LMS Tune, Transmission Slips & Traction Control

[AJP turbo]

I guess if ur fluid resembled dog s***...I didn't think ur fluid could be that bad on an 11'....some people never change trane fluid...I think the shudder problem can show itself intermittently with high pressures...some cars may tolerate it better than others...and it seems to handle shift high shift pressures of over 220 psi in above 2nd gear Nicely.not sure why tho

[SHOnUup]

I guess if ur fluid resembled dog s***...I didn't think ur fluid could be that bad on an 11'....some people never change trane fluid...I think the shudder problem can show itself intermittently with high pressures...some cars may tolerate it better than others...and it seems to handle shift high shift pressures of over 220 psi in above 2nd gear Nicely.not sure why tho

Exactly...so I'm sort of suggesting maintenance before tune adjustments. I feel with adjusting the tune you may just be masking an underlying issue.

I'd really like if someone with the stutter would try this before getting an adjustment made. My single experience is just not enough to confirm this.

Rich

[BiGMaC]

I guess if ur fluid resembled dog s***...I didn't think ur fluid could be that bad on an 11'....some people never change trane fluid...I think the shudder problem can show itself intermittently with high pressures...some cars may tolerate it better than others...and it seems to handle shift high shift pressures of over 220 psi in above 2nd gear Nicely.not sure why tho

Exactly...so I'm sort of suggesting maintenance before tune adjustments. I feel with adjusting the tune you may just be masking an underlying issue.

I'd really like if someone with the stutter would try this before getting an adjustment made. My single experience is just not enough to confirm this.

Rich

Good point Rich.... If the problem is maintenance... and the tune is adjusted.... there could be problems again after the maintenance is done!

[AJP turbo]

Rich I had a car with 3k miles and true synthetic amsoil...it's arguably the best fluid available....the pressures when set in some of these tunes at over 200 is way over stock and the tranny simply does not like that...I think the stock setting is about 175 but I'd have to look...might not seem like it but that's a huge increase...it doesn't take large adjustments to make a difference in shift firmness when using that scalar in the tune

[BiGMaC]

Rich I had a car with 3k miles and true synthetic amsoil...it's arguably the best fluid available....the pressures when set in some of these tunes at over 200 is way over stock and the tranny simply does not like that...I think the stock setting is about 175 but I'd have to look...might not seem like it but that's a huge increase...it doesn't take large adjustments to make a difference in shift firmness when using that scalar in the tune

True ajp... from the posts here it seems that as the (already increased) 200psi tranny shift pressures are exceeded unwanted behaviors develop.

[SHOnUup]

Rich I had a car with 3k miles and true synthetic amsoil...it's arguably the best fluid available....the pressures when set in some of these tunes at over 200 is way over stock and the tranny simply does not like that...I think the stock setting is about 175 but I'd have to look...might not seem like it but that's a huge increase...it doesn't take large adjustments to make a difference in shift firmness when using that scalar in the tune

I hear ya AJ. No arguing your point here. It's just with us LME guys....we have identical settings. So when something isn't working for one of us, but is for others...I start leaning towards personal car maintenance. Not saying people haven't maintained their car properly, just they aren't built exactly alike.

Example:

Guy has shifting problem and LME says it's fine, he goes to Torrie and he adjusts settings to "feel" better for driver. Issue seemed to be gone. Month later PTU explodes.

Rich

[Brucelinc]

TSS might jump in here but I know he had his transmission fluid changed and the stutter seemed to be gone for a few days but then returned.  He finally had the shift pressure reduced on the 1-2 shift.

I also had my shift pressure reduced on the 1-2 shift and, at first, I was afraid that it might hurt acceleration since the shift is so much more refined.  After a few 0-60 tests with the Aeroforce gauge, I discovered that performance was not hurt at all. 

I am not saying that dirty or burnt transmission fluid will not contribute to this but high shift pressures seem to be the common denominator.  Why the issue is so inconsistent, though, continues to puzzle me.

[AJP turbo]

True and hard to compare really because different software is used for tuning the tables maybe presented completely different and even if they are similar I don't know how well they would correlate...I'm not a software engineer..ie a torrie tune via sct and lms tune via mycal or whatever it is

[SHOdded]

In the FSM for the Edge, under Trans specifications, I see this:

Line Pressure Chart 
Gear  Line 
Pressures at Idle
P  372-413 kPa (54-60 psi) 
R  689-724 kPa (100-105 psi) 
N  372-413 kPa (54-60 psi) 
D  579-600 kPa (84-87 psi) 
L  579-600 kPa (84-87 psi) 

Pressure at Wide Open Throttle (WOT) Stall
P  372-413 kPa (54-60 psi) 
R  1,724-2,068 kPa (250-300 psi) 
N  372-413 kPa (54-60 psi) 
D  1,655-1,724 kPa (240-250 psi) 
L  1,655-1,724 kPa (240-250 psi) 

I am sure there are similar tables available in the SHO/Flex/XSPort/MKS FSM's.

[AJP turbo]

....I could be wrong but I don't think those are for shifts since it says "stall"...something with torque converter settings...the shift pressure tables are based on torque and ramp up with torque...at part throttle and low commanded toque areas the pressures are well below 50 even so the numbers u show look really high which also makes me think they are for something different that is not the culprit for the 1-2 shudder...but again I could be wrong

[SHOdded]

Mind you, these numbers are for the Edge (6F50), not the SHO (6F55), two different transmissions.  Besides I don't have any info on the actual range control capability for each of the shift solenoids, nor the "breaking point" for the actual gears/clutch packs involved.

[ZSHO]

I guess the same goes for meth injection,before installing it the car should be in great running condition preferably with lower mileage in order to get the full potential from your vehicle,and of course the the lower stat and new plugs,and fluids.Z

[14SHOCAR]

Time out team. LOL

There was a LOT of good information here. However, to better figure out the problem with the community, lets actually figure out what I should test. I'm ok doing new tranny fluid.

Rich -- Do you want me to get some of the from my transmission fluid to see its color? Do you suggest that I change out the fluid and see if I still get that shudder between 1st and 2nd?

Rich + Everyone else -- Remember when I have traction control OFF, I don't have this issue. That makes me lean towards tune + line pressure or slip sensitivity over mechanical.

Also to note, I was running in Sport Mode, not Drive. I hear from some people that I need to avoid Sport Mode with LMS 93 3bar V8

[BiGMaC]

Does anyone know how TC affects the tranny, other than locking out 6th gear?

[14SHOCAR]

Does anyone know how TC affects the tranny, other than locking out 6th gear?

TC affects the power distribution. Do you mean Sport Mode? The shift points on a "stock car" with Sport Mode are different.