Lately I have been tuning quite a few Gen 6 ZL1's with full bolt ons, varying pulley setups, with meth and full E85(E80 from the track). At the same time I have been testing the JMS FuelMax on my personal Z06 to see what I can squeeze out of the stock system. With that said, typically I tune SOI on the ZL1s in the base table and alcohol offset as to not exceed 360 and I try to keep the EOI above 180 and the pulsewidth around 5.5ms max on the hit and then down to 5ms by redline as the meth ramps in and takes over for the extra fuel needed. Not to start a discussion about relying on meth as fuel or anything please, I keep advising the shop I am working with to come up with a better solution, but they and their clients are okay with leaning on Meth for this. I have advised to add the JMS to assist with fueling on the hit while the meth ramps in. The JMS really does help with fueling on these cars. Not a ton, but for a bolt on car I would say it is a no brainer.
Anyhow, on my personal car I have tuned SOI to not exceed 360 SOI, but when I really push the fuel system it will creep up to 365 which is still after EVC so I'm not too concerned. But as I ramp up the ethanol content past E70 the EOI starts dropping as low as 140 which means I'm spraying into the compression stroke by 40 degrees. Low side maintains 80psi due to the JMS, the high side stays at 2600psi or higher(usually only drops to 2600 psi around 5200 rpms and then climbs back up to 2900-3000 until redline), and the injectors range from 6.3ms on the hit and drop down to 5.8ms by redline. Commanded Lambda stays on target the whole run and the car runs strong.
First, before you say "you're out of fuel", I already know that I'm at the limit but that isn't my question. My question is, do any of you guys ever spray into the compression stroke(past 180 EOI)? I know Doug at ECS does this on his personal 2019 Z06 with full bolt on and pulley and STOCK fuel system. He does have a ZR1 low side since it is a 2019 Z06. I'm pretty sure my JMS flows more low side than he does and I'm on a stock pulley and he is on a 2.3. For street driving I will be running E60-E65 as this keeps SOI/EOI between 360/180. But I want to run E75 during race events. I've read through a ton of old material on here to see if anyone had concerns or experience with EOI dropping below 180 degrees but most of the talks focus on SOI. Technically according to the stock Z06 cam profile I should be able to inject up to 368 degrees with the cam at zero retard so at redline my SOI could go all the way to about 375-376. But it is well documented that it is not optimal to spray at the end of the exhaust stroke even if the exhaust valve is closed.
Anyhow, new thread, new question focused on EOI. I'd like to hear some of your thoughts on this subject if you have any experience to share.