I thought I saw this question before, but I couldn't find it via a search. Does anyone know where/what color wire to tap a signal from for a Air/Fuel ratio gauge? Specifically, for an '82 Turbo.

 

It's the wire from the O2 sensor. Should be a black wire on the ecu plug. Between the Green & Yellow wire of the top ecu plug.

 

Thanks for the response. Is there a stripe on the wire? Otherwise, I thought solid black was always a ground.

 

I believe it's somewhat insulated to prevent radio interference. But it is black (notice that the wire coming from the O2 sensor is also black?).

 

now how do oyu build a a/f meter?

 

I suspect he's just adding an Air / Fuel meter to his car. Since there's already a 'narrow band' O2 sensor used by the EFI computer, he should be able to tap into that circuit and calibrate his gauge.

If you want to go crazy: http://www.innovatemotorsports.com/

 

Unless you have some mad electrical / mechanical skills, I wouldn't recommend trying to build an air/fuel meter, when you can buy one for $30 - $70 on ebay.

 

You know someone is being serious about tuning his car, when he's gone wideband!

 

I was seriously looking into a wideband, but I couldn't justify the cost when there's so many other priority items ahead of it. And I just really wanted to get my gauge cluster back together, so a narrow band will do for now. Though, when I used to have one in my Prelude, back in the day, I found it very distracting to have the LED bouncing back and forth.

Anyways, back to the wiring. Just to confirm, the position/color of the wire/plug is for a turbo ECU right (or at least the same as an NA)?

 

Use a narrow band gauge to fill the hole (get one with a needle, I can't stand LED's in my gauges) and you can borrow my LM-1 to tune when you get to that point.

The wide band is really only necessary for tuning. I wouldn't bother running it continuously. Once you get your car tuned where it needs to be, you can get by with a narrow band for 'monitoring' purposes.

 

just had to destroy my dreaqm of making didnt you?

 

Ooh sweet, I'll hold ya to that, thanks. ^_~ I've never seen a narrow band with a needle though, I assumed because of the speed with which it would need to change direction from the bouncing back n' forth.

 

http://store.summitracing.com/defaul...=KeywordSearch

 

I can show you how to build one for a few bucks. And it's identicle to the internals of the autometer a/f guage. The hardest part is soldering the damn thing together. And soldering aint hard. So what does that tell you You've got to have a few things to build it though and a soldering iron is one. You also need a voltmeter to calibrate it. Other than that almost everything can be had from Radio shack except for one part. The driver, which is only like $11 and has to be ordered from an electronics supplier. And thats more than you'll pay for the rest of the parts combined. As soon as I get that last part and put it together and get it calibrated I'll post up a detailed write up on how to put one together and calibrate it. Stay tuned.

 

J, you are right, but at some point it's a trade-off between doing it yourself and the value of your time. For $59 I can have a fully assembled unit that's nicely finished. Not to brag, but the number of hours I would spend putting it together would greatly exceed the cost of just buying one. Even if it's $100, I don't have to worry about whether it's going to work or not. Of course, I'm the yahoo that went out and bought a full LM-1 setup so who am I to talk...

 

I can appreciate that. I only mentioned it here cause Hoov was talking about building his own. Its always a trade off of whats more important (or available): Time or Money. Wouldn't it be nice if neither mattered though Then you could spend all your time thinking of ways to spend all your money

 

Aw damn, NOW I find an analog AF gauge. Oh well, I already cut wiring and installed my LED one, so there's no returning it now.

While we're on the subject of gauges, has anyone seen a knock sensor besides the MSD one? I'm not too fond of it being in a white casing. It'd be even nicer if someone made a knock sensor in a gauge-shape.

 

J&S Safeguard: http://www.jandssafeguard.com/index.html

That's the only one I'm pretty much aware of. I remember seeing it in SCC's old Subaru 2.5rs they turbocharged a long time ago. I have no experience with it though.

 

Ooh! That looks perfect! A/F gauge and Knock Sensor in one. Too bad it looks like I need to buy some whole system totaling several hundred! Anyone know anyplace to get a deal on this J&S stuff? Though I am unclear on whether or not it can also act as a replacement for my Crane digital ignition. It says:

"The unit has a high energy ignition with constant energy dwell controller. The system monitors the coil current, and adjusts the dwell time to achieve seven amps of coil current. Compared to a GM HEI, this is a 62% increase in energy stored in the coil. The system can also be used to trigger an MSD. "

That makes it sounds like it's also an aftermarket ignition too, but when it says it can trigger an MSD, that makes it sounds like it's actually not. Can anyone shed light on this?

 

That's an ignition controller. You can still use an ignition amplifier like MSD or something like that. What this would replace is something like what Crane offers to replace the IM.

 

I also wonder if you'd still need to use a tach adapter with the Safeguard like you do with the Crane/MSD ignitions.