Afr 16.1-16.3 glowing turbo

[quattrorunner]

Is it normal to cruise @80 mph with 16.2afr and have glowing header and turbo? I couldn't see it glow if there were light on it but in the dark it's dull brick red. I just richened my mix to try and reduce this but thought I'd ask. I'm on a short road trip.

[RarlyL8]

You don't really think that is normal. Cruise afr should be 14.5-15 optimally, 16.2 is way too lean, and turbos should never glow unless during prolonged boost on a high output engine. Why was your mixture so far off?

[quattrorunner]

It's just where I set it. I want 15.5 cruise but lately it's been a little leaner. On boost I see as low as 10's. my wide band had been faulting lately probably because of heat but not tonight. So it's cruising at 15.9-16.1 right now and still glowing.

[quattrorunner]

Idling at 11.5/1

[Norm K]

There's an old saying; "You can be rich forever but you can only be lean once."

Not an absolute, of course, but there's certainly something to it ...

[RarlyL8]

Here is where we target the AFR curve:
> 13.0-13.5 Idle
> 14.5-14.9 Cruise
> 11.0 Threshold Boost
> 12.0 Redline

[quattrorunner]

Here is mine. And tell me why please?
Idle 12.1/1
Cruise 15.5-16.1/1
Boost full 11-10.1/1
Redline(5500) 10.1/1
Why is my idle so off? I don't have idle controls. Only have a wur and that's it.

[smurfbus]

Your timing might be to retarded? Are you on boost while cruising over 60mph?

[quattrorunner]

No I don't think it's under boost at 60. Maybe a little at 70 though.

[RarlyL8]

The idle and cruise AFR can be set with the mixture screw, the other settings are static unless your WUR has been modified for adjustability.
First, with the engine fully warm, adjust the mixture at idle to 13.5:1 AFR. Then see where you are with the cruise AFR. Many things can muck up the works so this data will shed some light.

[jsveb]

My zork was glowing when my dist gave up and the timing was way retarded - I would check timing

[Mr Beau]

EGT peaks at stoich (14.7). Richer or leaner from 14.7 lowers EGT. When O2 sensors and catalytic converters were introduced (most) cars cruised around 14.7 for emissions. Better fuel economy can be had by running leaner than 14.7. Obviously you don't want to do this under boost but under light loads it's fine.

Retarded ignition timing causes more combustion to happen in the exhaust system which raises EGT. Have you checked your ignition timing and vacuum advance/retard?

[quattrorunner]

I'll check it when I get home. But I adjust the mix to 12.5/1 idle and I have 15.8/1-16.2/1 cruising 80mph. Couldn't see the glow today, too bright. If i set to 13.5/1 it's just way too lean at cruise, like high 16-17/1 afr!
I'm thinking maybe the ignition but more than that it may be my injectors? I have a slight rough/stumble at light cruise that I've noticed the past few months and have been trying to guess what it could be and now the off mix. Seems that my mix is trying to accomplish what bad injectors are doing. I don't know. We'll see.

[RarlyL8]

If i set to 13.5/1 it's just way too lean at cruise, like high 16-17/1 afr!

This is telling. The space between idle and cruise is too far apart. Like others have said it is time to check the ignition from idle to 4000rpm.

[JFairman]

I don't know if you have a Leask adjustable control pressure regulator. If you don't you should get one so you can adjust things for the better.
Along with checking timing also check the air flow meter sensor plate to see if it is at the correct hight when at rest.

This diagram shows where it should be and how to adjust it. It also has to be centered in the air funnel.

[slow&rusty]

Are you guys measuring your AFRs before or after the Turbo?

[mooney265]

Originally Posted by slow&rusty

Are you guys measuring your AFRs before or after the Turbo?

Was what I was thinking... And how far away from the exhaust outlet is the O2 bung?

[quattrorunner]

I'm building a new muffler that has the bung after the muffler but for now its right before the turbo.

[quattrorunner]

Btw my headers and turbo are no where near this bright:

after running it for a couple of thousand miles, went back in for an oil change and checking of head studs etc then onto the dyno for some tuning.







some scary looking headers whilst we sorted out the tuning











but a good result in the end, 375.6bhp and 351lb/ft. very please with the results even if i was hoping for a little more torque.







drives great, very responsive and useable power

[JFairman]

Originally Posted by quattrorunner

I'm building a new muffler that has the bung after the muffler but for now its right before the turbo.

According to Innovate and everywhere else the subject of wide band O2 sensor mounting location has been brought up, it has to be after the turbo to give accurate readings.
That's because there is alot of backpressure before the turbo and that pressure throws off the reading from a wideband oxygen sensor.
Before the turbo is fine for a narrow band oxygen sensor like the lambda oxygen sensor that was origonal in lambda emission equipped cars but the wideband sensor is different and can not be mounted there or it's a waste of time.

I took it for granted you had it mounted after the turbo where it belongs so I'm glad someone asked where you put it.
Anotherwords you're AFR readings are inaccurate and useless.