View Single Post
Pork Chops Pork Chops is offline
Join Date: Nov 2015
Location: Melbourne Australia
Posts: 169
Thanks John, per the above dwell was adjusted and made no improvement in the situation. The tuner will have made decisions based on safety and I have to trust he knows where that point is. He tunes all sorts of high hp turbo cars so Iím going to leave that decision with him. Honestly Iím not going to learn the system any more than I have as I donít intend to become a quasi tuner. Iíd be happy to explore the possibility of individual cylinder knock retard but donít really want to go back to the dyno until Iíve got a read on why the spark is blowing out.

Originally Posted by John at J&S View Post
In your first post you say the spark was getting blown out after raising boost. I assume that was solved by increasing dwell?

Increasing dwell increases coil current. Energy stored in the coil goes up with the square of the current. Theoretically, if you double coil current, you quadruple the energy stored in the coil.

Others have analyzed your timing map and have said it's conservative, which can happen when you tune for "no knock".

No one wants knock, but some cylinders knock easier than others. Overall timing is compromised when adjusting for "no knock", robbing power from the more knock resistant cylinders.

Your Vems has the capability to do individual cylinder knock retard. It may even allow you to set timing offsets on a per cylinder basis.

I suggest you learn the system, install the sensors and start tuning/calibrating, or pay your tuner to do some or all of it.
Old 05-23-2020, 04:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #40 (permalink)