Forum » Practical Dyno Tuning » Building a decent spark map on dyno without real time torque

Building a decent spark map on dyno without real time torque

Practical Dyno Tuning

Discussion and questions related to the course Practical Dyno Tuning


Page 1
Author
680 Views

My friends dyno does not have the torque cell on it so the only way to get a torque curve is to do a sample run is there any trick to tuning a spark map this way I have knock detection headphones so I can audioabley hear what's going on. Andre if you or anyone else could chime in that would be great I doubt my friend is going to buy it since it's pricey on a dynojet

If you're tuning on an inertia dyno you are only going to really be able to tune the ignition timing at WOT. In this case you can perform a ramp run under WOT, make an adjustment to the advance, and then run again. If you pick up torque/power then keep going (provided no knock is occurring). I haven't got a reliable way of tuning the part throttle ignition timing though unless you're using TPS as your load - In this case you can do ramp runs under part throttle to tune the ignition advance at some of the lower load rows. There's a limit to how far you can drop the throttle though before the engine isn't making enough torque to actually accelerate the dyno.

Can I chime in here with a related question? I only have tuning software with the availability of doing flash tuning. I struggle in this area on the dyno because I wouldnt hold it in steady state at each individual cell, then switch the car off, adjust spark map relflash and restart then go to the next cell. I'd be there for days. What's the best way to find MBT on EVERY cell when flashing?

The simple answer is that unless you have the ability to live tune the ignition table, you can't.

It is however less of a concern when reflashing as you're already starting with a well developed factory ignition map. This is probably going to be very close to perfect for a stock engine. Admittedly as you change the engine's VE then this spark table might become less accurate however the chances are unless you've made huge changes to the engine configuration, that you'll still be very close to MBT. In this case we can really focus our energy solely on the WOT area of open loop operation.