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      01-15-2020, 12:47 PM   #28
F87source
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Drives: Bmw M2
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Quote:
Originally Posted by ZM2 View Post
Is there a certain E mix where there are little to no gains on our platform vs full E85? Or is it completely turbo & tune dependent?
Honestly it's mostly trail and error when experimenting with ethanol mixtures, looking at logs and contrasting that with your goals. For example people who just need octane can expect to Max out ps2 with anywhere from E35-E50 depending on their altitude, iat's, mods etc and don't really need to exceed this. There have been users that have hit 700 whp on E50 when using the appropriate sized turbo and intercooler. So for those individuals there is no need to go pass E50 and worry about ethanol causing a lack of lubrication in the cylinders, fuel pumps, and possible drying out seals which generally gets worse past 50% concentration. However those of us who seek to use ethanol for it's evaporative cooling effect in reducing cylinder temps will want to run as much ethanol as possible to help the motor run cooler for track use. For example motoiq reported a drop of 20-30°F (iirc) when using full e85 on both coolant and oil temps. But when using this concentration of ethanol you'll need a top cylinder lube like what power plus cells to keep ethanol from causing lubrication based issues. Of course a fuel stabilizer to prevent moisture from ending up in the ethanol is important too. For me I'm going to run full e85 especially since it's available at the pump now where I live.

Quote:
Originally Posted by ZM2 View Post

For instance, if I upgrade the HPFP, can I get more power out of my Dinan turbo with higher than E30? If so, any idea the right E mix and how much more HP before we’re boosting out of its efficiency range and creating unwanted high IATs?
Probably not the stage 1 turbo upgrades are already being pushed to the max even on pump gas. You'll likely be pushing the turbo out of it's efficiency range. You'll likely be able to run richer afrs though with an upgrade hpfp which is good. A really general idea to figure out if you're passing the efficiency range check the amount of power you gain with 1 psi increase vs. how much more the iat's spike. If iat starts to increase more than power you're starting to pass the efficiency range. Otherwise with full turbo upgrades they usually come with efficiency range charts. Altitude plays a huge roll too, the higher you are the harder your turbo has to work.

Quote:
Originally Posted by ZM2 View Post
And, what are the answers to these questions if I switch to a PS2?
You'll probably be able to hit 500 whp on E35, and depending on your intercooler you may need a bit more in the summer when iat's spike.
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