V12: Very low very flat VE table

[Philip Lochner]

The VE table on my Rover V8 has values between 30 (small throttle openings and 70 (large throttle openings).

The VE table on the Jag V12 has a very flat table ranging from 30 - 45.

At some places, changing the value by 1 makes a substantial impact on the AFR.

Is this normal or does it indicate that my Req_fuel is perhaps not right?

Would this table get more 'body" if I should reduce Req_fuel?

[bubble]

I had similar problems on my suzuki. The low VE values meant that the "tuning" was too coarse.
I reduced the Req Fuel figure by 1/3 and scaled the VE table by 1.333.
This made the VE table values much larger which makes the tuning finer.
Only one thing I found that I'd missed was the warm up enrichments are % based from VE values so it went miles too rich on the next cold start.
The tuning is now much better.








MSII 2.36 V3 EDIS WBO2

[mops]

yep.

i'd suggest setting your fuel req to 50% of current and scaling your ve table *2

i'd even do it twice, so fuel req *0.25 and ve table scale by *4

ideally you want your highest ve values be around 210 (still gives you room to tune as the max value is 255)

your vetable might be flat because, possibly you are running raising rate fuel presure regulator, which pumps more fuel when you are on the gas, so the vetable looks pretty flat. aswell you have a v12 engine, so probably intake runners are short (or possibly non-exsistent) which would make vetable flat-ish.

[Philip Lochner]

Thanks guys, this helps a lot.

Might this also explain why I'm having difficulty getting it to run smooth when trying to tune it leaner than 16.5 at low MAP values?