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Hello, I am having an issue tuning my 1.8T modified Cruze. I have gotten the fueling and spark almost done, the car makes about 7PSI and when trying to go WOT from either a stand still or rolling the throttle will not open past 60%. I have noticed max engine torque is locked at around 128nm which is lower than stock? Attached are a log and tune file, any help would be greatly appreciated!
The throttle is hanging at 60% likely because you're trying to exceed "max engine torque".
Every calibration is different, but in many cases the "max engine torque" is a calculation that comes out of the torque model based on what throttle inlet pressure (the pressure reported by the BARO sensor) is. E.g. the ECM assumes the maximum power the engine can make is based on the throttle inlet pressure - which, unless you broke out the sensor and replaced it with a 2bar or 3bar, is still going to read atmospheric pressure. To fix this, you need the ECM to have accurate information about what the throttle inlet pressure is.
I have swapped in a 3bar Manifold pressure sensor, but these vehicles do not come with a tiap. I have the MAF which contains the baro sensor pre turbo and the intake temp sensor broken out post intercooler. The engine torque from what I can tell is directly referenced from the V torque tables but I cannot seem to raise the max engine torque as it seems like its more of a limiting factor... Do you think changing the sensor config to include TIAP/MAP will fix the issue?Quote:
Originally Posted by tunerpro
Thanks for your insight!
They do, actually, its the BARO sensor in the MAF assembly. The issue is the ECM needs to know what the pressure on the front side of the throttle body, on NA applications it gets this from the BARO sensor. Changing the sensor config won't help this.Quote:
Originally Posted by ColdShad0w
You need to plumb in a >1bar sensor post turbo / pre throttle body, wire it up to the BARO sensor signal inputs, and then recalibrate all of the BARO sensor settings so the ECM can "see" the actual pre-throttle body pressure.
Thankyou so much, great info! The sensor config in the tune threw me off realising that's how it worked. Just says NA-MAP so I assumed it was just using MAP/BARO(not used as TIAP) to calculate fueling. Will try temporarily adding a 3bar sensor pre throttle body before welding on an adapter to my IC piping. Will this not throw off the pressure ratio as I assume now BARO will read above ambient pressure with the placement of the sensor or is this calculated some other way?Quote:
Originally Posted by tunerpro
I'm not sure what pressure ratio calculations you're referring to. If you're referring to any constructs that reference BARO on an axis, this shouldn't cause any major issues as they are typically constrained to an upper limit.Quote:
Originally Posted by ColdShad0w
However, most (if not all) OE NA calibrations have an upper limit cap on the BARO sensor of 108 kPa, so you'll need to raise this cap up in order for this to work. Once you get this all set up, try logging Calculated BARO and make sure it reads accurately.
You're spot on the money, was looking through logs and noticed BARO was hitting 108kPa under boost. I thought this BARO value was derived from the BARO sensor, but that is not possible as its' placed pre turbo meaning this is a calculated value. I think my confusion came about because the BARO sensor is not actually acting as one, rather TIAP as you have said. Again thankyou so much for your help I've been chasing my tail thinking this was a TM related issue in the tune and I'm confident this will resolve my issues.Quote:
Originally Posted by tunerpro