Unlocked, you wouldn't even get a reading below your flashpoint. The graph would only show a curve from your flashpoint and beyond. Right guys?

As for your "interesting drop," I haven't seen your dyno sheet but my guess is it was probably detonation. At 4100 rpm the engine is under highest load and is more prone to detonation. Just my guess, I could be wrong.

 

Why wouldn't you get a reading? The engine, tranny and dyno would all still be turning. That's like saying that your car won't move till you reach your flash point if you ask me.

 

Maybe Bain or someone else can explain it better than I can but I'm pretty sure I'm right.

Basically, your converter just flashes up to its stall speed and the tires don't move much until the converter hits its flash point. At that point the converter grabs and starts to turn and the tires are also now turning and the dyno can begin making readings. That's the best I can explain it from what I know.

That's pretty much the case when you go from 0% throttle to 100% throttle. Not much happens until your rpm reach the flash point of you converter, then the car starts moving. Sure you might get a half revolution of the tire but it's not enough to get a reading.

 

That may be true if you started in first gear, but dyno pulls are usually done in third gear (in A4's). Given that you should have readings below your flash point.

 

When you dyno an A4 with a stall it will automatically flash to it's stall speed on the dyno when you hammer the gas in 3rd gear then it will start to taper off. Also if the 4000 converter was unlocked it would have shifted down to 2nd when you punched it at 3500rpm and messed up the dyno run.

Here is an example of an unlocked dyno

 

If you look at BAIN's dyno, you can see the converter "coupling point" at 6300 rpm. That's the rpm where the pump and turbine start coupling up and efficiency goes way up. Anything below the coupling point, you are using the the stator to multiply torque.

 

Does the absence of a coupling point indicate that the dyno was done with the converter locked?

 

the easy way to tell if TC is lock or not is to look at the RPM. The unlocked graph shows RPM way passed the 7000 (or way above the rev limiter), like in BAIN's dyno graph (I bet you that his rev limiter is not @ 7500). The locked graph like yours stops @ about your rev limiter.

 

Okay. Apparently all signs are pointing to my graph (or our graphs, actually) being locked. I changed my sig.

 

The difference between my numbers and blkz28's numbers are probably the 241 heads...My car was a late model 00'..other then that I think they are the same car, other then the pulley!