Hotpiped evo3 16G, should I still target 12.5:1 AFR on E85

[UofACATS]

(Technically E78) I'm going to start WOT tuning soon. With an I/C I targeted 12.5 and all was good, but I realized I haven't seen any AFR data with no intercooler. Should I still target the same AFR?

I'm installing the meth/water injection tonight, so the same question applies while injecting as well, if you have an opinion on that. (I need to be able to run with and without injection, so I'd appreciate opinions on both if possible.)

Thanks!

 

[donniekak]

Running a stock smic at 30 psi on a 16g i targeted about 10.8-11.2. With a fmic i target 12:1. The richer mixture on the stock smic(which pretty much is a hotpipe at 30 psi), allowed me to run plenty of timing, without knock. I did have to gap my plugs down to .020" to light off the super rich mixture at high boost. I'd be leery of running leaner than 11.5:1 with 200-300* iat's, as the rich mixture cools the charge down a lot more. This is all on e85, of course. Also, we never get e70 down here, all e85, and e74, unless you go further north.

 

[mike96]

running no IC in Tucson Az!!! i'd think you would get some nasty detonation without one. although i would imagine that the factory one doesn’t work all that good in 100 - 110 deg heat anyway.

 

[UofACATS]

Running a stock smic at 30 psi on a 16g i targeted about 10.8-11.2. With a fmic i target 12:1. The richer mixture on the stock smic(which pretty much is a hotpipe at 30 psi), allowed me to run plenty of timing, without knock. I did have to gap my plugs down to .020" to light off the super rich mixture at high boost. I'd be leery of running leaner than 11.5:1 with 200-300* iat's, as the rich mixture cools the charge down a lot more. This is all on e85, of course. Also, we never get e70 down here, all e85, and e74, unless you go further north.

Thanks bud. You know I had that E85 chart memorized two years ago, but I'd forgotten all about it. So E78 for about 1/3 of the year, and E85 the rest IIRC?

I am about 11.5 AFR when the 16G creeps up to 19psi or so. 18 degrees timing, and I did get a 0.4 degree blip. I managed to creep to 21psi on one pull where I saw 1.1 degrees. I'm a fan of a knock-free tune especially on E85 or E78 so I'll have to address it.

When I'm running no injection I don't need much power at all because I'll be on-track. If I can figure out how to keep the 16g at about 12psi then that's what I'll be running so really there shouldn't be any issues. On the street however, I'd like to have some power so I'll spray the water or meth and run some actual boost.

running no IC in Tucson Az!!! i'd think you would get some nasty detonation without one. although i would imagine that the factory one doesn’t work all that good in 100 - 110 deg heat anyway.

My old DVDT cooler worked great, except for the fact my radiator didn't.

Ethanol is a brilliant fuel