Just throwing this out there.. custom gauge idea.

[hottscennessey]

Hey guys and gals, I'm looking for help with my custom wideband gauge I'm gonna give a shot. Basically, I run a zeitronix wideband controller which has an analog output which can be used for hooking up compatable engine managment, and piggybacks (such as MAF Pro). The zeitronix is a wideband controller which doesn't use a linear voltage output (see chart). I was thinking, I could use an electric el cheapo gauge with a 0-5 volt scale and make a custom wideband A/F gauge using a new gauge face.

I was wondering if anyone knew of a certain type of gauge (water, oil psi, whatever) which used a 0-5 volt scale.


Thanks, I'd really appreciate any help. I know it sounds cheap but I dont have many options working with the zeitronix.. which I love for datalogging btw. I would buy the backlit LCD screen.. but honestly I dont see spending $150 on something I dont think looks all that great, and that I couldnt use for all its features (EGT and Boost).

 

[hottscennessey]

okay, so I've decided I'm going to use the stock boost gauge, rewire it using this guide http://www.freewebs.com/supraboost/files/1bar%20boost%20gauge.doc I'm going make a custom gauge face and turn it into my wideband A/F gauge.

I have a question.. in this guide it says to use a "capacitor på ca 4,7 µF" I could only find 4.7 µF capacitors, and 47 µF capacitors. Is this a typo? I picked up both just in case.

My other question.. I picked up a 100k ohm potentiometer.. it has three prongs comming off of it to solder.. the one he uses has two. All else fails I guess i should just test it with an ohmmeter or whatever you call those things.

 

[hottscennessey]

just in case anyones been following this thread, it worked. I just need to make custom gauge face now. The mod to make the needle move faster is very effective and is in sync with my computer logging the A/F. I now have a stock looking widebnd A/f gauge.

cost: ~$3

 

[brad92t]

just in case anyones been following this thread, it worked. I just need to make custom gauge face now. The mod to make the needle move faster is very effective and is in sync with my computer logging the A/F. I now have a stock looking widebnd A/f gauge.

cost: ~$3

hmm this is kind of interesting... esp since you used the stock boost gauge

i would like to note for clarification to anyone reading.. it looks like that write up was in russian or whatever at that part.. "på ca 4,7 µF" ... and most (all?) of europe tends to use commas where we use periods in numbers, so that 4,7uF is definitely 4.7uF

i'm not sure why it would be in another language for two words and a number, but meh.. it works that's all that's impt

 

[hottscennessey]

Thanks for chiming in, thats very true about the comma for the period. I completely forgot about that from spanish class. lol. You're absolutely right, the guy was not "USDM" judging by the gauge, and I cannot believe I didnt make the connection. Thanks a lot for the clarification!

 

[TurboStreetCar]

hey i was just wondering when i saw that wright up, if u keep it a boost gauge, what does it do about vaccum? the sensor will still read the vaccume but how will the gauge react? i guess when u put the needle on u position it so that its all the way down on the stop? that way when it would move for vaccume it just doesnt move but then it will move up for boost?? anyone else do this for a boost gauge?

 

[Disced]

The stock boost gauge has to read vaccuum from somewhere (inside the engine bay on the drivers side) You just unplug it.. And plug the line up w/ your new boost gauge and the old stock boost gauge now just sits at 0 all the time.

 

[shaeff]

or you can replace the stock boost gauge with the voltmeter from an N/A car. that way you have all working gauges.

-shaeff

 

[TurboStreetCar]

no no no no lol i was refering to using the boost gauge as a boost gauge and making it read up to 1 bar, like the guy used ti for in the wright up. he has it sitting on zero and no scale for vaccum. when u adjusted the potentiometer u set the zero, when he set the zero he set it with no room for any movement on vaccum. so i was wondering what happens when ur in vaccum, does the needle jsut rest against the stop and not move?

 

[hottscennessey]

^^ bingo, you adjust the potentiometer, put the needle back on just as it came off.

 

[TurboStreetCar]

whats the max pressure the sensor reads? it says that at 4.2 volts that would be 1 bar, so wouldnt there still be some room left for more pressure with a 5 volt sensor?

 

[TurboStreetCar]

what would happen if u were to grind out the piece of plastic that the needle fits into that has the stops built into it. lke grind the stops further back, would the gauge be able to handel a bigger sweep?

 

[hottscennessey]

I'm not sure nosechunks, my guess would be yes by how the needle pegs when you boost over 8 psi, or when i decelerate and my A/f goes lean.

 

[annoyingrob]

Here's another custom gauge idea for you. I'm very familliar with using various PIC microcontrollers (Miniature computers in a chip). I have designed 2 separate units, which can input a 0-5v signal into their ADC, convert it to the proper units within software , then output it to a display of my choice.

I have one unit that will display a 2-bar map sensor onto a character LCD screen (says "Boost: xx.x PSI"), and another that will display the AFR of my LC-1 onto three 7-segment LED displays (XX.X reading).

I like your idea as well though. You will find that most electronic gauges use 0-5v inputs, and most sensors will output 0-5v. Switching gauges around isn't all that difficult. You could repurpose old gauges for whatever you want. (Maybe an EGT gauge from an old oil pressure gauge.)

As for adjusting the stops on the gauge, you may be able to widen the range slightly (to use that 0-5v signal, as opposed to stopping at 4.2v), but you will reach a point where the gauge can only move so far with a 5v signal. It may look a little funny on the gauge face though, as the needle is not pivoting from the centre of the gage.