[ZHP to B58]

I've been running the TU HPFP for a while and only the Stage 2 (91 oct.) MHD tune since there's no 91 oct. map for the Stage 2+ (starts with 93 oct.).

Instead of getting a Flex Fuel kit, I was wondering if I'd be able to get away with just filling up 4 gal of E85 and the rest, 91 oct. Online calculators show that this should end up with an octane rating of 93 or slightly higher.

Anyone else ever do this? Not planning to ever run an ethanol map, just Stage 2+ (93 oct.) at most, but using an ethanol mix.

[marcthedark]

There is the option to set up Multimap "Stage 2 HPFP" and then one can choose 91 .. as 91 wouldn't make use of the HPFP w/o E that makes sense

[ZHP to B58]

Originally Posted by marcthedark

There is the option to set up Multimap "Stage 2 HPFP" and then one can choose 91 .. as 91 wouldn't make use of the HPFP w/o E that makes sense

Never noticed that - thanks. I wonder why they didn't just list 91 as an option under Stage 2 HPFP in the first place...

FWIW at least for my 240, even on 91 and Stage 2, the stock pump wasn't flowing enough and it'd cut power and backfire. Once I swapped to the TU HPFP, everything was normal again.