Wideband Tuning Basics?

I've been doing a lot of research on the subject but the one thing I want to know, I can't seem to find. I've got down running rich/lean and the stoichiometric ratio and whatnot. But what I want don't understand is what ratios are ideal for what conditions? I'll try my best to explain better.....

I've read that you want a different afr when entering boost than you do when you you're at full boost and also at peak torque? But no one ever explains exactly WHAT it should be. I know we have many intelligent members on here, anyone help a newbie out?

Since you are only running 5lbs of boost I would run your A/F ratios around 12.5 - 12.8 region. I have read that 12.5 is the magic number for making good power and also being really reliable.

I forgot to ask, what is your compression ratio? Just for reference sake. You know it would have been the next post anyways.

I am running about 9:1 I would guess and my A/F ratio in that load region is almost right at 12.5 and my car pulls like a mother. Obviously timing has alot to do with that, but I dont think we are able to adjust timing with the fuel unit you are using.

Stock compression ratio is 9.6:1 and no, my EFI system only controls the secondary injectors.

So then would my goal be to get my afrs at 12.5 all through the rpm range? I don't think I'm going to be attempting my own tuning cause I don't want to screw anything up but I'd like to at least have it figured out.

12.5 is awesome as long as your timing doesnt interfer and create knock. i run mine at 12.3-12.6 at WOT on 15psi and have no knock due to my total timing being where i run it... it's a secret because i run pump gas... no, not really, it's right around 24* total at 3000rpm. but i reworked my distributor for less mechanical advance so i can run more inital without it knocking on topend. i fiigure with e.f.i., you should be able to control those factors alittle more closely than i can with a carb, distributor setup...

Ya, this is what my program looks like, I just need to change the variables in the matrix to control injector flow percentages.

The injector scaler controls pulse width. The matrix at 1.00 is 100% of the scaler & 1.20 is 20% more fuel and so on and so forth. Should be pretty simple right?

Really its tough for any of us to tell you. Some cars make more Tq with more fuel. My car makes 30 more ft/lbs at 11.5:1 then it does at 12.3:1. The recommended area for boosted cars is between 11.5-12.5 And with your compression I would try and stay around 12:1 or richer and then try and dyno it. Just don't become a DSM style tuner and run tons of fuel just so you can run more boost. You really need to figure out how your car wants fuel with the timing and VE of your engine. But if you stick in the 11-12 range you should be safe. Heck some cars make more Tq at 10:1 it all depends on a lot of variables.

Thanks Jason and don't worry about me trying to dump more fuel for more boost. I've still got completely stock internals and won't be turning the psi up from 7 until I get build the motor with PT lifters, Eagle Rods, and JE Pistons to make it 8:8:1

Ahh I'd run 10 but that's just me, I guess I don't know much about your engine. On Honda's I would run 10-15 as long as the tune was good. On my stock block I made 411hp at 18psi. Its all in the tuning how long it will live.

The guy I bought the kit off of was running 10psi w/ a stock headgasket and everything with no problems. I have an multi layer steel HG so I'm not worried about it, but the way my luck goes, I'm gonna keep it at 7 just so it will last longer

Keeping it at 7psi might be a safe bet, unless you really want to throw some fuel at it. I am pretty stoked to see what she is running at right now.

Have you actually gone out and done any test runs to see what you are currently running AFR wise?

No, I havn't installed the wideband yet. Still thinkin of ways and a place to mount it and then I need the serial cable to connect it to my laptop (checking radio shack and if they don't have one I found one to order for $12)

I think I've done enough research now that I feel comfortable trying it out. I'm excited!!!

itll work out for you todd, ive had a fukkin black cloud over me for years, but i figured out that as long as i dont get overzealous with the timing and the boost, it can last a really really long time basically trouble free.

Also remember AFR's are really simple, stay on the rich side if you want to be safe and you can monitor AFR's easily. Timing is when tuning gets more complicated and harder to verify the effects of small changes. Tuning AFR's really is not hard, just don't get confused and think higher numbers mean more fuel ha ha. Seen that way too many times, people keep pulling more fuel and the AFR's keep getting higher.

haha, seen that happen too haha, in a backyard suburban with a turbo on it, they said its fuel injected and it will take care of the tuning on its own, haha, like hell it will.

If they make a system that can take care of everything by itself I'll take one! Or maybe I won't because we'll know they are lying. Although the crazy dudes in Europe are pretty close with there systems that monitor each cylinder for AFR, Cylinder pressure, EGT and knock. But then again none of us have an extra $100,000 laying around for a baller's EMS. Well I know I don't for sure maybe some of you do!

Im not going to lie, I am a big fan of the Autronic. It is a very user friendly system and it works very well once you get the hang of it. Of course there are always problems to work out like any other system, but they are pretty minimal.

I can't wait to dive in........ If the weather is nice for an hour this weekend then it'll be tuning time lol.