I have a few excel spreadsheets of shift schedules used by SuperChips. These were setup many years ago when the old FlashPaqs used to allow for transmission tuning.
I wanted to try a few of these out but I'm not really sure how to go about it because they're laid out in throttle position, and MPH, whereas HPT is in rotations of the (tailshaft?)
Would there be anyway to "translate" the settings in the spreadsheets into something usable by HPT?
2005 Starter Schedule.xlsx
Convert mph to output shaft speed and bingo
I'm not sure how to do that, also HPT has a lot more options like when it's hot or cold, and alternative 2nd or something like.Originally Posted by Jim P
Im not sure which gear would be the right gear for something like 2P up, and 3-2PDN.
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((MPH*Trans Gear Ratio*Axle Gear Ratio*63360)/(Loaded Tire Circumference in Inches*60))/Trans Gear Ratio = Trans Output Shaft Speed
You can use the VCM Scanner to tell you what your loaded tire circumference is.
Loaded Tire Circumference in Inches = (MPH*Trans Gear Ratio*Axle Gear Ratio*63360)/(Engine Speed*60)
Those formulas only work when in lockup.
What's loaded tire circumference and how do I get VCM scanner to tell me that?
I have sort of an issue maybe, it seems VCM scanner is lacking a bunch of channels for me that maybe should be there, but I'm wondering if it just my truck doesn't have those options. but one that's "missing" is injector pulse width, and I'm thinking that should be there for pretty much any EFI engine.
I have a ticket going with HPT.
So if they only work in lockup then what do I do about all the times I'm driving and not in lockup?
I feel like my trans hangs around in 3rd (I think) longer than it should and I have to get up to 65/70kph and let off the gas a bit before it'll shift up.
I also have to change my tire size, but I'm not sure how to do that in VCM Editor. It's at a stock setting of 30.75in in superchips, but my tires are something like 34.48"
2005 Dodge Ram 2500 5.7L
Loaded circumference is the circumference of your tire with the vehicles weight on it and the centrifugal forces acting on the tire.
Don?t worry about it when it?s not locked up. You?ll just have to adjust as you see fit for converter slip.
Put the formula in user defined math, set your axle ratio, set your highest gear ratio, set your mph PID where it says mph and set your engine rpm PID where it says engine rpm, have engine rpm and mph set in channels, set the user defined math in charts and have it read average, get out on the road into the highest gear, locked up at like say 75mph and log it at that speed for a few minutes while in the highest gear and locked up.
Use that average with the first formula in excel to convert mph to OSS.
Don?t know about your truck but on the Cummins you change it in the editor, not the scanner, where it says pulses per mile.
Yeah I don't know where the option is in Editor to change the tire size. I don't have the gear/tire wizard available anywhere and there is nothing under the vehicle special features in Scanner.
So where would I find the load tire circumference for my tires? I googled that and didn't get any results for that specific term.
Why would I not worry about it when it's not locked up? I don't spend a lot of time driving at a speed that locks up my TC. it doesn't go into lockup until about 75 KPH but the speed limits are 60 KPH, so I'm spending most time in 3rd or 4th.
I really wish I could change the lockup speed.
Last edited by Killavolt; 10-12-2020 at 07:57 PM.
You should have a tab in your editor that says speedo.
If you look above I told you how to get your loaded tire circumference...
If you already have non OEM sized tires on and don?t have the speedo corrected, you?ll have to do that first.
Sorry if I sound a little dumb, I'm about as new as new can be to tuning beyond using something like a FlashPaq, I'm not picking up on the "how" to find loaded tire circumference in the posts above?
There isn't anything I can really do under the speedo tab and no option for changing tire size, and as I mentioned, I feel like I'm missing a bunch of channels in Scanner, like I can't even show what gear I'm currently in which is something I personally would really like to know.
Speedo.PNG
If you get your speedo correction done and it?s really close, the formulas above will get you near bang on for OSS speed.
You don?t worry about when not locked up because you have to treat it like a manual transmission, ie. when locked up. You then adjust by what you feel you like for those areas/gears that aren?t locked up to account for converter slip which is constantly changing depending on the torque output of the engine. Under very light throttle it can drop to like 50-100rpm slip or under a heavier throttle or pulling a big load or going up a grade or whatever you could have like 600rpm slip. So you need to treat it like a manual or locked up then adjust from there.
You may need to use something like superchips tirepaq or something to change tire size.
In your VCM scanner you create a user defined math parameter for the formula.
Last edited by Jim P; 10-12-2020 at 08:25 PM.
You can use the tire manufacturers nominal diameter multiplied by Pi to get a circumference, you?ll be a bit high on the end result but close-ish. First you need to get the speedo corrected though.
If your oem tire size was a 265/70r17 you can use 99.29 for tire circumference with the first formula in excel and it?ll get the mph pretty close to the right output shaft speed for stock tire size if they were 265?s.
oh, shit, I just overlooked one of your posts sorry, I see the formula for tire circumference now. my bad man.
Any idea why I might be missing these features? is it just my truck? I was under the impression that 2005 was a pretty tunable year for my truck, but I feel like I might be missing things that would make it difficult to tune.
It?s all left up to HP Tuners to decide what they map out and give people. If you know what you want and where it is you can give them the info and ask them to add it.
I have a ticket open with them about it, problem is I'm not really sure what I'd need or what a professional tuner would need to do a good tune for my truck.
I know for my 2012 cummins the VCM Scanner is mostly useless, almost nothing works in it.
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