Allison 5sp: Can't hold 4th (for dyno)

[DAVe3283]

I tried to make a 4th gear hold tune for my trans (getting it dynoed today). It is set to hold 4th in tow/haul mode. However, it will still upshift and downshift. I can use the O/D lockout, but the downshift is the problem-- it keeps dropping to 3rd.

It hits the rollers in 1 hour, so I'll just try my luck with DVT for this pull, but I'd like to get this working for the "after" pull. Though after reading online, I am hearing that DVT may not hold it in gear either (plus I can't log at the same time).

Could someone look it over and let me know what I did wrong? Is there a certain OS that needs to be used?

 

[hondarider552]

Ive never used a 5th gear lockout tune in a 5 speed.. I just start the dyno at the mph where it wont downshift to 3rd

 

[DAVe3283]

That is what I'll do if DVT doesn't work.

Is it not possible to create a tune that holds 4th though? I'd think it should be possible...?

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[duratothemax]

Ive been able to log and use DVT's at the same time....?

That being said, the EFILive allison DVT's do glitch out half the time. If I dont really need to datalog, but I do want to make a dyno run, I just use the tech 2.

 

[DAVe3283]

Ive been able to log and use DVT's at the same time....?

I remembered reading it didn't, and never tried. I'll give it a shot. That would be most convenient.

That being said, the EFILive allison DVT's do glitch out half the time. If I dont really need to datalog, but I do want to make a dyno run, I just use the tech 2.

I wish I had a Tech 2. I should really save up and get one.


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[baggedLB7]

When I did mine I was able to lock out 5th and then lug it down to about 1800-1900 rpm and lay into it with out it shifting down.

 

[DAVe3283]

Was able to use DVT to hold 4th after all. Pulled from about 1500 RPM. I can use that again next time, but I am still curious if I did my trans tune wrong.

Anybody see anything wrong with it, or have a tune that's known to work?

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[baggedLB7]

Results

 

[DAVe3283]

Results

Posted over in [THREAD=40951]this thread[/THREAD]. Did 426/748 on a tune I wrote, with no smoke at all!

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[baggedLB7]

Nice