Weak point of transmission? Shifting or clutch pack?

[dweinhart]

For those with NOS..... At what point does the A340e give out? Is it the 2nd gear sprag or is it the clutch? I am trying to found out if running a RPM switch so the tranny does not shift while under power if the transmission will take more abuse. Or is it the clutch packs that let go?

 

[P Bateman]

A stock A340 cant take much more than about 200kw at the rear wheels before slipping clutches, so I guess it depends on how much nitrous you are running. They make around 150rwkw stock. A 50 shot should see you at the limit.

2nd Gear sprag will generally suffer on heavy throttle in the 1-2 shift.

Heat is going to be the killer of all autos and the A340 is not known for its strength, so I would suggest you consider upgrading the oil cooler, shimming the accumulator springs & winding up the pressure regulator.

http://www.lexusclub.co.uk/lsocautoboxmod.pdf

I will doing these mods to mine, prior to converting it to a T400. How long it lasts, though, is the question.

 

[dweinhart]

I am already running a cooler and have installed transgo valvebody kit which includes stronger springs and drilling out for higher pressure. Thanks for the info..Guess I will look for stronger clutches

 

[P Bateman]

How much gas are you running - and how is that combo in the transmission coping?

 

[dweinhart]

I am not actually running NOS. I am using a t76 turbo coupled with a brushless electric motor so it electronically shuts off boost at rpm cut and reactivates it at a set rpm in next gear. Hence I never shift under boost. I am trying to see how much I can turn up the boost on this thing before I lose my tranny. My brushless motor, battery bank and ESC will handle 75,000 rpm on t76 which translates to about 600hp but I know better than to turn it all the way up. Right now I have it set for 8psi which is about 50% of it's potential