There are 2 questions here. My story first. I got my Innovate Motorsports wide band 02 sensor installed. This thing is the bomb. I did more in 4 hours than in the last 3 months of tuning. First off I had a plug reading problem. The plugs kept telling me the mixture was too rich. So, I kept going smaller in jets until the car just didn't seem to be pulling as hard as it should. (I never got lean surge) I knew it felt, sounded, and the heat from the engine said it was too lean, but the plugs still said too rich. ( the black sooty look ) I started checking things out and it turns out that it was a valve seal problem. Now, I know your wondering how I could mistake oil for gas but, the plugs were never wet and always had that dark gray/black flaky look just like when its too fat. So last weekend I fixed the seal problem. Making no changes to the tune up I hooked up the meter today. At idle (1400 rpm for me) it said 11.5 to 12.0, light tip in 12.5 to 13.5, same for easy cruising at 20mph. When I got the car under some load, 14.5, 15.0, 15.5, 16.0 mostly. (a few times 18.0 and 22.0 when getting off throttle) My cylinder temps were 1450 to 1550. I think the high cylinder temps may have been causing the oil to bake away any wetness??? Has anyone had that happen??? I had been ignoring the high temps because I have been told so many times that egt's are not always that accurate and that any unburned fuel in the exhaust can make the temps go high. With the dark plugs I thought it was still fat and basically ignored the temps as being inaccurate. Anyway after doing some driving around it became clear that under load I was way to lean but ok around idle. I have 2 600hp double pumpers. They come from holley with the factory set up of 70 jets front and rear, and a front and rear 5.5 power valve. I was down to 65 jets front and rear and I kept the 4 power valves. So I started driving around today with the meter. I watched my my idle and light load cruise readings being sorta ok but, any real load being too lean. So I blocked off the power valves and went up to 74 jets front and rear both carbs. That was a very positive change. It netted an average afr of about 12.0. It varied from 11.5 to 13.5 under cruise, light load, load and WOT. WOT was usually 12.0 or less. Exhaust temps went down to around 1200 to 1300. So I went down to 72 jets in front and rear of both carbs. The car ran even better. This time driving around afr netted an average of about 13.0. It varied from 12.0 to the 14.0 range with 1350 exhaust temps. I decided to take the car for a 1/4 mile burst. For the first time since I lived in Phoenix I got the rear tires to spin. In a 15 sec run @ full WOT the average AFR was about 12.5 in second gear. I had to got out of it right after shifting into 3rd. One interesting thing was I started recording as I was loaded on the converter. You can see at about 3 sec into the run the afr drops to 10.0. I believe that was from the 4 accelerator pumps on the carbs. You can see on the graph where it clears out and hovers at around 12.0 to 12.5 in first gear, but then is fairly steady at 12.5 to 13.0 in second. I still have a lot more to do but I think this one of best tools I have bought yet. I ran out of time today so that is as far as I got. I do have one other question. Example, driving in 3rd gear at 2,800 rpm and let off. The afr immediately spikes way up to 14.0, 15.0, 16.0 or so. I would have thought that at close of throttle it would first go way rich then spike lean. My thinking is that since fuel is coming out of the booster before closing the throttle, it would momentarily go rich and then lean because of lack of fuel. I understand the closing of the throttle blades stops the fuel from being draw out of the booster, but I would still think it would go rich for a second and then go lean. Can anyone expand on this? Thanks for listening. Monte

When you close the throttle at say 5000 rpm you are essentially shutting off the air & fuel & burning nothing. That is what the sensor is seeing.
Talked with the folks from Inovate at the PRI show. Really nice folks with what I feel is avery good product.
I bought one a couple of months ago to compare it to the one I spent about $2000 on for my dyno but still haven't had a chance to compare them yet. Glad to hear you are happy with it. graemlins/thumbsup.gif

I think that thing is a killer deal. You'll get more tuning done in a couple days with that thing than in years without it.

If it hangs in around 12.5--13 under power that probably as good as it'll get. The A/F requirements are much different for power and cruise. I'd look for ways to run the power valves and still keep the 12.5 power ratio, see if you can get it up to close to 14:1 on lean cruise. This will keep your plugs clean so it runs good all the time without needing new sets of plugs. Try going back to near stock on the jets and PV's, see where that works out. If it's getting down to ten you probably need to dry up the pump shot some. That's black smoke territory. Does it have big pumps or small? If it has big pumps it may keep the pump shot going after the main system is functioning, that'll usually go pig rich. Being a tunnel ram throws me off, I'm not used to them. All I really know is I hear a lot of stuff about having to run real rich pumps to keep from bogging when hitting it hard at low speed.

Gotta watch out for oxygenated gas to, throws every thing off when you're close.

Don't know why you're seeing that super-lean deal on decel. Usually decel is fat, all the air is cut off but high vacuum is yanking a lot of fuel out of the idle ports and transition slots.

Incidentally, keep that sensor on and hot anytime you have the engine running. There's reports that it gets hosed up if it's off and in the pipe.

Tom

Wolf, thanks, I talked to them at Sema. They were very helpful. I would like to know what the result of your comparison turns out to be. Tom, from most of the research I have done, they say 12.8 to 13.2 usually makes the most HP. So I am getting close. I am going to go to smaller squirters to extend the shot and hopefully it will get out of the 10's. After that I am going to change accelerator pump cams to try and reduce the overall fuel. They are the 30cc pumps. Also, yes the instructions tell you to let the sensor warm up first otherwise it may incur damage. It takes about 60sec to warm up. What is the story with oxygenated fuel?? How does that effect the readings??? I was thinking along the same lines as you with the lean spike. I would think it should go rich first. I understand what wolf says as well. It will be interesting to hear the opinions of everyone. Anyone have the oil making a plug look rich situation??? First time I have seen it. They always "look" like its oil. Did the high cyl temps cause it to look dry??? Thanks Monte

It doesn't apply to you, but with the reformulated (oxygenated) California gas I shoot for 12.6:1 a/f ratio. Just something for others to keep in mind depending on what fuel you are playing with.

Thomas

Monte,
how did you fix the valve seal problem? Did you replace the seals? If so, then what type did you use. I have a set of AFR 195 heads that I know are letting oil in around the seals. I forgot to specify PC seals when I ordered them.
Doc

Wow, I'm about to pick up one of those wideband sensors. Maybe I can find a neighbor to go in on one with me!

I had trouble with the seals from afr so I went to a Manley Teflon seal. (24035-16 for the .530 guide) However about 1/2 of the Teflon seals were broken. Some intake some exhaust. I still dont know why. I thought I had a retainer or keeper hitting them but that is not the problem. I think they either failed or my inner spring is somehow catching on them. I put the new ones on and I am going to keep a close eye on them. Monte

Monte,
I have (had?) a very similar situation with my teflon valve seals! I had a recent engine hiccup that has caused me to tear it down. Now that it is down I have found several of my teflon seals were not staying seated on the top of the guide!
From what I can tell, the inner spring must be making contact somehow and pulling them up and off the top of the guide. I have not seen this happen before, and it is coincidental that you are experiencing the exact same thing!

Several of my teflon seals actually got crushed because they came off the top of the guide, then went crooked on the valve stem (as it is smaller in diameter) and then got crushed by the retainer the next time the valve was opened. This has happened to several of them!

Just wanted you to know that you are not alone. I have no suggestions on how to fix it, as I replaced my seals, and then sold the heads.

Yup same thing with mine. What heads do you have and what size guide??? Monte

If you guys have ever seen high speed video of valve springs in an uncontrolled condition, you will see that they move all over the place. If the springs aren't being controlled or are close to the seal I can see this happening.

Tomas

Coulds you explain why you shoot for that on cali fuel? vs other fuels.

>>California gas I shoot for 12.6:1 a/f ratio. <<

TAD

Tad, Cali = oxygenated fuel, which "brings" extra air to the party. In an EFI engine it probably wouldn't be a big consideration, I'm referring to a carburated engine. Not all carburated engines have perfect fuel distribution, so I want a little "extra fuel" for the cylinder(s) that normally get less fuel. More power could be made at ~ 13:1, I'm just being cautious since I value reliability over setting a national record e.t.

Thomas

According to Inovate when I talked to them at PRI you do not have to do this with their unit when using gas.
I don't really understand why but I will take their word for it until I have compared readings with mine.
With the unit I have on the dyno you have to change the offsets in the software with different gas or fuels according to the Hydrogen to Oxygen & Carbon to Oxygen Content in the fuel.

This will change how the sensor works.
For instance, when I go from Chevron TT101 "Spec" race fuel which is a 106 octane fuel to CA certified pump fuel I have to use the below inputs.
For PT-101 fuel use: AFR = 1.94 Vout + 7.78
For Calif P-II Cert Fuel use: AFR = 1.96 Vout + 7.82
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The new CA crap fuel that that is mandated for use starting Jan 1 will probably screw up the works again.
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Here is an excerpt from an email I received a while back when I was inquiring aboout this stuff:
"Are you at liberty to share some of your results or findings on TT-101 versus Phase II California Cert Fuel (aka street gas)?

Also, a Ethanol version will be mandated by California as of January 1, 2004.

This may add new wrinkles to the game.

thanks

Don E. Burnett
Product Manager, Specialty Fuels
Chevron Phillips Chemical Co., LP"
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What all this means is as Thomas said if you stay on the rich side of "best power" you will lose almost nothing in HP but if you stray the other way your engine (& pocketbook) may not be real happy :D