[Megahurtz]

Originally Posted by Future1LE

Would all the timing mentioned here apply to a port injection zl1 with stock heads and cam? Mine is a 2650 headers, intake, 103 inlet and TB, E85. Just stock heads and cam. Mine is currently 22* right now.

How much boost and what percentage of Ethanol?

22 seems pretty safe.

[Future1LE]

Originally Posted by Megahurtz

How much boost and what percentage of Ethanol?

22 seems pretty safe.

16# of boost. Pump E85 so comes out to be like E65

[Joshinator99]

Originally Posted by Future1LE

16# of boost. Pump E85 so comes out to be like E65

22 degrees on that combo is very reasonable. Might be worth trying an extra degree on the dyno to see if the combo likes it.

[Future1LE]

Originally Posted by Joshinator99

22 degrees on that combo is very reasonable. Might be worth trying an extra degree on the dyno to see if the combo likes it.

Thanks for confirming! My tuner actually stopped at 20* since this was his 1st time tuning a port injection setup on stock heads and cam so I know he is just trying to be safe. But the car just wasn't where I thought it should be, so after talking with a few guys on here with the knowledge and reading alot. I decided to throw 2 more degree in myself. Now the car is where I think it should be and maybe with a little more to go. No dyno numbers but did do some 60-130 dragy pulls as measurement and consistent improvement. I went 6.0 at 18*, 5.9 at 19*, 5.65 at 20*, and best was 5.4 at 22*. All with similar DA and Temp. Maybe 5.2 at 24*? lol but I'm nervous to throw that much in as I am not a tuner lol

[Joshinator99]

Originally Posted by Future1LE

Thanks for confirming! My tuner actually stopped at 20* since this was his 1st time tuning a port injection setup on stock heads and cam so I know he is just trying to be safe. But the car just wasn't where I thought it should be, so after talking with a few guys on here with the knowledge and reading alot. I decided to throw 2 more degree in myself. Now the car is where I think it should be and maybe with a little more to go. No dyno numbers but did do some 60-130 dragy pulls as measurement and consistent improvement. I went 6.0 at 18*, 5.9 at 19*, 5.65 at 20*, and best was 5.4 at 22*. All with similar DA and Temp. Maybe 5.2 at 24*? lol but I'm nervous to throw that much in as I am not a tuner lol

Yeah 20 is too conservative. If you’re adding 6 degrees of flex fuel timing then his base high octane timing was 14 which is too tame even for plain 93.

[Future1LE]

Originally Posted by Joshinator99

Yeah 20 is too conservative. If you’re adding 6 degrees of flex fuel timing then his base high octane timing was 14 which is too tame even for plain 93.

I think you are correct one the base timing of 13-14. Right now my flex fuel timing is like 9 lol. I would need to bump it to 10 if I want 23 degree of timing

[Megahurtz]

I wouldn't be afraid of 23-24 on that setup on E65. But to be clear, timing would be ramping up to that value and not that high on the hit. Peak timing would either start at 5600 or 6000 depending on what the dyno says. I do seem to be a little more aggressive than others on timing though. If the car stops getting faster, or barely makes anymore power on the dyno, then there is no reason to run more timing.

[Future1LE]

Originally Posted by Megahurtz

Maybe I'm crazy but I would be at 20 on pump and 25 on E60+ on that combo. Although to be clear, this would be ramping into the timing at RPM climbs. It wouldn't be at peak timing until 5600 rpms and higher. Although maybe since some of you're fuel is coming in via port injection I would back it down to 20 and 24. But it all depends on what the car does on the dyno. If you aren't making much more power going from 22 to 23 then it makes no sense to go beyond that.

Yea I added it up top around 4500+, and would hit 22 around where you mentioned. I agree that going from 22 to 23 maybe not worth it. But going from 22 to 24 might be lol. Maybe one day I'll readjust it to hit 24.

[Megahurtz]

Originally Posted by Future1LE

Yea I added it up top around 4500+, and would hit 22 around where you mentioned. I agree that going from 22 to 23 maybe not worth it. But going from 22 to 24 might be lol. Maybe one day I'll readjust it to hit 24.

To be honest, if it were my car I would be testing it all the way to 25-26 degrees.

[KingLT1]

I have had some bolt-on LT4's that wouldn't run 20 degrees on pump. My guess is that the wrong octane was put in the premium tank at the filling station. Either way I prefer to run them conservative on pump gas for that reason. I do 12 degrees in the base table on 93 with stock internal LT1's and 17-19 degrees on LT4's. Then add what it takes to get to desired in the flex table.

[Evansa22]

Originally Posted by KingLT1

I have had some bolt-on LT4's that wouldn't run 20 degrees on pump. My guess is that the wrong octane was put in the premium tank at the filling station. Either way I prefer to run them conservative on pump gas for that reason. I do 12 degrees in the base table on 93 with stock internal LT1's and 17-19 degrees on LT4's. Then add what it takes to get to desired in the flex table.

As usual, your info is spot on. My tuner has my timing on 91 at 15*, soon I'll be adding ethanol so we can bump that up. But it had to be dialed back from the previous tuner because he didn't give two s$its about knock.