I do not know where to really post this but I thought I would do it here. Yesterday I went to a dyno session with a bunch of diesel guys (I was the only gas truck) It was on a load cell mobile DynoJet. I had some issues with my truck going into REP mode at 5200 rpm or so but what I did not notice was they ran my truck in overdrive! My wheel speed was 155 before the REP was activated. Now I know the diesel guys run in OD to fully load the engine in order to get the turbo to spool but I feel this could have hurt me. Never heard of the gas trucks running in OD on the dyno.

 

Thats very very dangerous and stressful on your truck. You are lucky the driveshaft didnt explode or a tire blow.

 

I know! I'm not so worried about the driveshaft as it is 100% custom, 3.5" steel unit made for my truck with the 4L80 but I know my tires are not rated that high. I just don't understand the running in OD deal....

 

No need to run in od, even the diesels. The dyno will load the engine in drive. If the dyno operator wants to run in od I would find a different shop. As for the diesel guys needing to load the engine to spool a turbo, the dyno will give them all they want in drive, and then some

 

Dumb question, but when dynoing an auto, do you want it in 3rd, or whatever is a 1:1 ratio? If so, how do you keep it in 3rd without forcing it through scanning software?

 

1:1 is what you want to run in, 60e is 3rd, only way to keep the torque converter from unlocking is using software

a stock tune will lock the TC at WOT but you have to ease into it at the lower Rpms