Need Help tuning my 4L65E transmission parameters Please

[LS2Ttype]

87 Buick T-type Regal
LS2 (58x)
4L65E
E38/T42
08 Silverado OS

Novi supercharger
220/235 cam
ZR1 2.5 map sensor
LS3 MAF sensor

Long Story short, i dropped car off for tuning and was told the car needed bigger injectors , swapped out the #60's for FIC 80's, Tuner says car pulls like a freight train, runs great etc,
i pick up the car and notice that the car shifts to early , is in 4th by 36mph and converter locks up at 38 , it doesn't down shift although i havent smashed it to the floor , 4th doesnt kick down to 3rd , seems to just slip

i message the Tuner and its gets shady , he tells me to get a HP tuner kit and that i can upload and tune the Transmission parameters myself to my liking , I down loaded a stock 08 Silverado tune and what do you know i have basically a Tuned car with a stock transmission tune, Just doesnt make sense to give me back the car like that
Anyway i Now have a MVPI-2 Tuner and need to get this transmission figured out,
looking for a help from someone who has good experience especially with Truck operating systems

[5FDP]

Honestly a lot of it does come down to what you want.

It's easy enough to change the shift speeds. Like if you want 4th gear at 50 or 55mph and moving the other gears up in mph as well. Same with torque converter lock up speeds, move those as you change the mph shift speeds.


Also make sure the computer has the correct gear ratio and tire size under the edit tabs gear/tire wizard. If that data is wrong the transmission will never shift right.

[Jeff7577]

First thing to do is make sure your tire size and gear ratio information is correct.

[LS2Ttype]

hey thank you for the Reply , Yes exactly and he left my tire height at 31" when i am riding on 27", he did change the gear ratio to 3:42, i am new to this but i see how to move up the shift points and have the converter lock up later but what about the other patterns? example pattern A pattern B etc
also does the wrong tire height have anything to do with the transmission not down shifting?

[LS2Ttype]

gear ratio is correct (3:42) but Tire height is way off, 31" (27")

[Jeff7577]

because it is shifting based on speed and when you have the wrong tire size your speed is not correct. We are not saying this will fix all your problems but these need to be correct before moving on.

[LS2Ttype]

OK , And as far as 1-2, 2-3, and 3-4 shift points are concerned what is a good place to start? my 1-2 shifts at only 10mph

[Jeff7577]

At wot it shifts at 10 mph?

[LS2Ttype]

NO , AT WOT is set 1-2 shift (40MPH) 2-3 shift (75MPH)

[5FDP]

Change the tire size in the tune and then have it autoscale the transmission settings. Now take a look at your shift speeds and what they are.

You need to look at the table and read how it works. It should be based on speed and throttle percentage. Under low amounts of throttle it's going to shift at lower speeds. If you don't want it to shift so soon, then raise the mph settings to what you want.

At 80% throttle it's not going to shift at 10mph but at 10% throttle it might depending on how you have it set up. Remember to adjust the downshift speeds as well.

[LS2Ttype]

OK Thank you, I understand al of that,
When it comes to down shifts what does the MPH represent in the Table? the up shifts i understand and seems simple enough to raise and adjust to my liking
but not sure about down shift settings besides that the downshifts MPH has to be less than the upshifts for each gear

Maybe you can explain that to me Please

[LS2Ttype]

Can someone Please post a file of there 4L60 transmission Tune , Preferably a Truck performance Tune since i am a 58X LS2 and a E38/T42 running a 08 Silverado OS
At least something close that i can reference from

[LS2Ttype]

Change the tire size in the tune and then have it autoscale the transmission settings. Now take a look at your shift speeds and what they are.

You need to look at the table and read how it works. It should be based on speed and throttle percentage. Under low amounts of throttle it's going to shift at lower speeds. If you don't want it to shift so soon, then raise the mph settings to what you want.

At 80% throttle it's not going to shift at 10mph but at 10% throttle it might depending on how you have it set up. Remember to adjust the downshift speeds as well.

repulled after rob switching to EFI for VE table - 1.hpt

[5FDP]

The tune is a little worse than I thought. The transmission stuff is one thing that can be correct but I see other major things incorrect.

I assume this is running rather large injectors for the supercharger system. Injectors that flow more than the limit of this computer from the looks of it.

The injector flow rate limit on these early E38's is 63.5lb/hr and your tuner before you just maxed out that table which does throw everything off. The work around is to give the computer a scaled tune to make larger injectors work better. We would double the stoich value from 14.XX to ~29.XX to now give the computer a 127lb/hr injector limit. The flow rate would be cut in half, so if you are running 80lb/hr injectors you'd stick 40lb/hr in the calibration and we'd also half the IVT terms in the injector data to finished off the scaling. It's a good and easy way to scale a tune for most people.

I noticed that because of this the tune shows the commanded air fuel ratio in under power enrichment to be way lean. It asking for high 12's and low 13's and the tuner more than likely just spammed the VVE table with more fuel to get his desired air fuel ratio instead of actually tuning it right. Or he could not control what he was doing and just kept leaning out the commanded fueling until he reached it. Either way that's the wrong way to do it.

The proper way is to command a value and make the fuel tables reach that value. The commanded value should never change, if you want 11.5 it needs to stay at 11.5 afr. The MAF or VVE tables must be corrected to have it reach that value under the given situations.

The timing looks safe, so that is a plus.



And one kicker, you are running a MAF sensor but the tuner completely disabled it. You may or may not know that. So if you paid to have it tuned with the MAF sensor you bought on purpose, they didn't even do that for you.

[LS2Ttype]

The tune is a little worse than I thought. The transmission stuff is one thing that can be correct but I see other major things incorrect.

I assume this is running rather large injectors for the supercharger system. Injectors that flow more than the limit of this computer from the looks of it.

The injector flow rate limit on these early E38's is 63.5lb/hr and your tuner before you just maxed out that table which does throw everything off. The work around is to give the computer a scaled tune to make larger injectors work better. We would double the stoich value from 14.XX to ~29.XX to now give the computer a 127lb/hr injector limit. The flow rate would be cut in half, so if you are running 80lb/hr injectors you'd stick 40lb/hr in the calibration and we'd also half the IVT terms in the injector data to finished off the scaling. It's a good and easy way to scale a tune for most people.

I noticed that because of this the tune shows the commanded air fuel ratio in under power enrichment to be way lean. It asking for high 12's and low 13's and the tuner more than likely just spammed the VVE table with more fuel to get his desired air fuel ratio instead of actually tuning it right. Or he could not control what he was doing and just kept leaning out the commanded fueling until he reached it. Either way that's the wrong way to do it.

The proper way is to command a value and make the fuel tables reach that value. The commanded value should never change, if you want 11.5 it needs to stay at 11.5 afr. The MAF or VVE tables must be corrected to have it reach that value under the given situations.

The timing looks safe, so that is a plus.



And one kicker, you are running a MAF sensor but the tuner completely disabled it. You may or may not know that. So if you paid to have it tuned with the MAF sensor you bought on purpose, they didn't even do that for you.

Figures!! I sent you a PM 5FDP