Gasoline Engine Tuners

BurbMan wrote:
OEM tuning is a compromise of power, economy, and durability/longevity. Increase any of those 3 points and you will have an adverse affect on the other two. No free lunch...the OEM engineers know what the weak links are in the drivetrain when they design and test the vehicle, you likely won't find out until they fail.

OEM tuning also takes into account the lowest common denominator of poor driving habits, negligent maintenance and cheap, low quality cornerstore gasoline. Remove all those and a competent tuner can increase drivability and towing performance

OEM tuning is a compromise of power, economy, and durability/longevity. Increase any of those 3 points and you will have an adverse affect on the other two. No free lunch...the OEM engineers know what the weak links are in the drivetrain when they design and test the vehicle, you likely won't find out until they fail.

I added a banks monster exhaust and cold air intake. I did that at the same time as getting black bear to do a custom tune for me. I went from averaging 9 mpg towing to 11 mpg towing. The thing I like the most is it does not down shift all the time anymore. I have a 2010 GMC Sierra with a 6.2L

hmm.. $3000 for a gear swap vs $400 for a tune.. I know which one I would do..

Oops.. I mean did.

Blackbear was the best thing I did to my 6L.
And YES I gained MPG, it was 1-2 mpg across the board, which doesn't seem like much, but for all the other benefits, that is just a small plus.

If you have 4.10 or lower gears don't bother. If you have taller gears then put your money into replacing them instead.

For better fuel economy the key is slowing down or carrying or towing less weight.

I live near Detroit. Several of my friends are powertrain engineers for GM. I'd be happy to have one of them chime in as well.

So would I.
A little reading for you about TM.

More reading.

Read post 15.

And these are people that don't haul trailers and most are only pulling out 75% TM. Read the above to find out why.

BTW, TM has nothing to do with how hard or soft a tranny shifts. Anybody can program a tranny to shift as hard or soft as they want at full throttle. I could even do that with a T400 or 700R4.

IOW's OEM pulls throttle and timing out to stop breaking things and the soft shift is just a side benefit to the customer.

Turtle n Peeps wrote:
Here's the deal.

If you buy a tuner and remove the torque management from the puter you're playing with fire with a stock tranny.

The torque management from the factory is there for a reason. It's there to keep the plastic stock tranny alive. The stock 4L80E's are pretty strong but the 4L60's are like playing with a bucket of snakes IMHO.

Now is it going to blow up with the first stomp of the throttle? No, not likely.

What did Clint say? "Do you feel lucky punk? Well do ya?" :B

I must disagree with this. Another reason GM uses torque management is for comfort. Most people don't like firm shifts, so GM maps the computer to reduce throttle and extend clutch engagement to make the smoothest shifts possible.

I'll use my 01 half-ton Burb as an example of everything I "did wrong" to it. Please pardon the minor thread derail; I'll try to bring it back around at the end of my post.

- I bought it used with 85,000 miles, in 2005. At 100,000 I flushed the transmission with 16 quarts of ATF. The horrors!
- Even with the 4.10 gears, the truck seemed like a dog to me. I also wanted to squeeze every little bit of power I could out of the engine, so I pulled the PCM and had it tuned for 91 octane by Charlie Wheatley down in Texas. Among other things, he removed 60-70% of the torque management. His testing also indicated I'd pick up 15-20 hp. So that puts me even closer to the max torque rating of the transmission. :E
- The change was noticeable - firmer shifts, better throttle response
- I drive the truck hard. When I'm alone, which is a lot, I'm usually driving it like I stole it.
- Since the tune, I've logged over 20,000 miles on that truck pulling the trailer that is in my sig. This trailer is heavy enough that I've had the rear end blow out on my twice while traveling. Also the main reason I bought the 08 2500.
- We don't camp in Michigan; it's always out of state. I've used that 01 half-ton to drag the trailer down to FL multiple times (so I've gone through the Appalachians), and we've also gone out West, as far as Yellowstone, so I've dragged the trailer over 9600-foot passes.
- The truck now has 185,000 miles and the transmission still shifts perfectly - no slipping or any signs of any problems whatsoever.
- I do try to take care of it. Prior to any towing, I installed an HD cluster to have the transmission temp gauge. The transmission usually runs 100° over ambient, regardless of duty cycle.
- I also tow strictly in third gear, minimizing stress on the transmission - in third it's a 1:1 ratio, so it's simply passing through the torque and power of the engine.

Torque management is much more severe on the GMT900 trucks. The PRIMARY reason for TM is comfort - not to protect the allegedly fragile transmissions. Right or wrong - smooth shifts are a luxury feature that most buyers notice.

I live near Detroit. Several of my friends are powertrain engineers for GM. I'd be happy to have one of them chime in as well.

My SCT tuner from Mike @ 5Star works great. It made a big difference in my truck.

fla-gypsy wrote:
Tuners for gasoline engines accomplish little to nothing IMO.

Since we have the same truck, I have to disagree. The 5 Star tune really woke the truck up. I have increased throttle response and it pulls harder thru the gears. I know it didn't add diesel like HP, but it made a noticeable difference.

What people don't understand is the overall HP the tuner is making is not the problem. A tuner can make only a handful of HP on a gasoline engine so that is no big deal.

The huge deal is taking the torque limiter off during shifting.

The first time I even heard of TL was on a mid 80's Vett. My first thought was why do they put that kind of cr@p on a Vett? In those days they did not have throttle by wire so the only way they could save the plastic junk 700R4 tranny was to blip the timing when the shift was made. The tranny in the Vetts in those days were aaaaaa, how do I put this; less than robust. :B (read junk) :B

And this was the days of junk tranny's like the 700R4. Hell, even mighty Allison has TL on it.............same way with the Dodge and Ford. They all have TL on them and they are damn good trannies now days.

There is always a reason OEM does things. In this case, it's to save parts.

Do what you want. I don't care. Put a 500HP shot of fogger on it for all I care. I'm just explaining why OEM puts things like TL on these new cars and trucks. :)