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repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 11:31 AM
by akluminus
I'm posting this here because most people that end up with a wideband O2 sensor in their car also like to push a lot of exhaust past it. :)

Curious if anyone else is interested in this. I think I'm going to add a small circuit to my new megasquirt installation to use the extra analog output of the LC-2 wideband to drive the fuel economy gauge, since that is/was useless. There happens to be a mark right at 15 mpg, which is pretty close to stoich. It would probably be hard to tell exactly what the AFR currently is, but it would be an easy way to know if you're running lean or rich without having to add gauges to the interior (something I'm somewhat trying to avoid).

I'll post a video when it happens...

Aaron

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 11:37 AM
by akluminus
Arg, typo in the title I can't seem to correct, sorry.

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 11:46 AM
by tig
I like! Subscribed.

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 12:29 PM
by T_C_D
Don't waste your time. You should never have to monitor AFR in realtime once properly tuned and you would never use an analog gauge for tuning anyway. If you want to do it just to be distracted then go for it.

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 12:48 PM
by akluminus
Definitely wasn't thinking of using it for tuning. My car is in the processing of getting straightened out on megasquirt, so I don't totally trust it yet. What could cause a car to go lean after it was tuned? FPR or fuel pump failure?

Aaron

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 1:16 PM
by akluminus
Oh, and also agreed on the overall usefulness of it if everything is operating correctly... My thinking is that it would be nice for that gauge to display something, and the AFR would be easy.

What will be more useful is the buzzer I'm wiring for some audible alert of both overheating and lean conditions (both output from the megasquirt).

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 6:00 PM
by Nanajoth
This is a neat solution for a boost gauge if you are looking for something to repurpose it.


http://www.e30tech.com/forum/showthread.php?t=117682

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 05, 2014 7:26 PM
by Cjames570
I would love the boost gauge option for our clusters! AFR, as stated, is not that important to watch once the car is fully tuned..... but still a neat re-purpose!

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 08, 2014 1:55 PM
by akluminus
Very nicely done, especially the replacement panel!
Nanajoth wrote:This is a neat solution for a boost gauge if you are looking for something to repurpose it.


http://www.e30tech.com/forum/showthread.php?t=117682

Re: repurpose fuel economy gooahj for AFR?

Posted: Sep 08, 2014 10:10 PM
by M. Holtmeier
I contacted that guy about a year ago to do a boost gauge in our clusters. He told me he doesn't know to make it work for the e28 cluster.

I was willing to send him a cluster and he was willing to give it shot, but the whole thing lost momentum and now I don't even have a turbo on my car anymore...

Re: repurpose fuel economy gooahj for AFR?

Posted: Nov 02, 2014 11:12 PM
by Shadow
I agree with todd this is sort of an old school way of tuning maybe using a adjustable rate FPR
you have to hop out the car and tighten a nut, jump back in, do another run etc..

Tuning my friends car he has one, but I never look at it when tuning. It's one of those cool ricer things for
the passenger to look at. :cool:

Re: repurpose fuel economy gooahj for AFR?

Posted: Nov 04, 2014 3:34 PM
by akluminus
Ah! This thread (and the horrible subject typo) keep coming back to haunt me. My intention wasn't a tuning device, just to get a dead dash gauge to do something useful. And useful, as you all pointed out correctly, is arguable.

Aaron

Re: repurpose fuel economy gooahj for AFR?

Posted: Nov 06, 2014 8:11 PM
by Jeremy
Correct your spelling and the thread title will be fixed.

Oil temp or something like that would be more useful, but even oil temp isn't a big issue in these cars. Boost gauge would be neat.

Re: repurpose fuel economy gooahj for AFR?

Posted: Nov 07, 2014 7:13 PM
by jc72
oil pressure would be nice instead of just having an idiot light.

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 14, 2014 8:35 AM
by SmokeyJohn102
Any update on this? I'd be down to try to get the boost gauge thing going....should I start contactin him? Anybody want to donate a cluster?

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 14, 2014 2:16 PM
by akluminus
I've opted to go a different and probably more useful route.

What I really want in the car, and I believe others would too, is a fairly low cost digital gauge that interfaces with the Megasquirt via CAN bus directly. So, no extra sensors to install in the engine bay!

I'm currently working on a prototype that roughly has:
- a 2" to 3" diagonal, rectangular color graphic display
- touch screen to cycle the display through different sensor readings
- some sort of bezel mount system

I'm shooting for a price point that would make it reasonable to buy 2 or 3 of these for a complete digital gauge setup. Should be applicable to any Megasquirt conversion that has the CAN bus (and eventually any other aftermarket CAN enabled ECU that can deliver the same sensor data).

I'll start a new thread when I have something to showable. In the mean time, I also of course welcome any feedback on what sort of features / sizes / interfaces would be of interest.

Aaron

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 14, 2014 3:34 PM
by akluminus
Oh, and yes, I can just buy a tablet for cheap and use Bluetooth and Shadow Dash... but I personally want the built in look in this case. Thoughts?

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 16, 2014 1:33 PM
by SmokeyJohn102
I down for that. Maybe something that fits in a vent or something along those lines. My buddy has a 3d printer thst we might be able to use

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 16, 2014 1:53 PM
by akluminus
I was planning on making it fit in a vent actually! In my e24, I was going to put them in all the vents above the radio, since there is another set in the middle of the top of the dash anyway.

Aaron

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 16, 2014 4:18 PM
by George
I've given some thought to using something like this: http://www.race-technology.com/content. ... &cat=31027

Its designed around lap timing functions I believe but it also supports ECU variables and analog inputs.

I'd like to replace this: Image

with something that could also show fuel pressure, peak EGT, peak boost, etc...

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 16, 2014 4:53 PM
by SmokeyJohn102
You could make some sort of alpina replica thad be sweet as hell. I'm definitely interested seeing as I am going forced induction this spring and just purchased a megasquirt

Re: repurpose fuel economy gooahj for AFR?

Posted: Dec 22, 2014 9:37 PM
by Shadow
there's a guy on r3vlimited who sells those replicas they're bad ass but only for e30 or not? maybe check.