The Lotus Cars Community banner

1 - 9 of 9 Posts

·
Registered
Joined
·
522 Posts
Discussion Starter #1 (Edited)
Hello All,

I finally got my AFR gauge installed and was wondering if the AFR guru's can weigh in on my initial readings. Just want to make sure everything is working properly ... Thanks!

Mods:
3.1 Pulley
Cup Intercooler
Cup Airbox
RC 550cc Injectors
Stock Exhaust and Cat
Koldfire Custom Tune

At Idle: 14.7-15.1
Cruising with Steady Throttle: 14.8-15.7
Full Throttle: 10.8-12.4
Releasing the gas pedal from Cruising: 22.4 ??

What values are considered "Dangerous"??

Also the guy who welded in my O2 bung put at an angle that touches the exhaust as per the pictures. Is this OK? as the outer rim of the exhaust shouldn't be too hot ... or should I get the bung moved? I assume an aftermarket exhaust would also solve the issue as I'm sure the can is much smaller.

Thanks!
Zoomby_U
 

Attachments

·
Registered
Joined
·
667 Posts
Your AFR's look OK to me, too, though if I were the tuner I might target a slightly richer (numerically lower) AFR at WOT. But I'm saying this without knowing the advance table (timing), intake air temps, exhaust temps, and not having the car on a dyno, so what do I know? I suggest you ask the good folks at Kold-Fire, and see if your WOT AFR's are in line with their intent. At cruise and idle, it sounds like it is cycling around stoich (14.7), which is exactly what it should do when running closed loop. Don't worry about the very high (lean) AFR on throttle-lift, it's normal for the ECU to completely cut fuel on lift-throttle over-run, you're just seeing the gauge max out.

Regarding the O2 sensor location, I think you're right to be concerned. I would get that fixed, either relocate the bung, or change the exhaust. I don't think the sensor wires will survive long up against the hot muffler like that.

HTH,
 

·
Registered
Joined
·
522 Posts
Discussion Starter #5
Thanks for the responses guys ... I double checked and the AFR is dropping down to around 10.8 if I really give it ... and that's up to around 7000RPM or so. About the sensor placement ... I'm hoping that the edge of the exhaust doesn't get too hot as it's only the body of the sensor touching it ... the wire is a couple mm away.

Cheers,
Zoomby_U
 

·
Plug Whisperer
Joined
·
6,305 Posts
Those AFRs are perfect.

The reason it looks so lean when you let off the throttle is because the injectors are actually off at that time, decel fuel cut...

Looks like she's running well:up:

Best,

Phil
 

·
Registered
Joined
·
522 Posts
Discussion Starter #7
Thanks Phil ... any input on if the O2 sensor position is ok? Would hate to have to remove everything to move the bung.

Cheers,
Zoomby_U
 

·
Plug Whisperer
Joined
·
6,305 Posts
No problem...

Ya, not super excited about that 02 sensor location either. Too close to the can. A smaller muffler would probably fix that... Other odd thing is that it's pulled out of the exhaust stream a bit with that long 02 sensor bung. You're obviously getting OK readings, but better to have it full in the stream with a standard depth 02 bung...

Sorry- not the great news...
 

·
Registered
Joined
·
522 Posts
Discussion Starter #9
Thanks Phil ... not sure why the shop welded the bung so high ... I assumed it would be deeper as well. I think this may be an omen to upgrade the exhaust :)

Cheers,
Zoomby_U
 
1 - 9 of 9 Posts
Top