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AFR reads 18+ when rolling to a stop
Posted: Tue Sep 05, 2017 11:20 am
by rofeksos
So I'm trying to get a decent base map going so that I can drive to my tuner to have my B18C5 JRSC Supercharged properly tuned. When driving around the block to do some data-logging I noticed that my AFR read super lean when I let off the gas while the car is moving both in gear and in neutral (0 reading on gauge but shows it's on the lean side and 18+ reading in SManager). Is this normal? When my car is rolling and almost at a complete stop readings go back to 12 - 13 range and stays consistent when I'm at a dead stop and idling.
Re: AFR reads 18+ when rolling to a stop
Posted: Tue Sep 05, 2017 3:00 pm
by Spunkster
This sounds pretty normal, as the injectors cut off on decel.
Re: AFR reads 18+ when rolling to a stop
Posted: Wed Sep 06, 2017 12:00 pm
by rofeksos
Spunkster wrote: Tue Sep 05, 2017 3:00 pm
This sounds pretty normal, as the injectors cut off on decel.
Thanks Spunkster I'm glad this is normal.
On another note, I need clarification when I'm reviewing my data logs. In the screenshot it shows that my AFR is super lean at 18+ when I'm cruising at 12 mph in 2nd gear. However, in the matrix when I selected "Show recorded/datalog lambda" it shows 12.xx readings at my current position. Is this because when I'm revving the car at idle, it's contributing to samples collected for these particular cells?
If this is the case (and since I'm doing a noob street tune w/o a dyno) ideally I could put my car on jack stands to have the wheels spin freely tricking the car into thinking I'm actually driving, I can get more accurate readings? I do plan on taking my car to a tuner, I just need to be able to safely drive there.
Thanks in advance.
PS. If you needed them, I've attached my calibration but I couldn't attach the datalog since it's too large (I recorded 17 mins of neighborhood driving)
Re: AFR reads 18+ when rolling to a stop
Posted: Thu Nov 30, 2017 1:29 pm
by G. Wiffington
Lol the jackstands thing sounds super dangerous..but, if you are obviously using a wideband then are the numbers the same on the wideband compared to the sManager?
Re: AFR reads 18+ when rolling to a stop
Posted: Thu Nov 30, 2017 1:31 pm
by G. Wiffington
Wait your reading shows the VOLTS not the actual AFR!
You need to change your sensor to the AFR instead of the voltages. (I know because I did the same thing when I was first starting lol)
Re: AFR reads 18+ when rolling to a stop
Posted: Fri Dec 01, 2017 2:23 pm
by rofeksos
G. Wiffington wrote: Thu Nov 30, 2017 1:31 pm
Wait your reading shows the VOLTS not the actual AFR!
You need to change your sensor to the AFR instead of the voltages. (I know because I did the same thing when I was first starting lol)
That's how it is displayed in SManager but it is AFR and not voltage. Aside from the lag It's pretty consistent from what is displayed in SManager and my gauge.
Re: AFR reads 18+ when rolling to a stop
Posted: Wed Dec 06, 2017 12:19 pm
by G. Wiffington
Sorry I was talking about on the display gauge & not looking at the table.