Just looking for any thoughts on my A/F ratios. My mods are listed in my signature. I'm running 93 octane fuel. Runs 1-3 were at 20 psi, run 4 at 18.5. All four used the same SAFC settings. Any suggestions from those more experienced than I am would be greatly appreciated.

 

Forgot to add my settings:
3500 +3
4000 +0
4500 +4
5000 +0
5500 -2
6000 -8
6500 -8
7000 -13

 

Anyone have any thoughts on this? I'm just looking to get feedback from people with more experience than I have tuning cars.

 

if they had the same settings why was run 1 so different than run 2 or 3. also what are you using to measure your a/f ratio's? do you have a wideband installed on the car or were you using one at the dyno?

 

The yellow line looks the best but it looks like you need to add some fuel back in at 4500 if you can. I am guessing from your settings that you are on the stock fuel pump so you might not be able to change it much but it would be worth a shot so it does trend back up then down, you are getting a little lean and your car could pull timing as a result right at that point becuase of it which would result in a loss of power. I always try to target 11.1 afr on 93oct fuel. I hope it helps

3500 +3
4000 +2
4500 +5
5000 +0
5500 -2
6000 -8
6500 -7
7000 -12

is probably what I would try and see how it feels, the AFC has two data files so put those settings on the other data file and compair the two and see which one feels best and which one reads lower knock voltage.

 

I have a wideband installed in my car. As far as the differences, I'm not sure. I'm wondering if maybe the car is sensing some knock and is adding fuel in runs 2 and 3.

 

I'm actually on the Walbro fuel pump, so adding fuel shouldn't be too much of an issue. Unfortunately I have the SAFC-I, so no knock count or dual maps. I will try your settings and see if it smooths out the bump around 4500. I just wasn't sure if it was enough of a bump that it would matter. I've more or less been trying to tune based on what I've seen of A/F ratios from 93 octane dyno sheets on the site. Some have the A/F ratio drop to 11.5 by 3000RPM, but others have it hanging around 12 until 4000-4500. I'll see if smoothing out the bump helps. Thanks for your advice.
Paul

 

looks too rich, keep it between 12.5 and 12.0 or go as rich as 11.7 if you want to play it safe. If you become concerned about knock, lower your boost, but any richer than this you start loosing power

 

The strange thing is, after going back through my logs I was fastest from 40-80MPH on runs 2 and 3 where I was below 11. ~4.7 seconds for runs 2 and 3, ~5.0 for runs 1 and 4. Unfortunately there aren't and 4 wheel dynos anywhere close to me, so I can't check on power gains and losses.

 

I'm guessing but did you do these runs pretty much back to back ?

Runs 1 & 2 when the car was still relatively "non" warmed up, but for runs 3 & 4 the Evo is plenty warm and it is starting to add fuel to possibly ward off any knock.

When I've done runs, if I do back to back WOT runs without letting the Evo cool down a bit in between I get the richening up that you see from runs 1&2 to 3&4.