KR in 3rd gear only at Englishtown

[A2000SSinJersey]

I made 4 runs at Englishtown at the recent SLP day.

Dont ask.........LOL I had other issues............LOL

I logged my runs and in my best run I got some serious KR in 3rd gear only. All the other runs did not show any KR in any gear.

The KR was anywhere from .01 to 4.

Any one have any idea why it would only show up in 3rd gear only???

Thanks and have fun.

[EC_Tune]

Load applied for a longer period of time (3rd gear for example) will increase cylinder temps more than 1st & 2nd gear, possibly causing the KR you are seeing.

[bartender_77]

Load applied for a longer period of time (3rd gear for example) will increase cylinder temps more than 1st & 2nd gear, possibly causing the KR you are seeing.

Same thing happened to me a the track the other day, no knock on 1st or 2nd but i was getting KR of up to 4 on 3rd, so I'm interersted to see how do you fix this thanks.

[A2000SSinJersey]

Thanks for the Info EC Tune.

I will check my log and see if it started right away in 3rd gear.

Bartended.........hope we can find an answer.

[A2000SSinJersey]

Load applied for a longer period of time (3rd gear for example) will increase cylinder temps more than 1st & 2nd gear, possibly causing the KR you are seeing.

In looking at my log. The KR started on the fourth frame after shfting into 3rd gear. With 4 degrees and stayed in the high 3s halfway thru the gear and then into the 2s until I shifted. Fourth gear had none.

Would this still confirm your theory? Any help or thoughts would be appreciated.

Thanks

[EC_Tune]

Now I'm not quite as sure. Although it may have something to do with the amount of RPM dropoff between gears. Just a theory at the moment....

[A2000SSinJersey]

Now I'm not quite as sure. Although it may have something to do with the amount of RPM dropoff between gears. Just a theory at the moment....

Thanks

Would there be anything else I could monitor that may give me a clue?

All the other usual parameters were normal.

Thanks

[EC_Tune]

Check the amount of RPM dropoff and see how much it is dropping (RPM delta) between 1-2, 2-3, 3-4.

Funny thing is I think the 1-2 shift has the most RPM dropoff.

[A2000SSinJersey]

Check the amount of RPM dropoff and see how much it is dropping (RPM delta) between 1-2, 2-3, 3-4.

Funny thing is I think the 1-2 shift has the most RPM dropoff.

Ahhh

Okay and what will that tell me???? Duh is me.........

Thanks

[EC_Tune]

Shift speed may play in there as well because of the inertia transfer from the shift adding heat to an already warm combustion chamber. 1-2 shift transfers more inertia because of trans/rear end gearing (load is lighter). In 4th you have a lot more airflow going over the car for "adiabatic cooling" as well.

BTW: Do you spin at all on the 1-2 or 2-3 shift? That might have something to do with it as well.