ChargedMB

Someone correct me if I'm wrong, so to summarize the cold startup comparisons:

Stock, Renntech and CETE all will have the same initial cold startup sound "theoretically."

• Stock cold startup, the valves close again automatically once the oil is heated
• Renntech cold startup, the valves remain open after the oil is heated as long as the module was activated with the remote
• CETE cold startup, the valves close again automatically, unless someone hits the exhaust switch

If this is accurate, the CETE mod makes the switch work like how it should have from the factory...

x96535

I can’t speak to the CETE, but that is incorrect about the ASR or Renntech EVM. You can make the startup 100% valves open every time and it stays on the same setting the whole time the car is on or off until you change it with the EVM remote. Cold or warm start.

ChargedMB

Yeah I was only talking about cold starts, I think with warm starts the valves in stock form dont open up initially.

Are you saying the car doesn't start up with open valves in stock mode during cold starts? Man this is confusing as hell

Skilly

I can't speak for RENNtech; however, the CETE option removes the cold start valves open from the factory. The car defaults to cold starts with valves closed - it seems like an oversight on their part, but that is how it works nonetheless. Outside of that you are 100% correct - it makes the valves work how they SHOULD work from the factory.

@AMG 17GT this is why these threads pop up. very popular mod and still we arent quite sure on the functions/operations of each of the options. *moderator* - any chance of a stick thread and folders for modification threads? Seems like exhaust and suspension come up every couple of months.

ChargedMB

Ah thats interesting. Can you still do the emotion start up at least on the 20s?

x96535

It depends on how cold it is outside during a cold start. Being that I live in Arizona, almost none of my cold starts are loud. It only happens on really cold mornings.

doulehr

Correct, EXCEPT on warm starts with the renntech you still get aggressive start-up and idle. The difference is significant.

Skilly

I have a late model 18 so cant confirm. My emotional start is simultaneously hitting start and moving it to "I" to get a sound that wakes up the neighbors.

BBS63

CETE module is here. Will be installing it tomorrow and report back. 3 days with UPS to my door. That’s some fast shipping from Germany to the US, I was shocked.

BBS63

CETE module is on, doesnt remember the activate sport mode on exhaust after cycle. Will see how it sounds if any different with the claim of 100 percent always open after driving it.
Something tells me it will be removed as I probably jumped the gun and bought it without reading ALL the posts here,LOL

Oh well I live, I learn.

At least I was able to put the black hood badge on, 2nd time around and I got the right part.

Skilly

I gotta say, reading this thread and the others, I am confused as ever about the operation of the RENNtech let alone comparing them all against factory. Maybe we do this and @DriveAMG can help with completing the RENNtech section:

STOCK:
cold start valve position default: 100% open but closes to default close after warm cycle - approximately 30 seconds
exhaust valves open at start: NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual or when drive settings set to S+ or RACE, I (if programmed)
valve setting when selected: <100%

CETE:
cold start valve position default: CLOSED
exhaust valves open at start: NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual operation or when drive settings set to S+ or RACE
valve setting when selected: 100%
switch operation to activate/deactivate the modification: NO (hardwired only)
factory exhaust button work per factory function: YES

RENNtech:
cold start valve position default: ?
exhaust valves open at start: ?
saves exhaust valve setting (open, close, over rides factory settings etc) from previous run cycle: ?
exhaust open setting: ?
valve setting when selected: 100%
switch operation to activate/deactivate the modification: ?
factory exhaust button work per factory function: ?

DriveAMG

[QUOTE=Skilly;8195876]I gotta say, reading this thread and the others, I am confused as ever about the operation of the RENNtech let alone comparing them all against factory. Maybe we do this and @DriveAMG can help with completing the RENNtech section:

STOCK:
cold start valve position default: 100% open but closes to default close after warm cycle - approximately 30 seconds
exhaust valves open at start: NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual or when drive settings set to S+ or RACE, I (if programmed)
valve setting when selected: <100%

CETE:
cold start valve position default: CLOSED
exhaust valves open at start: NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual operation or when drive settings set to S+ or RACE
valve setting when selected: 100%
switch operation to activate/deactivate the modification: NO (hardwired only)
factory exhaust button work per factory function: YES

RENNtech:
cold start valve position default: WIDE OPEN
exhaust valves open at start: WIDE OPEN
saves exhaust valve setting (open, close, over rides factory settings etc) from previous run cycle: SAVED.
exhaust open setting: ?
valve setting when selected: 100%
switch operation to activate/deactivate the modification: REMOTE. NEVER CHECKED FACTORY BUTTON AS I ONLY DRIVE WITH VALVES OPEN 😎
factory exhaust button work per factory function: ya

Skilly

[QUOTE=DriveAMG;8195879]Thanks - so what I see is that the RENNtech option isnt really an integrate to the system, its an over ride with an "on" or "off" from the key fob....that makes it clear! One more quick question, if you are "off" does it go back to factory settings where the buttons and settings do their normal factory functioning?

titus820

[QUOTE=Skilly;8195893]for Renntech, button 1: valve open 100%, button 2: stock setting.

Skilly

we will get this figured out eventually

DriveAMG

Renntech module : all original factory buttons work as designed regardless of mode. Module only makes every level louder

Skilly

OK thanks for helping clear this all up. Thats different from what you said a little earlier:

cold start valve position default: WIDE OPEN
exhaust valves open at start: WIDE OPEN
saves exhaust valve setting (open, close, over rides factory settings etc) from previous run cycle: SAVED.

None of the above describes how factory settings work. The valves are by default in the closed position except for cold start, but then they close soon after. And, no matter how you ran the car (race, S, etc valves open) in the factory settings, you always start in C with valves closed.

Saudio

I still don't understand this. If the valve is open 100%, wouldn't it be the same volume in any setting? The sound you get from having the valve 100% open?

The only difference from setting to setting should be adding or subtracting pops and crackles. Sport vs Sport+ or Race. If you are counting the Pops as "louder" I understand.

Skilly

STOCK:
cold start valve position default: 100% open but closes to default close after warm cycle - approximately 30 seconds
exhaust valves open at running temp start: NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual or when drive settings set to S+ or RACE, I (if programmed)
valve setting when selected: LESS THAN 100%

Saudio

Man I'm trying but I can't seem to get my brain around this. It seems like what is being said is that the Renntech module opens the valve 100% and it stays there, unless you turn the Renntech off, then factory settings apply.

But what it seems like you are saying is that when you turn on the Renntech switch it stays at 100% only until you engage the factory exhaust control, then it changes.

What am I missing here? Sorry I'm dense on this.

Skilly

Im as confused as you are on the different descriptions of the RENNtech, so you aren't alone.

I have the CETE and all it does is run inline with the factory system and instead of the factory setting with the valves partially open (and therefore quieter) it instructs them to open fully. Its an integrated system that you wouldn't know is there, operating completely off of the factory inputs and normal operation. The only "tell" it has that its inline is during a cold start up the factory GT settings will for a short time (and only when the engine is cold) start with the valves open (fully). In this cold start up, they are open it would appear 100% without selecting or pressing anythings. The CETE installed stops that cold start valve fully open setting from happening.

With stock functions, the car always starts in "C" and therefore the valves are closed by default. It's only ever different during a cold start like I describe above that the factory settings will start with the valves open.

titus820

Renntech
button 1, valves open 100% ALL the time regardless which mode, which means at any mode it should sound the same. At S+ and Race modes, the engine idles at higher RPM thus "louder". Which also overrides the factory exhaust button.
button 2, return the valves setting back to stock.

Orcbolg

I don't blame you, the issue is that conflicting info has been posted here and there.


Stock:

• Cold start = Valves opened almost fully for 30 seconds, then they revert to whatever setting you have the car set to.

• Warm start = Valves are basically closed until after 30 seconds, then they revert to whatever setting you have the car set to.

Valves only ever fully open when you push the car past about 4500rpm, while in Race Mode. Otherwise, even in Race, the valves never fully open.


With ASR/Renntech module:

When set to open, the valves NEVER close. Not matter if you hit the exhaust button, or change the driving mode, they will NOT close at all unless you turn it off, at which time it reverts to the stock settings for the driving mode you are in.

*Caveat to this is that the ASR module, which Renntech just rebranded, doubled the price, and forced them to stop selling to people in North America, has a Quiet Mode. Quiet Mode keeps the valves closed at ALL times, but you should never rev past about 3500rpm when in this mode. This mode is great if you want to keep your Cold Start from waking neighbors.

DriveAMG

factory cold start is default wide open than closed in c

Skilly

very clear - thank you!!

STOCK:
cold start valve position default: 100% open but closes to default close after warm cycle - approximately 30 seconds
exhaust valves open at start (post warm up): NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual or when drive settings set to S+ or RACE, I (if programmed)
valve setting when selected: <100% (limited open to reduce noise)

CETE:
cold start valve position default: CLOSED
exhaust valves open at start (post warm up): NO
saves exhaust valve setting (open, close etc) from previous run cycle: NO
exhaust open setting: manual operation or when drive settings set to S+ or RACE
valve setting when selected: 100%
switch operation to activate/deactivate the modification: NO (hardwired only)
factory exhaust button work per factory function: YES

RENNtech:
button 1 (on): overrides all factory functions and opens the valves to 100% open
button 2 (off): reverts back to factory settings

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