EFIDynoTuning Forum

FN620(TV_PRES) - EPC VFS transfer function is at 0xb99a but not sure if it is a good idea to modify.

fn622 and 622a do not appear to be implemented in A1c AFAIK

I'll work on locating these:

TVPMIN = Global minimum TV_PRES clip, psi.
- TVPMN1 = Minimum EPC clip, PDL = 1, GEAR = 1, psi.
- TVPMN2 = Minimum EPC clip, PDL = 1, GEAR = 2, psi.
- TVPMN3 = Minimum EPC clip, PDL = 1, GEAR = 3, psi.
- TVPMX1 = Maximum EPC clip, PDL = 1, GEAR = 1, psi.
- TVPMX2 = Maximum EPC clip, PDL = 1, GEAR = 2, psi.
- TVPMX3 = Maximum EPC clip, PDL = 1, GEAR = 3, psi.
- VSSTAL = Maximum vehicle speed to do stall EPC.

We are obviously running into some minimum clip. I tried going further negative on EPC for 3rd and 4th but it made no difference. Since the latest update, it is shifting hard in third and fourth all the time

I hope this is good. First time I've burned out lol. has cold start at 36 degrees. Had to crank it 3 times.

IIRC the tprel/epc functions can be ignored in certain circumstances. Sometimes it shifts beautifully and others it is slamming into 3rd and 4th still. I wonder if we could force it to use the tprel/epc funtions all the time.

OK I'll do it again from a stop. I shifted at 6k but is 5500 ok this time?
speed is correct, 1st gear is 2.71:1, 3.55 gears and 33" tires makes for 1mph per 100 rpm assuming the converter is locked.
I think KIHP is already in the xdf. Does it just need to be set to 0?
There is no factory knock sensor hardware on the 5.8 or ecu. Not sure why Henry left it out. I just used a wire that was left open ended in the intermediate engine harness connector.

I don't think the dual in line cats were ever designed to flow at this power level. I inspected them when I had it out of the truck but could only see the backside of the rear converter. It definitely moves a lot of air, so it is not completely blocked.

Ok that makes sense, nice to see wot load in a more reasonable place.
I used the knock sensor wire since it was already running up to the engine harness connector and was not used. I don't remember what pin that is.

Converter is locking normally but back to hard shifting into 3rd. There were a few hard shifts in the wot log (wot pull right at the end)

Way less torque below 2k. Converter does not like to lock up for some reason. Idle and shifting is better for sure.

I'm honestly not sure how I messed up FN825A so bad. Pin 21 is referencing the CPU pin not the main connector, I definitely have an IAC.
I adjusted 820b by feel and it idles nicely. Thanks for the help dialing in correctly.

Timing was based on the factory 351w tune and that was as good as I could get without a dyno. I messed with timing till I was blue in the face. I am looking forward to trying this out.

Idea with the fan patch was temporary. I plan to use the datalog hook on the console routine when ready to turn off datalogging.

fn074a was copied from my stock tune since I figured they measured it for the stock pipes/cats I am running. It definitely seemed to help but remember I am just a tooner. I am not sure how engine mods effect fn074a or how to dial it in correctly. Is that in the write ups? I may have missed it.

I didn't change injector offset. It is the same as the startup tune you sent over. I just set the fuel pressure to 30psi and went with it.

I'll fire this up and report back. Thanks again.

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?