Wacky VE scaling!
 

I'm wanting to run more boost soon. I'm at 7psi now and I want 10psi soon. There's a problem with my VE scaling it's way off. It runs in the 212 kpa cells when I'm only boosting 7psi!!! :nuts: It thinks I'm running about 15psi when it's only 7! Woweee!!!! The table maxes out at 230 kpa but I never reach those cells.

I've searched and no one else seems to have this problem. My tuner didn't know how to fix that. He said it has something to do with my MT his MT reads correctly. How can I fix this?

I want to post my MSQ, copy and past didn't work.

Try Tuner Studio first because TunerStudio >>>>>> MT

Because surely the solution is to introduce more variables. :bang:


Are you sure your configurator is set up for the correct MAP sensor? Is the correct sensor selected in the Engine Constants page?

No, but because some of the n ewer Firmware versions don't seem to work very well with MT anymore afaik...

But I would also surely check the variance between my boost gauge and the MT gauge.

the problem lies within the laptop. specifically configurator settings.

Sounds like it is set for the wrong MAP sensor to me.

Ditto, just had this problem and question. Felt like an idiot.

It does sound like you're running a stock 250kPa sensor, and yet MegaTune believes you have a 400kpa sensor.

http://img38.imagefra.me/img/img38/2...om_2c7a630.gif

I've done that many times but this is the only time it stuck. It was telling me MT was already running and needed to close then I would open it again and it would be gone but it stuck this time. odd.

So now I'm set for 250kpa map sensor. The VE goes from 14kpa at the bottom to 196kpa at the top. Is that correct?

I guess I will now need to retune my fuel and timing maps now that it should be reading pressure correctly?

You can scale all tables (including the VE tables) however you want, and the software will interpolate. My VE table is scaled (non-linearly) from 23 kPa to 230 kPa.

Basically, you want your bottom-most row to be the lowest pressure that you expect to accomodate just short of decel cutoff, and the highest pressure to be slightly greater than whatever the maximum MAP you expect to encounter under full boost. (This latter decision is made to give the system a little bit of headroom in case you overshoot.)

If you'd previously tuned them for the incorrect scaling, then yes. One thing which you could do if you wish would be to re-scale the kPa column by hand, and then use Table Transform to apply a scaling multiplier to all the data cells.

It sounds like he had a shop dyno tune the car on their own laptop, so it was just a display problem on his own laptop. In this event, the tune (hopefully) would be pretty solid as is.