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Adjustable settings on SCT tuner

76K views 15 replies 8 participants last post by  q13dogg 
#1 ·
I have a question. I got my SCT SF3 today, and loaded the performance tune. At first I told it to lock convertor in 1-2-3, firmer shifts, turn off EGR, etc... Well, the locked convertor I assume is for WOT, balls to the wall throttling, because on the street, under lighter to moderate throttle, it would shift and just drop out to nothing for a second, enough to make my turbo "huff" and make it sound like someone had put a straight shift into too high of a gear, and was lugging it. I went back in, set convertor lock to normal, left the shifts firm, made sure I had the correct axle ratio, and it shifts MUCH nicer now. OK, to my question: what does convertor lock @ CT mean, and on the speedo calibrate/tire size, how do you determine how many revolutions per mile a 305 70R/16 makes? It would be easier to list sizes, but they don't, it asks tire revs per mile. Maybe there's a chart? A calculation? And lastly, does anyone have any suggestions on the trans pressure settings from one gear to another, or should i leave that alone? I just want to get it as good as possible, have good solid shifts, but not make it shift TOO harshly for a DD until I get custom tunes on payday.
 
#3 ·
I have 305/70/16 and they measure at 99 inches and divide that by how many inches are in a mile and I get 640 revolutions per mile
 
#4 ·
After doing some researching, I got the same number as WoodBoy for my 305 70R 16's. Basically it's 615 on the tuner. I got my info from Discount tire's website using this: http://www.discounttire.com/dtcs/infoTireMath.dos
If you're using 640 for your number, you may wanna check it against a GPS or something, see how they compare. I'd say your speedo and shifts could still be off slightly. (if that link takes you to the home page or whatever, click on the box that says "Inflate your tire knowledge" and you'll find the calculator in there somewhere.)
 
#5 ·
According to that calculator I mentioned above, a good 305 70R 16 is supposed to be 103.08 in circumference, so that's where your difference is. I don't know, just going by that, you may have actually measured around yours, but I've already seen several places say 614.67/615 RPMile for that size.
 
#6 ·
The only way to get the correct Revs Per Mile setting is to hand measure...
 
#7 ·
Makes sense. I didn't know the math to perform once I got that measurement, so I looked for that calculator. I may just measure mine in the morning and see how close (or far off) I am to the 615 I used. For all I know, his 640 may be dead on.
 
#8 ·
My shift pressures are adjusted up a bit(10-15%) I think. Had it that way for about 2 years now. I do not have it set for firmer shifts, that was a little to firm for my wifes dd....
 
#12 ·
Here ya go;

Street: This is used for general performance increase and is more conservative than the performance file. It will give a significant power gain over stock, but still safe enough for towing small loads.


Performance: This is the most aggressive file. It can be used for street and racing. It will usually give better fuel economy than street or tow, but cannot be used to tow as EGTs may become dangerously high causing damage to the engine and other components.


Towing: This file should be used when towing any significant loads. It has more power than stock, but less than the other files to prevent breakage. It also has changes to the shift schedule to aid in towing and keeping trans temps down.


Jake Brake: This is used as an exhaust brake to increase engine braking while coasting towing heavier loads. It will help lower brake temperatures as well when towing over steep grades.


Locked at CT: This will keep the torque converter clutch locked during decell. to aid in engine braking. This is less aggressive than the Jake Brake file so it may be ideal for smaller loads. It can be used in conjunction with the Jake Brake as well.


Aggressive Tow-Haul: This file will give a more aggressive shift schedule helping keep the engine in its power band longer while towing. This will also aid in engine braking as well.


Lock in 1-2-3: This is mainly useful for drag racing. It will transfer more useable power to the transmission after the vehicle is moving. It will also aid in engine breaking as well as slight fuel economy improvements.


Raised Shift Points: This will raise the MPH that the transmission shifts putting it closer to its power band. This may not be ideal in all situations.


Shift Firmer: This will increase the firmness of the shifts above what it is already tuned with.


Shift Points at WOT: This is the speed in MPH above (+) or below (-) that the vehicle will shift to the next gear at wide open throttle (WOT). These adjustments will be made to the current tune.


Shift Pressure: This is a percentage change to the transmission fluid pressure above (+=firmer) or below (-=softer) that the transmission will shift at. This controls how firm the shifts will feel. These adjustments will be made to the current tune.



Notes: Shift Point Up / Down does not apply on manual transmissions.


Caution: On 1994-1997 vehicles, it is necessary to remove the battery cables after programming to clear the PCM's adaptive memory.


The above files are optional and should be used at the owner’s discretion. Some files may cause undesirable drivability symptoms when not used as recommended. Personal preference may also dictate which files you want to use. We highly recommend using the base tunes without modification before selecting options.
 
#13 ·
BTW, the above info was for my SCT TSX but still explains most options on most SCT Ford diesel tuners.

Getting it to shift right has been a slower work in progress for me. I also have "locked in 1,2,3" off as it shifted to harshly on mine too. I am finding that I like it with "firmer shifts" on, letting 1-2, 2-3 shifts shorter or, less then zero on the mph option and leaving those close to 0 or 5% pressure then from there up, I use a little extra mph say, 3-5 in all the rest of the gears and setting the pressure to 0.

So far, that works pretty good for me but I'm still not 100% happy with how it shifts into 3rd. It's clunky under light and medium loads but perfect under full throttle. Once I got these close on the street tune, I applied the setting to the performance tune. You'd think it would be the same but it's a little bit different and not as smooth so, i'm still working on that.

This otherwise dead stock truck will just slide sideways in 1st through 3rd any time I hammer it though. On the performance tune, I can start in 3rd, get upto 20mph, pin it and just roll the tires. This supprised me. I also ran a 14.9x in the 1/4 at 96mph with a rediculous 2.9 60'. That points heavily towards a 13 second ET had I not spun for "over 300'" according to several friends watching that pass. I'm beyond impressed with this tuner.
 
#14 ·
Wow! Thanks a bunch, YBS_MIKE! That answered pretty much all the questions I had about the tuner. I am currently using firmer shifts, no changes in pressures, and raised the shift mph 1-2 on 1st and 2nd, and about 3 on the others. I'm pretty happy with the way it shifts, especially with the slop I was used to using the BullyDog on it before. I too am very much liking this tuner. I'm beginning to really like my Edge CTS as well. I'll be getting under it and installing the EGT probe in the next couple of days. I've had it as long as the CTS, but haven't had the time to put it in yet, so I haven't done any quarter mile runs yet, without being able to watch my EGT's, but have made some good launches in 4 wheel high. Feels awesome when you feel the front steering wheel pull slightly while the front tires are getting their bite, but then it just goes. I take it yours is 2 wheel drive, with the spinning you mention? If not, lock those hubs up and put it in 4 high, it'll go MUCH better.
 
#15 ·
Glad to help. Yea, I'm only 2wd. It's a posi but needs to be gone over to get it back. BTW, I do have the EGT setup and it's never gone past 1000 or so. I'm pretty happy with the temps. My EOT and ECT delta are usually within 3 degrees in city and 8 or so on highway. I may try a custo tune just to try it. I'm also getting 16mpg on the street tune.
 
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