In the last few months I have developed a circuit that works in conjunction with a permenantly installed wideband O2 sensor. This circuit was designed to monitor a permanently installed wideband oxygen sensor and alert the driver when air/fuel ratios rise above and adjustable threshold under boost. The unit triggers a bright blue LED mounted in the cockpit, which cannot be missed even in bright sunlight.

Of coarse, this requires a wideband oxygen sensor to be permanently installed in the car, as well as a boost pressure switch, which are about $20 from NAPA. I have mine setup to alert me of AFR’s above 11.7 over 10lbs of boost. It is adjustable to match almost any 0-5v wideband analog output, such as the Techedge, or FJO. On my car the light flickers slightly in second and stays off in 3rd+. This lets me know for sure that my engine is getting the propper fuel.

I am thinking getting some PC boards printed up if there is enough interest from to make it cost effective. I am thinking if I can get 20 people on board the cost will be under $50 for everything except the pressure switch. If you are interested you can e-mail me at radkins317@msn.com or post here.

As soon as the forum stops acting up I will post a pic of the light installed in my car.

 

Sounds Interesting, allthough, by the time it heads into leaner afr's, it's usually too late... I like alarms, but I'd like it better if it retarded sparc if it noticed a lean condition... but I also know that's beyod the scope of your project...

I was reading something about pressure sensors in spark plugs to detect detonation !? That sounds cool, how much for plugs !?

 

I realize this is not a fail safe device for sticking injectors and things like that (although possible). It would be more along the lines of a safeguard to drastically changing intake temp or a number of other things that could cause a car to lean out. This will replace my AFR display because it is almost impossible to watch a AFR readout while on the gas, and after all, unles your tuning you are only watching it to make sure you are in the safe zone. This will tell you imediately if you are not.

 

I think it's interesting! If there are 20 people, how much would that be....w/ boost sensor. I'm interested in a complete kit.

 

i'd be interested if it was that cheap!

 

I'd be interested too.

 

Sounds good, i'll check back for pics of your installtion.

 

Eh, unless it can proactively add fuel. it is worthless.. Driver would most likely react to slowly..


And to make it worthwhile you would need one on each exhaust port.

 

doesnt aem make a wideband you can run permanently ???

 

Will it work with the innovate? My innovate already logs boost from the map sensor. Will it work in conjuntioin with that?

 

It will work with any wideband that has an analog output, and I believe they all do.

 

I respectfully disagree, but I will count you out. One on each port would be nice, but I know my L1H1 wouldn't take the heat.

BTW, is anyone else having problems posting pics?

 

Yes posting images, has become a nigtmare, the post just stalls...

 

Yes

 

This actually sounds like a great idea to me. I'm not one to 'squeeze' every last drop out of my engine so I'd prefer to run AFR that is 0.5 on the conservative side. I could set the light/cut to come on if it exceeds my tuning number which still has some margin for error in it thus giving the system time to react (hopefully).

I'd love to see pics and install steps.

 

Good idea. Sounds like you're using a voltage comparator on the WBO2's analog output. Why not do the same with the stock MAP output instead of using a boost-switch?

 

Yes, a compatator circuit with some histeresis and other goodies. I never thought about using the MAP output. I already had the boost switch in my car running my IC fan and never intended to mass produce it or anything till I realized how much I liked it. Does anyone know the voltage of the stock MAP?

 

Random thought:
Most people that run higher boost have some sort of aftermarket boost controller. Could another step (say 0.5 above the warning level) be added to kill the power to the boost controller via a relay? Using stock turbos and your set point as an example: 12.2 AFR may spell trouble at 15lbs, but be ok at 7lbs. Not fool proof, but could be helpful in many situations.
I like the idea, but if it could be made proactive cheap and simple would make it even better.

 

wideband O2 sensor last about ~500 hours on pump gas

 

You could also use the power used for the blue light to activate a solenoid valve which in turn would vent your boost simmilar to a pop-off valve, but controlled in conjunction with a/f ratios. You could set it up to turn the light on where you feel uncomfortable and set it to vent boost when you feel your motor would be close to kaboom. The blue light being on would cause you to lift your foot which would help you to not overspin your turbos. The Blue light would be a warning and if you didnt react quick enough, the valve would be the last ditch effort to save your ***.

 

Stock MAP is 0-5V, vac-to-boost. According to my datalogit logs, when the PFC measures 10psi, the MAP output is around 4.03V.

 

I've had my FJO installed and running all the time for over 2 years - most of that time on race fuel - still working fine.

If you have a turbo car (especially one as fragile as the 7) you are crazy not to have one IMO.

 

I guess OEM's such as Honda and VW don't have a clue when they put them in eh?

 

The widebands that are being cheaply set up use the OEM oxygen sensor from a certain Honda, I think the Civic VX.

OEM emissions systems must stay functional for a minimum of 50,000 miles or the manufacturer must make repairs for free. (That might be 100,000mi now) Are you suggesting that Honda assumed an average speed of 100mph, including stops and idling, for their little economy car?

 

Maybe you should stick to discussions on carbon fiber...