Part throttle shift points

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FE3XCLONE
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Joined: Mon Feb 16, 2009 11:31 pm

Part throttle shift points

Post by FE3XCLONE »

Is it possible to change the part throttle shift points with the I3? I have a 2008 Sierra with the 4L60E trans. It recently snapped the output shaft and I had it rebuilt. They put all the "good" parts in it but with the 87 octane tune and no TCM changes other than torque management set to zero% the 1-2 shift is horrible at part throttle. Its waiting way too long to shift. Like 3500+ rpm with less than 25% throttle. I've gotten the point now where I'm letting off the gas a touch just to get it to shift earlier.

Thanks,

Andrew
Andrew
2008 GMC Sierra 1500

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mikel
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Re: Part throttle shift points

Post by mikel »

can be done with custom tuning, but I cant imagine what they changed internally thats not allowing it to shift like it used to...
Mike Litsch
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FE3XCLONE
Posts: 14
Joined: Mon Feb 16, 2009 11:31 pm

Re: Part throttle shift points

Post by FE3XCLONE »

I had a Trinity tune in the truck a few years ago. When I returned everything to stock it apparently didn't return the stock TCM tune to the truck, just the ECM tune.

Didn't find that out until I bought the I3 and it wouldn't tune the truck. Saw the TCM file in the truck had diablotune in the file name. That would explain why the trans always seemed to shift late/hard after I removed the trinity. It just wasn't as noticeable when the trans was stock. Now that it's been rebuilt with parts to make it shift harder, it's almost unbearable with the tune that's in there.

Tech support had sent me a calibration file that let me tune the truck but it much not have returned the stock TCM tune because it still shifts way too hard. I returned everything to stock last night then reloaded the 87 octane tune. Only parameters changed in the ECM tube was speed limiter and DoD. I told it to skip the TCM tune and there was no change in shift quality or timing.
Andrew
2008 GMC Sierra 1500

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mikel
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Re: Part throttle shift points

Post by mikel »

if we sent a file to set the tcm back to stock, then its all stock.

Once you build most late model transmissions you really need custom tuning to dial them in in most cases.
Mike Litsch
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST

tech@diablosport.com
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