Non Lock Rpms
- Thread starter j l smith
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With a non-locking converter, rpms vary with engine load. IOW, at cruise, constant car speed 60, not uphill or down, look at your tachometer. Note engine speed, and with 3.73 gears it would be a little over 15% higher, assuming same tire size used. IOW, IF you are turning 2500, new rpms would be about 2875, as an example.
@karthief See, all that "crap" I harbor does occasionally prove worthwhile, no? imp
See https://lmr.com/products/Mustang-Speedometer-Gear-Calculator for more help.
You will need your current or proposed tire size as well before you can accurately use the calculator.
Last edited:
mikestang63
SN Certified Technician
That is a lot of stall for such a mild build. You should be more around 2500 as your powerband is no where near needing a 3500 stall.
Second, I hope you have a decent trans cooler with a non lock up cconverter and that high a stall.
In order to determine what rpm your car will turn at you need to provide your tire size
Assuming a 26" high tire... your tach will be at around 2100 with 3.73 gears and 1750rpm with 3.23 gears at 60mph
An AOD is around .70 to 1 in OD
https://www.ringpinion.com/calculators/Calc_RPM.aspx
Oh and......
.
Second, I hope you have a decent trans cooler with a non lock up cconverter and that high a stall.
In order to determine what rpm your car will turn at you need to provide your tire size
Assuming a 26" high tire... your tach will be at around 2100 with 3.73 gears and 1750rpm with 3.23 gears at 60mph
An AOD is around .70 to 1 in OD
https://www.ringpinion.com/calculators/Calc_RPM.aspx
Oh and......
.
@karthiefRaggedy was answering for me.
He's my friend
You evidently have far more friends than I. Lucky you.
I'll say this: sparring back and forth here is a good tension easer considering the "far-out-ness" of some of my beliefs/opinions. imp
I really can't answer that question, beyond my pay grade.
I can tell you thats a pretty high stall for your combo. There are many factors in determining stall speed, I think in your situation a higher numerical gear can get you to your stall speed for cruzing but do you want to be swinging that crank that fast just to cruze down the highway? A smaller numerical gear puts your rpms below stall speed and the slippage will heat up the transmission fluids causing premature wear. If this is a race car with future mods intended then go for the taller gears, if it's a street car you may need to rethink you parts combination.
Just my opinion and not based on any personal experience or facts.
And if I'm wrong the more experienced guys here will hit me with the appropriate tire iron.
I can tell you thats a pretty high stall for your combo. There are many factors in determining stall speed, I think in your situation a higher numerical gear can get you to your stall speed for cruzing but do you want to be swinging that crank that fast just to cruze down the highway? A smaller numerical gear puts your rpms below stall speed and the slippage will heat up the transmission fluids causing premature wear. If this is a race car with future mods intended then go for the taller gears, if it's a street car you may need to rethink you parts combination.
Just my opinion and not based on any personal experience or facts.
And if I'm wrong the more experienced guys here will hit me with the appropriate tire iron.
I really can't answer that question, beyond my pay grade.
I can tell you thats a pretty high stall for your combo. There are many factors in determining stall speed, I think in your situation a higher numerical gear can get you to your stall speed for cruzing but do you want to be swinging that crank that fast just to cruze down the highway? A smaller numerical gear puts your rpms below stall speed and the slippage will heat up the transmission fluids causing premature wear. If this is a race car with future mods intended then go for the taller gears, if it's a street car you may need to rethink you parts combination.
Just my opinion and not based on any personal experience or facts.
And if I'm wrong the more experienced guys here will hit me with the appropriate tire iron.
I can tell you thats a pretty high stall for your combo. There are many factors in determining stall speed, I think in your situation a higher numerical gear can get you to your stall speed for cruzing but do you want to be swinging that crank that fast just to cruze down the highway? A smaller numerical gear puts your rpms below stall speed and the slippage will heat up the transmission fluids causing premature wear. If this is a race car with future mods intended then go for the taller gears, if it's a street car you may need to rethink you parts combination.
Just my opinion and not based on any personal experience or facts.
And if I'm wrong the more experienced guys here will hit me with the appropriate tire iron.
Don't think I understand completely here. Stall speed is the eng. rpm reached with throttle wide-open and drivetrain locked stationary by brakes. Let's say that number is 3500 rpm.
That has little or nothing to do with the fact that during normal driving, 3500 eng. rpms will be seen often, but but not with throttle wide open.
So, @karthief , what is your meaning in connection with stall speed related to cruising? imp
That has little or nothing to do with the fact that during normal driving, 3500 eng. rpms will be seen often, but but not with throttle wide open.
So, @karthief , what is your meaning in connection with stall speed related to cruising? imp
I maybe wrong or not have a clear understanding of converter stall speeds, higher stall rpm is reached by converter slippage, this allows the engine to reach the desired 'sweet spot' when launching off the line, other things in play here but thats my basic understanding, when cruzing below the stall speed, say 2200 rpms on a 3500 stall converter, I would have to think the converter is slipping at that point causing the fluid temp to rise and premature parts wear, if he had a 2500 rpm stall converter or maybe a lockup there would be less to no slippage, less heat, less wear or a lockup that has no slippage.
Now these are thoughts of someone that reads about stuff but has no actual experience with this stuff, are my ramblings correct, close to correct or wayyy out in left field?
I want this member to get good advice cosidering what we know about his setup.
Now these are thoughts of someone that reads about stuff but has no actual experience with this stuff, are my ramblings correct, close to correct or wayyy out in left field?
I want this member to get good advice cosidering what we know about his setup.
