Spark Plugs with Two-Step

[Ed Wright]

Bobby, mine doesn't automatically go into Open Loop on the 2 step. Are using the FAST 2 step?
WOT is the only place I use Closed Loop. Unless you have really long collectors, or the O2 sensor before the collector, at idle & low RPM driving around the pits, cams with a lot of overlap like we use, it will pull clean air back in the collector during the overlap cycle. That looks lean to the ECU, and it will add fuel. I had a muffler shop make me a long slip-on extension with a 30 deg bend, for tuning my idle and part throttle. That stopped it from pulling in clean air during overlap, and made the sensor read correctly. I put in closed Loop for that, and just kept tapping the L key while I drove up & down the return road with that extension on it. Then back to open Loop there.

I use closed Loop going down the track. It never makes corrections anymore. My VE table is pretty well dialed in for any weather & elevation I run at any more.

[Bobby Fazio]

Ed I have the sensor in a primary so the closed loop would be somewhat accurate around the pits. My tune going downtrack has a good reading and I have a sensor in the collector for that. I think a great new option for any EFI company to set themselves apart from the competition (hint hint) would be to use multiple widebands at different RPM or Loads. For example, it would be cool if under 4500 RPM or certain load %, my closed loop is controlled by my primary tube's o2 sensor and then when I transition to a full throttle RPM, above 5000RPM or over 80% load let's say, it switches its closed loop decision making to the o2 sensor in the collector.

[Ed Wright]

Bobby, after I put the long collector extension on mine, and did the part throttle tuning, I pulled it back off, and put it back in Open Loop there. I see no need for further corrections there. My spark plugs are always white, with the little tan ring around the bottom.

[Bobby Fazio]

Gotcha. Yes I guess I could try the long extension to get those areas tuned. The fast xfi 2.0 automatically goes into open loop when two step is active. Also, before I forget, how do you feel about iridium/platinum/copper plugs? Has anyone tried Denso plugs in their race engine yet?

[Ed Wright]

If your not experiencing misfireing, I doubt you will lower your ET with any of those.
I just use non-platinum Autolite plugs. Gapped @ .050" in mine. I have found no ET improvement in different types of metal in spark plugs. Correct heat range (one step colder than factory is what I use in mine) and no misfires is as quick as anything I have stumbled onto. Somebody smarter than me may have found something different.
When I had my shop, all I did was tune ups & drivability diagnostics, and AC service. Replaced a ton of AC plugs with failed resistors (looked just like bad a plug wire on the 'scope), and Champions with a loose center electrodes. Several NGKs with high RPM misfires. Not as many as faulty resister AC plugs. They may have cured those things now, that was before 2010. Never encountered a defective Autolite. Started using those in everything. NAPA parts store guys called me Autolite Ed. LOL
Did not like to have come backs. Bad for business.

[Bobby Fazio]

haha got it, thanks as always Ed!

[Darrel Goheen]

Originally Posted by Ed Wright

I had a muffler shop make me a long slip-on extension with a 30 deg bend, for tuning my idle and part throttle. That stopped it from pulling in clean air during overlap, and made the sensor read correctly. I put in closed Loop for that, and just kept tapping the L key while I drove up & down the return road with that extension on it. Then back to open Loop there.

Hi Ed, how long of extension pipe did you find was required to do the pit/cruise tuning? What's your opinion of having the WBO2 in a header tube vs the collector? Thanks.

[Ed Wright]

Darren, I had muffler shop next door to me make the extension. It was 24" long, with a 45 degree bend at 12". Swedged to slip over my collector. I made 2 band saw cuts, and clamped it on. Had to put it on at the track. Would not go in the trailer with it in place. I run one wideband in the collector. I race it going into closed loop at 6000. The funky air/fuel numbers from the 2 step are gone by then. I have worked on the intake air temp correction table so even in different temps it seldom ever shows more than 2% fuel corrections on the logger. I would not now run one without the air temp sensor. Helps a good bit with consistency. At first I just zip tied the sensor to a fuel rail, then pulled my head out, and screwed it into one of the bungs in the back of my Hogan plenum. The car is deadly consistent. It could use a better driver. LOL

[Darrel Goheen]

Originally Posted by Ed Wright

Darren, I had muffler shop next door to me make the extension. It was 24" long, with a 45 degree bend at 12". Swedged to slip over my collector. I made 2 band saw cuts, and clamped it on. Had to put it on at the track. Would not go in the trailer with it in place. I run one wideband in the collector. I race it going into closed loop at 6000. The funky air/fuel numbers from the 2 step are gone by then. I have worked on the intake air temp correction table so even in different temps it seldom ever shows more than 2% fuel corrections on the logger. I would not now run one without the air temp sensor. Helps a good bit with consistency. At first I just zip tied the sensor to a fuel rail, then pulled my head out, and screwed it into one of the bungs in the back of my Hogan plenum. The car is deadly consistent. It could use a better driver. LOL

Thanks Ed. What engine do you have in your Firebird? I have not ran my Firebird (LS1) yet but it didn't have an air temp sensor when I got it. I've since put one on it but then thought later that was probably as waste of money. I still have a lot to learn. It's the one that has the O2 sensor in a primary tube. I look forward to visiting with you. I don't believe we've met yet. If we have sorry I don't remember.

[Ed Wright]

Mine is an LT1. I don't remember meeting either, but I'm very old. You will see. LOL