Hey guys I'd like to get some gears turning brain wise! Bear with me through the explanation but I think this could get some intelligent responses.

I am slowly modding my DE as my budget allows and am going to do some head work soon. After the heads I'd like to get a tune and get everything talking correctly. I'm not rich so things have to be done on stages hence the issue at hand.

Running across the fact our engines like to run lean after multiple mods I'd like to brain storm a few ideas to prevent this condition until I can afford a good tune.

List of mods (before I can afford a tune)-
Popcharger
Z1 plenum spacer
OBX long tubes
Greddy true dual
Port and polish

Possible Temporary Cures-
Small washer to pull back upstream O2
Change resistance values in MAF (researching this now)
Increased fuel pressure(doubt it will work since pulse width will remain the same)
Restriction plate in exhaust (50mm opening in 70mm tube)

Let me know what you think and remember this is temporary. Thanks for reading guys!

 

post a log of your car running lean with the mods you listed.

until then, you are worrying about nothing.

 

Thanks, good to know. I only started to worry when I saw the inside of my exhaust manifolds and they were completely clean... no carbon at all. I know EFI is accurate but that seems too clean.

 

In regards to manipulating the MAF, it's probably a bad idea. Assuming the ECU doesn't freak out you are effectively making a shift in the entire fuel map which may help certain areas but you could go way too rich in other areas. Which is somewhat safer than lean as long as it's not too far but at a point it's not healthy either. Most mods are going to show gains but likely only in certain regions of the 3D map. You may in fact require less fuel in certain areas because you are changing the harmonics of the air stream.

The best thing you can do is log how the engine is running and correct the maps accordingly.

 

Wideband/gauge before you worry about tuning. My car had Short ram, V+ plenum, test pipes with injen exhaust and I was running 13-13.5 afr at WOT

 

low 13s are fine for NA on 93 octane

 

Thanks QTB, good point on the mapping. I'll have to do more logging to see whats actually going on and where/when.

Deadeye - Wideband is in my future definitely, any suggestion on placement when using long tubes?

I'm researching piggybacks and tuning options versus doing the heads first. If you guys have any prior experiences love to hear cost vs effectiveness.