Getting an allison to hold TQ

[TwistedDiesel]

I have an Allison 2400 behind my 7.3 powerstroke that now has 400mm injectors and a 74mm VGT turbo. Now I'm playing tranny catch up!


I did the converter flow valve modification so I don't lose any line pressure during lockup now, and that helped a lot. I can no longer slip it while locked in gear, but if I let it shift under any good amount of power it shifts too slow and flares badly and if I'm really in the throttle it will the lose it altogether and the engine will go to redline and that's it. It just cant shift solidly enough under power. I can't do any sort of defuel with my engine so that's out of the question. What does the transgo jr kit really do? Does it make the kind of difference I'm looking for? Any other modifications I can do without sending it out to a really good builder that knows all the tricks? I've got a full machine shop here and am not new to the internals of an Allison, just never had to make one hand this kind of torque before.

 

[PureHybrid]

So it's all stock currently besides the converter valve mod?

Contact Evan at Limitless Diesel, he'll hook you up with the parts. Or do some searching here and you'll piece together what you need

 

[Mike L.]

Why would you take it apart only to do the flow valve mod? You still don't have enough pressure and clutches.

 

[THEFERMANATOR]

Without defuel you're going to have to go full built to accomplish much, and then you might end up with broken shafts and such like was common place before tuners stopped turning defuel off completely. A clutch to clutch trans really needs defuel to shift nicely IMO. Without defuel your build will have to be stouter than equivalent power output DMAX, and your trans tuning will be critical to avoid tie ups. I understand defuel isn't an option for your ECM, but it's putting you at a disadvantage. Clutch selection may be a little tricky with the extra abuse yours will see on the shifts.

 

[NC-smokinlmm]

This will be difficult bc Allison transmissions are inherently slow shifters. I'd have gone full built 47rfe or maybe a duraflite. Good luck and buy billet shafts if your pushing over 1000flbs of torque...

 

[TwistedDiesel]

Thanks for all the great responses. Mike L I see you have options for 290 and 310 PSI, that doesn't stress the case lugs? I'm going to have to get with you for some PR and trim springs. I'm going to give you a call in about a week when have some more cash, so feel free to leave me a list here of what you recommend to save phone time. I come from the MD and HD side of Allison so forgive me for not having mu light duty shit together!

At some point in the future I will have SEM (shift energy managment) capable ECM but for now I need to get this working without it. I'll be running a DDEC IV 60 series Detroit ECM and it has J1939 and SEM messaging and I'm very familiar with tuning/hacking them.


I was looking at limitless diesels kits, they're pretty inexpensive, and from what I hear Evan really has these figured out. Will his kits have the correct selection of clutches to do what I need or since I'm talking to mike already should I just have you put a kit together for me?


I sure appreciate the help.

 

[Mike L.]

Get Evans kit. It will have all my stuff in it.

 

[Chevy1925]

Get Evans kit. It will have all my stuff in it.

That’s a terrible list, Mike :rofl:

 

[Mike L.]

That’s a terrible list, Mike :rofl:

The new Alto G4 clutches are looking very good so far.:happy2:

 

[coker6365]

The new Alto G4 clutches are looking very good so far.:happy2:

Are those still the same keyhole design as the G3? Curious how they do under a lot of power through the shifts.

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[Mike L.]

Are those still the same keyhole design as the G3? Curious how they do under a lot of power through the shifts.

Sent from my SM-G965U1 using Tapatalk

My prototypes are still key hole. Production design should have solid design.

 

[Chevy1925]

The new Alto G4 clutches are looking very good so far.:happy2:

good cause the new motor will be trying to kill all the shit hooked to it :roflmao: