Need help with o2s

[redhotrod]

Hey there
I'm trying to get my car tuned in for the new race season starting this coming weekend and I'm having trouble with knock relating to O2's I believe.
Heres the setup I'm working with--
84 hotair motor, ported tb(60mm), ported intake, ta49 with .82 exhaust housing, 2.5" dp, k&n filter, 42.5lb injectors, comp 212 cam, new valve springs and timing chain, walbro 340, adj fp regulater, adj wastegate rod, twin electric fans, and 86 ecm with chip burned for above mods. I do have a diy alky kit on order at the moment but don't want to just band aid my problem with knock.
Just to try and get rid of my knock, I have the static fp at 43lbs, which is running a bit rich at idle(850mv) but when I get into the gas above 11 psi boost, knock comes in and O2's are down below 750mv. Right now I have my wastegate rod as tight as i can get it and if I really stand on it, knock comes on quick.
Is there a way for me to fix this with a chip? Or is the alchohol the only fix? I can email turbolink files if anyone needs to see. Oh yeah, and I do run nothing but sunoco ultra 94 with their added methanol.
Thanks

 

[BoostKillsStres]

Please explain the following: "Right now I have my wastegate rod as tight as i can get it"

 

[redhotrod]

I'm playing with the wastegate rod trying to turn the boost down to see how low I have to go to get no knock. So far the farthest I got it down to is around 11 psi.

 

[dennisL]

Hot Rod, there are a bunch of things that can cause knock besides too much boost. In fact, if you're currently at 11 psi then you can rule that out.

The O2 below 750 mV might be a factor but I'm guessing its either a combination of things or being caused by something else. The tranny shifting causes knock, as does lousy gas, too much advance in the chip, and more.

You didn't say how much retard you get. The knock count is an indicator to watch but you really need to look at the amount of retard for each knock event. When a knock is shown on the scan tool, you need to check all the other sensor readings at that point (and before and after) to better understand what the engine was doing at that point. Are you logging the runs with a scan tool? Please say yes because if you are concerned about lights on a knock guage then I can't help you.

 

[redhotrod]

Thanks for the reply
I did finally figure it out. My fuel pressure regulator had the wrong vacuum source and wasn't supplying the extra fuel under boost. After I corrected that, I'm getting 19 psi with a max of 1.8kr. My static fp is at 40 and my idle o2s are up in the 840/850mv range. This is probably too rich, although at 19psi at the top of overdrive(>90mph) my o2's are coming down to 790mv. I would probably get more power if I lean it out(turn fp down) and bump the boost down a notch, right? I would think idle o2's and coming off the line should be in at least the low 800's or upper 700's
And yeah, I am saving my runs on tlink v4

 

[Slow91z]

If you up the boost, then that alone will lean it out...If you have the octane take the boost up a notch, this will lean it out...If it leans it out to much or not enough then adj. your FP to compensate.

 

[redhotrod]

How do I trim my bottom end o2s, isn't 850mv too much

 

[dennisL]

Hotrod, at what rpm are you referring to as the low end (when its rich)?

Do you have a bin file of the chip? I'm guessing the fuel is programmed a little on the rich side, which I'll be glad to check if you send me the file.

 

[redhotrod]

Low end is from idle to around 3000 rpms, I'd be glad to email a file out for ya. I don't think I have a bin file though I do know the characteristics of it. Let me know where to send the tlink file

 

[redhotrod]

I ended up lowering my fp down to 37lbs static, My O'2s are closer to 820mv now. Still able to run 20psi boost on 94 octane with minimal kr, but my 60' track times still really suck, best so far is 2.2 on nitto 275/50/15 drag radials aired down to 18psi, launching with 2psi boost, with coil airbags set to 15 and 30 and bilstien shocks all around. Tires really didn't slip if at all, just seems bottom end rich. my top end though is strong, from the 1/8 to the 1/4 I gained around 43 mph (53-96)but thats also with 5 seconds. I guess a torque converter could help.

 

[Slow91z]

You need some chip work I think.