6l90 shifting issues

Not too sure where to start with this one but here goes. Ill start off by saying im not looking for anyone to fix my tune for free, or to do it for me but rather point me in the right direction. I suppose what im asking is weather or not my issue could be tune related or a physical transmission issue. The platform is a 2011 ctsv 6l90 transmission. Mods are a cam,ported stock heads, ported blower, injectors, headers, pullies, intake ect..with a stock converter and transmission. Issue im having is the car wont make its shifts under wot 1-2 and 2-3 without hitting the limiter, and in general occasional lazy shifts under part throttle and low load. Ive had a few people suggest the tq model is incorrect, but I would like the see what the forums think. Including a tune file and a log as well.Attachment 109056 Attachment 109057

I have the same platform with similar mods to yours. I cant look at your tune / log at the moment (at work). I'll have a look at your tune and log tonight.

For the torque tables for high / low throttle shifts; In the scanner at WOT you should be seeing lets say roughly around 800NM+ of engine torque. If you are seeing that your torque model is ball park enough to get wide open shifts ok. Also look at around 30-35% TPS if your reported torque is around the 200-300NM your part throttle shift should be ok too. What I can say is my torque tables are stock. If your injector data is good (I.e.Injector Dynamics) then you should not have to change the torque model at all. My injector data is scaled so no where near as accurate as Injector Dynamics but my torque model is close enough to get the trans to shift (in my opinion) perfectly all beit with some very minor increases to pressure and a large reduction in shift times I.e 0.2s at WOT.

For your WOT shifts; as an example my WOT 2nd to 3rd shift speed is 90km/h and rpm is 6500. This gives me a shift +/-50rpm at 6500rpm. If you looked at speed / rpm in the scanner you would notice that my value at 90km/h is well behind where the trans will actually shift at.

To check your shift points, look at a log with a couple of wide open runs and with speed and rpm plotted. Put the tracer at the required shift rpm, then move the tracer back around 0.6 to 0.8 seconds. This will be the km/h you input into the WOT shift table for that gear. This will get you close to hit the road and fine tune.

Couple of things from your log...
No torque management advance on the 2-3 shift???
The trans is not hitting it's target shift times.
Your rev limiter is close to your shift point. Maybe give it another 100rpm more room on top of what you have now.

I'm not an expert, but I have merged in my trans tune into your tune file. See how you like it if you want to bold and give it a go as is. The calibration is based off a Holden VF GTS. If you do give it a try, remember KOEO adapts reset / preset is required plus a small learn drive. Heaps of changes from yours. Note my shift points are 6500 so if you decide to keep the tune as a new base then that will need to be fixed to get back to your 7000rpm.

I've also put your min spark and trq management spark back to stock. This will let it pull more timing between the shifts. It will shift faster if more timing is pulled.


Attachment 109122

100rpm difference between the commanded shift rpm, and rev limiter is not enough. That needs to be at least 200, but 3-400 is not uncommon.

The commanded shift vs actual shift is never going to be the same in 1-2 (commanding 7000 will not yield a 7000 shift... That's when it will START trying to complete the shift). The commanded shift rpm will need to be staggered out, because the acceleration is so much more rapid in 1st gear, vs for example 4th gear. If you want to have an actual shift of 7000rpm, your commanded might end up looking like this EXAMPLE (it will vary based on HP and other factors)
1-2 (6700)
2-3 (6800)
3-4 (6900)
Rev limiter 7300

Again, this is an example, but it is very common to command an earlier shift on the 1-2 to achieve the same rpm completed shift as the higher gears.

I would back the 1-2 and 2-3 shift rpm down to 6800 and set the rev limiter to 7200 and get a log to see what happens. I have a feeling you'll end up with your 1-2 around 66-6700 and your 2-3 around 67-6800 to net the 7000 shift you want

Thanks a lot for your input and taking the time...I will load that up and give it a shot. I will report back.

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Originally Posted by davidchristian83

100rpm difference between the commanded shift rpm, and rev limiter is not enough. That needs to be at least 200, but 3-400 is not uncommon.

The commanded shift vs actual shift is never going to be the same in 1-2 (commanding 7000 will not yield a 7000 shift... That's when it will START trying to complete the shift). The commanded shift rpm will need to be staggered out, because the acceleration is so much more rapid in 1st gear, vs for example 4th gear. If you want to have an actual shift of 7000rpm, your commanded might end up looking like this EXAMPLE (it will vary based on HP and other factors)
1-2 (6700)
2-3 (6800)
3-4 (6900)
Rev limiter 7300

Again, this is an example, but it is very common to command an earlier shift on the 1-2 to achieve the same rpm completed shift as the higher gears.

I would back the 1-2 and 2-3 shift rpm down to 6800 and set the rev limiter to 7200 and get a log to see what happens. I have a feeling you'll end up with your 1-2 around 66-6700 and your 2-3 around 67-6800 to net the 7000 shift you want

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Thank you...I will be playing with shift points as well....im not really sure why they're set so high. Im still learning...

hey guys
i'm interested in this as well. So good you have raised the topic. i have similar mods making 660rwhp
Agree with Hjtrbo that spark>torque is set at positive 5 degree. really need to change. mine is -18 (negative). this function is to pull timing out to take the load off for the shift.
Your high octane spark table say 17 @1.36spark airmass. some people use this as a guide as to the max timing to pull out.

I myself am looking at adjusting the oncoming and off going pressure presets
trans>shift pressure> adaptive.
your settings are higher than mine. have you modified these from factory? did you notice any difference.

Hjtrbo - ours are the same settings here. Any thoughts on this one.

Attachment 109230

Quote:

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Originally Posted by GENFGTS

Hjtrbo - ours are the same settings here. Any thoughts on this one.

Attachment 109230

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Post up your tune and I'll have a look. I'm guessing the difference between mine and yours is I have higher base shift pressures. I have not found the need to hit the oncoming pressure tables as my shifts are pretty good at WOT. Around 0.15s with good feel. Shifts right at commanded.

Attachment 109239

These are my bluecat settings. Its spot on. I don't use his tool for regular shift points just the WOT stuff. Only the highlighted areas have been changed.

Attachment 109241

hjtrbo - good point
yes your base pressures are higher than mine.
i have the standard stall. did you up pressures before you put the stall in?
my tune attached and run file attached 1/4mile occurs between 84s-95s
On the track I use pattern A (sport mode) and this is linked to pattern Y - in shift pressures.
Pattern B is my general drive and purposely different.
my 1-2 is a little slower and the main one i'm working on.
my shift rpms are a little lower relative to yours.
I have the BTR3 cam.
Attachment 109243Attachment 109244

1) Looking at your trans slip PID one would think you're blowing through the trans on 1st gear. Do you feel the same?
2) Very little torque management. Still got 10-12 deg of timing in on the shift which from a rough guess from your virtual torque tables is 600Nm+ of torque going through it. Way to much. Your tyres are breaking loose. Don't know if that's how you want it?
3) 1st to 2nd is not hitting your commanded shift time. Fix 2 first.
4) Not so sure about the large change to output torque factor you have, I've never played with that table.

1:- Try upping the max line pressure in D1 by 50kPa and see how the next run goes.
2:- Put 100% torque management back in. Use the adder modifier to take some torque management out of the low to medium torque areas to get some feel back.
3:- See if (1) will get it closer to start. On coming pressure presets / shift pressure later...
4:- ?

Also good to add torque, all PCS channels, torque converter slip and torque converter pressure to the scanner. Set the polling time on torque to 20Hz and PCS to 50Hz.

What was the fluid like last time you pulled the pan off?

I inherited this trans tune. I'm sure the previous tuner upped the pressure because the virtual torque tables are still stock and are under reporting by a couple of hundred Nm on the top end. The only bits I've really played with is putting back in torque management and using adder modifier table instead, dialling in torque converter desired pressure table, shift times and shift schedules. Box is factory and the fluid looks good when I drop the pan for a look every 3 to 5,000km. I hate the stall converter that's in it. No need for a high stall in a PD blower car with medium cam. I'm going back to a OEM one after my fuel upgrade is done.

not quite pushing through it i don't think.
i did see on that run timing didn't come down enough, its set at -18 will adjust back to -20
i'll add more channels like you say there.
i had upped the shift pressure slightly before this run vs previous meet and it improved the shift. I'll give it some more i think. I'm slowly/cautiously etching it.
looking at another mates tune he appears to be running more pressure than yours and the gearbox is running strong. The challenge is always deciding how far it can be pushed.
i don't drive the car often but will have a play and let you know where i land.
cheers

Coming back to this and I have questions after doing lots of reading. I keep getting mixed opinions. I see people saying the 6l90 makes its shift based on speed, some say speed and rpm. Can anyone clarify that?

Quote:

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Originally Posted by GENFGTS

hey guys
i'm interested in this as well. So good you have raised the topic. i have similar mods making 660rwhp
Agree with Hjtrbo that spark>torque is set at positive 5 degree. really need to change. mine is -18 (negative). this function is to pull timing out to take the load off for the shift.
Your high octane spark table say 17 @1.36spark airmass. some people use this as a guide as to the max timing to pull out.

I myself am looking at adjusting the oncoming and off going pressure presets
trans>shift pressure> adaptive.
your settings are higher than mine. have you modified these from factory? did you notice any difference.

Hjtrbo - ours are the same settings here. Any thoughts on this one.

Attachment 109230

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They are increased a bit from factory. The shifts feel very positive. Heres a good read https://forum.hptuners.com/showthrea...lling-me/page2

Quote:

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Originally Posted by hjtrbo

Post up your tune and I'll have a look. I'm guessing the difference between mine and yours is I have higher base shift pressures. I have not found the need to hit the oncoming pressure tables as my shifts are pretty good at WOT. Around 0.15s with good feel. Shifts right at commanded.

Attachment 109239

These are my bluecat settings. Its spot on. I don't use his tool for regular shift points just the WOT stuff. Only the highlighted areas have been changed.

Attachment 109241

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Curious as to why you dont want your converter locking up during WOT? Just going off your picture of the blue cat tool...

Quote:

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Originally Posted by Silverelex

Curious as to why you dont want your converter locking up during WOT? Just going off your picture of the blue cat tool...

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My single disc high stall won't survive 1000Nm+ though it locked. Breaks away at about 500Nm from my logs so I just leave it unlocked and only lock it in 6th at low throttle percentages. I'm not using all the features the Bluecat tool offers. Only WOT shift speed / rpm as he has that nice anticipation function based on rate of speed change per gear. I handle the rest myself.

Quote:

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Originally Posted by Silverelex

Issue im having is the car wont make its shifts under wot 1-2 and 2-3 without hitting the limiter, and in general occasional lazy shifts under part throttle and low load. Ive had a few people suggest the tq model is incorrect, but I would like the see what the forums think.

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How are you going with the shift point changes mentioned to you earlier by a couple of us? All sorted now?