Jerking after installing my Cobb AP

[mikebuffer]

So, today I installed the v103 93 octane map on my otherwise stock FiST and noticed a slight jerking after shifting into most gears. Not sure if this is the rev-hang that others were talking about, but I found it to be very annoying and was wondering if anyone could give any input on how to correct for it/eliminate it. Thanks!

 

[bobjob]

wheel chirping? or engine shutter?

 

[51t]

I feel it too. Upgraded from the v102 to v103 and now my shifts feel jerky. Driving steady state and pressing in the clutch I can see the rpm needle hang for about half a second. I tried reflasing the v103 93 Stage 1 and even tried the v103 91 Stage 1 map. The rpm hang was still there. I'm going to reinstall the v102 map today just to make sure it's not all in my head.

 

[mikebuffer]

I feel it too. Upgraded from the v102 to v103 and now my shifts feel jerky. Driving steady state and pressing in the clutch I can see the rpm needle hang for about half a second. I tried reflasing the v103 93 Stage 1 and even tried the v103 91 Stage 1 map. The rpm hang was still there. I'm going to reinstall the v102 map today just to make sure it's not all in my head.

hmmm so the 91 octane does it too?? I was hoping that maybe it was just the 93

 

[bobjob]

i use 91 v103 and dont recall any jerking

 

[Ghostwhite]

There is a difference in how the stock and cobb OTS maps handle shift assist.

 

[mikebuffer]

There is a difference in how the stock and cobb OTS maps handle shift assist.

so I guess its just something I should get used to?? I just wanted to make sure nothing was wrong

 

[Ghostwhite]

so I guess its just something I should get used to?? I just wanted to make sure nothing was wrong

Yeah just have to get used to it

 

[iso100]

This is the Rev hang I have been talking about. It is only present in the tunes.
I don't have my car right now but do you mind flashing Stage 0 and let us know if the Rev hang is still present?

 

[iso100]

I have been working with Braden from Cobb on another thread about this very issue. I'm glad others are reporting the same problem because now I know it's not just me or my car.

 

[BlueBomber]

So, today I installed the v103 93 octane map on my otherwise stock FiST and noticed a slight jerking after shifting into most gears. Not sure if this is the rev-hang that others were talking about, but I found it to be very annoying and was wondering if anyone could give any input on how to correct for it/eliminate it. Thanks!

Hahaha, you've just discovered the inadequacy of your stock "Rear Motor Mount" aka Roll Resistor. Cobb Tuning offers a complete replacement that completely eliminates the stock RMM piece, and you can EASILY install it yourself in 15 minutes with just a 13mm deep socket, ratchet and 6" extension. They sell for $155. If you're really cheap and prefer to do things the hard way, you can also order Powerflex bushing inserts to replace the too-soft OEM bushings in the RMM unit, which allows it to "bottom out", creating that jerking you are feeling. This is much harder and more time consuming to do. I think the guy who bought that setup here ended up spending more on the Powerflex's installed than he would've paid to have just gotten the Cobb one.

It's a question of preference as to which, but that'll resolve the problem.

Cheers.

 

[iso100]

No. This is not spirited driving. We're talking shifting before 3000 and at 2 percent load. The Rev hang is there. Drive. Uninstall. Then watch your revs in between shifts.

 

[iso100]

That said, I plan to get the Cobb mount...

 

[BlueBomber]

No. This is not spirited driving. We're talking shifting before 3000 and at 2 percent load. The Rev hang is there. Drive. Uninstall. Then watch your revs in between shifts.

I had to explain that a bunch too when I was trying to figure out why my shifts were so harsh. Yup. RMM.
Hanging revs are possible as I do seem to chirp the tires more with tunes loaded, even in econ mode.

 

[51t]

iso100,
I noticed you also felt that the power band was a bit weaker down low and better up top. I experienced the same feelings. Maybe it was resetting the ecu. I know in my other car the ecu learns your driving habits. The first couple of days after a reset can drastically change the cars feel.

I'm going to do a bit of data logging tonight and switch back to v102 and see how that feels.

 

[51t]

Oops,
Lost my v102 maps. Anyone have a copy they can send me?

 

[iso100]

Remember that the difference between 103 and 102 is just FFS and LC. The power delivery is not changed. I was told this by Braden at Cobb directly.

Do try Stage 0 v103 though and let me know if Rev hang is there.

 

[51t]

Ok,
After back to back testing of the v103 Stage 1 91 and the v103 Stage 0 I absolutely see a difference. Stage 1 hangs there while Stage 0 falls almost right away. I data logged a couple of runs. I drove at 3,000 rpm's in 3rd gear and pressed the clutch in with accelerator pedal full off.

Stage 1 stayed at 2960 rpm's for .25 seconds and dropped to 2826(-134) after .48 seconds.
Stage 0 dropped from 2947 to 2899 in the first .12 seconds and to 2508(-439) after .48 seconds.

 

[Kip2MyLou]

So it is the tune then? I wonder if Cobb can change this. I haven't noticed it but I'm sure I will now that I'm looking for it. Ha.

 

[iso100]

Thank you 51t! Braden is waiting for logs so he can see about remedying the issue.

Perhaps post them on my thread?