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EVI
May 27th, 2010, 09:46 AM
I'm working on a LS1 Camaro with about 440 RWHP. I've put 4 rebuilt transmissions in it over the last year. Every one of them has taken 3-4 clutches out between 1000-1500 miles. I know the transmissions are right, we've done 20 or so of them over the last couple of years and this is the only one that has failed. I finally looked a little deeper into what is causing this and found the line pressure was too low. This was caused by the PCS not getting to a low enough amperage because the delivered torque is only reading bout 250 ft/lbs. Under WOT the MAF is reading about 9800 Hz , the TPS in 100% and the MAP shows 103 kpa. With all this the delivered torque is only 250?

My question is, how is delivered torque calculated? and why is it reading so low that the line pressure isn't enough to keep from burning up clutches?

joecar
May 28th, 2010, 02:43 AM
Hi EVI,

Can you post the calibration file and some log files.

The PCM uses calculated airmass for calculating engine torque, and from there it calculates or looks up torque signal pressure [we don't have that table]...

If the source of airmass is incorrect (too low) then engine torque and torque signal pressure will be low...

(PCS solenoid regulates torque signal pressure which assists the pressure regulator in increasing line pressure)

EVI
May 28th, 2010, 03:15 AM
Thanks for responding. I can't afford another trans! I don't have a log file right now but if you absolutely need one I will get one. I've used a PCM that I tuned for the car as well as another PCM with a stock tune for the same car. I've used a SLP MAF as well as a Stock MAF. Every combonation yields the same results which is about 250 delivered eng torque. I could very easily rescale some tables to deliver max line pressure at lower torque numbers to fix the problem but that wont help me understand why the delivered torque wont go higher than 250ish. Any ideas?

joecar
May 28th, 2010, 05:58 AM
Can you post the tun file... what mods are on the car...?