I'll be getting my new greddy a/f guage tommorow. I have a haltech installed in my car. Would it be ok to splice in the haltech o2 wire to the greddy oxygen sensor? I don't want the readings to mess up if the haltech gets spliced into it. I want to be able to use it with the haltech so I can datalog. Does anyone have this setup?

C

 

It should work. Is the Greddy sensor a 4 wire sensor?

 

Hey,
Is four wire. I just openned it and saw the harness. The harness comes with an optional wire on the side to hook up to the ecu. That solves the problem. Now for installation,lookslike a bitch,theharness is kind of thick. It will be a long day.

C

 

Which harness is causing trouble?

 

Dont try to doit because it wont work
I found out that myself the greddy o2 sensor uses a wide band sensor , that is why it need the litle computer to work out the maths and translate it into the gauge the haltect sofware itwas made to read 0 -1 volts only.
Dont even bother try to find the wire from the o2 sensor.

But the conector that hooks to the O2 sensor has a green wire that they say that you can hook to the ecu or the haltech. but I found out myself that it does snot work. I destroy my engine doing it. I broke the corner seals and destroyed the number 1 housing.

Solution, What I did, spend a good amount of money to buy a wide band sensor from MRM or RP. You will spend at least $800.00 for a good wideband sensor. There is no cheper way.

By the way after you have a good O2 device you will need to calibarte your greddy sensor.

Good luck on your quest.
Remember to play it safe on the rich side, I rather sin on the rich side. Better to flood the engine than to destroy it . Dont trust the maps on the net usuallly they are very lean.

 

Hey Bruno,
I"m going to use the gauge to just watch my mixture. I just wasted to hook it up to the haltech thru the green wire to datalog my runs.

Is it normal for the guage to be so jumpy?

Must of the time is stays on 8 when on idle, I'm guessing the little computer need some recalibration.

What do you think>
C

 

Right now I am in the process of rebuilding my engine again
but before I screwed it up I noticed that the gauge stays at 8 (make sure you follow the instructions to make it work propely)
when the engine is cool 300 to 450 degress Centigrade as the O2 sensor gets normal operational temps the nedle will go up to about 11(about 550 C). depending on your exhaust temps.

The gauge wont work at low tempetures. Lets say you want to tune your engine at idle no cant do. the greddy will lie, and is going to make you think that the mixture is very rich wich is not.

Well maybe you have a friend that has a wideband sensor, or the money to buy one like I did. You can buy one within some other friends.
Aparently the gauge works fine and is supposut to be calibrated
but you need to fine out at what tempetures.
The greddy sensor has also a feature to lower the tempetures depending on the type of engine you have. but again if you what to tune your engine at idle you need to figure out which setting works best. but you will have to change the setting again as soon as you accelerate your engineor drive the car.
Suming up I wasted my money on the greddy gauge I think. But it is a very good idea to buy a egt gauge I got mine form greddy too. and it works perfect.
If your gauge shows you about 12 or 11 at idle you are lean and asking for trouble.
If you still have the oem ECU try to record how the gauge behaves at idle after you have drive the car for a long time, It will help if you have a EGT, you can record mixtures Vrs. temps of egt that way when you change your ecu to haltech you know what to expect.
It will cost me about $3000 to rebuild my engine haha. plus the wideband sensor, oh I forgot I also need to rebuild my turbo a T-78 and god knows how much is going to cost me.
Well is going to cost me a lot of money but again I didnt know how to or someone to tell me this things befiore.
I am trying to safe you money.
God luck and may the force be with you and your gauge.
I bought my wideband from here
http://www.rx7.com/cgi-local/3catalog.cgi?cat=12&part=6

Bruno

 

Thanks bruno,
I had to try it to see it myself. Yup, it doesn't work with the haltech at all. MY car has been tuned, I just got it to keep an eye on stuff.

ALso notice that on the correct setting it marks well but depending on the exhaust temp. I think I will be also investing on an egt.

Thanks
C

 

Hmm....I do not think you blew your engine because you wire the greddy a/f output to your haltec unless your haltec runs in closeloop at full throttle. The oxygen signal is only used for cruising. When you do full-throttle, it goes to the open loop mode. You blew your motor is probably because your fuel map or igntion map were not right. The Greddy a/f gauge output should not have anything to do with it. I wire the greddy a/f input to my Power FC and I had no problem with it. How do you know it's a wide band sensor? Did you measure the voltage? Even though it's a wide-band sensor, it will work with the stock ecu 0-1V. The greddy instruction manual clearly states that if you have a lean burning engine, you cannot use the output from the green wire. If you know, the lean burning engine uses wide band oxygen sensor. So either the green wire's signal is already modified to be 0-1V range or the greddy a/f gauge does not use a wide band sensor. BTW, if you are looking for a wide band lambda sensor, I will buy the one from Motec. The price is dropped to $1300. You can buy one from www.hondata.com. Good luck.

Chuck

 

All,

I would have to agree with Bruno here. Here is an example.

One night while tuning my car I was dataglogging every run. THis was before a huge event the next day. The last event I ran a 11.5 running really rich and I wanted to run 10's so I decided to lean the air/fuel mixture just a little.

First datalog the 02 readings per the Greddy A/F guage were upper 900's. Very rich. The guage itself was reading 12's. Greddy EGT temps were normal.

Now, I leaned the car out a little more. 02 Sensor reading went to low 900s and the EGT temps rose. THe A/F guage itself went to 13's. I should have known at that point but the car was feeling so good.

Like an idiot, I thought the most accurate readings were the direct 02 readings and decided to lean it again to get uppper 800's. WRONG IDEA. Next pass in 3rd gear all felt great. I was done. I was ready to make my 10sec pass. Guess what? All was ok until I ran out all the gears. 1st - 2nd - 3rd - and then 4th. In fourth the car felt weird.....yes i blew a corner seal. THe motor still idled well but the vacuum dropped to about 10.

I knew right away. I still drove the car as is for another couple months then had T and R build ANOTHER motor for me. What did we learn?

1. GET A REAL WIDE BAND (Dont get me wrong, I have friends who use the Greddy gauge and it works well but I would say dont use the 02 datalog way to tune the car. Look at the guage itself.

2. Your EGT guage will not lie. If you see that guage jumping all over the place, I have never seen it go past 850C and that night it did. (you guys prob all know this, i learned it that night)

3. Get on a dyno, pay the $150, tune your A/F with the wide band that they have, while tuning, compare the readings to the greddy. Now that you have an idea, use your Greddy A/F to have an idea where you are. IF you the numbers going crazy, now you know something is up.

Anthony

 

IMHO I don't think the Greddy gauge uses a true wide band sensor. The function of a true wide band O2 sensor is fundamentally different from the standard sensors. Bosch offers a sensor (LSM-11) which is supposed to have wider response, but still be compatible with standard ECUs.

A true current-driven lambda sensor will still run run you ~$250 for the sensor alone and require special electronic circuitry to work. I'm currently building a system based on a Honda UEGO sensor with readout to fit in a 52mm form factor and having a replacement signal for the standard ECU O2 sensor.

-Mike P.