Does wheel weight affect dyno numbers?
#1
#2
Re: Does wheel weight affect dyno numbers?
Yes it will. Smaller diameter, lighter and lower inertia rims/wheels will make a big difference. Also, the more sticky a wheel is, the less slipping on the dyno drum, hence a better reading.
<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>
<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>
#3
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Re: Does wheel weight affect dyno numbers?
Wrong. The weight of the wheel does change the way the Dyno shows your readings. I have been doing dynos since 1996. And have seen people actually swap out 18inch wheels with 15" wheels just for the dyno, and the hp difference can be as high as 10 hp.
Your buddy doesn't know what he is talking about. Just like how a ASE mechanic says that dino oil is the best to use in a engine and not synthetic.
2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com
Your buddy doesn't know what he is talking about. Just like how a ASE mechanic says that dino oil is the best to use in a engine and not synthetic.
2004 Infiniti G35S, 6MT, Premium, Sport, DP
Mods: JDM Clears, 20% tint, Z-tube, Stilen CAI
Track: 14.32 at 98.79 mph 2.2032 60ft
Dyno 07-07-04 - 234.2 hp & 233.8 tq
http://www.g35world.com
#6
#7
Re: Does wheel weight affect dyno numbers?
Dynos work by measuring the acceleration of the drum. Gear ratios have to be programed in but anything else that lets the wheels spin up faster will show as increased horsepower. Smaller diameter tires will in effect change the final gear ratio and should be accounted for in the set up. But lighter wheels, tires and rotors will accelerate quicker without effecting the gear ratio and will show as higher HP numbers.
Mark
2003 Sedan AT. Ivory Pearl/ Willow
20% tint. Z-tube. Clear Corners w/ PIAA.
Aluminum Pedals
Mark
2003 Sedan AT. Ivory Pearl/ Willow
20% tint. Z-tube. Clear Corners w/ PIAA.
Aluminum Pedals
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#8
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Re: Does wheel weight affect dyno numbers?
...and the same principle applies for other rotating masses - ie flywheel, accessory pullies, driveshaft, etc. Reduce the mass of those guys and you get a Hp increase.
G35s 6MT Garnet Fire, Premium, Aero, Aero Body Kit, Winter Sport
Mods: Crawford V5 Plenum, 350 Z Tube, K+N Panel Filter, 7 Wire Ground Gear, Coupe Mid Pipe
G35s 6MT Garnet Fire, Premium, Aero, Aero Body Kit, Winter Sport
Mods: Crawford V5 Plenum, 350 Z Tube, K+N Panel Filter, 7 Wire Ground Gear, Coupe Mid Pipe
#9
Re: Does wheel weight affect dyno numbers?
Unfortunately Dynojets don't reflect the real world acceleration because the drum weights less than the vehicle and the lack of wind resistance which slows the engine acceleration significantly...........the two things plus the higher friction from tire being deformed on the smaller diameter drum makes for some crazy error prone numbers.
Vehicle weight on each rear tire has lots to do with tire friction against roller.............you can add trunk weight and many times get a HP increase or change rear tire inflation pressures. To get a faked up graph to display to your friends.
Vehicle weight on each rear tire has lots to do with tire friction against roller.............you can add trunk weight and many times get a HP increase or change rear tire inflation pressures. To get a faked up graph to display to your friends.
#11
Re: Does wheel weight affect dyno numbers?
Actually the 19s aren't costing you horsepower. the motor is still making the same horsepower with 19" wheels and tires as you are with the stock 17s. The unsprung rolling mass is greater causing slower acceleration. Not an actual loss of power.
Mark
2003 Sedan AT. Ivory Pearl/ Willow
20% tint. Z-tube. Clear Corners w/ PIAA.
Aluminum Pedals
Mark
2003 Sedan AT. Ivory Pearl/ Willow
20% tint. Z-tube. Clear Corners w/ PIAA.
Aluminum Pedals
#13
Re: Does wheel weight affect dyno numbers?
Having more inertia on the wheels only affects the rate of change of RPM. Changing wheel inertia can affect 0-60 times and 1/4 miles times less so, but steady state HP and terminal velocity will be unaffected.
HP is the ability to do work. You can give the engine more work to do by increasing momentum and/or inertia but the engines ability to do work is unchanged. You can put three passengers in your car to decrease the acceleration rate, but carrying three passengers in the car won't change the wheel HP.
In Theory, practice and theory are the same.
In Practice, practice and theory are not the same.
2004 G35 6MT Blk/Blk Sedan Stillen Air, Stillen Exhaust
HP is the ability to do work. You can give the engine more work to do by increasing momentum and/or inertia but the engines ability to do work is unchanged. You can put three passengers in your car to decrease the acceleration rate, but carrying three passengers in the car won't change the wheel HP.
In Theory, practice and theory are the same.
In Practice, practice and theory are not the same.
2004 G35 6MT Blk/Blk Sedan Stillen Air, Stillen Exhaust
#14
Re: Does wheel weight affect dyno numbers?
"but carrying three passengers in the car won't change the wheel HP. " ? other than changing the [tire to road] friction coefficient by increasing the load on the rear wheels/tires......the rear wheel power won't change but the measurement will. So will the acceleration be decrease by some factors for each 100 pounds [~~0.1 second in quarter mile time].
#15
Re: Does wheel weight affect dyno numbers?
"the rear wheel power won't change but the measurement will. So will the acceleration be decrease by some factors for each 100 pounds [~~0.1 second in quarter mile time].
"
Correct! ;-)
In Theory, practice and theory are the same.
In Practice, practice and theory are not the same.
2004 G35 6MT Blk/Blk Sedan Stillen Air, Stillen Exhaust
"
Correct! ;-)
In Theory, practice and theory are the same.
In Practice, practice and theory are not the same.
2004 G35 6MT Blk/Blk Sedan Stillen Air, Stillen Exhaust