How to change shift points and firmness?
Has anyone played around with the shift settings? What settings change shift firmness and shift points?
I have a built 4l60e with 2000 rpm stall converter and 2.73 ratio rear with 29.5” tall tires behind a 5.3 LM7 with a moderate sized cam. Needless to say, not an ideal rear gear ratio, but it’s what I’ll need to live with for a few months until my budget recovers. In the mean time, I’d like the trans to hold its gears to higher rpm, as well as increase the firmness.
Have you figured anything out? I am attempting to get some definitions and instructions from Fitech, but I think my contacts are out of pocket this week.
Not yet. We just got hit by a bunch of snow this week, too. So, will likely be a week or two until I can get it out of the garage and play around with settings.
Hoping someone will chime in with some experience/suggestions, before I try winging it.
I spoke with Donnie at FiTech. He referred me to the Go Shift instructions for the transmission controls. Unfortunately, the instructions only cover the initial setup selections and does not delve into shift point and firmness calibration.
He and the Go Shift instructions did confirm that the Upshift Offset screen fields increase shift points at the specified TPS location. The higher the value, the higher the mph shift point. For example: line 3 references "1-2 15TPS Upshift". Increasing the value of this line to 20 puts the shift point from 1st gear to 2nd gear at 20mph when the throttle position is at 15% open, but under the next level (50TPS). Presumably, I will want to set these values progressively as the TPS increases, so the trans will hold gear longer the more throttle I give it.
As for the Downshift Offset screen, the values represent MPH in which downshifts occur.
For shift firmness, editing the values in the Line Pressure screen impact this. The higher the line pressure, the firmer the shift. Like the Upshift and Downshift functions, the value fields are in increments of gear and TPS. For example, 1st gear has three value fields, one for 10% TPS, 30% TPS, and 60% TPS. It's the same for 2nd, 3rd, and 4th. Like the Upshift function, I am assuming that having progressively higher values in relation to TPS % is preferred. (More throttle = harder shifts) However, someone could also go the opposite direction for softer shifts at higher throttle to help to reduce tire spin and drive train damage in high horsepower applications.
As an added note, I also noticed that the initial settings in the Trq Converter screen default to the TCC activation at 1450 rpm. In other words, it'll lock the converter over 1450rpm (if the brake is not applied). Since I have a 2000rpm stall converter, Donnie confirmed that I should set the TCC activation rpm above my converter's stall rpm. How far over, I'm not certain. As for the TCC deactivation field, that defaults to 950 rpm. Given that the default deactivation is 500 rpm less than the activation, I am assuming this will need to be set within 500 rpm of the new activation setting.
I'll post my findings once I can drive the car again and play around with the settings. I'm also going to consult my transmission builder to see if he has any advise on what he thinks may be appropriate settings to start with for my engine/trans setup.
To be continued.....
Great information, thank you.
I was fortunate enough to get a couple hours behind the wheel over the holiday weekend to play with the transmission settings. And I was surprised at what I learned.
Shift points (both upshift and downshift): These settings are Offsets from the "factory" shift point settings. Hence the word "Offset" in the menu selection name (duh, I should have guessed that from the start). Then, as mentioned in my previous post, the offset is set at stages of TPS. For example, if the factory shift point for 1-2 upshift shifts is 15mph between 0% & 14%TPS, then setting the "1-2 oTPS Upshift" to 5 will effectively increase your shift point at this TPS range to 20mph. Transversely, changing this setting to -5 will decrease your upshift rpm by 5mph, down to 10mph.
Line Pressure: I'm still kinda guessing at this one, but it appears that the line pressure settings are % multiples of the pump's pressure capacity. In other words, if your pump is capable of 200psi, a setting of 50 will effectively give you a line pressure of 100psi (50% of the pump's capacity).
Now, this opens up the discussion of what line pressure is considered "good". Generally speaking, low pressure will give you weak shifts and allow the trans clutches to slip more, effectively raising heat and premature wear. Higher line pressure will increase shift firmness, shift speed, as well as clutch holding capacity, reducing heat from slippage.
A person can burn up a stock transmission really quick if not running enough line pressure, so be mindful of that. However, too high of pressure can cause premature pump wear, blow out lines, gaskets, and can even blow out your torque converter if the pressure spikes too high.
As for my setup, I'm running a modified 4l60e with upgraded clutches, pump, etc, along with AN lines and a heavy duty external cooler with fan. So, I have some extra margin of error on the high-side. As of this weekend, I set my line pressure for all gears at 65 for TPS 10, 75 for TPS 30, and 85 for TPS 60. (90 is the highest pressure setting) These seemed like good settings. When I had the pressure setting below 65, the shifts seemed a little slow. 65 at TPS 10 seemed like a good setting as it was fast but didn't snap my neck at light throttle.
Disclaimer: If you're running a shift improver kit, the type of shift kit used will dramatically change the shift firmness and speed, too. The kit in my trans isn't too aggressive. I'd imagine that an aggressive shift kit with a high line pressure would be a recipe for disaster.
Torque Converter: This one is a little tricky. I still don't have it set quite right yet, and probably won't get a good setting until I get better gears in the back. As mentioned in my previous post, I'm running a 2000 stall converter. Presumably, I wouldn't want the converter to lock up until it's over its stall rating. However, with the 2.73 gears currently in the rear, I am only running about 1600 rpm at 65-70 mph in 4th gear. I ended up setting the TCC lockup at 1450 (this is also the stock calibration from FiTech), but increased the TCC MPH threshold to 60mph. So, the converter won't lock up until I'm at speeds above 60mph.
I then have the converter stay locked down to 1000rpm, effectively allowing the engine to downshift and compression brake upon deceleration.
I will say that when downshifting the converter does feel like it's staying locked, effectively decreasing downshift acceleration performance. However, for less-spirited driving, these converter settings seem to be ok for now.
There also appears to be a min and max TPS setting for the converter lockup, but I am not sure what it does nor have I found any information on it, so I've left that at its factory settings. I'll have to make another call to FiTech to see if they can lend some insight into it's function. (Ideally, I'm hoping these settings will allow me to control converter lockup by TPS position. This would help solve the converter staying locked in downshift acceleration issue.)
I will add information to this post as I continue to tweak the settings and learn more.
Thank you for posting this information.
I bought a 70002 with trans control over a year ago and just started the car.
IS there an update because I do not see anywhere in the hand held that has these options for the transmission. Only in the initial set up to select the transmission.
Thank again for this forum, it has been very helpful on this project.
Quote from Damerjo on May 5, 2019, 8:02 pmThank you for posting this information.
I bought a 70002 with trans control over a year ago and just started the car.
IS there an update because I do not see anywhere in the hand held that has these options for the transmission. Only in the initial set up to select the transmission.
Thank again for this forum, it has been very helpful on this project.
Have you enabled the Pro Tuning menu. In the display menu to enable.
Quote from Austin DeHaas on May 5, 2019, 8:19 pmQuote from Damerjo on May 5, 2019, 8:02 pmThank you for posting this information.
I bought a 70002 with trans control over a year ago and just started the car.
IS there an update because I do not see anywhere in the hand held that has these options for the transmission. Only in the initial set up to select the transmission.
Thank again for this forum, it has been very helpful on this project.
Have you enabled the Pro Tuning menu. In the display menu to enable.
Yes sir, I did enable the Pro Tuning Menu and look through it. I will look again I probably missed it.
I take it there is not an update for the LS system, I was just curious.
Thank you
Quote from Damerjo on May 6, 2019, 3:04 pmQuote from Austin DeHaas on May 5, 2019, 8:19 pmQuote from Damerjo on May 5, 2019, 8:02 pmThank you for posting this information.
I bought a 70002 with trans control over a year ago and just started the car.
IS there an update because I do not see anywhere in the hand held that has these options for the transmission. Only in the initial set up to select the transmission.
Thank again for this forum, it has been very helpful on this project.
Have you enabled the Pro Tuning menu. In the display menu to enable.
Yes sir, I did enable the Pro Tuning Menu and look through it. I will look again I probably missed it.
I take it there is not an update for the LS system, I was just curious.
Thank you
No, there isn't an update. Only a boosted software that gives those guys some extra tuning parameters.
I personally don't have an LS system. Hopefully one of the others will chime in.