Preferred tuning method

[VIN7]

What would be the preferred method in this case:

In order to get wot wb tracking correction tighter (i.e. less than 5%) should I add fuel (pump gas) or increase alky gain? I'm at about 8% added fuel (correction factor) to maintain 10.8 a/f and position 6 on the alkycontrol gain knob (single m15).

Mike

 

[murphster]

I would add fuel, but even then it won't be perfect. At WOT the alky references boost and the alky output stays fixed if your boost is constant. However, as your rpms rise throughout a run, your injector output and hence fuel output rises. Thus, the fuel/alky ratio changes throughout the run and may affect the wideband readings. You add enough alky so that you are good at the top end. Other than that, you have more alky then you need in the lower rpms, so adding more alky is just a waste if you are keeping the boost/timing the same. You may be able to take advantage of that with something like FAST that can add in more timing at lower rpm.

In addition, if you have an older alky pump, it may already be reaching its max output at your current boost setting. Lets say a new alky pump maxes out at over 200psi but an older one maxes out at only 160psi. It may reach 160psi on the current controller settings at 20lbs boost, meaning at any boost over that it stays at 160psi. So adding any gain to the alky settings will just add more alky at the lower boost settings and keep the same alky at the higher boost. So you'll fatten the car down low and keep it the same up top, accomplishing nothing except wasting alky.

Its good to know how the controller works as it can affect some performance and can really affect the street manners. On a stock turbo with instaboost, the progressive nature doesn't make much of a difference but with a slower spooling turbo the alky ramps have a larger effect.

 

[Razor]

Use fuel to correct AFR issues.

Use alcohol to correct knock issues.