Tire size vs converter stall

[Marco]

Hi everybody,

I'm currently running 26inch tall tires and my stall rpm is about 2700 rpm if I were to replace the 26inch tires with 28inch ones would this increase/decrease or have no influence on my stall rpms. Rear end ratio is 3.55.

Thanks in advance!
Gr Marco

 

[oldkimmer]

The torque of the motor determines the stall. Kim

 

[Marco]

Hi thanks for the fast response!

But the custom converter shops also always ask for the tire size, rear end ratio and vehicle weight so im guessing changing tire size also influences it at least a little??

 

[diesel_lv]

Hi thanks for the fast response!

But the custom converter shops also always ask for the tire size, rear end ratio and vehicle weight so im guessing changing tire size also influences it at least a little??

It will have no effect on the stall. They ask so they can build the stall, higher/lower, appropriate to what you're running.

 

[oldkimmer]

They just need all info u can supply. Kim

 

[Curiousyellow71]

slightly higher...but doubt you will even notice even looking at the tach.

 

[33 IMP]

If you are running 3.55 gears and 25" tall tires, you will get a different converter than if you are running 30"tall slicks. But once you have a converter, the tires wont change stall any.

 

[Nate S]

Curiousyellow got it right. Flash stall will increase a tiny bit with the increased resistance to motion. Static stall will stay the same. Probably nothing you’ll be able to notice.

 

[Marco]

Aahh that's amazing! Thanks for explaining, I did not want to raise it do its good to hear that it will stay about the same!

Gr Marco

 

[MoparLeo]

Maybe a good definition of what "stall speed" actually means will help some members understand it better.
https://revmaxconverters.com/part-understanding-torque-converter-stall-speeds/
https://revmaxconverters.com/part-i...ced when high stall speed converters are used.

 

[dvw]

The rpm of the flash wont change. However a taller tire or less gear will hold the converter at flash stall speed for a longer amount if time. Take a manual valve body car. Leave in 1st gear. Then try leaving in 2nd or 3rd. .
Doug

 

[Yeahrightgreer]

The rpm of the flash wont change. However a taller tire or less gear will hold the converter at flash stall speed for a longer amount if time. Take a manual valve body car. Leave in 1st gear. Then try leaving in 2nd or 3rd. .
Doug

Doug - is the longer amount of time that the car is held at flash stall meaningful? In a heads up shootout, would it make much of a difference? If any?

Additionally what happens if the gears are changed out for deeper gears instead of lesser. Currently my car has 4.10 gears with a 28" tire. Would switching to a 4.56 gear make any meaningful change to the stall speed of the car?

 

[dvw]

Won't change the speed of the stall at all. The benefit/hurt of how long it stays in flash depends on the engine combo. In my experience is the flash speed is good, you can jockey the gear around some and it doesn't make a ton of difference.
Doug

 

[Curiousyellow71]

The gearing can also affect the converters ability to move the car at the lower speeds well below the flash or stall speed. When you have a custom converter that set up tight for driving... the extra resistance to motion makes a difference. That is partly why the better tranny shops ask for details. Our dynamic flashes at 4200 but its moving the car at 2000 with 4.10...if you drop down to 3.23 the resistance to move the car is more, it doesn't move the car as well at the lower speeds. When your just talking a tire diameter change, that likely isnt enough to affect the convertor really in much of any way that is noticable.