A little background. I bought my motor used and besides not knowing how well it was tuned to start with, I changed out the 4 into 1 headers with a set of Chris Foley's 4-2-1s.. Sometimes I get pops & flames out the exhaust on decel so I'd like to see if my Webers are jetted right.

I don't have easy access to a chassis dyno and am considering a wideband Air/Fuel Ratio Gauge so I can log and monitor the data at the track.

Again, I'm curious how my normal AFR is with just my Phase 9 (sometimes I'm getting pops & flames out the exhaust on decel) and also what happens to my AFR when I add my supertrapp onto the Phase 9 for <=90db tracks, etc. (This usually eliminates the pops & flames)

I could make a long tow to a chassis dyno somewhere but I'm thinking the gauge might be more helpful longterm to have ongoing access to the data..

Anyone use one of these?



AutoMeter

or one of these?



NGK

I know there are lots of other brands out there too (AEM, etc.) Anyone get good enough data for tuning purposes? Or should I just go find a chassis dyno?

Thanks in advance for any feedback on your experiences

Greg,

how much is the autometer guage?
it looks nice. It looks exactly like the innovate version that I use
Here is a picture of my wide band set up in the race car:

and not so close up:

I have a narrow band that has been a great help in tuning.
I just scored a wide band today as a matter of fact.

For some reason I just found a big load of power by going down a main jet size and air corretion tweak. Cold air hot air sometimes drives me crazy But I am learning and logging all the time.

Hi Brant,

The best price I can find on the Autometer, including Bosch sensor, is $379.

I've found the AEM for $299 at Summit Racing.

I hadn't seen the 'innovate' brand yet. Going to go find some info!

Greg

Hi Joe,

I had read on other forums that the AFR gauges did not help with tuning... Glad your experience shows the contrary!

Thanks for the feedback.

Greg

I have an open spot on my gauge console where an unused leftover gauge from my car's aircooled days (head cyl temp gauge) still lives.

I was thinking of replacing it with one of these air fuel ratio gauges:

K&N

or

C.B. Performance

I am leaning heavily towards the CB Performance one because it fits better with the existing VDO gauges. Also has the benefit of costing less than the K&N. The only problem is having to weld the nut on the exhaust for the O2 sensor. gotta find someone with a welder to do that since mine is long gone.

Is it worth getting a 3 wire heated sensor? Seems like the single wire is fine, just make sure it's warmed up before doing any tuning.

For carbed cars, this seems like a really nice gauge to have, esp. for the $80 or so that it costs. Seems like it would be really useful for tuning, and making sure things are running right.

I've seen the K&N unit but hadn't come across the CB Performance gauge yet. It is a better match for VDOs, which I have too. Thanks for providing that info

Here is the AEM unit. With the Black face, it looks kinda like VDO too...



Looks like there is more than a few choices!

If this is a race car, read your spark plugs. I think once a car is tuned reading your afrs can just distract you. You will spend lots of time wondering why you are getting funny readings at different throttle positions. With out a way to determine throttle position and MAP readings I doubt you will gain much by having an AFR meter by itself.

Narrow band gauges are nothing more than a pretty light show. They don't tell you anything useful.

I've heard that reading the plugs is hard, too...... since technically you should turn the car off from a WOT event and coast into the pits, then pull the plugs.

I've got EGTs on each cylinder, but I will add this in the next month or two.
LC-1

It will plug into my data collection system.

Hi Brett,

I agree that the narrow band AFR gauges don't help with tuning.

I guess they are just 'binary' and show 'lean' or 'rich'. The one I saw looked schitzophrenic.

Greg

Looks like another vote for Innovation Motorsports! Found their site and reading now..

Up until now I've been looking at my plugs. I get some info from this but I agree that if you can't do a WOT run and then shutoff the motor and coast to a stop without going back to the lowspeed or idle circuits you don't get accurate readings. By the time I slow down, come off track and get even to the hot pits, the WOT plug readings are long gone.

I have a TraqMate Data Acquisition system and I'll be able to log any of the AFR gauges with the 0-5v senders... I'm hoping that looking at the AFR data along with RPM will help me out rather than watching the readings while ontrack.

Just came across this photo in the 'CFR Header' thread in 'The Garage' showing the O2 Sensor install in the collector.



Same header I'm running.

Anyone know anything about this one?

http://www.plxdevices.com/cgi-bin/shopper....mp;keywords=all

Looks like $269 for the set pictured below. I like the analog output. You can get the module and Bosch wideband sensor without the gauge for $195 and use a 914 VDO voltmeter rescaled as a lambda meter...

Click to view attachment

i like the idea of seperate egt's and cht's for tuning...

true that as for the spark plug reading, it's not always practical to do a plug chop (i.e. kill at WOT and coast in)... it can be done though (i've tried to make it part of my karting routine).

I would set the majority of your fuel mixture on the dyno. Then use plug readings to set your mixture at the track. If you are using race fuel it will darken the plugs nicely. You will need a light and magnifying glass to properly read plugs. You have to be able to look at the base of the porcelain and the ground electrode. You should always do all plug cuts in forth gear at WOT. Shut the engine off and immediately put it into neutral.

Always use NEW PLUGS for any plug reading tests.

If you can tie your wideband into your DA unit don't bother with a gauge. What are you going to do while driving around the track? Read it later in relation to speed, elevation, rpm, etc and EGT.

I have the AEM unit in my turbo Civic. It is useful but annoying sometimes.

Kevin,

my innovate is fed by an LC-1
the thing is amazing...

but I'm not data logging it.
despite the above comments about having it become a distraction, it is not for me. I ran at track this year anywhere from 5500ft elevation down to about 900ft

I use the wide band to re jet during warm ups and practice.
I don't find it a distraction and when I'm out on the races, I just ignore it.

funny or perhaps dumb story from september.
I was picking up an extreme lean on the high rpm intermittently.
I saw it through a couple of corners and decided to shut down the practice and come in easyily... went about 4 more corners and felt a single miss... by the time I pulled into the pits I heard a loud wapp..wapp..wapp sound.

well, I like to brag that I've never run out of gas yet.

the car was still running when I came in.

but the wapp.. wapp.. wapp.. was the 1st (of 2) fuel pumps running dry.
The main cell was ZERO

the part of the story that is neat for me is that the guage showed this before anything else did. I read the lean blips on the guage, before the car cut out and before I could feel a power loss. I know thats not the purpose of the guage, but I think its amazing how accurate the real time wide bands are.

brant

Good points, Brant.

Brett, I do plan on logging it and looking at it after the session. For me, the lights and digital readout would be distracting, but I'm pretty set in my "low-distraction" ways. I really go for a minimal numbers of guages... right now I only have the AIM display and the quad-EGT guage. I'd like to keep it that way.

The plan is to use the EGTs to balance the cylinders and the wide-band O2 sensor to get the overall jetting correct. Hopefully it works that way.

One day Production racing will adopt aftermarket fuel injection in leau of carbs..... maybe .... one day.

Kevin, I have to agree with you. the less gauges the better. You should be concentrating on racing. Look at the F1 cockpits. All business. A light for the oil pressure and a shift light. No need for a tach. Your datalogger will give you all of that info. EGTs are a good way to go.

If production would go to fuel injection I would come back and play. My street car has spoiled me. No more carbs.

AEM does the wideband box without the gauge. it can be input to FI or datalogger. I noticed last year Finch was running an AEM on Mark's car.

I started to compare some of the units discussed above.
If you have the info, let me know what to put in any of the blanks or any corrections that need to be made.

Click to view attachment

More interesting comparison data on some of the AFR gauges.

Here are the LED ranges & color codes.

What reads better to you:
* Lean to Rich (PLX, AutoMeter) or
* Rich to Lean (AEM, Innovate)?

Also shows that the Red, Yellow, Green color codes vary quite a bit.

What do you think the color codes should be? You can program the Innovate unit to whatever you want!

Anyway here are the readouts approximately 'centered' around the 14.7 stoichiometric point.

Click to view attachment

From your replies and some seaches on past threads, it appears 13:1 is a good WOT AFR for a TIV. With that info, the Innovative AFR Gauge could be programmed something like this. Idea would be to watch for a yellow or red (along with shift light, oil warning, etc)

Click to view attachment

Feedback?