I just tested the local e85 pumps and found one with e83, so going to switch over after this weekend and start with my tuning for it. Just curious what to do with the timing tables when switching over. Should I give it more timing everywhere or just in the wot areas? and how much timing is too much for my setup(stock longblock, 2.8kb, estimating 21-22lbs). I'm at 16 degrees now on 93 @ 19lbs. Was planning on just 18-19 degrees but if more is plenty safe I may push it a little further.
Timing with e85?
- Thread starter ctgreddy
- Start date
22 degrees is rather mild on e85 still. I have seen 26-28. 20 would be a good starting point.
not on E85. I think the suggestion to start at 20 and work your way up is a good one. Keep adding a degree until you stop making TQ…then back down to the previous setting. My bet is you settle in around 23-24 range
With that much timing I wonder if I should even up the boost. I just want a solid 720-750whp. I'm thinking the aid of e85 and 4+ more degrees might be enough to get me there. Then there'd be less strain on my stock head bolts.
you're making decent hp right now on gas, but the tq is lowish. I don't see any way you're going to make 750 on 19lbs of boost on a factory 8.5/1 motor. You could keep the 19lb pulley setup and see what happens….but my bet is you'll desire to add the extra 2-3psi very quickly and gain that TQ hit...
When you guys are running 22 - 26 deg timing at WOT are you having a look at the spark plugs to see where the timing mark is on the ground strap ? I am running 24 psi with 18 deg total timing on E85 and my motor is 8.8 to 1 compression and my timing mark on the ground strap is just below the bend. I would say that my absolute max would be 20 deg before burning the strap to the weld which would indicate a burn down situation.
Anyone with a higher compression build on e85? Just switched over and tuned mine to 20 degrees. Doing to a dyno day this weekend, and wondering if I should keep it at 20 or push it further. Are you maintaining a set timing or ramping up slowly after peak torque?
Try it at 20 then go up a degree at a time and see if it picks up torque, if not back it down to be safe. Timing should ramp up from the hit so you don't detonate the motor. Higher compression will narrow the tuning window and limit the toal timing and or boost that can be run. How much boost are you going to run ?
It will only hit 8lbs. 7,500ft DA and a little S trim.
At what point do you sacrifice low end power in order to increase timing with rpm? How much do you need to gradually increase timing by to avoid detonation, I had it pull timing from 20 degrees to 17 up top and it didn't detonate.
Would I be better off ramping the timing up to say 23 degrees and increasing the air fuel ratio vs. sacrificing low end power by slowly increasing timing to 20 degrees.
Considering that boost and elevation you should be able to run 24 deg total timing without any issues, but creep up on it. At wot evey degree of timing should be worth 7 - 10 hp I don't think you would have to sacrafice any low end power especially on E85. You should be able to run lots of timing down low and be able to run 24 at wot. When you are ramping the timing down from high to low you want a gradual decrease so the motor isn't dealing with big jumps. I would keep afr at 11.5 - 11.9 on a gas scale and just play with timing.
Thank you! I appreciate the info. Hard to get good info when doing your own tuning.
Yeah it's easy to get carried away with timing especially when on a dyno as we are all chasing the " dragon " so to speak to get that magic number. But just take your time and use comon sense you'll be fine, Hat's off to you for tuning yourself.
I ended up only putting 18 in my setup, Mainly because at that timing I made 722 and blew the spark out right up top. Now how much timing do you guys have in lower rpms(2k-4500)?? That's what I'm confused about, I saw zero signs of detonation where I'm at now so I'm sure I could sneak 1 or 2 more in the midrange but dont want to get too greedy.
What is your plug gap ? When I go wot timing starts out at 12 deg and climbs to 18 at 6500 rpm.
plugs were at .030. Didn't even think about gapping down when I switched to e85. I put in a fresh set and down to .024. That's about what my timing does, I have 18 degrees in by 5000 but not sure how aggressive to ramp it in.
Users who are viewing this thread
