Towing with 33” tires versus 35” tires

[kylenautique]

Torque management and abuse mode are when the accelerate, the ecm pulls out some timing and slowly puts it back in, so that’s why when you stomp on it, the truck slowly responds. Abuse mode is 0-20mph, and torque management is everything above that. If you remove it, the truck responds very quickly to the throttle.

 

[Jesse_Wenting]

Torque management and abuse mode are when the accelerate, the ecm pulls out some timing and slowly puts it back in, so that’s why when you stomp on it, the truck slowly responds. Abuse mode is 0-20mph, and torque management is everything above that. If you remove it, the truck responds very quickly to the throttle.

Can abuse mode be decrease without being fully disabled? 0-20 is where I'm looking for the most gains. Doesn't sound like I'd see much difference by removing torque management other than during passes, I don't WOT very ofter. Feel like I'd be happy with a 30-50% reduction there?

 

[kylenautique]

I think its a on/off setting. Reducing torque management say 80% will help you pass people and tow better. The two combined make the truck a totally different beast. I have a tuner locally, but I would suggest going through Black Bear for your truck.

 

[Jesse_Wenting]

Been wanting to invest in an EFILive FlashScan V3 for a bit now. I'm north of the border and as my daily driver I really don't wanna wait 2 weeks for my PCM to be shipped down, tuned and shipped back up.

If I were to disable abuse mode and reduce TM by 80% as you recommended, what kind of accelerated wear am I going to see? Again daily driven, not very aggressively but I like putting my foot into it at a red light sometimes. Not burnout level, just being pushed into the seat for a few dozen meters

 

[1998_K1500_Sub]

So its a pretty big difference eh? I mean, I went from the stock 31" tire to the 33, and with the shift point corrections in the ECM it felt the same as the stock tire. Adjusting the shift points don't do enough with 35" tires?

Going from 31" to 33" is roughly a 6% change, that's the better part of 10%... and 10% is typically a "one step" change in rear end ratios (3.08, 3.42, 3.73, 4.10...). So 10% larger tires effectively drop the rear end ratio by one gear (e.g., from 3.42 to 3.08). For 35" vs. 31", figure 13%... more than one gear change. These numbers are back-of-the-napkin based on overall diameter, they don't acccount for the effective radius from the hub center to the tire patch, which would make the % change even larger in this comparison.

From a performance perspective, it's also akin to increasing the vehicle's weight, in your case by 6% (33/31). The truck's harder to accelerate and harder to stop.

When I change tire sizes I try to change the rear end (and front if 4x4) accordingly, so that the vehicle performs the same (towing, acceleration).

If the gears aren't / can't be changed, the shift points / TCC lockup can be tweaked to accommodate the change and give the truck a better feel as was mentioned earlier in this thread, but it's not the same (not as good, IMHO) as changing the gears to match the changed tires.

But any tire change doesn't change the brakes. When I put larger tires on my S10 Blazer (about 10% bigger), it made a noticable difference in the brakes and not in a good way. Now... a pickup truck is a bit different story brake-wise because it's designed with excess brake capacity to handle the GVWR and not just the truck itself, and I'm willing to bet the typical K1500 has more "excess" brake capacity than my little S10 Blazer... so the change in tire size might go virtually unnoticed, up to a point.

FWIW.

 

[Supercharged111]

Abuse Mode: kill it entirely. It's stupid. It pulls timing for a certain time when you floor the thing and it perceives it's being abused.

Brake Torque Management: get rid of it. It kills torque all the time even when you're locked up in OD.

Torque reduction: keep it. It only pulls timing on upshifts.

There's a lot more to do in the tune than that, but I wanted to clarify these items as few actually understand what they do.

 

[1998_K1500_Sub]

Bootstrapping off Supercharged111's comments....

A couple other things to consider if you haven't:

- Change the Power Enrichment delay to 1s (I'm not sure what happens if it's set to 0, you can try that on your own)

- Change the PE enable thresholds to enable PE based on MAP and not, as from the factory, throttle position. Enabling PE at or around 6-8" of vacuum (6" of vacuum corresponds to MAP of 80, 8" of vacuum --> MAP of 73... at least at lower altitudes) works pretty well, and follows the old practice of enabling "power mode" on a carburetor at those vacuum levels.

- Play with disabling the EGR (I've seen this make a notable improvement in driveability on my own 1995 S10 Blazer VIN W)

 

[Ehall8702]

Can abuse mode be decrease without being fully disabled? 0-20 is where I'm looking for the most gains. Doesn't sound like I'd see much difference by removing torque management other than during passes, I don't WOT very ofter. Feel like I'd be happy with a 30-50% reduction there?

Best results would be to do a 0411 ecm swap and hptuners. More control with the newer ecm, hptuner is alot cheaper than efi live and in my opinion easier to use. I just built a 6l with 243 heads, sloppy stage 2 cam, thinner head gaskets and milled heads. About 10.:5.1 compression , roughly 550ish to the crank, all infront of the factory 4l60e. A 40k cooler and torque management is all that's saving the stock trans. This is an 09 Silverado (. 6l from a 01 2500hd tho). The torque management for in the newer ecms are very tuneable, but the newer torque converters are built differently too, think they use carbon fiber inside the newer converters to handle the extra slippage tho.

 

[Supercharged111]

Bootstrapping off Supercharged111's comments....

A couple other things to consider if you haven't:

- Change the Power Enrichment delay to 1s (I'm not sure what happens if it's set to 0, you can try that on your own)

- Change the PE enable thresholds to enable PE based on MAP and not, as from the factory, throttle position. Enabling PE at or around 6-8" of vacuum (6" of vacuum corresponds to MAP of 80, 8" of vacuum --> MAP of 73... at least at lower altitudes) works pretty well, and follows the old practice of enabling "power mode" on a carburetor at those vacuum levels.

- Play with disabling the EGR (I've seen this make a notable improvement in driveability on my own 1995 S10 Blazer VIN W)

You can set PE timer to zero, mine are like that.

I have mine set to MAP, but also TPS. This way I can get PE to come on juuuust before a downshift. Handy when towing and I don't want it to downshift, tells me when I'm maxed out.

I kill EGR too, keeps the intake cleaner.

 

[Supercharged111]

Best results would be to do a 0411 ecm swap and hptuners. More control with the newer ecm, hptuner is alot cheaper than efi live and in my opinion easier to use. I just built a 6l with 243 heads, sloppy stage 2 cam, thinner head gaskets and milled heads. About 10.:5.1 compression , roughly 550ish to the crank, all infront of the factory 4l60e. A 40k cooler and torque management is all that's saving the stock trans. This is an 09 Silverado (. 6l from a 01 2500hd tho). The torque management for in the newer ecms are very tuneable, but the newer torque converters are built differently too, think they use carbon fiber inside the newer converters to handle the extra slippage tho.

Headers? Intake? Tune? You're not making 550 crank with that motor. I don't doubt it's rowdy, but if you're going to spout numbers you need to hit the Dyno.