wide band O2 sensor

[gigem75]

One of the neat things about the Hot Rod Power Tour was the Holley guys. One of their reps looked up in their catalog for me a wide band O2 sensor you can put in your car with a gauge. This would be great for Spica cars in that the mixture can be set exactly instead of just listening to the engine or doing a plug chop. The Holley part # is 534-201 if anyone is interested.

[Reale]

Hi-
Yes that is the former FJO wideband system, really super-tough-the controller is completely encapsulated. They have a video someplace of the controller getting boiled in a pot of water, run over with a car, etc.-while operating. Not sure when/hot stuff like that would happen in your car though-ha ha! It is also nice that it can use either the NTK or Bosch wideband sensors. I have the FJO-branded system in both my racecars-it is pretty bulletproof. Another system to consider is the Innovate LC-1, which only uses the Bosch sensor, but is less expensive. No financial interest (except wanting to save a buck here and there!).

[Seabird]

I have been using the LC-1 since I got the new engine in my car and its great. Since I don't have the experience yet to tune by ear I just look at the gauge. It's also nice while driving down the road, I don't have to visit the dyno to know I am in the ballpark.

Innovate has a wide selection of gauge faces to choose from too. Not that it is a perfect match but they even have a clean analog sweeping gauge that does not look out of place next to our fuel and temp gauges.



Regards,

[AlfistaChris]

I have used narrow band sensors with special gauges since the early 80´s and got my first wide band O2 controller (industry equipment) long before Innovate made them reliable and inexpensive.
It is the only way to tune injection and carburetor cars today if you want performance, economy or both. No matter whether you use it on the road or on a rolling road, as tuning tool or permanent install. Because of the easy and long lasting calibration, right now the Innovate MX-L is my favorite for DIYS, as it is inexpensive, replaces factory sensors and can be upgraded. If you are a professional you will find other systems / brands suitable for you.

The attached shoot is from the Innovate LM-2 with a throttle potentiometer fixed to a Weber. It shows AFR, RPM and load. By driving around at different speed / load you clearly see where the fueling is right and where it needs improvement. I would be very interested how this would turn out with a well running Spica.

(The throttle position sensor is not adjusted to zero degrees, but 90°, so if the red line vanishes, there may be up to 5° opening. This log was run for initial testing, not fine tune.)

[AlfistaChris]

What you can actually see from this shoot is a full throttle lean problem starting at 5000. Next usually would be a smaller air correction jet. In this special case the jets did not cure the problem, an 4.5 auxiliary ventury instead of 3.5 proved to be the better solution.
The rest of the information, starting at 3:20 is not interesting, as it is just driving the car to a save stop. You always have to write down absolute time and jetting / changes, so you don´t get confused. Erasing most logs if the final setup is found seems a good idea, because you easily get lost in all of that data...

The final judge is still your driving impression, but the right AFR always drives right. There is no exception from this rule. Hesitation on transitions are cured with the pump and it´s components, not by enriching the whole table and calling it a "race setup".

[gigem75]

Great information, many thanks! Having more than one to choose from is nice, I'll check out the Innovate and go from there.

[Seabird]

AlfistaChris,

I am just starting to learn how to tune so this may be a silly question, please forgive my ignorance.

Do you just try to tune your carbs for WOT or during linear acceleration conditions? Why is the "driving to a safe stop" data less important?

I would have imagined most of our driving is int that "driving to a safe stop" world. I would seem reasonable to want to verify A/F mixtures there too.

At the moment I have only used the A/F ratio meter to tune the idle circuit and to make sure I am not way out of wack at WOT. Soon I will be doing data logging and work on the other areas of the throttle range. Looking and reading your earlier posts helped me understand a bunch already, thanks!

Regards,

[gigem75]

What kind of reading do you get when in decl in 4th down around 2000 rpm? With my Spica hp pump, higher lift and longer duration cams and porting I get a series of burbles bordering on back fire during the transition from 2000 to 1800 in a foot off the throttle condition. Everywhere else above and below that it is a smooth decel. Far as I can tell the CSS is good and doing it job? At idle the throttles are closed and the engine can be killed by squeezing the black tube from the manifold to the airbox. I was thinking that the longer duration and higher overlap may be part of it. Not a stock motor by any means but not a full out race motor either. Just wondering and hoping someone who knows more than I do will add some insight

[AlfistaChris]

Hi,
the initial logs are much longer, this one is about 4 1/2 minutes. This is the engine I have featured here:
http://www.alfabb.com/bb/forums/engi...-into-gtj.html

As the lower range performed quite drive able, I went for WOT first. This is only the fifth combination of jets!
The headers used where not working when installed on a 2 liter engine, so I first went for WOT settings, to see whether the combination of components was a total miss or could be used. As you can see, it pulls in a straight line up to 6700, so basically this will be quite a neat engine if perfectly tuned.
What you see from this run: The WOT over 6000 rpm leand out too much, so no need to push the engine that high.

There is one rule most hobby tuner don´t follow: Only change one carburetor part at a time. Even as you may be absolutely sure another idle jet was necessary and the high rpm range needed a smaller air jet as well, if you do both you will loose control of your changes. So this run was only made with a 160 air jet instead of a 180. Anything else was was left as in the log before.
Now all I do is to take a previous log with same throttle, gear, rpm combination and put it as overlay on the new one. You see exactly the changes this single jet did.

So my typical tuning session for WOT looks like this: Engine started and driven to a free stretch of road (engine is already warm!). Deceleration to 3rd gear /2000 rpm, full throttle up to the necessary rpm important for the change, maybe shifting to 4th gear to see transition and drive to a save stop. Next correction, same procedure, next session.

If I go for part throttle settings, I use another gear and floor the throttle for maybe 20° opening, just so much the car accelerates very slowly in this gear. This gives a long black line, slowly rising and the exact change in AFR can be seen. This way you can perfectly see the reaction for a different idle jet or main jet. Slow changes of the throttle are necessary, because at fast moves of the right foot the acceleration pump starts injecting and causes incorrect AFR readings. I usualy put my foot in a position that remains stable even on street bumps or even use the hand throttle (very dangerous!) on empty roads.

The point is you, if you only change one jet, there is only a limited region where it affects fueling. You put this into one drive, then do the next jet, next test.

Only at the very start (when huge changes in jets may be indicated, because you where completely wrong) and at the end of tuning, when all is OK, you do a complete log, using multiple load/ rpm/ and gear conditions.

If this is as perfect as you can do, you go for transitions, where you try to provoke hesitations and find acceleration holes.
This is still a very carefully tuned 1600cc, so a near stock behavior should be the aim.
(Of course, you can not expect a 1300cc engine with a 308° race cam, 45 Weber, 40 mm main ventury and a 6 foot exhaust system to take sudden full throttle at 900 rpm and start to strongly accelerate, even in 5th gear. You have to see the technical limitations of a basic set up.)
This engine takes full throttle from 2000 rpm and runs through different regions of behavior. If driven in a civilized manner, given not more than 45° throttle, it makes the car feel as if it had lost a third of its weight, because it pushes it around so easily. That is where you realize how much fun a well tuned engine makes, even driven in traffic. Up to 3000 it is very tame, then pulls as usual until 5000 and then suddenly starts to show it´s special parts by rocketing over 7500 with ease. So if you do a really hard start, you have a surprisingly quick car.

The 4 in 1 header seemes to have pushed the maximum power range much higher in rpm, but it is no race engine at all as some predict with such an exhaust.
The same cam on other engines did show quite less sympathy for high rpm, but as this engine has been optimized for flow in any aspect, this is not really a big surprise.

Because of bad whether I could not work on it for the last weeks, but I will post a long log you can load into tuner pro and watch your self if I`m done.

[AlfistaChris]

Sorry,
I can´t give you any reverence for Spica cars, as I have only measured carburetor cars and electronically injected.

The Spica has it´s "map" in the 3-D of its steering part and modifies these basics with other inputs as temperature etc.
This is from the idea like some early Bosch D-Jetro injection systems, that had only a small basic program that was changed by analog calculators (The marketing called it computer, but it was none as today).
But it was set by the factory to be lean at cruise, rich at high load and stable at idle, thats for sure and is just the same AFR target as any other engine, however it is feed!

I wrote somewhere I was interested in the behavior of a really well working Spica system, driving for a complete log as mentioned in the post before. So one could see the AFR over rpm, with fixed throttle positions, on a real car, in driving in gears at a real road (a rolling road does never hit the real world loads a car has while driving, thats why I prefer road tuning).

With conservative means this would be a complicated, time consuming task, but with a cheap throttle potentiometer and rpm input it is done on a fun drive at the weekend in 10 minutes.
This could provide a basic data source for all having problems with their Spica engines.
The readings from a log can be converted into a diagram / list with a few mouse click´s (in LogWorks for example).


I know, as always, some old professionals will not like this idea, because imperfections could be seen by anyone able to spent 190$ for a hardware that´s available anywhere.

But you Pros have to see this positive: People will accept much easier there engines need repair if they can see it in a log! There are so many cars driving like ill natured camels out there, because the least Alfa owners know how a perfectly sane Alfa really drives! Many believe these defects are the soul of a vintage Alfa! So it will show more people the necessity to take professional help and stop to fool around.

(The AFR meter, just like the Internet, will not disappear some day, they are a reality we must live with for the future)

So if you wanted to check your Spica equipped Alfa, just fit a AFR display and run it to the points where it may feel incorrect or make problems. You don´t need to do the complete data logging again, brain and foot can find the right throttle/ rpm/ gear too and eye can read the display. So you easily find spots that are a problem.

We just need someone doing such a log!

[gigem75]

er hum ok what the heck

[PeterD]

For what its worth ... I have the same burbling at the same RPM on decel as Gigem75. I have been trying to "tune" it out but no luck so far. I have balance the throttle bodies the best they can be (the fixed pair of plates are not perfectly matched). Throttle plates closed at idle and hot gap at exactly 0.019. I am thinking the cause might be the fuel cut off switch in the Spica pump ('74), a dribbling injector or air leaking past the throttle plate shaft bushings. I also have the wide band 02 sensor gauge at the top of my shopping list. I was looking at the AEM 30-4100 which is alot like the Innovate brand.

[slyalfa]

Way back when my 72 was stock I put in a NBO² my spica was way way pig rich in WOT
and nice and lean in low loads and idle. it seemed like it was set up for a much better breathing head or better cams. at the time I put on a wes moded bell crank with a slide and moved it all the way in so it would not move much at all when I stepped on it and it still went pig rich.
I just think the 3Dcam in the spica's were just a few steps behind what the cams were to make the smog numbers. at lest in my 72.
also used a a older system where it had a bridge with 2 heated thermisters one in the flow in one a normal air that worked like a WBO² before the nice pumped cells we use now.

[gigem75]

Went to the beach to build sand castles with my Granddaughter and when i got back by golly there was my Innovate MTX-L on the stoop waiting for me. Had to update the nvidia display drives but that was no sweat so i've got the manual open now and need to do some reading but I'm looking forward to this.

[gigem75]

Got the Innovate LMX hooked up and it works but now it time to mount it. How did any of you run the wire from the sensor into the car. I don't necessarily want to drill a new hole and was wonder how ya'll did it? There is a rubber floor plug right there and I could go through that and seal it off and come up under the carpet. I was thinking of mounting the gauge right above the side pocket mainly to keep from drilling into the dash even if it's on the bottom to mount the bracket.