disconnected with a sim. So surely it should not be able to function or move based on brake pressure. I’m starting to believe that the idle/brake sound is more so a function of the ECU (not just the valves), and may require some deeper digging into reprogramming/flashing to get the desired sound.
I’m honestly at a loss as to what causes the idle to get quieter since the two rear valves are forced open with the ASR and the h-pipe valve connector is physically disconnected with a sim. So surely it should not be able to function or move based on brake pressure. I’m starting to believe that the idle/brake sound is more so a function of the ECU (not just the valves), and may require some deeper digging into reprogramming/flashing to get the desired sound.
#32
Quick update. I just installed the sim on the h-pipe valve and gave it a test. Unfortunately, I don’t think it made any difference. Any increased volume I hear is more than likely placebo, and unfortunately (and most importantly), the annoying issue with the idle sound getting quieter as you press harder on the brake when in gear is still present.
I’m honestly at a loss as to what causes the idle to get quieter since the two rear valves are forced open with the ASR and the h-pipe valve connector is physically disconnected with a sim. So surely it should not be able to function or move based on brake pressure. I’m starting to believe that the idle/brake sound is more so a function of the ECU (not just the valves), and may require some deeper digging into reprogramming/flashing to get the desired sound.
I’m honestly at a loss as to what causes the idle to get quieter since the two rear valves are forced open with the ASR and the h-pipe valve connector is physically disconnected with a sim. So surely it should not be able to function or move based on brake pressure. I’m starting to believe that the idle/brake sound is more so a function of the ECU (not just the valves), and may require some deeper digging into reprogramming/flashing to get the desired sound.
Last edited by rekrul; 06-02-2018 at 01:43 PM.
#33
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Here's a pic of an AMG performance exhaust exhaust someone posted on here, I just highlighted the 3 valves:
![Name: Y41wAIQ.jpg
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#34
Did you guys notice any loss in power or is it just me? I just installed these and while they do work, the valves are open and the car sounds significantly louder, when I punch it, it doesn't feel as strong as it did before. I'm tuned and I'm almost certain that I've lost power. With the valves open all the time, is it possible that there could be a loss in backpressure resulting in power loss? I'm going to uninstall them in a bit and see if there is any difference..
#35
Ok to confirm, I just uninstalled them and the car is back to normal. I can confirm that I lost power from these things but I couldn't tell you why. Unless I installed them wrong, which I doubt since it's only 2 plugs. I literally felt like my car was in 'limp' mode with them installed. I can tell that I lost a significant amount of power with these things. Maybe I'll try to reinstall later again to take videos so you guys can see.
#36
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Ok to confirm, I just uninstalled them and the car is back to normal. I can confirm that I lost power from these things but I couldn't tell you why. Unless I installed them wrong, which I doubt since it's only 2 plugs. I literally felt like my car was in 'limp' mode with them installed. I can tell that I lost a significant amount of power with these things. Maybe I'll try to reinstall later again to take videos so you guys can see.
1. Park and lock vehicle. Determine the range of the keys (pro-tip: I put the keys in a Faraday cage to easily block the signals):
- Step away from the vehicle and attempt to lock or unlock the car using the key fob.
- Continue to move away until the car no longer responds to the key. This is the range of the key.
- ALL keys must be completely outside this range. If a key remains within range of the car, the vehicle may respond to the key and awaken unexpectedly, which could result in a stored fault and reduced engine power.
2. Leave the vehicle undisturbed for 10 minutes. This allows adequate time for the electronics to go to sleep.
#37
Senior Member
Ok to confirm, I just uninstalled them and the car is back to normal. I can confirm that I lost power from these things but I couldn't tell you why. Unless I installed them wrong, which I doubt since it's only 2 plugs. I literally felt like my car was in 'limp' mode with them installed. I can tell that I lost a significant amount of power with these things. Maybe I'll try to reinstall later again to take videos so you guys can see.
#38
Super Member
At low RPM, the best way to scavenge the exhaust gas is with a smaller exhaust (in our case, a partially closed exhaust)
Then at higher RPM, the valves open 100% to allow the best flow for maximum top-end power.
Perhaps that's what you guys are feeling?
My first bet would be on limp mode due to not following AlexZTuned's instructions. But if it's not in limp mode, maybe it's what I said above?
#39
I wonder if one of the reason's why the valves don't open 100% at low rpm from the factory is to help with the low-end torque.
At low RPM, the best way to scavenge the exhaust gas is with a smaller exhaust (in our case, a partially closed exhaust)
Then at higher RPM, the valves open 100% to allow the best flow for maximum top-end power.
Perhaps that's what you guys are feeling?
My first bet would be on limp mode due to not following AlexZTuned's instructions. But if it's not in limp mode, maybe it's what I said above?
At low RPM, the best way to scavenge the exhaust gas is with a smaller exhaust (in our case, a partially closed exhaust)
Then at higher RPM, the valves open 100% to allow the best flow for maximum top-end power.
Perhaps that's what you guys are feeling?
My first bet would be on limp mode due to not following AlexZTuned's instructions. But if it's not in limp mode, maybe it's what I said above?
#40
I will try to install them again -- maybe my keys were still in range (didn't check) plus I was messing with the car (installed a front lip, had to jack it up and lower it) maybe the car detected that...
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amalgam (06-04-2018)
#43
Just tried to reinstall them, made sure keys were far away from the house and out of range and can confirm loss of power. Pull from 60 to 100 is ridiculously weak and slow, even the HP gauge on the screen confirms. Normally pinned at 500hp at WOT and when I get to around 60mph and WOT the gauge shows a drop to 250-300hp. I'm not sure if that's considered 'limp' mode but it feels like my dick after a bottle of whiskey
#44
Just tried to reinstall them, made sure keys were far away from the house and out of range and can confirm loss of power. Pull from 60 to 100 is ridiculously weak and slow, even the HP gauge on the screen confirms. Normally pinned at 500hp at WOT and when I get to around 60mph and WOT the gauge shows a drop to 250-300hp. I'm not sure if that's considered 'limp' mode but it feels like my dick after a bottle of whiskey
#45
Yes over 10 minutes. Do you have the HP gauge on your model? If so try to do a couple pulls with it and let me know if it reads as it should. I can just press the exhaust button I suppose lol
#46
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Just tried to reinstall them, made sure keys were far away from the house and out of range and can confirm loss of power. Pull from 60 to 100 is ridiculously weak and slow, even the HP gauge on the screen confirms. Normally pinned at 500hp at WOT and when I get to around 60mph and WOT the gauge shows a drop to 250-300hp. I'm not sure if that's considered 'limp' mode but it feels like my dick after a bottle of whiskey
I thought I was very clear in my instructions that this could very well happen if you don’t follow the procedure to put the car to sleep before attempting this mod. If the car is within range of a key fob and pings it, or you open a door/trunk/etc, you’ll wake the ECU and potentially go into limp mode.
I’ve swapped out these sims several times, installed an ASR module, installed and removed a sim on the h-pipe, and never once had a problem with the car throwing a code because I always made sure electronics were asleep so it would not wake up.
#47
Reinstalling the sims again is not going to magically clear the soft code that’s now stored in your ECU. Generally, once you’re in limp mode, you’re at the mercy of a dealer (or a shop with the latest MB diagnostic tools) to clear it and get you out of limp mode.
I thought I was very clear in my instructions that this could very well happen if you don’t follow the procedure to put the car to sleep before attempting this mod. If the car is within range of a key fob and pings it, or you open a door/trunk/etc, you’ll wake the ECU and potentially go into limp mode.
I’ve swapped out these sims several times, installed an ASR module, installed and removed a sim on the h-pipe, and never once had a problem with the car throwing a code because I always made sure electronics were asleep so it would not wake up.
#49
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It’s a soft code so it will not trigger a CEL. And yes, my HP/TQ gauge shows full power (and I have a Dinan tune).
#50