did a search to no avail

In what way do torque converters affect dyno numbers? I hear that they can "kill" these cars on the dyno and wondered if there's a calculation or SOMEthing to correct for it. I lost 6 rwhp and 21 rwtq with a better flowing exhaust, FC-1000 ignition, a shift kit/tranny rebuild, and 2800 stall.....and probably 30k more miles. Talking to the dyno guy he said: Did you put a stall in it? They'll kill the numbers on these cars.

 

There is no standard conversion. The amount of rwhp loss will vary with the converter. In general, the higher the stall, the more loss you will see, but details of the converter design make this just a generalization anyway.

Fred (Injuneer) has some before and after chassis and engine dyno numbers going from a T56 to a TH400 with a high stall. You must have seen these if you did a search. I think he saw ~12% loss with the M6 and ~20% with the TH400. I don't have as direct a comparison, but think I lost even more with going from a T56 to a TH400 with 4,200rpm stall. I doubt you are losing anywhere near 8-10% with a 2,800 though.

Rich Krause

 

I can't find his post on it, but it just gets me that because I have a stall I can't see what the minor mods I've done since the last time did for me. Seems wierd that a part that helps makes your numbers drop!

 

Well, the explanation is not that esoteric. What you see with a converter is (typically) a quicker ET but a bit slower through the traps. Better loss, but less hp at the big end to keep accelerating.

Rich Krause

 

Just out of curiosity even with the higher parasitic power loss are you seeing faster 1/4 times with the high stall TH-400 than the T-56?

 

The motor and blower are different too. It's not completely sorted yet, but it's been somewhat disappointing that my 60' aren't any quicker (to date) than with the T56.

Rich Krause

 

If its on a different set-up are you just have more traction problems than you were when you were on the manual?

How much more powerful is the new set-up

 

Not sure whay the 60' aren't better. I need more track time to determine that (with videos, data recording, etc.). I don't know how much more hp the new setup makes, I do know the rear wheel numbers are disappointing. Normalizing for conditions, it only shows an additionl 20-30rwhp in spite of 3-4psi more boost, a better cam and a bit of head work.

Rich Krause