Using your Torque converter as a built in Dyno???

[amichie]

The A340E automatic in My cressida has a factory stall speed of 2200rpm, and sure enough if I test it running on unleaded I get 2200rpm. Only takes about 2 seconds 2 do this test. If I switch over to LPG the stall speed goes down to about 2100rpm indicating a small drop in engine output torque at low rpm.

Question is if the low end torque of my engine is increased due to modifactions/upgrades etc will the stall speed go up? Assuming I am getting more power down low and not tuning for top end speed etc etc.

If this is the case I guess we all have a built in Dyno for the low rpm range ( Those of us with auto gearboxes anyway).

Disclaimer: Do not try this at home without reading the manual first otherwise you may fry your tranny.

BTW I found this site pretty informative.
http://www.kennedysdynotune.com/Torq...ter%20Tech.htm

[Bored?]

You can also measure peak power by using a tape measure to check the length of black marks left on the road. Oh wait, it's the 2nd of April now.

[chris davey]

I don't see why it couldn't. I know my old setup made SFA low town torque and stalled to 2500rpm. I am hoping that with the changes this should increase o 2800 or so.

[1JZ.747]

well i found the reverse

with the 1j my stall was 3300 to 3400

with the 2j bottom end even with the big cams its not 2800

[chris davey]

so it was 3300 or so without nitrous?

big cams should reduce low end torque so drop the stall rpm. But the .5L should obviously help offset that.

2800 with no nos as well?

And you did get a slightly bigger turbo as well so...?

[1JZ.747]

thats without the gas, having said that i have never seen my stal speed increase with the cag, its just a matter of its easier to get it upto stall speed quicker.

the turbo is actually a lot larger in the back end, its running the ta45 style flange and a biiger rear housing, before i had a t4 flange and a 1.00 rear housing.