A/F placement

you're going to have to weld a bung to your header right after the first 02 sensor.

here's a good rule of thumb:

place the 02 sensor in the exhaust system at least 18 in downstream from the exhaust port. if you anticipate high EGT's (over 800C), run a turbo, run at high rpm for extended periods of time or plan on running leaded race fuel then you must mount the sensor at least 36 in or more downstreem of the exhaust port as all of these can cause the sensor to overheat.

Click to expand...

cool thanks... I also have the draxas header, would it be alrite to us the first bung that is on the draxas header? I just have a plug in it right now.

i would weld in a new bung.

If you are not using the existing o2 sensor bung then use it.
But you can pretty much put a W/B o2 sensor anywhere on a N/A car as long as it is before the cat.
You will usually need to worry about heat only with a turbo.

Would it be alright if the wideband is only reading from one cylinder? Or does it have to read all 4?

all 4

All 4 is the best way to go. Honestly I don't know why you are spending the money to put a WB02 on an NA car unless you are pushing the tuning of the vehicle to the limits, but your perogative. Reading off a single cylinder is a bad idea, the A/F is not going to be the same between all of them. Generally the cylinder closest to the throttle body runs the leanest with the one furthest from the throttle body running the richest. So if you are reading only a single cylinders exhaust you are going to have a poor measurement (of course reading it off all 4 gives you just an average and the leanest/richest cylinders are probably going to be at least .1 A/F off some of the time, but better then reading an extreme).
-Matt

he's about to install a standalone ecu dude

Thanks guys for your help. So i gather that it needs to be 16" away form the head, and reading all 4 cylinders. Also is it alright for the first stock o2 sensor to read one cylinder?

[quote author=thatoneguy link=topic=65915.msg1131378#msg1131378 date=1167858568]
Thanks guys for your help. So i gather that it needs to be 16" away form the head, and reading all 4 cylinders. Also is it alright for the first stock o2 sensor to read one cylinder?
[/quote]

Whats does the instructions tell you to do?
I know that different ones stated different positions and have different features.

As stated it wouldn't do you that much good to have it read a single cylinder.

If you can't use an existing bung then I would have one put after the header to make it simple to do.

herb, he's got a draxas header. his cat is further back in the exhaust, so would putting it after the hi flow cat give an unaccurate reading?

[quote author=the415 link=topic=65915.msg1131429#msg1131429 date=1167859786]
herb, he's got a draxas header. his cat is further back in the exhaust, so would putting it after the hi flow cat give an unaccurate reading?
[/quote]

Yeah you don't want to put it after a cat.

I meant after the first part of the header if it was 2 parts. That way he would not have to remove the header which is not all that fun to do.

Does the Microtech use the o2 sensors? If not I would use one of the exisiting bungs. Both would be good placement for the sensor on a N/A vehicle with the further being the best.

misread your post. you said header, i saw cat. nevermind.

[quote author=AzMz3 link=topic=65915.msg1131446#msg1131446 date=1167860130]
[quote author=the415 link=topic=65915.msg1131429#msg1131429 date=1167859786]
herb, he's got a draxas header. his cat is further back in the exhaust, so would putting it after the hi flow cat give an unaccurate reading?
[/quote]

Yeah you don't want to put it after a cat.

I meant after the first part of the header if it was 2 parts. That way he would not have to remove the header which is not all that fun to do.

Does the Microtech use the o2 sensors? If not I would use one of the exisiting bungs. Both would be good placement for the sensor on a N/A vehicle with the further being the best.


[/quote]

I'm running the stock header and used the 1st bung, before the integrated cat. The microtech doesn't need an o2, it's used for tuning. Not needed but needed if you get my drift. I don't use the gauge all that much, just more for a quick glance cause I have my laptop with me at all times. The header is a pain to remove but I had to pull it to get the original o2 out cause the threads stripped.

So the secong bung in the draxas header would be fine?

yes...didn't know they had a 2nd one.

yup its bout 3 inches away from where it goes to one pipe. Thanks much.

What would be a good safe A/F ratio? What would be a bad not safe A/F ratio?

Also does anybody know any good dyno tuning shops around the texarkana, dallas, houston area?

For WOT? For safe I'd shoot for best rich torque, but when not WOT stoich is 14.7.