When looking at this datalog, does the RPM after I hit 3rd gear seem normal? I feel as if it's pushing the converter, starting to slip more than it should. Maybe I'm completely wrong and it looks perfectly fine. Turbo 5.3, th400, custom 245mm converter. I'm looking to maybe add a couple psi here this year and maybe go to 3.31 from 3.55. If its a stupid question and looks normal, that's ok, just tell me.

 

Are you referring to the amount of RPM fall back on the shift or something different like bahavior? fallback is about 600 which is a touch on the low side(LIKE MAYBE 200RPM low) for a turbo heads up car. If you were bracket racing I would say its perfect. Behavior wise I don't see anything out of the ordinary.

Another thing to note is you may want to move your seat forward or your pedals back. Looks like your foot is coming off the pedal some when the car leaves. (Look at TPS in the 32-34sec range)

 

This would be pretty much what I want to see for a very consistent Bracket Car.
Maybe 700-800 RPM.

 

Ok. The fall back is more so what I was referring too. It has a little bit of a naturally rising boost curve by gear that you can see. Being that it's only falling back 600 and not 800 that means the converter is slipping more than it should? So if I add more power, it will only get worse?

 

yes more powerwill make the converter slip percentage increase. If you have more power to put in still you definitely have room to tighten the converter on the down track front but you also have to consider spool times. It looks like your spool time is about 5 seconds which is acceptable but I wouldn't want to see it get any longer than that. Tightening the converter can make that worse. You could combat that with a dump valve...

What are the details on the cars setup? engine size: (5.3L) , turbo size(include AR housing size), end goal boost pressure, target HP numbers, type of use(street/strip vs. race only), weight, gear, tire size, trap speed

 

Rod/piston 5.3, 243 heads, ls6 intake, btr stage 2 cam, vs80/96 1.25 t4. That run it peaked at 26psi, I'd possibly run 28psi if I can. Best pass is 9.004@151 with a 1.31 60ft. Raceweight for that pass was 35xx. It had 210lbs of sand in the trunk to make it hook. It doesn't have an anti roll bar but I'm planning on that for this year. 3.55 gears, 28" radial. I don't care too much about power numbers. It's 90% street, 10% track.

 

If you can take the 200lbs out and keep it hooked that will help with converter efficiency. Otherwise I wouldn't change the converter knowing its a 90% street car. If you were looking for every last bit of ET then ya I would tighten the converter, add a dump valve and go back testing. But as it sits right now it would be reliably fast and consistent. The only other factor to consider there is drive-ability if that's a concern at all.