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RMM and false knock?
- Thread starter Chuckable
- Start date
The last pic is on a 1,000% bone stock un-modded cobb ots 93oct stg3 tune.
And to add to that, not since ever have I ever seen low rpm normal driving knock on Cobb's tunes. Ever. Its 1, sometimes 1.50 or so, i'm not losing sleep, over it, lol. And I very much think that a cobb mount or a nicer mount would do a much better job of stopping this from happening. The 2J race mount is just that. I paid $40 for it. I'm happy with my $40 worth.
And to add to that, not since ever have I ever seen low rpm normal driving knock on Cobb's tunes. Ever. Its 1, sometimes 1.50 or so, i'm not losing sleep, over it, lol. And I very much think that a cobb mount or a nicer mount would do a much better job of stopping this from happening. The 2J race mount is just that. I paid $40 for it. I'm happy with my $40 worth.
I just mail them my address and they send it out the next morning, right? Lol. Actually, i will do the cobb when i can afford it 
I think its breedt that is building a really cool one that splits in half and you can change the inside. Maybe its bomaba that's building that one... But for now, I'm happy with my $40 hotness
I think its breedt that is building a really cool one that splits in half and you can change the inside. Maybe its bomaba that's building that one... But for now, I'm happy with my $40 hotness
But that's the thing, I don't know if anyone is actually reporting that timing is being pulled, let alone whether it's actually the RMM causing it, let alone which manufacturers mounts may/may not be guilty. All I've seen since I joined the community in May are claims that it might/does happen, but no actual data to support it. With all of that lack of information it doesn't even include the possibility of poor maintenance practices...
I know that I haven't personally seen anything with my car on my datalogs, but I have the Cobb RMM and maybe that isn't strong enough to induce it. Quite honestly it just seems like an unwarranted fear right now (to me) that's perpetuated by people that are possibly running too aggressive of a tune. I obviously can't say for sure, but just like above it's sometimes easier to blame something without actual proof of cause.
Some people may get upset with me for wanting to see datalogs, but I try to make my decisions based on data as opposed to speculation. The only way you're going to know for sure if your RMM is the cause is to datalog the car with and without the mount in question, under the same tune, fuel, and conditions.
I know that I haven't personally seen anything with my car on my datalogs, but I have the Cobb RMM and maybe that isn't strong enough to induce it. Quite honestly it just seems like an unwarranted fear right now (to me) that's perpetuated by people that are possibly running too aggressive of a tune. I obviously can't say for sure, but just like above it's sometimes easier to blame something without actual proof of cause.
Some people may get upset with me for wanting to see datalogs, but I try to make my decisions based on data as opposed to speculation. The only way you're going to know for sure if your RMM is the cause is to datalog the car with and without the mount in question, under the same tune, fuel, and conditions.
If someone wants to pm me with how to do a log and what driving conditions, I will gladly give it a shot. My car sits 100% stock with a Cobb stage two + cbe waiting to be installed. So I'll log tomm then swap the mount and log again with Cobbs RMM . This would all be on a stock tune. Or after I install everything else I'll log on stage two before and after the cobb RMM gets installed.
It would of never occurred to me that a engine mount may cause enough vibration to signal the ECU to pull timing because of "knock". It seems a little far fetch to me but the detonation sensor(s) may be very sensitive to certain frequencies, I have no idea really.
As for who perpetuated this theory, it related to Mountune and why they don't manufacture a RMM for the FiST with a well know tuner mentioning the vibration and "knock" problem.
If you guys felt the vibration this specific mount has, you'd understand, lol. I could really see a nice designed mount never seeing this issue.
As far as "too aggressive of a tune".... If a cobb stg3 OTS tune is "too aggressive" at less than 0psi running 93oct... I don't know what to say to that, lol.
It really is about frequency. The thing is, when you vibrate the entire car, a zillion things are making noise at different frequencies. Not too hard to imagine SOMETHING SOME WHERE on the car crossing that line for a milli-second. But again, this is a full race mount, not a cobb or other mount that is more of a "sport" than a "race".
As far as "too aggressive of a tune".... If a cobb stg3 OTS tune is "too aggressive" at less than 0psi running 93oct... I don't know what to say to that, lol.
It really is about frequency. The thing is, when you vibrate the entire car, a zillion things are making noise at different frequencies. Not too hard to imagine SOMETHING SOME WHERE on the car crossing that line for a milli-second. But again, this is a full race mount, not a cobb or other mount that is more of a "sport" than a "race".
+1...sounds like a very good first step
I saw this post on another forum by a fairly experienced / credible source....I think the statement he made (below) is what ignited the initial concern where installing an aftermarket RMM can lead to creating false knock events ...
http://www.fiestast.org/forum/fiesta-st-performance/3058-aftermarket-rmm-bad.html#post44269
"Unwanted NVH can be created once you start swapping out mounts. The ECU calibration can be very sensitive to this. So if you get false knock that means you are reducing power output. I see this all the time. It's a huge issue I deal with on the Focus ST and Fiesta ST. "
I saw this post on another forum by a fairly experienced / credible source....I think the statement he made (below) is what ignited the initial concern where installing an aftermarket RMM can lead to creating false knock events ...
http://www.fiestast.org/forum/fiesta-st-performance/3058-aftermarket-rmm-bad.html#post44269
"Unwanted NVH can be created once you start swapping out mounts. The ECU calibration can be very sensitive to this. So if you get false knock that means you are reducing power output. I see this all the time. It's a huge issue I deal with on the Focus ST and Fiesta ST. "
Talking about knock, I remember the procedure to test the knock sensor for a GM 3.8 litre V6 from a Gregory manual I use to own. It went something like this. "With the engine idling at operating temp, use a hammer and lightly tap the intake manifold. The engine idle speed should now reduce indicating the detonation sensor is retarding ignition timing".
You could try tapping your RMM Sourskittle while data logging, lol.
You could try tapping your RMM Sourskittle while data logging, lol.
Thread Starter
#60
Wow, what a lineup of cars!
I've read anectodal information about the 1.6 EcoBoost knock sensor, and from what I understand it's much more advanced that what was used even a few years ago, much less a decade or more ago. Does anyone have any specific information about knock control on this engine, or is that more the province of knowledgeable tuners only?
I've read anectodal information about the 1.6 EcoBoost knock sensor, and from what I understand it's much more advanced that what was used even a few years ago, much less a decade or more ago. Does anyone have any specific information about knock control on this engine, or is that more the province of knowledgeable tuners only?
