08-02-2016, 08:19 PM
Join Date: Sep 2007
Total Cats: 24
E85 Naturally Aspirated Tuning Thread
Hey dudes, I just went through the process of throwing a VVT motor in my NA, and finally got around to getting the flexfuel sensor set up. I followed Savington's procedure for tuning fuel for MS3 last night (copied below).
Originally Posted by Savington
Here's how I would set up a fresh MS3 flex fuel install.
1. Dial everything on gasoline and save your tune.
2. Install the flex fuel sensor and set Baseline Ethanol% to the value you get with "100% gas" (in CA this was ~8% for me)
3. Turn on flex fuel, but leave all the alternate maps off. This just leaves the global blend, but doesn't allow blending between VE1/VE3 (or Spark 1/Spark3, etc)
4. Drain the tank and fill it with E85. Tune the spark/fuel, AFR target, ASE/WUE/Accel maps, and all the other maps that have switching available in the software. Tuning all these maps on VE1 will let you use Autotune like you normally would. Put a few tanks of raw E85 through the car to get the content up as high as you would ever see it, and make sure the tune is dialed in.
5. Load the set of E85 maps into the alternate map positions, load your gas maps from step 1 into the primary positions, and turn table switching on. Set the flex blend curve so that the ECU switches over to the alternate maps by 80%EC
6. At this point, you're about 95% of the way there. The only setting left to dial in is the flex blending map, and that will happen by trial and error with varying levels of ethanol content in the fuel.
At this point, my intent is to deck the head and install my 264/264 Maruhas over winter, but I'd like to semi-optimize the tune for the moment (planning on hitting the dyno in the spring post-headwork). Does anyone who has tuned an E85 car on a dyno have any idea (approximately) what sort of timing changes showed results? Currently my car is a BP6D, RB headers, Squaretop, properly sized intake & exhaust, MS3Basic. I realize this question is in a lot of ways, a bad one, but I'd like to know if the E85=faster flame front phenomenon actually necessitated adding timing on cars that were already hitting MBT on gasoline. My ignition map is below, and is more or less just the Reverant basemap. Ignore the fact that I threw away half my resolution by leaving in boosted rows.
Non-sequiter, but this is a pretty neat note about E85 cruise tuning
Last edited by albumleaf; 08-02-2016 at 09:33 PM.