Accuracy of dyno A/F? - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

sspaul · 04-27-2012, 11:26 PM

do you have cats on the car? b/c that will mess with his reading at the tailpipe as well

LonghornLove · 04-28-2012, 07:38 PM

yes I have cats

JANNETTYRACING · 04-28-2012, 08:35 PM

Quote:

Originally Posted by LonghornLove

I had my car dynoed (mustang dyno). The a/f is measured by something they stick in the exhaust.

At WOT my A/F was 11.1

My Hp/Trq. were really low too, 317/308, adjusted. (had all mods listed below)
The tuner said 35% loss thru drivetrain... 470 HP
(That's off topic, just thought I would add.)

So how accurate??

It is Highly unlikely the car is this rich unless CAT Overtemp protection fueling kicked in due to Testing procedures, Possibly the car was too hot or ran too hard and long before the dyno pull or there is something wrong with the calibration of the tail pipe sensor.

That is Richer than we like our target AFR is 12.4-12.6.

I would be happy to review your logs and go over your tune for you.

Email me.

Ted.

sspaul · 04-28-2012, 09:26 PM

hey ted wouldn't him having cats affect his a/f reading at the tail pipe?

BLACK10 · 04-28-2012, 11:29 PM

Quote:

Originally Posted by sspaul

hey ted wouldn't him having cats affect his a/f reading at the tail pipe?

it would make it read leaner at the tip..........

grocerygetter · 04-28-2012, 11:46 PM

Hey Ted...that's your tune in my car at 11.3. My sensor is post cats, drivers side. Near junction of cat back to header.

JANNETTYRACING · 04-30-2012, 10:09 AM

Quote:

Originally Posted by grocerygetter

Hey Ted...that's your tune in my car at 11.3. My sensor is post cats, drivers side. Near junction of cat back to header.

Boosted Cars are 11.3, NA cars are 12.4 ish

Oxygen sensors Don't Read Fuel they read Oxygen content.

If the Cats are working it should read Richer at the tail pipe.

Cats re-burn unburned Air Fuel, burning up oxygen.

grocerygetter · 04-30-2012, 10:45 AM

yup...that's what I was thinking.
OP...do what I did with Ted that Saturday...datalog for him back and forth and get it polished up.

04-27-2012, 11:26 PM	#15
sspaul Drives: 2010 ss camaro, imperial blue Join Date: Sep 2009 Location: new orleans Posts: 939	do you have cats on the car? b/c that will mess with his reading at the tailpipe as well __________________ my youtube my facebook www.myspace.com/1djchampagne www.twitter.com/1djchampagne mods: borla long tube headers, borla atak catback, lingenfelter gt-9 cam, ported heads, ecs base kit running 11 psi on top end, 1" bmr drop spring, aam 3.70 gears, ported throttle body, 160* thermorstat, lethal racing tune 750/641 rwhp/rwtq

04-28-2012, 07:38 PM	#16
LonghornLove My Grille so Icey Drives: Black 2SS/RS Join Date: Sep 2011 Location: Pearland, Tx Posts: 217	yes I have cats __________________ Kooks 1 7/8 LT headers and exhaust sytem, CAI. cai w/ADM scoop, JRE tune. L99

04-28-2012, 09:26 PM	#18
sspaul Drives: 2010 ss camaro, imperial blue Join Date: Sep 2009 Location: new orleans Posts: 939	hey ted wouldn't him having cats affect his a/f reading at the tail pipe? __________________ my youtube my facebook www.myspace.com/1djchampagne www.twitter.com/1djchampagne mods: borla long tube headers, borla atak catback, lingenfelter gt-9 cam, ported heads, ecs base kit running 11 psi on top end, 1" bmr drop spring, aam 3.70 gears, ported throttle body, 160* thermorstat, lethal racing tune 750/641 rwhp/rwtq

04-28-2012, 11:46 PM	#20
grocerygetter instigator Drives: 2020 6.2 Trail Boss, 2022 XC90 Join Date: Jan 2010 Location: 72034 Posts: 3,979 View My Garage	Hey Ted...that's your tune in my car at 11.3. My sensor is post cats, drivers side. Near junction of cat back to header. __________________ -John S. Last edited by grocerygetter; 04-28-2012 at 11:56 PM.

04-30-2012, 10:45 AM	#22
grocerygetter instigator Drives: 2020 6.2 Trail Boss, 2022 XC90 Join Date: Jan 2010 Location: 72034 Posts: 3,979 View My Garage	yup...that's what I was thinking. OP...do what I did with Ted that Saturday...datalog for him back and forth and get it polished up. __________________ -John S.