EFIDynoTuning Forum

Here is my current tune and a log pulling in low range. The hope is that TCC lockup in 1st will be just the right gear ratio with 33" tires in high range when pulling trailer up the 17% grade up to my house. Truck has SD 80s, AFR heads, 9.8:1 compression running e85. Tripple disk 2k stall converter. She holds 55gallons of fuel, so range is over 400mi driving the foothills of norcal. On the open road range is 550+. Shes as beast off road and in the snow.

Goals I have yet to accomplish:
1. OD lockout switch to hold 1st gear. Patch is included in attached XDF but still needs work.
2. Create VSS based TCC lock/unlock points for when locked 1st gear.
3. 3rd and 4th gear sometimes shift a bit hard. Lowered EPC to 0 below 300 TPREL and that helped but still occasionally shifts hard on hills. I added clutches (totaling seven in 3rd and three in 4th) when I built the trans so not surprised just need a little help pulling some pressure. Also, the manual 2-3 shift is strange and harsh.
4. Thinking I need to bypass the radiator trans cooler. Seems that the engine coolant bypass from the intake to the cold side of the rad is just heating the trans. Engine and trans temp are usually identical. Probably not a bad thing in the winter.

Thanks for the help!

I simply want this:

If in first gear and od lockout switch is on, do not shift into second gear under any circumstances.

The point is to be able to lock the converter in 1st gear. The E4OD in manual low is hydraulicly unable to lock the converter. I need to prevent shifting into second with the selector in Drive. I have it mostly working by just setting fn12s to 125mph but as soon as rpm and speed stabilizes some other logic is forcing the shift.

Looks like shift validation is only about sending trouble codes for missed shifts. I tried forcing GR_DS to 1 but it keeps shifting up and down. Looks like I'll have to bypass the code. Is setting tstrat while driving even advisable?

Yeah thanks for that. The goal is to keep the transmission from shifting into second when the OD lockout switch is on. I wrote code that has replaced fn12s and now VS_SH_VAL2 and is working great except once the speed and RPM become stable something else is forcing the shift. I did not want to modify the main shift routine, but I may have to if I can't do it with calibration constants.

Think I may have found it. Will validate later today.

VS_SH_VAL2 = Minimum vehicle speed to validate an upshift to 2nd gear.

So I wrote some code that replaces fn12s with all shift points above 120MPH. It is activated by the OD selector switch. It works but as soon as I stop accelerating some other code is forcing a shift to 2nd. I have been unable to identify what is causing it to shift. I was under the impression based on the lhbh1 docs that ne12s (5500RPM) and fn12s are the only functions that control the 1-2 shift. Any ideas where else to look?

Naw too heavy. There was a 7.3 power stroke stuck in the ditch when I took this pic.

red5.0fogger wrote: ↑2024 Mar 18, 06:17
what's in the 7000lbs trailer? Can you take anything out of it?

I could remove the horses but then might as well leave the trailer behind :)

Yeah I have had those thoughts as well. 1st gear (with shift lever in drive) with the TCC locked is the next and final test before going to boost. That should be 100rpm per mph which would be on the high side of ideal. I don't really need to go faster than 40mph up these hills.

I just don't want to give up the nice 1600-1700 RPM cruise at 65mph by changing the gears.

You guys seen this? Seems like a winner for short bursts. Not sure if the motor would survive several minutes continuous.
Bench test at 11:39
https://www.youtube.com/watch?v=t-5pptoTMYM

I didn't think the tfs1 cam was a good choice for turbo