34 mile round shopping trip yesterday provided some interesting results following above checks and changes. Engine started and ran fine but had my OBD2 dongle connected and bluetoothed to OBD Torque app on my phone.
![[Linked Image]](https://i.imgur.com/IbSFE3y.jpg)
Should have taken a screenshot before app shut down, but these are figures I noted from the customised dial setup I have which record max and min in many cases and are quoted below:
Max speed xxx kph
Max revs used 4700 rpm (wasn't rushing)
Max coolant temp 98°C (normal)
Load 100% max
Throttle 75% max
MAF max 173 grams/sec
Intake temp range 22 - 36°C
Ambient temp range 22 - 25°C
I was a little surprised the throttle butterfly only reached 75% (same as with engine off) since I know I floored it for a few seconds, until I discovered a thread on a Lotus forum that is, where the same figure had been found. Discounting the usual BS that such produce the best answers concluded the throttle spindle itself causes some restriction such that the final 25% of movement makes little or no difference, hence the PCM controlled limit to allow quicker throttle response.
I was very pleased to see such a high MAF peak though showing excellent volumetric efficiency despite only 4700 rpm being used. A rough guide for normally aspirated engines is engine capacity in litres x 40 to give a max MAF in grams/second, i.e. 149 for my 3.7 V6.
Max intake temperature seemed high until I remembered being stationary at idle for some time at level crossings. Pleasing bit are the minimums recorded though showing that my air intake mods seem to be working fine keeping temp the same as ambient once on the move.
Next week a few of us have a dyno session booked near Royston. I will be up against a Brooklands Roadster with the factory ECU upgrade and an Earls tuned +8. Watch this space
