This is supposed to be super temperary. 10 minutes on, 10 off if need be. I'm going to use this to TRY to get some base reading on the d-jet. So if/when I start to make mods I can keep it all close to tuned.

Control box

Did I mention Getto. It needs an ignition on power line. So I ran it off the line to the radio
I wired a fuse in their too. It should sit right on the pagenger's sholder

I accualy have a O2 bung to weld into the exhaust, but no welder. So my Dad rigged this up.

Here it is in action. Yes, it hose clamped to the tail pipe.

Half way throught the install my brother showed up with a new car for his wife. It's kind of like give a bowling ball with your name on it. It a new 2005 Legacy GT. Same 2.5 that's in the STI just a little detuned. He got it for $23.5k. Is that a screeming deal or what!

Dad to help smell for burning wires when I reattached the battery. Mom for moral support, she must know something about these cars

Last one of the set-up. I figure I'll tie it to the grill and the gauge will reach in through the passanger window. Not super conserned about reading it, cause the divice can data log to it's internal memory and be downloaded to a laptop later.

I did start it for about 2 minutes, and the gauge was reading around 16-17. It would blip down to 14 when I gave it throttle but then come back up. Strange, concidering it should be in warm-up mode and running rich right? Maybe, it's reading lean because of how close the sensor is to the outside air? I'll have to wait till tomorrow to test some more.

I can tell you that the last time I tried to use the end of the exhaust for a o2 reading..... it was WAY off in the comparitve analysis to the bung/weld install.

I know.... I used rolling dyno for both installs. The same day... the same dyno... And compared the two with a Horiba gas analyzer. (the bomb)

The bung install was relatively close to the Horiba.

The tail install was terrible. And inaccurate.

The o2 gets contaminated with air as the pulses go out the tailpipe.

Therefore. I got BAD readings.

Thats just my experience. Yours may be differant.

That makes a ton of sense Twystd1. If I don't get better results after the car warms up a bit. I'm going to go the bung route. Do you think putting it in the Cat bypass pipe would be far enough up the exhaust to get accurate readings?

HHHmmm.. I don't know what a cat bypass pipe looks like. or where it is for that matter..

Ya got a pic????

Twystd1

By theway. is this a PRE-Heated sensor? (3 or 4 wire)

o2 sensors have heat ranges that they are more accurate.

Right were the gap is, is where the bypass pipe goes. So around in there.
I believe it has 4 wires. I know it self heats, and instruction say you should not run the car with out the unit getting power.

My RSA and other cars where I've replaced the O2 sensor always had the sensor before the cat. The cat scrubs the exhaust to reduce emissions, so after the cat could give false readings too.

Good Luck, Don

Weld a bung in before the muffler as close to where the pipes join into 1. You should be able to get a muffler shop to do it pretty cheap cause it only takes a second. When you aren't using the O2 sensore stick an old spark plug in as a plug.

Here's an idea. If you run rich you could rig up an extra coil back there with a switch and blast the hell out of the people behind you.

Dave

From the pics of the muffler you are still running the late style HE's so that is a good idea to install the bung in the CAT test pipe. Should give you good readings compared to the pos tailpipe mount you rigged up.

Drill the hole yourself first then take the pipe to the muffler shop to weld in for a few bucks. 5 min job.



also, rip out that ratty firewall pad as water gets in behind it and rusts out the firewall.

By the way Gerry and I ran kind of a crazy tune down in Portland a few weeks ago. The result was when Gerry was on the skid pad and got off the throttle and then back on it lit off some extra fuel in the exhaust. Nice loud pop and about a foot long in the daylight. Too bad it wasn't at night. It would have made for some good entertainment. Needless to say we junked that file and are running a little more conservatively now.

Dave

Now that file should be labeled as "Tailgater remover Stage One"


Worked fine on the RX7 Turbo!

It's already in the recycle bin. Gerry put on a good show. He had the inside wheel spinning and the ass end out so there was plenty of smoke. Add to that a couple of good pops and a little flame and dad's anal sphincter got a little tight.

Dave

I looked around, and I can't seem to find that bung(moving sucks). So I added a little extention to the pipe and it brought the reading down to 13.5. I'm not really sure what I should be shooting for. I'm going to try connection the laptop to see if I can set it up and grap some data

I love that kind of engineering. There is nothing better than scrounging around for something that might work and then finding out it works pretty well. The uglier the better.

It may well be all you'll need but, I don't think there is anyway to be sure without comparing it to a known well calibrated WBO2 in a known good place in the exhaust to sample, on your engine. Barring that your reading will be ballpark which is really all any of us get from our setups anyway. I think itis generally felt that a well tuned D-jet cruises at 13.5, and WOT is 12.5. I'm not sure about idle.

If you can use relative AFR for what you are doing I'd say you are good to go. If you need hard numbers then I think you need to find a way to calibrate the setup and that may be tough to do.

Dave

So here's what I've got so far. I'm not sure how to get the time to chart into the graph(first time with excel, ever). This is from start up, thus the 18 reading before the engine is running. The steady even blips are me turning the AFR knob on the ECU. Each blip(11) is on click from the center CW. When it finally smoothed out the ecu is on Full rich, Can't turn the knob any farther. I've heard this is not a good setting, but the engine sounds good there. Then you can see in the graph as I slowly incress the RPMS(No WOT yet) and snap it closed.

Got it Tuned! I think
No matter what, it's way closer then it was. ECU is 3 clicks rich of center, and the pressure regulator is turned up some(no pressure gauge, so that could have been the problem). I also changed the throttle body to cure a bucking issue(faulty TPS sensor), and the car drives much much better. Most impotantly, I think it's running cooler. Multipule redlines and the CHT never went above 350. We'll see how it goes tomorrow on the highway in 5th, around noon.
Wideband O2 sensors