So i'm curious about timing with switching over to e85. Since the burn times are way different would it be harmful to the engine to run my pumpgas timing with e85?

I do'nt even know where to start with timing on e85 although i have a pretty solid pump gas timing map.

veterans, care to share what you do for e85 tuning and where you start adjusting from?

Thanks

 

Id say start there or slightly higher and see how it works out, then tune from there. You should be able to run a little more timing than regular gas, but the basic idea is the same.

 

Jeff, I've done a number of e85 tunes... bring it down and I'll get the tune straightened out. As for stock block power 400-450whp, I wouldn't bother with e85... stick to 93. To answer your question, yes you can start from the pump gas timing values.

 

i sent you a text this evening. I think your number might have changed. I had a few questions that you could probably answer pretty quick on the phone.

I think i've decided to do the stock block while i get a new block to finish my build and swap engines this winter. I need to at least get this car out of the garage.

Hal, why do you say stay away from the e85 for the stock block? i have the large fuel system already setup so i figured why not benefit from the safety of more octane. Then maybe i could push it to upper 400's

I'll try to call you at the shop tomorrow but it will probably be around 4pm or so your time.

oh, the reason for asking about starting with pumpgas timing numbers was my fear for being too low of timing on the e85. I know how too low can cause just as many adverse problems as too high.

 

Because with the stock block, you are limited by the rods not the octane.

 

Exactly... at 400-450whp, 93oct pump gas has enough octane to be safe with a proper tune.

 

in general, with E85 you can hit MBT before you run out of octane.

Thats when you really need to put confidence in your tuner to make sure they are actually tuning every cell for MBT. Thats also when a load based dyno really plays an important part. You can keep the same rpm while increasing load and then advance or retard the timing to get MBT.

Like Hal has said though, with a turbo kit, you'll run into mechanical limitations before octane

 

fixed.

 

damn, alright alright....i was just trying to be safe to keep away any possible detonation like people that use meth on stock blocks but i guess i'll knock off that non-sense. It sucks because e85 is 1$ cheaper a gallon than premium here.

 

if e85 is easy to come by, then by all means tune for it. Noone has realy posted MBT timing for the midrange with low boost.

Either way, you will have faster spool with E85 due to the increased volume of gases, since you use more E85. That aspect alone is worth the effort.

 

ya, here in st louis i have 2 stations that are right around the corner and i have a 35 gallon fuel tank in my garage to keep it stocked up just in case.