Tuning: 100% TCC application in 2nd?

[TripleTransAm]

We don't have a tuning-info-specific forum here (yet?) so I'm prefixing the subject with the word 'tuning'.

I don't have the s/w or h/w to do this just yet, but this idea has been bouncing around my head for the past week or so: is there any negative side effect to increasing the part-throttle 2nd gear TCC application PWM value to 100% instead of the circa-55% the stock programming provides?

Stock, there is the 1-2 upshift, followed by a 50% TCC application (where I always felt an upshift to 3rd gear would feel best) and then finally there's the 2-3 upshift with the immediate TCC application at 100%. What I'm wondering is if there would be a reliability issue with changing that 50% in 2nd gear straight to a 100% application.

Driveability-wise, yes I realize that the engine RPM would bog something fairly nasty (if I kept the application speed at the stock range). I'm just wondering if there is an impact on tranny life or something else.

By the same token, I'm wondering if it's possible to slap a 3rd gear upshift at that earlier point instead of a 50% TCC application. ie. make it go 1-2, 2-3 early (circa 15-18 mph, where the current 50% TCC application is), and THEN apply the TCC 100% at the point where the stock 2-3 upshift is (25 mph).
In other words, I'm curious why they didn't choose earlier upshifts in their quest for CAFE results rather than stay in 2nd longer and slip the TCC the way they do.

Any insight greatly appreciated.

[RF Overlord]

I TOLD you all not to let /Steve buy an AutoTap...NOW see what you've done...I'm gonna be up half the night drawing lissajous curves of line pressure vs. TCC duty cycle...

Seriously bro, I think it's pretty well accepted that Ford programmed the 4R70W in the MM to get into the highest gear possible as soon as possible, primarily for CAFE reasons...exactly why they took a specific route, I guess only Jerry W. can really answer...he's going to be at Indy, maybe SOMEONE should ask him... :eek:

Another member posted about a conversation they had with Steve Babcock where he mentioned that they originally wanted 3.90s (IIRC) but had to back down to the 3.55s to avoid the gas-guzzler tax, so I'm sure there were a lot more compromises made in that same vein, and transmission programming was one of those victims...

Here's another thought...no matter how they programmed the shift schedule, ½ the people will say it's too soft, and the other ½ will say it's too firm...maybe the weird-o TCC duty cycle is their best-guess attempt at a performance oriented compromise...?

[TripleTransAm]

I agree the tranny shifts were programmed for CAFE, and I'd agree that early shifts would be a result of this orientation. But I'm confused why they didn't just choose to grab 3rd a bit earlier without the 50% TCC slipping and then nail the TCC at 100% rather than the current "slip the TCC at 50% for a while and THEN grab 3rd/100%".

The reason I'm even thinking about this is because I don't believe that CAFE necessarily represents real world fuel consumption. I understand that certain distinct tests are required in order to provide a basis for comparison and evaluation, but I also believe that some manufacturers sometimes go overboard addressing CAFE-specific situations to the detriment of overall real-world consumption. An example of this is the "skip-shift" feature on my WS6's 6-speed, which would on many an occasion "lockout" 2nd and 3rd gear on the shift gate and force me to perform a 1-4 upshift. By eliminating this "feature", I have seen a marked improvement in my overall fuel consumption, even though my particular car may not perform as well on some specific CAFE scenario. I am wondering if I can achieve the same thing on my MM: improved shift feel while seeing improved fuel consumption based on my local driving scenarios and conditions.

Don't get me wrong: I still fully believe CAFE is responsible for the great powerful yet economic muscle engines we are enjoying these days.

I'm hoping some 4R70W-familiar folks on here can provide their $0.02 on what I proposed above: I want to avoid pursuing any idea that will make my tranny go "sproing" in the night. ;)

[TAF]

We've got all this^^^ worked out and perfected here in Atlanta with the custom tuning being done by Aric at Team Ford. All of the parameters (wants) you've expressed are available for fine-tuned adjustments. :up:

[Zack]

You simply paste the 3-4 upshift schedule into the 3rd gear torque converter lock up screen. The converter will lock right when it shifts into OD.
I have the software (the entire package, not just Marauder specific)
The car will drive very nice by doing this :up:

[BruteForce]

How about we get some of these tuner mavens to go on a nation-wide tour? Could use some help up here in the NW with getting the MM tweaked to perfection. :burnout:

[David Morton]

As far a CAFE requirements go, this is a manufacturer total sales requirement. Basically it means that after all of the cars of all of the types that are covered (SUV's and trucks are exempt) have been sold they must have a fleet average of whatever the requirement is. They are not applied to specific models and since the total Marauder sales for the three years has been less than 15.000 cars, I don't believe CAFE was high on their list of concerns for our shift program. There has been some relaxation of the rules since the eighties and that is why we don't see Cadillac selling dressed up Cavalliers and calling them Cimmarrons. :rolleyes:

Emissions certification has a standardized test called a "driving loop" that makes the vehicle go through a set of RPMs and gear changes supposed to be representative of common vehicle usage. I think that is probably higher on their list and more likely to be the reason why we have this weird shift program rather than CAFE standards.

The official FMC site had some info on the 2004's 4R75W tranny and it said the PCM for this uses an adaptive program that learns the driver's habits and adjusts, so perhaps this TCC duty-cycle stuff is a way they obtain better emissions for sale and then later we get to have a better program after the PCM finds out none of us Marauder owners have a "common" way of driving our cars. :rock:

[MitchB]

The shift schedule is up to you. But whatever you do, bring lockup either on or off. Don't slip the converter.

Mitch

[joflewbyu2]

all i know is that for the 2 days i drove around stock w/o the superchips tuner program - it SUCKED !! car shifts were soft and sluggish and 2nd gear torque converter slippage made the car feel slow. put back the SCT program and WHAM! crisp hard fast shifts and little slippage now.

[metroplex]

I programmed my vic so that the TC never locks up in 2nd gear unless I'm racing.

It only locks up around town in 3rd and 4th gears.

[studio460]

You simply paste the 3-4 upshift schedule into the 3rd gear torque converter lock up screen. The converter will lock right when it shifts into OD.
I had some detonation issues at low RPM, so SCT modified some of my .zcf tuning files so that the "TC would 'lock-up' up to 50MPH." Not exactly sure what they did, or what tables values they changed. I would like to understand this a little better. Anyway, what they did helped the knocking significantly. I'm going to try to look at what Zack's describing here so I can better understand the effect of the changed values. It would be nice to somehow be able to copy and paste specific table values to a post, (without tunring it into a .gif or .jpg) so that they're still copy-and-pasteable.

Triple-T:
Your "tuning" keyword is a good idea. I will try to use that word in the subject of my tuning-specific posts (since you can't search using just 'SCT').

[studio460]

I'm gonna be up half the night drawing lissajous curves of line pressure vs. TCC duty cycle . . .
Well, that would be awesome, RF! I wish someone WOULD post some TP pressure values of some cool shift curves. Since I changed my tires, my shifts seem a little out of whack. My first gear downshift seems really out of whack . . . if I punch it while traveling at a reletively slow speed, the transmission dumps into first, jerking the tach to 5,500-6,000 RPM for like a half-second, THEN upshifts abruptly to second. Not a very smooth power curve!

P.S. All my TP pressure values/shift schedules have been modified by either Jerry, Chris, or David of SCT.