Just went back to the track this weekend and it did pretty well. Ambient temps were low 80s so it is significantly cooler here in TX.
I think what happened was the original tune post-rebuild was too lean and just f'd everything. It would have been fine except I kept going to the track. I'm thinking that FI'd non-Ms cannot handle 100's on the track even with an oil cooler. I could use meth instead of isoalcohol but that's a bandaid on a bandaid.
The MS45 takes IATs from the MAF whereas the MS43s took IATs from the intake manifold. Even my limited run TS intake mani has a plug for an IAT. Easy, right? Just snip the wires to the MAF and then run them to an OE BMW IAT. Apparently there is a circuit inside of the MAF which steps the voltage down from 12v to 5v. My shop is trying to dissect and MS45 MAF and rig up a sensor to put into the mani but that's not a solution I want to take. What if I need to replace the sensor? Just more electronics to fail as well. And then who knows what other issues that will create. I don't see why any company would further develop an FI system/tune for track use because most people have sense and go with a just as capable E36 or E46 M3.
I'm considering a stand alone ECU at this point. Its going to be a track car so I'm willing to sacrifice streetability. I would like to keep the ABS so I'm wondering if I lose that if I scrap the OE DME. I'm being told that ABS is an entirely separate module but I'm not willing to believe the Germans, especially BMW, made something simple and non-integrated.
Last edited by bigjae1976; 11-05-2012 at 12:02 PM.