Converter lock up at the dyno

[Craig 94 TA GT]

I recently had the car dyno tuned and the converter seems to be acting strange. The dyno operator did not want to touch the converter settings as PCMforless knows the fix for the 3000+ stall on 1994s. He noticed that it hit around 90 mph, then the whole car hesitated, and pulled harder. He figured out that it's locking up around 90 mph. The dyno graph shows a huge loop at this speed, then continues on. So my question is, is there a reason for lockup at this speed? I would assume it would slow the car down because the time it takes to switch to lockup seems to be a bit high - as I can see a giant "loop" in my dyno graph.

[Craig 94 TA GT]

Just as an update, I found out that sometimes programmers lock up the converter at the end of the 1/4 mile to gain more trap speed. I don't know if this will decrease ET though because of the time it takes to lockup.

Well, there is another issue. Even though it was locked, it only put down 336 RWHP, 326 TQ. The dyno operator says those are good numbers because he believes the converter was still slipping, even though it was locked. He also said the 9" robs quite a bit of hp - roughly 25 RWHP. The motor was also heat soaked when dyno tuning, and 336 was the last run. He tuned it to around 31 degree spark advance (PCMforless did 37), and 12.5 AFR, so it was fairly conservative. So the theory is that the following are restrictions and there is nothing wrong with the engine:
- SLP Shorties with cat, 3" Borla
- Slipping converter, even though it was "locked"
- 9" rear
- heat soaked intake from the constant running and shutting down then tuning

The theory is that a stock 10 bolt, M6 with full exhaust should put down 400+ RWHP on this motor. However, Advanced Induction still thinks there is something wrong and I should be in the 380 range right now. I don't know what else to check. I will post the graph soon - thanks for any suggestions.

[Craig 94 TA GT]

Here is the dyno chart. The second is stock on the same dynojet, but stock 10 bolt + stock stall/tranny. Probably not a good comparison but maybe a reference point on how the dynojet performs. I've never seen a dyno chart where the converter locks up during the run (here at 5k), so I'm not sure how to compare this?

AI heads/cam:


Stock with bolt-ons & 1.6 RRs