Trans temps w/ pi converter?

1fastTRX · Dec 6, 2017

I'm going to try ANOTHER radiator. Both mishimoto radiators (old version and new version) flat out cannot keep up in regards to engine cooling and transmission cooling. Maybe those radiators were a contributing factor to my temps. Next is the performance radiator. I'll post back once the swap is done. Maybe another week or 2.

Hey Mark,
How much contribution to trans cooling is the radiator responsible for?

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Mark Kovalsky · Dec 7, 2017

The radiator does at least half of the trans cooling. It is a very efficient cooler and receives the hottest fluid right out of the transmission.

1fastTRX · Dec 18, 2017

Tried the radiator from performance. Filled the fresh water tanks on the toyhauler (16-17k lbs with just water) and went up the local grade (cajon pass). Ran the IDP tow tune which tends to run the trans hot and doesn't like locking up unless the stars are aligned. Engine temps actually did well considering I was running her hard, but tranny hit 237. I'm sure the gear head tune would've had lower temps. Either way she's still pretty warm.

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mandkole · Dec 20, 2017

20k trailer pulling El Cajon ? It sounds like the truck and trans is fine, but rather it's way overloaded and beyond supported power level for cooling capacity. Get an f550, leave it stock and temps will be fine.

1fastTRX · Dec 22, 2017

mandkole said:
20k trailer pulling El Cajon ? It sounds like the truck and trans is fine, but rather it's way overloaded and beyond supported power level for cooling capacity. Get an f550, leave it stock and temps will be fine.

Used my buddy's truck as a baseline right before we went up in mine. Same day, same trailer just switched trucks.

Differences between trucks being he has stock 3.73's vs my 4.10's (same tire size), he has 175/30 injectors vs my stock injectors. He has a Twisted tranny with DPC converter vs my Warren with PI converter. More fuel, more power, and taller gears. Technically I have the advantage.

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mandkole · Dec 23, 2017

The post was a poke given the weight you're managing, but I was glad to get rid of my PI. Did your buddy's converter lock more during the pull? Have you monitored input and output speeds for slip?

1fastTRX · Dec 23, 2017

I didn't monitor shaft speeds. I only have the Torque app for Android to monitor stuff so I'm not sure if I can. His tranny stayed unlocked the whole haul up the hill same as mine. The one big difference was who's tuning each of us used. I know IDP tuning struggles to lock my TC and feels "looser" and is what I used this go-round. Buddy ran GH tune.

Why the excitement to get rid of your PI converter?

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mandkole · Dec 24, 2017

In my case, and noting I have a 7.3, my converter was older and a real hodgepodge of junk. It wasn't a triple disk, more like 2.5 with a dodge stator and some goofy other parts. It had been drifting for awhile as well, so the clutch was hammered. When the trans was freshened, we spent time on making sure the tcc valve at the pump was well balanced and sealed. We put low stall 6.0 converter back in it. It naturally builds a heat on hard, hot pulls but locks in 3rd (4r100) and stays locked. It still hasn't gotten over 195 and cools as soon as the load is gone.

I'm surprised a lock isn't commanded in lower gears. PWM eases it in but tuning would lock depending on shaft/wheel speed/throttle input/load. You may have a tcc circuit pressure/ flow issue in the pump or the converter choice is a little too loose. All that said, I have no experience with 6.0s or such an overloaded condition. That's a massive trailer.

1fastTRX · Dec 24, 2017

Considering the engine was able to finally run cooler I've decided to keep the truck. Trans I can work with for now. She was on the verge of being sold, because she wouldn't stay cool with the trailer. Stupid Mishimoto radiator.

Trans and converter were completely rebuilt last month. Maybe one day I'll throw in a DPC converter and see how she does. I want to try the BD Tap Shifter strictly for towing. Ideally I'd like lockup as low as 3rd gear and sometimes she needs an extra downshift, but strategy doesn't command it unless I slow down a couple mph which ruins all my momentum.

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