WOT Converter Lockup

[psrumors]

What is needed to lock up the converter under WOT in 2nd gear and hold it through the shift and into 3rd?

Shift lock is enabled, my release speeds are less than my engage. I seem to be locking at about 87 mph in 3rd even though I have my tables set to lock at 76 mph which would be 2nd.

I'd rather not list the tune as it is a commercial tune.

I have heard you can't do this with the stock OS??? If not, what can be done?

[psrumors]

No one has any input?

[Galvatron]

I haven't tried locking my TBSS converter in 2nd but I did notice when trying to lock it 2-3 mph after the 2-3 shift I have to set the values 4mph less. Your 11 mph difference and locking in 3rd. I have mine 84mph to lock and release at 76.

How about just taking a snap shot of your TCC settings? and post up a scan.

[jimmyblue]

Unless your converter is a real POS you will be better
off (for acceleration) hitting into it unlocked. My 3500/2.0
converter has better unlocked acceleration out to past
5000RPM.

I recommend you do some pulls, locked and unlocked,
use Excel to scatter-plot your MPH vs time and see
how that plays with your vehicle. You will most likely
want to lock later, and you should pick the point for
doing it, by where acceleration rate crosses over. I
used a direct accelerometer for that but you can get
the same info off the scanner (just less resolution).
Let the vehicle show you what it likes.

[Bluecat]

If you can get on a dyno, Make a pull locked and un-locked in the same gear. Graph it by MPH (not RPM) and where the two HP (not torque) lines cross is the speed where you want to lock the converter. You'll be suprised, especially the people who think they want to lock the converter in the bottom of 3rd. With a good converter its usually toward the end of the gear.

Here is a example on a stockish auto. The first picture (#1) is locked vs unlocked. You would think you would want it locked as early as you can get it locked by just looking at it, especially the torque difference locked. But graph it by power at speed (#2) and you can see you don't want to lock the converter until 84 mph. The ineffecency of the unlocked converter is out weighted by its "liquid gear" mechanical advantage in the lower speeds. Its why we all want stall converters in the first place.

Attachment 10642

Attachment 10643

[EC_Tune]

I love it when someone shares some very good info that most would overlook! Thanks Bluecat!

[psrumors]

Thanx for the info guys.

I will be on the dyno the end of next week. I'll run the speeds then and see what I come up with.

[Blades]

I have mine set to lock @ 49mph in 2nd.. both WOT and part throttle.. I can "manually" put it into second and hold it steady... it will not lock.. It just seems to be stuck on keeping stock lockup values for WOT (3rd gear seems to lock at ~84 no matter what).. and completely ignoring 2nd gear lockup (part throttle and WOT).. Wonder if this can ever be fixed. A commanded lockup via scanner works fine in 2nd and 3rd. Alvin @pcm4less (i think hes on here) has fixed this via tcm swap.. I just don't know if hpt would be able to read/write to the new module.

[jamesthacker]

If you can get on a dyno, Make a pull locked and un-locked in the same gear. Graph it by MPH (not RPM) and where the two HP (not torque) lines cross is the speed where you want to lock the converter. You'll be suprised, especially the people who think they want to lock the converter in the bottom of 3rd. With a good converter its usually toward the end of the gear.

Here is a example on a stockish auto. The first picture (#1) is locked vs unlocked. You would think you would want it locked as early as you can get it locked by just looking at it, especially the torque difference locked. But graph it by power at speed (#2) and you can see you don't want to lock the converter until 84 mph. The ineffecency of the unlocked converter is out weighted by its "liquid gear" mechanical advantage in the lower speeds. Its why we all want stall converters in the first place.

Attachment 10642

Attachment 10643

Bluecat,
Thank you very much for the info. Really appreciate it.
Jim

[69redmach1]

What is the stall of that converter? It looks fairly loose?
Pete

[rrmccabe]

I am in the process of playing around with TCC as well.

I will be the first to admit I am not a tranny guy so just going to share a recent post. I have a RPM stage V in my TBSS with a Vig 3600. I am sure most agree FLT and RPM know what they are doing when it comes to trannies. I think his comment was directed towards daily drivers.

Vince with FLT recently posted the following about NOT locking during the shift.

"The thing is that with the converter locked, the crank and the input shaft of the trans are turning one to one. This is very hard on the transmissions internals. I have seen many broken parts caused by this. "

So for now I am planning on just locking after 3rd.

[blucreek]

I am also in the process of adjusting my TCC settings after a -/+ 1% VE/MAF tune in a LQ4, 80e(stock verter) with about 3k lbs. worth of Welding attire. I have been trying to get TC to lock up sooner, or am I thinking in the wrong direction also?

BTW lots of good info in this thread!!



chris

[comm]

Will our A4's torque converter's lock up clutch stand up to wot 5300rpm
lock ups in 1st and 2nd. That seems very severe to me, the clutch part isn't
that big is it? Or are the rpms equal, hence no load across the clutch.
Btw how would we know if the lockup clutch was burned out or not?

[jpr5690]

guys, unless you got a converter thats specifically built for wot lockup... i dont think anyone would suggest wot lockup at any rpm.. simply put youll probally end up blowing out the clutch