Megasquirt Fine tuning question

[toofast2race]

Long time no post. 

After what seems like an age of no tuning ( I checked it was 5 years(!) since I last tweaked anything on my 2100.), I recently lent my car for a fortnight to a South Australian member of the TSOA for the National rally week held in Margaret river. Lending a car means you become suddenly conscious of all it's quirks that you tend to get used to and drive around. The car performed very well although it definitely needs a LSD for competition work(see video link) https://www.youtube.com/watch?time_continue=1&v=62wPONMdDNs

However I was getting increasingly frustrated with a slight miss / hesitation when coming from coast back to cruise throttle at 2000-3000rpm. I seem to have cured this by adding fuel and a bit of advance at that point but now I am getting slight shunting / surging on the over-run at 2000-3000rpm which I think why I removed fuel and advance there in the first place. Any simple tricks to get a shunt free coast / over run condition? 

[Nick Jones]

Tyre and rev-limiter abuse! Thought that was your road car 

Re the tuning issue. If the firmware you are using has the option of over-run fuel cut off, you could try enabling that. It will cure the shunt but occasionally causes hiccups at the cut back in point. You can adjust that too.

Alternatively, it sounds like your table might be a bit too compressed at the high-vac end meaning that the light cruise and over-run bins are too close and limited scope for tuning the difference. Reorganising you’re table in that area may help. This applies to ve and spark. 

[toofast2race]

Refresh my brain, very low fuelling and what sort of advance on over run ? Assume lots of advance?

[toofast2race]

Adjusted MAP bins and dropped VE to 5 on over run - big improvement. Also found wideband throws a wobbly after about 30 secs. Hopefully fresh air calibration sorts that