Spark Plugs with Two-Step
 

Who has a spark plug recommendation? I have been running Autolite AR in both cars for a while but I have to change the stocker plugs often and the sub 3000RPM two step launches seem to foul them up. Have tried AR24 and AR25. A fresh set of plugs sounds very crisp on the two step but declines after 10-15 runs. Leaning out the two step hurts the launch. I check at least 1-2 plugs after every run to keep an eye on it. Is it possible that plug quality isn't that great anymore I was thinking of checking out Denso due to their being a contingency sponsor and trying to sift through their many plug options.

Re: Spark Plugs with Two-Step
 

I run Autolite 985 plugs in the Jeep 4.0 (Factory heat range). Have no problem with fouling (2800 on step). I run them 20 runs and replace them. Fouling might occur an the return road?

Re: Spark Plugs with Two-Step
 

I used to think it was pits driving and return road also so I really honed in on those areas and actually have it tuned slightly lean to protect myself in those low RPM, low load areas and running in closed loop down there so when I check plugs after warming her up in the morning and driving through the pits at operating temp they are kinda white when I get back.

Re: Spark Plugs with Two-Step
 

We run the plugs from the start of the year until BG points race then we put in a fresh set getting ready for Indy.

Re: Spark Plugs with Two-Step
 

I run my engine on the rich side on the 2step and only change them once or twice a season,no problems. How long are you on the 2 step?

Re: Spark Plugs with Two-Step
 

If you are tuning your air/fuel ratio with your wide band, when on the 2 step, it is actually very rich. The misfireing on the 2step puts a lot of oxygen in the exaust, which equates lean to an 02 sensor. All they measure is oxygen content, to calculate air/fuel ratios. You will see a bogus lean condition on your data logger. Rich there will dirty up the plugs in just a few runs. I have never had to change plugs during a race season. I put new plugs in each spring, just because. The plugs I pull out still look new. I've put a stock converter in mine to get a look at the actual WOT air/fuel ratio at as low as 3000 RPM. Sometimes it is hard to get the dyno to hold one that low for tuning at that low an RPM. Hope this helps. Just how I do it.

Re: Spark Plugs with Two-Step
 

As soon as 4 bulbs are lit I get on it. 2-3 seconds I guess. It's probably my tune still needs help in that two step area then. Yes Ed it always shows lean on two step so I try to use converter flash to tune the two step. It is the riches part of the run, when the converter hits.

Re: Spark Plugs with Two-Step
 

Bobby, on Patterson's dyno we were able to load mine at 3000, I set it to 12.5-1, richest part of my runs as well. Looks like about 15-1 A/F sitting on the 2 step.

Re: Spark Plugs with Two-Step
 

Bobby this what I have been using NGK UR45. Mine are grey to white. On the 2 step same as you. You can run lean around the pits and return road cause you have very little load on the motor. With out fear of burning a piston. Somebody correct me if I am wrong still learning.

Re: Spark Plugs with Two-Step
 

16 VT battery system and problem fixed. Use to have to out a set in every race with the Cleveland. Got smarter and started using it to play the qualifying game

Re: Spark Plugs with Two-Step
 

Off subject but where do you get a less than 3000rpm 2 step chip? TIA

Re: Spark Plugs with Two-Step
 

With the EFI systems, you just type in any RPM you want and it takes care of the rest. I'm not sure who sells chips that go down to 3000. Don't have anything that low in the super stocker that's for sure!

Re: Spark Plugs with Two-Step
 

MSD makes an adjustable module which goes down below 2000 - plugs in like chip - I have mine set at 2800 for launch.

Re: Spark Plugs with Two-Step
 

The low RPM chip that MSD sells is red, and it comes with a small slot blade screwdriver that is used for adjusting the limiter RPM screw located on the side of the chip.

Re: Spark Plugs with Two-Step
 

Bobby, I use the 8670 MSD adjustable RPM module. Has a lead that plugs into my MSD box where the chip would plug in. Goes down to 3000 RPM, turn the knob to select RPM, in 200 RPM steps.

Re: Spark Plugs with Two-Step
 

Biondo sells a push button below 3000 setup. Nice. Used it for years.

Re: Spark Plugs with Two-Step
 

Re: Spark Plugs with Two-Step
 

I did not see any mention of open or closed loop. Maybe if stayed in open loop on 2-step, could keep from adding unwanted fuel, and then go to closed loop very soon after releasing brake. You would have to be close on your fuel map. Also, you might consider talking to the tech line guys at NGK. I have found them easy to get a hold of, and very knowledgable. I have always been impressed with the quality of NGK plugs.

Re: Spark Plugs with Two-Step
 

You most certainly do not want it in Closed Loop on the 2 step! Only at WOT. If you use a FAST XFI, there is a delay after start up you select in the Closed Loop enable paramaters, I don't remember how many seconds my delay is set to now, but it goes in Closed Loop part way into first gear. Some time after the launch.
I have had to replace so many new NGK spark plugs to cure misfires in customer's vehicles on my dyno, when my shop was still open, that I won't use them. I have had fewer problems with Autolite spark plugs than any others.

Re: Spark Plugs with Two-Step
 

FAST goes into open loop automatically whenever the two-step is activated. I have closed loop pretty much turned off at high rpm high load. I only use it around the pits to keep the plugs clean.

What are your thoughts on irridium vs platinum vs copper?

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

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?

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

haha got it, thanks as always Ed!

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

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

Re: Spark Plugs with Two-Step
 

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.

Re: Spark Plugs with Two-Step
 

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