I have a 2000 Z-71, I got HPtuners and played with the 00 PCM a little, I also have an 02, but its locked right now. I have 0 tqman in the 00 tune, and it flat *** runs, the 02 is good, but I think theres a little tw management left. I have a 6l LQ4 with a cam, and a rebuilt 4l60e with a shift kit, and the vette servo, my question is how much torque management can I remove, and expect the trans to last? Ive heard 5% Ive heard 0% just trying to get a better idea now that I can change it how I want it.

 

The way I have started thinking about TM to myself is that GM has introduced it as a band aid way to decrease the amount of drivetrain warranty claims. Instead of totally rethinking their light truck transmissions, they pull out timing to reduce engine output in situations where driveline parts are stressed ie: just before and during shifts, whenever there are large TPS angles with low VSS readings(launching from a dig) or even large TPS angles with high VSS readings (dropping the hammer to pass).


I look back to 1991-1993 454SS trucks that made 405 lb/ft of torque at a low 2400 rpm, these were 4600 lb trucks, although they didnt make much power (255 net hp same rating as my 1997 c1500) that torque number is quite large, even besting the LQ96.0's 380 lb/ft numbers, at least on paper. GM knew that the 700r4 would not do well with 405 lb/ft in front of it, so they installed the 4l80e trans as well as the 14 bolt SF 9.5" ring gear 3rd member. The 80e, 14 bolt combo can take a reg cab shorty reliably down into the high 11's. I have seen an axle break in a 14 bolt, but only due to wheelhop, a set of Strange axles as well as lateral traction bars cured that.


It seems to me that these transmissions survived without TM, sure there were failures but the th-350 was and is a VERY reliable 3 speed automatic trans.
I do see that todays levels of power on average are MUCH higher today than back in the day. Today an L33 all aluminum L33 comes with 310 net hp, this 5.3L engine equates to roughly 400 gross hp, so it has roughly 100 gross hp over that hi-po 300 gross hp L46 of 1970.
When GM produced a hi hp car, like the ZL1 Camaro, or LS-6 454 Corvette that made 500 plus gross hp, they did indeed fit it with an appropriate transmission, be it a th 400 or a M21 or M22 Rockcrusher 4 speed manual.

It seems as though GM is making all this large and effecient hp and the trans technology is dragging behind. Todays 4l70e is a DIRECT descendant of the early 80's th 700r4 trans, the 1-2 and 3-4 band apply servos (vette servos) are even interchangeable. Gm is throwing a 400+ GROSS hp L33 int a 5500 lb truck and still using a "slightly" modified OD trans to harness it. Lets not even talk abot the Vortec Maxx and Vho B4V trucks with their 345 hp net and 380 net lb/ft of torque, this Lq9 engine is pushing 450-460 gross hp all thru the 4l70e, which is a beefed 700r4 with 5 pinion planets and hardened parts.

IMO GM should have been placing the 4l80e trans in every truck with a 4.8, 5.3, 6.0 GEN3/4 and Vortec 305 and 350 GEN 1-E engine. Heck in the late 90's GM was placing the 200 hp Vortec 4.3L V6 in fullsize cargo vans with a 4l80e behind it, why not in the 1/2 ton trucks?
Sure the 80e has a long 1st gear, but its the same 1st gear that was used for years in the TH400 (2.48:1) and VERY close to the 1st gear used for years in the TH-350 (2.52:1) and nobody seemed to mind back then.
Yes its a little less effecient than the 60e and its variants, but add a PCM tune and you are back on top hp wise and then some.
Yes its OD is a little shorter being 0.75:1 vs. the 4l60e's 0.7:1 but the difference in ratio only means 140 rpm when cruising on the freeway. Adding a 2" taller tire gets that back.
The added reliability in my mind, would make up for all of the 80e's shortcomings. I just think back to when parish was running over 600 rwhp all thru a stock 4l80e with just a simple shiftkit, I break a 60e just looking at it wrong.
The GM upgrade from the 8.5" rearend to the 8.6" rear is a joke, I am thrilled to see that GM has put the 14 bolt behind the Trailblazer SS, 2wd SS Silvy as well as the Vortec MAXx package. In a few years there will be some very nice rear ends to be picked out of the boneyards thats for sure.

If GM had never introduced that 3.06:1 1st gear way back in the early 80's we never would have missed it. That short 1st gear is awesome for launching but leaves something to be desired in terms of rpm drop and torque recovery.

Ideally when installing the 80e in these truck, they should "borrow" the 1st and 2nd gear ratios from the Buick TH 200r4 trans with its 2.74 1st gear, 1.57 2nd 1:1 3rd and awesome 0.67:1 OD ratio. Nice close ratios, not too short not too long 1st gear, and nice deep 0.67:1 OD for cruising and top end speed.

I have had $2500 4l60e rebuilds with shift kits, servos, extra clutches, the works in a pre 1998 1 piece bellhousing 60e. I have also installed a USED junkyard 1999 bolt on bellhousing 4l60e with ZERO mods to it except for a STOCK L35 V6 TC which stalls to 2500 rpm behind my bolton Vortec 350, it doesnt shift hard, but I have more miles and drag passes pn this trans than the other rebuilds and it is still going strong.

To make a long story short (LOL) I have removed TM 100% about 6 years ago, the performance difference was VERY noticeable, from a dig it was VERY different and the 1-2 shift was much improved, it used to bog after the shifts, with TM gone, my truck was a much more enjoyable truck.

I wouldnt follow GM's thinking in regards to transmissions. Rather than relying on the PCM/TCM to modify the engine output to suit the needs of the driveline, actually build the driveline strong enough to suit the needs of the engines.
To answer your question, since you have allready installed the shift kit and the Vette servos, I would remove TM 100%. If you want the trans to last avoid WOT shifts and WOT launches, at least performing these manoevers all the time.

sorry for the book

peace
Hog

 

Im definatly aware of teh difference between 5% tm and 0%,you wouldnt think it was mutch, but it is. im just wondering if I take all TM out of the PCM how soon I'll be looking at doing the 4L80 swap.
I guess I was really wondering if the shift kit and servo strengthen up the tranny enough to reliably run 0 TM, or if I should leave 5-10% just to be safe.