This is on a truck I tune, runs mid 8's.
Transbrake TH400

They bought HPT so I could remote tune etc. Just makes sense so I don't necessarily need to be there for every race.
Everything worked great. We have two external inputs for the WB and Fuel pressure. I was pleased with the better data quality of the MPVI2.

Near the end of last season he pulled the trans for clutches etc, and after that this odd problem cropped up.

Data logs perfectly, until he lets go of the transbrake.
All of the engine data goes to ****. Nothing reads correctly. Neither in the Channel list or in the charts.
Except, the WB and the fuel pressure.

Data all comes back once he lifts at the finish line. Then it's fine.

So we tried my laptop and MPVI1, no issues at all.

In both cases the laptop is in the truck.

HPT suggested that he update the software.......which isn't going to make a difference. We are both running 4.44.

Anyone seen this? Ideas?

I guess we could try a different laptop, I suppose it could be that. Since standalone logging isn't available, we are stuck with the laptop in the truck.

Ron

 

PM or email me....I think I know what it is.

 

PM sent

 

solid state drive in youd lappy and a spin drive in his?

wild assed guess

 

Mine has the spin drive actually.

minytrker and I converged on a possible cause. Simple part on the way. If it gets here today we will know tomorrow at the track.

 

So after all summer and s bunch of issues with the truck, we solved this.

We used a TVS (Transient Voltage Suppression) diode across the trans brake solenoid. Got it from Lingenfelter.

Seems to be working well!

Ron

 

Thats what I figured. Its crazy what a TB can do to voltage.

 

I’m assuming the MPVI2 is more sensitive to it.

 

Its usually from bad grounds in the car. I have plenty cars with holley and stock ecm's kick off my laptop or when on the dyno or make my dyno software act weird. I can usually ground them better with jumper cables as a test and it goes away.