Lets talk about retards....

[siman]

LOL.....retard as in TIMING.

I just got off the phone with my friend, he currently owns 2 grand nationals...the lower horsepower one is around 500'ish whp...the race car is 1200+hp.

We got to talking about octance and gas and such and he brought up my/our o2 sensors being heated or not.

See, he told me that some cars from the factory come with cold o2 sensors that if you run say 116 octance race gas ( what he runs daily, about $4 a gallon here in TN) the lead inside the gas would fowl ( foul?) out the o2 sensor...essentially it would clog the o2 sensor up.

Now, does ANYONE know if our factory o2 sensors on our turbo 7m's are heated or not? I know there is 3 wires...one is the blue wire that may be a power wire for the heat core???

All this is just asking, if I run 116 octane leaded race gas inside my supra for a dyno run sometime soon ( with the new rebuilt turbo) and turn UP the boost to about 16lbs, would I see my o2 sensor crapping out?

And another question, is there a device that plugs into OUR cars knock sensors that can show knock and retard/advance as his little device does in his GN's???

What is your guys views or thoughts on these subjects?

-Jonathan Mann

 

[MDCmotorsports]

IIRC you can actually use a volt meter to see if the computer is reducing (not retarding) the timing from the knock sensors.

Also, yes our O2 sensors are heated. And yes it will crap out on you early if you run leaded race gas.

 

[ToyoHabu]

Three wire O2 sensors are heated, two wires for the heater the third is the actual sensor lead.

Common failure modes

Lambda probes have a limited lifespan since the exposed sensor element is subjected to high temperatures which causes fatigue over time. Probes become sluggish, failing to react quickly to changes in the condition of the exhaust gases. This can be caused by contamination from the engine, fuel or additives. One common fault is silicon buildup on the probe sensor. A common source of silicon contamination is through the use of silicone sealant in repairing water system leaks. Lead build-up from the use of lead additives or leaded petrol will also damage the probe, as will carbon build-up from excessive burning of engine oil.

It would be expected that a probe would last for 3 years or 40,000 miles (about 64,000 km), but it has been observed that probes will last for up to 3 times this length.

 

[siman]

Ok the knock sensor readings can be tackled rather easily I presume?

But the thing is, is it just the sheer design of our O2 sensors that although being "heated", they are just to old to cope with the leaded gas vapors?.....Tom ( my friend with the GN's) runs Ford O2 sensors....he does not know which exact car they are from YET.....will figure that out tonight.....but as for now he says his car runs PERFECT on race gas....he uses some device to measure knock, he is running 28 degrees timing on a regular basis with race gas!!!!!!!!! And the only retard'ing he see's is about 3degrees negative to ZERO all the time! Only on HOT days has he seen the retardation of 3 degrees!!

Its just all making sense.....but where could I land one of these good heated o2 sensors so I CAN run 116 leaded gas? Would the Zetronix (sp?) wide band o2 do it?....?

-Jonathan

 

[siman]

So my turbo blowing out oil smoke/vapor might of already ruined by BRAND NEW o2 sensor eh?

ugh.

-Jonathan

 

[IJ.]

It's the Lead in the fuel that kills the 02 sensors the heater has nothing to do with it.

If the 02 is mounted close enough to the flame front at the Turbine you can get away with an unheated one. (but this reduces it's lifespan)

Another cause for failure is if you drop one as you're installing it.

 

[siman]

Another cause for failure is if you drop one as you're installing it.

LOL.... :nono:


I am just trying to figure out the best ways to get free HP out of this motor! A new wiring harness and grounding cables would do the trick. My buddy patrick ( 518whp 7mgte mk3) had ZERO ( yes thats "0" ) gauge grounding wire for his car....he said the power increase could be felt and the car just started and idled better...much more better spark!

That is something I am going to look into really soon as well..but that will inlovle some tinkering around the starter region which I HATE with a passion!

I will get some thick wire for the grounding of the coil pack and head to firewall too!

I think this would help keep stress off the stock wiring harness for my headlamps when I get HID's too! Wow, i got so off topic...

anyways.

I will rebuild this turbo, run some 116 leaded race fuel, turn the boost up ( shims ? LOL)...and see what my baby churns out...hopefully around 350whp and = torque.

how many of you are running seriously CUSTOM grounding kits...not these cheap fake ebay ones or Apexi/buddy club/ or HKS earthing systems...

-Jonathan

 

[IJ.]

I'm serious they can't take a knock and will die soon after

 

[siman]

/\ read that post....LOL I edited alot :naughty:

 

[IJ.]

A lot of the 02 sensors we use for standalones and WB's aren't even for cars ! (most are meant for Kilns/Furnaces)

My battery cables and ground wires are .5" multistrand welding cable with soldered ends. (can't say I can notice a difference but my stock grounds were all cleaned/sanded the 1 st time I pulled the motor way back)

 

[siman]

So can I just go the the neighborhood funeral home and get a cremation furnace O2 sensor and go? :rofl:

 

[tubbie]

Just make sure you don't get it from the Tri-State Crematory, apparently theirs do not work..... :rofl:

But really, o2 sensor is o2 sensor..... They all work the same.....
Ground cables are ground cables too. Even the cheap ebay ones are better than none. The problem is finding places on the motor that will really help grounding.

 

[thesupraman]

Just a suggestion, if you are going to be running less than 20lbs of boost, I would run 104 unleaded. You want to run the lowest octane possible without getting detonation. Unless you plan on dumping race gas on top of pump gas, in which case I would go for the 116.

 

[mrnickleye]

All too true, (Read it in MOTOR mag) the heated O2's are done so to help the computer get into 'closed loop' operation quicker. That's all. But on 1996 and newer (OBDII) vehicles, the computer monitors the heater too, and failure will set a code.

Lead KILLS O2's, real fast.

 

[jaydm16]

so which wire for a 91 is the actual signal wire from the o2 sensor?

 

[thesupraman]

so which wire for a 91 is the actual signal wire from the o2 sensor?

Blue I think. The two black ones are for the heater.

 

[mosely]

****LOOK THIS QUESTION WILL BENEFIT ANYONE WITH A 7MGTE******
ok I've been trying to find a way to relocate the hoses and wires in the 7MGTE's because when I look under the hood it seriously looks too messy. Its like the engineers never thought anyone would look under the hood for some reason. anyways if anyone has any advice on how to relocate the hoses and wires on a 7MGTE let me know please. Once we figure out how to do this the engine bay will look much better and you wont have wires and hoses running everywhere. you can also email me -mosely900@hotmail.com

 

[mrnickleye]

Well, one way is to use much longer vacuum and coolant hoses. Use some of that colored flexible plastic wiring loom stuff, and run bunches of them in the direction they need to go, then feed them out as you need to the hook up place. Do the same for all wiring that is not dependant on a certain length for a required resistance.

 

[Nick M]

Its like the engineers never thought anyone would look under the hood for some reason.

The demographic Toyota marketed the car to don't open the hood for the most part.

 

[mosely]

well anyway me and my buddy got a supra he's still working on his and mine is coming a long but we are tryin to figure out a way to get all of this shit under the hood organized. i mean it really looks ugly i can't even see the damn engine under all of that shit. Excuse my language but it really is pissing me off cuz these types of engines are in the top 10 and I can't see why anyone wouldn't wanna show that off. HELP PLZ

Thanks for them ideas mnnickleye