O2 Clamp: Answer to "Lean Tip-In"?

[Dzaster]

So we were tearing up someone's Welcome thread with info on this O2 clamp.

I figure get a dedicated thread started so we can get some on topic and focused convo/info going. O2 CLAMP!!!

So one of the write-ups I've read a couple times is this guy's, Fernando in Barbados. He appears to be one fo the earlier formulators of the Autotune and O2 clamp.
http://www.bajanchameleon.com/autotune.html


Seems to be the same thing here. I wondered if Olderguy from MiataTurbo is this guy Fernando. :confused: If not, someone may be borrowing info from the other unless its just info pulished somewhere else publicly. IDK.

http://www.miataturbo.net/forum/t2572/ (http://www.miataturbo.net/forum/t2572/)

MessiahX had a link to another thread on MiataTurbo that talks exclusively about the O2 Clamp--function, operation and cost. It's here in the link below, but you must be a member of MiataTurbo and signed in to view.
http://www.miataturbo.net/forum/t7987/
(http://www.miataturbo.net/forum/t7987/)


And here is the diagram of the O2 Clamp.
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/oxygena.jpg


However, does the, yet undiscussed, Acceleration Map in the EMB not deal with this "lean tip-in" issue? A friend brought it up as being a possible means of correcting the "lean tip-in". Again :confused:.

If someone has experience with that Acceleration Map and has the time to do a decent writeup/explanation I suggest they start a dedicated thread for it then we can link it here if need be. Just because these are both good topics of discussion that could use more defining for me and other noobs.

[messiahx]

There are two sources I know of for an o2 clamp:

Flyin Miata ~$125
http://flyinmiata.com/index.php?deptid=4524&parentid=0&stocknumber=07-46300

$75 shipped
Olderguy (Bruce) at MiataTurbo.net
http://www.miataturbo.net/forum/t2572/
He also sells autotune--see the link for more info.

For those who don't know, the o2 clamp simply sends a holding voltage (typically lean or stoichiometric, this is adjustable, however) in place of the o2 sensor to the ECU so that it does not try to remove fuel under boost. In vacuum, the stock o2 sensor output is sent to the ECU. This makes it much easier to tune since the ECU is no longer fighting fueling changes under boost.

As far as the accel map...idk what that does. Some insight would be nice. It may be able to help with lean tip-in, but without a clamp, the ecu will try to pull fuel as soon as it sees a rich condition anyways, so this may be a moot point.

I should be installing my o2 clamp from olderguy tomorrow as well as my gm 3 bar map sensor. I will post my results here.

[Dzaster]

Mind posting up a pic so I know what I'm getting?:D


Here is something similar,but seems to be more of a full time O2 simulator. I believe mainly for those with OBD-II cars that get a CEL when doing away with the catalytic convertor.
http://www.mkiv.com/techarticles/oxygen_sensor_simulator/

[Accord2nrz]

Well surprised it to say on mohd auto parts there was an o2 sensor adapter, which is basically a clamp. After speaking with greddy over the whole issue I came to the conclusion that Greddy knows nothing of their products.

I have tried the o2 sensor adapter and it does work. basically it wires into your Vtec cross over point and the signal of the primary o2 sensor. Using the vtec map on the EMB is cuts the signal from the o2 sensor causing the car to refer to the pre-programmed base tables thus ignoring the sensor input. The result is the car goes super rich as is the OEM manufacturers design to keep the car from leaning out. Having the ability to set this point you can set it to the exact point of when your boost fully spools up without throwing a CEL.

Example: On my car regardless of the gear, (AUTO) i fullly spool at exactly 3,000rpm. Setting this cut point at 3100. I go rich for a split second and then boom I'm tuning for boost based off of input from the GM 3 bar map that I wired into the emb instead of the factory MAP monitoring system. The result is a steady 12.5 all the way to 10lbs.

[tersplat]

how would it be used with the non vtec guys, is your's clipping when you hit boost or when you hit vtec, or are you doing both at the same time?

[Accord2nrz]

my car is non-vtec =)

[tersplat]

so you have it controlled by the vtec controller on the emanage not the vtec solenoid. I think i got it now. instead of hitting vtec you are hitting o2 clamp

[Dzaster]

I founzit!!!

http://www.addictiveracing.com/ProductDetails.asp?ProductCode=15900908

So does it clamp signal or just cuts it all together? What happens when it just eliminates, it just goes full rich? Would disconnecting my O2 sensor replicate this device and tell me whether I would get a CEL or my ECU go into failsafe? If it does go into failsafe, is that a matter of having to reset ECU or if signal is detected again, it comes out of it. I am just trying to see how things might run for my car/ECU with this O2 adapter. Sounds like this might not be fore some, perhaps the reason why the O2 clamp.

Accord, would you be willing to explain the wiring in, and basic setup?

It's adjusted in this map of the Support Tool right?
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/VTECforO2adpater-1.png


I managed to find the wiring for the O2 adapter.
http://i525.photobucket.com/albums/cc340/dzaster96799/Tuning/O2Adaptor.png

[messiahx]

There is a difference between cutting the signal and clamping it. The warning for CELs is because some ECUs will dump in loads of fuel when the o2 sensor isn't sending a signal to be on the safe side, then tell you something is wrong with the primary o2 sensor. So that seems to be the only potential downside. If you have an ECU that dumps too much fuel in, you have to make sure you can trim it and that it is consistent in how much it dumps in so your tune remains good.

I say a bit more research is needed on this, but it sounds like this would be a decent alternative to a clamp, provided your stock ECU tolerates the lack of an o2 signal well.

Anyways, got my o2 clamp installed this weekend (along with wiring my gm 3 bar map sensor into the emanage tps) and wow does it make things easier. No more lean tip-in or general lean-ness below 4k (this is an issue with miata ecus -- closed loop below 4k at anything less than WOT).

Dzaster, sorry I can't take pics as I don't have a camera (yet, buying full 2.75" exhaust first :) ) but the clamp is just a pressure switch with three terminals and a pill box with some resistors and a POT for adjusting the clamping voltage. Also the switch is adjustable ffrom .5 - 4 psi. I left the switch at .5 psi and the POT at .32v which sends the ECU a lean signal making it dump in a bit more fuel. My tune is slightly rich right now, but AFRs are consistent and easy to adjust. Obviously these settings will be dependent on the vehicle, but none of it's hard to work out.

[Accord2nrz]

Very well =)

The wiring runs as follows.

Ground to Ground obviously, The yellow wire on the o2 sensor adapter connects to the vtec output wire on the emb main harness. then the o2 sensor signal wire from your primary o2 sensor gets cut just before the OEM ecu. the wire coming from the o2 sensor connects to o2 sensor adapter white and the the green on the adapter connects to the ECU o2 signal wire.

The map you have shown is incorrect. you're looking for a vtec map itself. Adjusting the crossover point changes the RPM point where the adapter kicks in and cuts the signal going to the ECU. This in turn throws you into open loop or failsafe mode. From there you can easily tune with the other maps becuase the computer isn't fighting you trying to achieve 14.7 or stoich. On my honda its a Godsend becuase I am still OBD2 and i dont hit open loop till engine load of 80%. I spool way before then so cutting signal throws me into open loop and just take fuel away from the pre-programmed value using the injector map.

I know what your saying...how am i taking fuel away with it.. Well I set my Emanage to think I have much bigger injectors than I actually have so it's cutting the fuel back waaaay more than need be. When I am in obd 2 the OEM ECU continues adding fuel til it hit's the 10% thresh hold most ecu's have. Then i take over an add fuel that way. When i go into boost. the vtec adjustment set at 3k i go open loop but since my fueling is cut back so much already It brings me pretty close to stoich, then I just add alittle bit of fuel to put me at 12.5 and adjust up as boost increase. My FPR is currently set for 60PSI and my injectors are 310cc, normal is 255 for my motor. I also have my EGR system removed to increase the heat allowing me to spool a couple hundred RPM sooner since my snail is larger than required for my 2.2L engine. Dealing with an OBD2 Automatic car teaches you to get a little creative when dealing with these things...so far from what the shops tell me is that im one of the first to successfully tune an AUTO OB2 accord of my year.

[Dzaster]

Nice explanations guys. I actually ordered the O2 clamp from OlderGuy on MiataTurbo. He sent it out today. Happy about that!

Messiahx, what I meant is I think the Greddy O2 adapter sends NO feedback to the ECU when told to clamp signal, thus causing the ECU to bypass the O2 sensor all together. However, the O2 Clamp that you have from OlderGuy, although it cuts signal, it actually still sends a simulated O2 signal--~14.7 and is adjustable--so it really isn't forcing the ECU into open loop but is tricking it into thinking it is seeing and consistent 14.7. This may also be the better for me since my injector upgrade is more than 2x my stock injectors. This way it isn't dumping kaboodles of fuel.

And so Accord, the ECU comes in and out of this limp mode state with no problem?

[Accord2nrz]

Mine does... I'm sure obd 1 cars think the same way. When you think about it. It almost has to...

On every car when your engine exceeds a certain load the ECU has to throw it into open loop/limp mode simply becuase there's so much air getting into the motor and your moving so quick that the ECU may not be able to keep up in closed loop mode Perhaps turbineguy can better explain this fact.

But in a nutshell, mine has no problem switching back and forth. the only time it hiccuped when switching was when I used the factory MAP. that caused issues on my car big time.

[messiahx]

Well it looks like we have a couple solutions then for lean tip in and fuel control. And the Greddy part is only $25!

Accord, you should definitely sticky this thread when you get a chance.

[Dzaster]

Got my clamp from OlderGuy today.

http://i525.photobucket.com/albums/cc340/dzaster96799/Turbo/IMG_1767.jpg

Shipped in two days and came in great shape with detailed installation instructions. Came with a nice Hobbs pressure switch as well. Gonna wire it up tommorrow, but have to get the car down to the exhaust shop to have a second O2 bung welded to relocate my WBO2 sensor and reinstall the stock narrowband O2 sensor to run with the O2 clamp.

Will provide some detials and feedback later.

[messiahx]

Dzaster, can't you just wire the o2 clamp into the simulated output? That way you won't need the factory sensor back in.

[Dzaster]

Dzaster, can't you just wire the o2 clamp into the simulated output? That way you won't need the factory sensor back in.
Olderguy said "NO". I didn't really querstion him on why because I was wanting to relocate my WBO2 further from the turbo anyways so I will use that new open bung for the Narrowband O2 sensor.

However, I have a question about O2 sensors in general. My stock O2 is 2 wire and has a flange that is fastended with 2 bolts. The bung I have is threaded so the O2 sensor I need has to be 2 wire and threaded install type.

I think mines is Zarconia type(whatever that means), but I am wondering if most O2 sensors operate bascically on the same voltage and what not.

Do they?

[messiahx]

The voltages would have to be universal...how else could wideband sensors have a simulated voltage that works across different vehicles? Also I searched autozone's website and they have universal sensors available.

Also, 2 wire means the O2 sensor isn't heated. 4 wires sensors are. The only difference is that the 2 wire takes a bit longer to put out accurate readings.

[Dzaster]

Good point about the simulated narrowband.

I went to a JY when I was in California and checked about 100 cars and only found one car with the 2 wire, threaded type O2 sensor. It was a 1991 NA Eclipse. I could not get that beast out even when I stood on the wrench and jumped--yes in the engine bay and in the junk yard. I left without it, but at least I now had a car to reference.

Well I referenced it at Kragen and they said that model was a 1 wire. :rolleyes: I then went to Pepboys and the guy basically let me, personally, go through their entire stock/selection of Bosch O2 sensors. I found a couple but were $100+.:eek:

I just wrote down part numbers so I could source some online. I found some for like $40. However, I did a search via eBay and found that one seller had a 2 wire, threaded O2 sensor for the Eclipse. I bought it and confirmed with the seller so it is on its way.

I guess a few more days without boosting for me.:mad:

[Dzaster]

Alright everybody, installed the O2 clamp today along with a new narrowband O2 sensor. So I am no longer simulating a narrowband signal for the ECU with the Innovate WBO2. I also relocated the WBO2 sensor further down stream in the exhaust piping about a 1.5' away from the turbo.

Since replacing my head gasket, I've not been boosting. I kept the actuator arm disconnected from the wastegate lever ont eh turbo. I may have seen .7 psi once.:p

Oh, and how does the O2 clamp fair you ask? IT WORKS!!!!!!!!!!!!!!!!

I haven't experienced the lean tip-in and I was holding it partial throttle too. It doesn't go full rich actually--just a little rich at like 10.8AFR. I will dial back some fuel later when I can do more street tuning. I laid into it with 9.3 psi max tonight at felt good. I missed it!

So basicaly guys, it does what it claims.

[Dzaster]

Update, still using the O2 clamp. However, I have since gone back to using my WBO2 simulated Narrowband signal to the ECU instead because I find it gets me a leaner/better AFR at idle and off-boost. And as theorized by messiahx the O2 clamps works just fine with the simulated narrowband signal output fromt eh wideband.

I have now deceided to get the O2 clamp with the Autotune built into it that Olderguy from MiataTurbo sells. Its been paid for and waiting for its arrival. Will prolly start another thread for this one.

BTW, I must have accidentally selected the thumb down icon. Didn't notice until after I posted.

[Dzaster]

So my Autotune w/built in O2 clamp is now installed so thie O2 clamp only intem I have for sale. See HERE (http://www.diytuning.com/forums/classifieds.php?do=showad&adid=5&title=o2-clamp)

[Accord2nrz]

Did you add the o2 clamp to the marketplace? I can't see it there.

[Dzaster]

lol Lin. Check the date of my posting brother. Nearly a year ago. It's been sold. Actually though, I think I still have a part up there that I need to take down. I was having trouble accessing market place for a while.

[Accord2nrz]

Holy crap! My bad hahaha.

[phantomneo]

u guys are lucky. my car is on closed loop all the time. from idle till full trotel the ratio will be maintained at 14.7 huhu..i tried EGO signal trimmer by PS which simply telling the ecu to go open loop during full trotel but my engine jerks badly. signs of incompatibility i guess..took off the ego signal trimmer and jerking gone. but still lean AFR prob huhu..seems that the only time the ecu goes to open loop is when the o2 sensor goes kaput..then it goes rich..11 to 1..there goes power n economy too..:(