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Only when i first got it tuned, he wasn't to sure on why it was doing it. Told me to speak to Nistune, who told me to do the boost sensor.

I'll give him a call shortly, there is one tuner down this way, going to see if he happens to have Nistune software.

  • 1 month later...

Just thought i'd add some info to this for future reference and people searching.

I still have not fixed the limiter issue, i broke the gearbox so thats getting fixed now haha.

But i plumbed the sensor in as i posted, and fuel economy is WAY better, drove 120km return to and from the track (home with a g/box stuck in 3rd) and around 30-40 laps of the track and only used 1/2 a tank, i used to get 230klm's to a tank before i hooked the sensor up.

So it does not affect af/r under power, mainly under cruise. Massive difference.

Neo ECUs use a volumetric efficiency table in addition to the normal fuel map. Matt from Nistune has only recently worked out that the X axis for the VE isn't simply TP load like eveyone previously thought, and there seems to be a lot of logic around whether the VE map is activated to control mixtures or whether the ECU falls back to the fuel map. Closed loop flag is raised across the whole fuel map, you can't control whether it is on or off, but the ECU is clearly able to switch itself in and out of closed loop. It is therefore quite possible that the boost sensor might be part of the logic as to when and why it runs in closed loop (and hence why you're getting better economy with it connected).

I think if we are really forced to keep the boost sensor connected, we're going to end up running a bleeder T on them just like a boost controller. Bleed off some boost and limit how high the sensor reads. Still reads vacuum, job done. Having said that, the sensor is connected to the crossover pipe, so should never see vacuum. Should only ever see slight vacuum + boost.

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