How Bout' a "Snow and Ice" tune

[soutthpaw]

I drove up to Denver today in the snow and ice and came up with the idea of a Snow and Ice tune. currently I only had the 60 80 and 100 HP tunes loade. several times when i gave it gas on the hill climb on the freeway the wheels would break loose. Maybe Bill could add this to their selection of tunes for the FU and flip chip. basically we want to avoid wheel slip as much as possible. also want to stay off brakes as much as possible when slowing. Here are some of the things I was thinking about

• below stock power levels on light to med throttle
• hold the higher gears longer
• allow 2nd gear manual start
• slow soft TC lockup delayed unlock
• engine braking automatically on decel
• Longer glow plug on times
• faster engine warm up

any other ideas? As I am clueless about auto transmission stuff I am kinda hoping Cody or Bill can throw out some ideas...

I think this should also be a good MPG tune as we would be backing off the power and fuel levels :o

[cleatus12r]

Originally Posted by soutthpaw

I drove up to Denver today in the snow and ice and came up with the idea of a Snow and Ice tune. currently I only had the 60 80 and 100 HP tunes loade. several times when i gave it gas on the hill climb on the freeway the wheels would break loose. Maybe Bill could add this to their selection of tunes for the FU and flip chip. basically we want to avoid wheel slip as much as possible. also want to stay off brakes as much as possible when slowing. Here are some of the things I was thinking about

• below stock power levels on light to med throttle How about reduced power across the board...EASY to do. Limit torque to about 50% at all times.
• hold the higher gears longer
• allow 2nd gear manual startCan already be done by putting the gear selector in "2".
• slow soft TC lockup delayed unlock Easy. I'd keep the unlock points the same....only because it's safer to use brake applications vs. engine braking.
• engine braking automatically on decelEngine braking (or lots of it) is bad on ice. If you get the rear tires to lock up with braking, it's unlikely they'll start to roll again if there is too much resistance.
• Longer glow plug on times They're already on for a stupid-long time as it is. Glow plug usage after the engine is started and has been running for 30 seconds is a waste of a good alternator.
• faster engine warm up That's ALL determined by the driver. These engines will not get warm at all just idling away (or running with the exhaust backpressure valve closed @1100 RPM). Driving them is the only way to improve warm-up times. You have to realize that idling causes exhaust temps in the <300 degree range. With all the coolant that these beasts hold, it takes a good long time to get it hot without any combustion heat. Gassers typically run at 900-1100+ degrees at an idle which heats up the coolant a lot faster....even without a load on them.
  
  

any other ideas? As I am clueless about auto transmission stuff I am kinda hoping Cody or Bill can throw out some ideas...

I think this should also be a good MPG tune as we would be backing off the power and fuel levels :o

You have a good idea, but for the most part the only thing you can do to keep from spinning is using a stock program or less than stock power levels.

Keep the thinking cap on!

[soutthpaw]

I thought if you put it in second it still drops to first if you stop or put too much load on?
with engine braking you are forcing the front and rear axle to stay at the same speed rather than one end locking up though.... would be fun to try out some tuning ... at some point Ill get some quiet time to look at my maps and see what I can change

Humm what about increasing the amount of torque reduction in the up shift. Im thinking higher throttle position the more torque reduction you would want???

[907DAVE]

Maybe make the idle when extremely cold (about -20 to -40)not sound so freakin loud. Kinda scary sounding.

Also I think all the shifts should be really smooth and early, lock the TC sooner than normal to keep RPM's low(below 1800).

This is one of the main reasons I want the Minotaur Software.

[cleatus12r]

Originally Posted by soutthpaw

I thought if you put it in second it still drops to first if you stop or put too much load on?
with engine braking you are forcing the front and rear axle to stay at the same speed rather than one end locking up though.... would be fun to try out some tuning ... at some point Ill get some quiet time to look at my maps and see what I can change

Humm what about increasing the amount of torque reduction in the up shift. Im thinking higher throttle position the more torque reduction you would want???

Nope, no matter how far into the go-pedal you get, if the selector is in "2", then the truck will be in second. It is a function of the manual valve only (the one hooked to the shift cable). GM on the other hand....

The problem with driving in four wheel drive is that there is ALWAYS the increased possibility of a slide due to ALL tires losing traction. During engine braking, it's not really likely. However, when in 4x4 with a mechanically linked transfer system (like our SD trucks and Excursions have) if one wheel locks up....they all lock. Also during turning maneuvers, the risk of the rear tires pushing the front through a corner is increased....especially with a limited slip rear differential because the binding created in the drivetrain WILL be alleviated through the drive wheels.

The factory "torque reduction" strategy is great. The way they are set up in most aftermarket tuning is too harsh. Bill and I have already went into this a little.

[cleatus12r]

Originally Posted by 907dave

Maybe make the idle when extremely cold (about -20 to -40)not sound so freakin loud. Kinda scary sounding.

Also I think all the shifts should be really smooth and early, lock the TC sooner than normal to keep RPM's low(below 1800).

This is one of the main reasons I want the Minotaur Software.

Been there, done that.

I use 5/40 in the winter and have written programs to address this concern relating to SOI vs. EOT and SOI delay when the engine is really cold.

I agree with the smooth shifts....always have agreed no matter if it's for icy roads or driving on pavement in the summer.

The problem with applying the torque converter clutch earlier is that even though there is less torque available in sub-1800 RPM ranges, the drive wheels get a direct power input from the engine. Conversely, when the TCC is not applied, the slippage in the fluid coupling greatly softens the "impact" of torque application to the rear wheels.

[907DAVE]

Maybe change the PWM of the TCC to soften its application, and have it unlock immediatly when you let off the pedal, for me any way to keep the R's down would be nice.

[cleatus12r]

Originally Posted by 907dave

Maybe change the PWM of the TCC to soften its application, and have it unlock immediatly when you let off the pedal, for me any way to keep the R's down would be nice.

Piece of cake. The TCC apply rate can be changed to apply the clutch softly. BUT "burn time" is not good and the longer the apply takes to reach 60+% duty cycle the more friction material damage due to heat. I use the value of 60% because it is usually enough to create a lock and hold condition depending on EPC or "line pressure".

Unlocking the TCC on deceleration is also possible. Heck, lots of PCM strategies out there do that anyway. It's possible to change a few parameters and get even a PMT1 to do it.

[907DAVE]

Originally Posted by cleatus12r

Been there, done that.

I use 5/40 in the winter and have written programs to address this concern relating to SOI vs. EOT and SOI delay when the engine is really cold.

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Is there any harm by doing this? Shouldn't the engine noise level be similar on a cold engine as a warm one? Or are there other things influencing this? I realize that it wont be as quiet but damn this thing can get really loud. As a tuner how would you know when you have gone too far?

[cleatus12r]

Originally Posted by 907dave

Is there any harm by doing this? Shouldn't the engine noise level be similar on a cold engine as a warm one? Or are there other things influencing this? I realize that it wont be as quiet but damn this thing can get really loud. As a tuner how would you know when you have gone too far?

There isn't any real mechanical harm in "retarding" the start of injection when the engine's cold. As far as retarding the SOI goes, it's not really "retarding" since it's more accurate to say that it's just less advanced. A lot of folks sell quiet tunes....even PHP has a Whisper Mode. Incorporating less advance in both the Start Of Injection for RPM vs. EOT and the Start Of Injection Delay for EOT vs. ICP maps allows the PCM to delay the commanded injection event slightly for the thinner oil when cold since the whole reason that map is there is because of the oil viscosity along with slower combustion rates and longer ignition time. Using 5W/40 oil when cold results in a "faster" injector than one utilizing 15W/40 at the same temperature therefore less advancing of the timing is necessary.

The noise level will always be slightly higher with a colder engine because it is working harder just to stay running. The drawbacks to not enough injector "lead time" when cold could be harder starting, white/bluish smoke, and sluggish performance. It takes quite a bit of "less SOI advance" to get these drawbacks so once you get to the hard starting or smoking, you've gone too far with that particular truck. Too much SOI advance is definitely audible and it's something that should be avoided for fear of a junk engine.

If you've ever heard of people recommending being easy on the engine while it's cold, it's because of these EOT related maps. There is A LOT of "advancing" going on there. Add into that the increased SOI of aftermarket tuning (RPM vs. Mass Fuel Desired) and you get some pretty awesome timing.