Allison Questions

[ebod]

Even though I don't tow/haul really heavy loads (no more than a light trailer w/ a few dirtbikes), I am considering a truck with the 8.1/Allison combination.  My main reasons for this is I like a lot of power even in everyday driving.

 

I've learned (mainly from this great board) that the Allison tranny is not set up to optimize everyday driving (understandable, it's got to work for those who are always putting a lot of stress on it).  That is, I hear (i) that it short shifts, before the revs get to the sweet spot, and (ii) that, as it's big, strong and heavy, it introduces a lot of resistence (along the lines of pumping losses and rolling resistence) between the engine and the wheels.

 

Is there anything I can do to minimize these problems in light of my anticipated application?  For instance are there any transmission "chips"/reprogrammers that will change shift points?  Similarly would different/thinner ATF reduce the resistence (I understand that this could cause problems with heavy towing)?

 

Thanks for any thoughts.

[CMNTMXR81]

Let's have a little correction first.  IT drives FINE for everyday driving.  Matter of fact it's smoother and more user friendly than my 4T60E in my Monte.  It's never out of power range, but that of course is due to the prodigous amount of torque available on tap.

 

I'm the one that complains about it short shifting and it's higher power sapping potential.  These complaints I have are ONLY when I get into Wide Open Throttle drag races from stop light to stop light.  I still win, I just wish I had another 500 - 1,000 RPM in each gear to wind out.

 

There is nothing you can do about it's power sapping ability.  That's just the nature of a HD torque converter turning HD internal components.  There are a few programmers out there that *claim* to work with 8.1's and Allison's but there options to mess with it are limited and pretty much the basic stuff one would want to eliminate (I.E. TORQUE MANAGEMENT) are not available to alter.  That is because the Allison has it's own controller and Allison hasn't let out their programming wizardry.

 

Once again, for everyday driving, it drives like a champ.  If you plan on drag racing with it, you'll note the problems I have.  But as you mentioned, that's not it's intent purpose in life.

[BlackSilver]

CMNTMXR81 pretty much nailed it.

 

My Allison is perched on the back of a DuraMax diesel so I can't comment on the 8.1 combo, but it is almost spooky how well matched it is to the power curve of the Dmax.  "Normal" driving, or towing loads, it always has what seems like precisely the right gear in place for the conditions.  With the kind of torque coming from the 8.1 or the Dmax, the small amount of loss due to extra rotating mass considerations get lost in the noise level.