TCC Lockup RPM

[jwbronco]

Is there a simple way to lower the minimum lockup RPM? I'm trying to program one for a diesel and the 2200 RPM is not low enough. I changed the numbers in the ini file to reflect 1200 but I don't think that is really a change other than visually. I've been building the program using 5099 and that is one of the biggest issues.

[Bernard Fife]

jwbronco,

The limit is only a function of the INI. So once you change that, you should be good to go. However, the code doesn't have a minimum TCC rpm as such (except for the full-time TCC which is a specialized function); instead it has a minimum speed (see: http://www.msgpio.com/manuals/mshift/V5tune.html#nt).

So you need to lower the 'Min. TCC Lock-Up Speed' if you need a lower rpm value to lock up the convertor.

Lance.

[jwbronco]

So if I changed ini to allow the full-time function to be 1200rpm will that truly be 1200? Does full-time trump anything because I haven't found anything that references that it's anything other than active which means if I shifted and mph and gear was met but I was below the full-time rpm would it lock up? Good example, if I'm in 2nd gear and above my minimum of 20mph and say 1400rpm but my full-time said had to be 3rd and above 2200rpm would it lock up?

[Bernard Fife]

jwbronco,

The full time lockup is supposed to trump everything else (though it hasn't been tested or used under the conditions you plan, so there may be some glitches).

The full time lock up shouldn't lock until you reach the upper rpm (unless the normal parameters indicate it should), then it will stay locked as long as the rpm stays above the lower rpm (and the gear stays at or above the minimum gear setting).

At least that's the way it is supposed to work. If it doesn't, could you post an MSQ and a datalog that illustrates the issue?

if I'm in 2nd gear and above my minimum of 20mph and say 1400rpm but my full-time said had to be 3rd and above 2200rpm would it lock up?

No, it would not lock up because you are not in 3rd gear or above. You are also below 2200 rpm so that would also prevent it from locking up. However, it might lock based on the normal settings (if you have those set sch that you are above the minimum speed and below the maximum load).

Don't confuse the TCC functions. There are two mostly independent TCC strategies:
- full time lock up is intended to lock the TCC at high speeds/rpms/loads to get a few more mph in absolute top speed. Full time TCC parameters are not intended for controlling the TCC in all situations. The full time TCC settngs are the bottom four parameters in the menu below.
- the regular settings (the top 8 parameters) are intended to lock the TCC at low speeds, loads, rpms ans higher trans temperatures (and unlock it at cold temperatures to allow the trans to warm up more quickly). This is the 'normal' control' strategy for a TCC, and based on what you have said I believe this is where you ought to concentrate your tuning effort.

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Lance.