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

LonghornLove · 04-26-2012, 10:21 PM

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??

grocerygetter · 04-26-2012, 10:49 PM

You could barely lean that out so it would look good on the dyno...but man, it may be spot on when the car is on the street. My car is 11.3 on the street. Everyone I have talked to says that's on the money on pump gas.

The Stig · 04-26-2012, 10:53 PM

35% drivetrain loss? Maybe with a 9". Auto is 20% and manual is 15%

LonghornLove · 04-26-2012, 11:18 PM

I know and I knew this before he said it. I'm sure he could tell I'm not a huge car guy. I didn't say anything though. This was awhile back, like 2 months ago.

Kind of funny how he just pulled a number out of his ass and acted like he was using the calculater. I'm getting 492 if I were to calculate it.

I thought it was suppose to be in the mid 12's? The guy said if he were going to do the tune he would do 12.6 on the A/F.

Parapdrapa · 04-27-2012, 01:06 AM

12 is generally the most desirable for power. Optimal for fuel efficiency is 14.7:1.

InfernoSS454 · 04-27-2012, 06:49 AM

What you have longtube headers wow. That's really low mine dynoed 330 stock.

Tampa Tuning · 04-27-2012, 07:08 AM

Mustang dyno's are great tuning tools and are heart breakers on the numbers. They are about 10-12% less then a dyno jet. That doesnt mean the car is making less power, its just reading it differant.

upper 11's - low 12's and 5 degrees of knock retard on a stock car at WOT is pretty normal. Most dyno operators use the tail pipe for a O2 reading unless the car has a header bung.

If you tune out the tail pipe and depending on which wideband you use, it can be a 1/4 to 1/2 point richer at the motor. Just know your equipment.

These motors really like the 12.4 to 12.7 AFR range for best power.
Phil
www.TampaTuning.com

WheelmanSS · 04-27-2012, 09:21 AM

A dyno is a tuning device - nothing more, nothing less

People get too wrapped up in numbers. An accurate and dialed-in AFR is far and away more important than a subjective horsepower number.

bmorecam · 04-27-2012, 12:12 PM

Quote:

Originally Posted by WheelmanSS

A dyno is a tuning device - nothing more, nothing less

People get too wrapped up in numbers. An accurate and dialed-in AFR is far and away more important than a subjective horsepower number.

So true. Also, dyno is useless if you have no baseline to compare against. You can come out of a dyno with 30hp more or less than expected. If you have no baseline to compare against than you have a useless dyno number. Mustangs and DD can also be calibrated to read properly, it does not have to be considered a heart breaker dyno, most dyno op's these days calibrate their dyno to read high, after all, peoples love high numbers LOL. Also, peoples tend to think dynojet read the highest, but this is far from the truth. You have dynojet's that read lower than mustangs and DD. It all depend on temperature, condition, calibration, etc..etc..

LonghornLove · 04-27-2012, 03:12 PM

Quote:

Originally Posted by InfernoSS454

What you have longtube headers wow. That's really low mine dynoed 330 stock.

Yea.. IDK if you have the L99, I think you do. But yea, I know mustang dynos read lower but that is really low for all mods. I've seen a few stock L99's in the dyno thread that have higher numbers on the mustang dyno. Not really worried about my numbers. I just want to know I'm not losing power from running rich.

LonghornLove · 04-27-2012, 03:14 PM

Quote:

Originally Posted by WheelmanSS

A dyno is a tuning device - nothing more, nothing less

People get too wrapped up in numbers. An accurate and dialed-in AFR is far and away more important than a subjective horsepower number.

If I were wrapped up in numbers I would of made the thread title about my low numbers. I'm concerned about the A/F being on point.

WheelmanSS · 04-27-2012, 03:58 PM

Quote:

Originally Posted by LonghornLove

If I were wrapped up in numbers I would of made the thread title about my low numbers. I'm concerned about the A/F being on point.

Just sayin

Especially since you listed the other hp numbers. The AF should be correct.

*GTAHVIT* · 04-27-2012, 04:02 PM

Quote:

Originally Posted by WheelmanSS

A dyno is a tuning device - nothing more, nothing less

People get too wrapped up in numbers. An accurate and dialed-in AFR is far and away more important than a subjective horsepower number.

QFT

BLACK10 · 04-27-2012, 10:38 PM

we see a nearly a 1 point rise between the tail pipe and the header bung. 11.1 is rich.....

04-26-2012, 10:21 PM	#1
LonghornLove My Grille so Icey Drives: Black 2SS/RS Join Date: Sep 2011 Location: Pearland, Tx Posts: 217	Accuracy of dyno A/F? 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?? __________________ Kooks 1 7/8 LT headers and exhaust sytem, CAI. cai w/ADM scoop, JRE tune. L99

04-26-2012, 10:49 PM	#2
grocerygetter instigator Drives: 2020 6.2 Trail Boss, 2022 XC90 Join Date: Jan 2010 Location: 72034 Posts: 3,979 View My Garage	You could barely lean that out so it would look good on the dyno...but man, it may be spot on when the car is on the street. My car is 11.3 on the street. Everyone I have talked to says that's on the money on pump gas. __________________ -John S.

04-26-2012, 10:53 PM	#3
The Stig knows 2 facts about ducks Drives: ...and they're both wrong Join Date: Aug 2009 Location: The HMS Invincible Posts: 25,072 View My Garage	35% drivetrain loss? Maybe with a 9". Auto is 20% and manual is 15% __________________

04-26-2012, 11:18 PM	#4
LonghornLove My Grille so Icey Drives: Black 2SS/RS Join Date: Sep 2011 Location: Pearland, Tx Posts: 217	I know and I knew this before he said it. I'm sure he could tell I'm not a huge car guy. I didn't say anything though. This was awhile back, like 2 months ago. Kind of funny how he just pulled a number out of his ass and acted like he was using the calculater. I'm getting 492 if I were to calculate it. I thought it was suppose to be in the mid 12's? The guy said if he were going to do the tune he would do 12.6 on the A/F. __________________ Kooks 1 7/8 LT headers and exhaust sytem, CAI. cai w/ADM scoop, JRE tune. L99

04-27-2012, 06:49 AM	#6
InfernoSS454 Drives: 2010 camaro ss Join Date: Feb 2012 Location: houston,texas Posts: 382	What you have longtube headers wow. That's really low mine dynoed 330 stock. __________________ Texas speeds 1 7/8 longtube headers and full exhaust vararam air intake. Lethal racings night fury cam and yank 3400 stall. Dyno tuned by lethal racing 465 rwhp 434 rwtq.

04-27-2012, 01:06 AM	#5
Parapdrapa Drives: 2010 Camaro Join Date: Jul 2011 Location: NC Posts: 174	12 is generally the most desirable for power. Optimal for fuel efficiency is 14.7:1.

04-27-2012, 07:08 AM	#7
Tampa Tuning Account Suspended Drives: TAMPA TUNING FACEBOOK & INSTAGRAM Join Date: Oct 2010 Location: Tampa, Fl Posts: 3,044	Tampa's GM Camaro Corvette GTO Trans Am performance tuner Mustang dyno's are great tuning tools and are heart breakers on the numbers. They are about 10-12% less then a dyno jet. That doesnt mean the car is making less power, its just reading it differant. upper 11's - low 12's and 5 degrees of knock retard on a stock car at WOT is pretty normal. Most dyno operators use the tail pipe for a O2 reading unless the car has a header bung. If you tune out the tail pipe and depending on which wideband you use, it can be a 1/4 to 1/2 point richer at the motor. Just know your equipment. These motors really like the 12.4 to 12.7 AFR range for best power. Phil www.TampaTuning.com

04-27-2012, 09:21 AM	#8
WheelmanSS Logic is dead Drives: 2010 Camaro 2SS/RS Join Date: May 2010 Location: Chicago, IL Posts: 1,804	A dyno is a tuning device - nothing more, nothing less People get too wrapped up in numbers. An accurate and dialed-in AFR is far and away more important than a subjective horsepower number. __________________ 2010 Camaro 2SS/RS (LS3) 573 RWHP 498 RWTQ - Vortech V3 Supercharger - Kooks Stepped Headers, Magnaflow 16580 - Suspension by Pfadt, Hotchkis. 2007 Trailblazer SS- Sold 2001 Trans Am WS6 431 RWHP 408 RWTQ - Sold 1994 Camaro Z28 - Sold

04-27-2012, 10:38 PM	#14
BLACK10 Drives: 2010 CAMARO. 10.04@133mph, 1.4 60' Join Date: Jul 2009 Location: Lafayette, Louisiana Posts: 4,585	we see a nearly a 1 point rise between the tail pipe and the header bung. 11.1 is rich.....