I have spent the entire day gathering this data. I was finally able to orchestrate this test with a friend of mine who also frequents this board. He was witness and also passenger data logging. Firstly, the test conditions were such:
135i, stock downpipes, stock intercooler, JB4/G4 alpha tune. Ambient conditions 72F. Engine warmed up fully, heatsoaked for both runs. Boost kept constant for both runs. Meth mixture 90/10. Flow rate for meth was about 310-340 ml/min TOTAL.
Multiple runs were done 2nd through 4th gear, best back to back runs were compared.
Runs sometimes had to stop at 6000 RPM, but the ones that didnt I will comment on.
The results speak for themselves. I initially ran the car at about 15.5-16 psi with little taper.
This is not suggested by BMS nor any of their affiliates by any means, it is risky to do but I chose to do it on my own accord to gather data.
This will let the pre turbo injection do its job on one end of the spectrum. The HOT end..
Best NO METH run, IATs hit 183F by the end of 4th.
Best Pre METH ONLY run, IATs hit 167 and DID NOT increase, they plateaud there for the remainder of 4th gear and did not exceed 167 where without meth it was hitting 180+ and climbing. I must emphasize that the pre turbo injection REALLY SHINES in 4th and 5th gear where the turbos are working hard.
Also, PWM was less for Pre METH, which means the turbos are definately spinning slower with this system.
Pre-methanol works for runs like these, as you can see, for gears 1-3 it does little to effect IAT but it does help Ignition advance as one would anticipate.
Ignition advance is helped greatly in gears 3 and 4. In the NO METH run ignition was pulled out, in the Pre METH run ignition DID NOT pull out and kept climbing.
IN BOTH runs ignition was below par and dangerously low for 93 octane, this is a risk I TOOK to try and test the benefits of pre-turbo injection.
I am not saying the ignition is good, I am saying it had improved versus the NO METH run with this injection system.
Note that there was no other injection taking place, ONLY the pre turbo injection which was about 150 ml/min PER TURBO. or about 300-340 total.
I had ISOLATED the pre turbo injection variable and now I show you the results.
Please comment and all feedback is welcome.
P.S. The G4 is a dream, I really love this tune. It is extremely easy to use and boost is controlled so finely. I very much enjoy G4 and I am not sure how else it can be improved.
Also, please rep me if you find this useful because this data was not easy to get.