air fuel ratio..

lucasoil4u · 06-13-2009

im running a dsm 2g and i just put in a wideband air fuel ratio gauge. i have 2.0 16g walbro 255 and 560s and apexi neo. What should my air fuel ratio be so its safe. Thanks for the Help.

**Shane@DBPerformance** · 06-13-2009

There isn't a guaranteed safe A/F ratio. Boost and ignition timing will still blow up your motor at a very safe A/F ratio. You need to monitor timing, knock, boost and A/F ratio and figure out what combination of each makes the best power. If you are running moderate boost like 15-18psi with a good FMIC, then might be able to run in the very low 11s or aroudn 11.0:1 on pump gas. If you are trying to push the boost or setup then you might have to run richer and still get knock. A fuel controller like an SAFC or Neo is going to have the side effect(usually unwanted on pump gas) of causing the car to run more and more ignition timing the farther negative you are in the airflow settings.

lucasoil4u · 06-13-2009

it is set at 10 but then it creeps to 17 or so ... how can i fix that?

4g63tcrazy · 06-13-2009

That's boost creep. You're never really gonna be able to get rid of it. When mine started creeping I just upgraded everything to run the boost that it creeped to. Then it just held that boost perfectly. So in you're case, 17psi.

lucasoil4u · 06-13-2009

there has got to be a way to get rid of it 99 percent

4g63tcrazy · 06-13-2009

Search boost creep and you'll come up with some ways to try to get rid of it. But you already have the mods to support 17psi, so why not just run 17?

lucasoil4u · 06-13-2009

Its not a steady 17 its 17 when it wants to be .

Gravy · 06-14-2009

Porting the 02 housing worked for me. Porting the 02 and matching the exhaust got rid of it for me, and will be doing it to my new manifolds and 02 housings for the 13g upgrade i'll be doing soon. VFAQ has a nice bit about doing it, but i'm sure you can find someone on here to do it for you if you don't want to. If i'm not mistaken i think the 2g's have the same 02 housing as the 1g's, can get a ported and dumped o2 housing on e-bay fairly cheap.

lucasoil4u · 06-14-2009

i had the dump tube originally but that gets old after a while. i got a LIPP o2 housing that is open with no divider in the o2 housing. Is anyone else running the LIPP? i wonder if that will help me out when i put it on or not.

4g63tcrazy · 06-14-2009

That should help out quite a bit. And you said you start at 10 and it creeps to 17. If you just set you're boost at 17, then you'll no longer get creep and hold 17psi solid. That is all I'm trying to say.

Mike Neal! · 06-14-2009

you could goto a external wastegate set up... that should control it alot better. little internal wastegates can only bypass so much exhaust before its starts to make the turbo spin faster.

but..

Who runs 10# anyway? lol

-Mike

lucasoil4u · 06-15-2009

well i set the boost at 17 and it creeps to 22! its a never ending game! maybe ill just unplug the wastegate and see how much boost that 16g can make..