tlillard23
Senior Member
Trans Juice? Who knows, the shop that rebuilt the trans and i had to visit them 7 times in 3 years isn't on my Christmas card list!! LOL
I suppose I don't know how exactly hill descent works but I know the newer models of vans have it along with the additional gears. If you had access to one to suck the programming out of that would be interesting. To be frank, my 1991 Dodge Roadtrek with the 318 handled down hill grades better than our 2004 Chevy.
@Stevemo I see booster already replied but, You might be mixing up your terms??
Hill descent is for 4x4 operation on slippery slopes, using ABS and gears to keep traction - otherwise the ABS sees wheel lock and just lets go, no brakes (plenty of breaks though!!)
I believe you're referring to the engine braking/trans braking that is coded into the tow haul feature of newer vehicles. (GM calls their system "grade braking") I think you could sort of program that into your tow haul button, but it wouldn't know if you're on a downhill or not and keep the torque converter locked up all the time when coasting. perhaps normal mode would be for flat surfaces and tow all for uphill downhill.
I did a little looking and yes you can do it, they have a high speed and low speed throttle torque converter activation/ deactivation on Coast. You could possibly toy with those numbers enough to make it relatively usable. but you'd have to shut off tow/haul on the freeway, and anytime that you just wanted to let off the gas and coast. but if you're doing that you could just make the "normal mode" equal to tow haul without the grade brake.
I know this is an older post with lots of technical info. I understand some of it. I am trying to keep both engine and trans temps down. The question(s) I have are:
1. Which is the best tune for the average driver
2. Do you have to change any hardware?
3. Is it just software change?
4. How would I install the change?
Thanks a lot for all the info you guys provide.
Ok, I think I ain't too smart but. Do I understand that tow/haul will lock the torque convertor, therefore when running up a long steep grade the trans should run cooler?
Thanks Booster. I had my 05c210v reallly heat up when we driving thru Bear Country USA, South Dakota. Had to open all windows and turn the heat on full. To me this was unsat. I would like to be able to load a program such as yours to be able to lower trans/engine temp.
Another issue causing low speed overheating is having the hot air from the radiator recirculate to the front of the cooling stack. Mitigating this by making sure that the air does not recirculate over the top and sides of the cooling stack will make a huge difference in cooling system performance in low speed and stop and go situations.
What is the cooling stack? I think I understand, but a little help here. If you are referring to anything under the hood and basically past the radiator going to the rear, then I would almost understand.
Yep, this is what tlillard was referring to earlier.
I did this a long time ago and it is described in the thread.
I found it did not radically change looping out the sides of the area around the radiator, but there was some. Most of the looping was air that came out from under the van if there was any breeze from the rear.
The bigger benefit for us was in low speed cooling and a lesser benefit at higher speed as sealing the bypasses around the radiator put all the air going into the engine compartment through the radiator instead of around it. The benefit was magnified with the larger radiator we put in so got even better.
Our radiator only cools the engine as the trans is on it's own coolers so engine stays very cool.
Not having to do with class B but for our Safari Trek on a Chevy P30 chassis I had to install an air dam on top of the radiator, pipe tubing down the sides of the radiator and then installed chloroplast in the open area in front of the cooling stack on the bottom. This has all performed well for low speed driving/crawling compared to before and improved highway speed cooling significantly. The cooling fan now does not engage nearly as much as it usta. Crawling engine temperatures and A/C performance when crawling have greatly improved.
A strong tail wind does make the cooling fan run noticeably more, especially when the A/C is engaged in the heat.Yep, as long as you are moving the hot air usually makes it to the sides or rear to exit and not go out and back around. Sitting still with a light wind from behind can be really bad.
Have you even noticed you will run a touch warmer on a very windy day even at highway speeds if it is a full on tailwind. We had over 50mph tailwind for a while once and it was very noticeable on the scangauge, but we can even see it at 25mph wind. A lot probably depends on where the thermostat is. The LS engines have it on radiator to the engine instead of in the hose to radiator like the old engines did.