[Twinturbo Ranger]

I put this over in the SCT forum but no replies so I thought I'd try here. I've got a wierd issue and I'm not sure whats causing it. I have the factory lock and shift schedules currently (except for WOT shifts). On normal acceleration for my truck it would go 1-2-3/lock/4. It does this correctly when I'm accelerating normal. At a slightly higher TP (like going up a hill) it will go 1-2-3/lock-unlock/4. The lock and unlock happens within a second. I originally thought there was a mechanical issue given a new trans and higher stall converter, but when I logged the converter lock flag it showed the PCM locking then unlocking the converter. Looking at the lock schedule it should be locked and stay that way but something is unlocking it. I added the datalog showing the converter locking and unlocking. If you choose rpm and converter lock in Livelink you will see it around timestamp 200.

The PCM code is CXN1 with a MNAE0 strategy. The vehicle is a 01 Lightning with a 4V/turbo swap. The transmission is a factory 4R100 built with a 3500 stall converter. The only thing I'm logging for the converter is the flag for on off. Is there something else I should log or look at ?

Thanks Mike

 

[Twinturbo Ranger]

Adding a log with better parameters. Time stamp 70 will show it again lock and unlock.

 

[Twinturbo Ranger]

I lowered the MIN SPEED RATIO TO LOCK IN 3RD and its locking and staying locked now. I was under the impression it wouldn't lock at all unless this was met but evidentally it will.
Thanks Mike

 

[MF/Ken]

In addition to the ratio change (which is normal to address when stall changes significantly) - also log NV and see if its out of step with what's in the tune. If so, then go rescale the shift points by the ratio (base nv/actual nv) - this will help get shift points better overall since shifting is based on which hits first: rpm or speed.

How are the lockups compared to before? Too hard, too soft? Any "clunks" during lockup?

 

[Twinturbo Ranger]

My shift point's seem to be correct at PT. However I haven't done much with WOT, but what I have seemed to match . Lockup's are pretty smooth to me. It's not a hard hit more of a gradual pull down.
Thanks Mike