Rolling Road

[andyleaves]

OK, yet another question!
Why are most places like TDI etc., telling me they cant run auto's on a rolling road to get horse power reading...

2ndly, anyone know where I canget mine done in the essex area, no it's not a tip, just a bog stock auto box...

[aboo]

I think it has to have the tip so it can be taken down the gears for a proper reading.
I may be wrong but I'm sure someone will now for sure.

[andyleaves]

Would this also mean then on that information that having a re-map would be impossible?

[Eurospec]

You can dyno autos, depending on car and dyno it should not be a problem.

The first issue is you need to be able to hold it in a gear. With galants, since they are tips, this is not a problem.

Second is the torque converter. This introduces losses that some types of dyno (inertia) cant handle, since loss is calculated using a roll down method. You cant put an auto into neutral at 90 and let it coast down- it will kill it. Retarder dynos that use models to calculate loss can be used no problem.

Third, getting an rpm reading is normally achieved by using a fixed ratio between wheel speed and engine rpm. This is easy peasy on a manual, but on an auto it can be tricky since the rpm varies as the torque converter loads/unloads at any given engine speed. It can be done, but it isnt ideal. More modern dynos have an inductive rpm pick up which can be a bit tempremental but solves the issue.

Cheers,

Ben.

[andyleaves]

Damn, Anyone wanna swap an auto V6 6a13 box, for a man unit??? :(