The weight of wheel will affect your dyno result?????

[edw-R]

Anybody know the weight of wheel will affect the dyno result?? How much they will affect?? For example: 16" wheel. One with 11kg. Another one with 7kg.
Andthen, what do you think with lightened wheel??
Hope can share your opinions:D !!!!!

[ian]

good question. i have also pondered about this edw-r..........hmmmmmmmm
somehow, i think it may affect it some way or the other since i certainly feel the difference on the road between my 18" and 15" wheels..........let us see if anyone can shed some light.

[linkorr]

yes it will (read disclaimer :p). Weight of the wheel and the level of grip the tyres produces. When u run a dyno, you will want to run a tyre which has a resonable amount of grip, something which will not generate 'too much' friction with the rollers, When you are about to dyno your car, choose a tyre that will give you enough grip to transfer all the power onto the rollers, but not 'stick' to the rollers.

About the weight issue, the ligther wheel takes less power to rotate, therefore increasing your response (as far as the dyno reading is concerned).

disclaimer :D I've never run a dyno before, this is all off some megazine, so if anyone can correct what i've said, that'll be good.

[edw-R]

I found some info.
185/65-14 34 lbs = 113.5hp
205/40-17 42 lbs = 108.1hp
205/40-17(another wheel) 43 lbs = 107.9hp
Hope can share with you!!!

[Psyklops]

I would have thought rolling circumference would be just as important as the weight...the further the wheels have to travel would have an effect on this for sure

[Kawasaki]

the heavier the wheel is the slower it will be to get the power up and running, fairly simple science. I want to dyno my ed6 and see what i can put out, whats the price for a dyno run?

[Civic Type R]

i like this thread :thumbsup:

[tinkerbell]

also tyre pressure plays an important role...

[spoondc2]

I think the most important thing is the GRIP, and then the engine condition (Heat, Temp, intake volume....etc...), so it will never accurate

[EG_2_TEG]

just use a hub dyno...

[toE]

*Moved*

[edw-R]

Does anyone have experience with the same tyres but different rims??

[tinkerbell]

wheel alignment and toe-in or toe-out also affects the results...

[PhatSol]

Since most dyno runs are done with the car accelerating, not holding flat at peak power rpm, IMO the weight of the wheel would make a diffrence.

[bumography]

common sense if you think about your car trying to spin a 200kg wheel!
just use your imagination
:)
and i dont even know anything about dynos :D

[edw-R]

common sense if you think about your car trying to spin a 200kg wheel!
just use your imagination
:)
and i dont even know anything about dynos :D
Thx....i get my ans now.:thumbsup:

[panda[cRx]]

i never thought thong of all people would provide the simplest logical answer :p

[edw-R]

']i never thought thong of all people would provide the simplest logical answer :p
Simple is prefect.

[Sp3rMz]

Bigger the wheel, slower the car.

[SINISTR]

im with Omar then - Hub dyno is most accurate...

[Limbo]

I don't know about that cos if you think about it your gonna drive with your wheels on so technically you would want the tyres and wheels your gonna run on to give you an accurate reading with Friction otherwise your readings kinda useless unless your just trying to find how how much you could potentially make?.... Also depending on different dynos you will even get different readings! doesn't even matter if you use same car....??? makes you think aye? ;)

[tinkerbell]

I don't know about that cos if you think about it your gonna drive with your wheels on so technically you would want the tyres and wheels your gonna run on to give you an accurate reading with Friction otherwise your readings kinda useless unless your just trying to find how how much you could potentially make?.... Also depending on different dynos you will even get different readings! doesn't even matter if you use same car....??? makes you think aye? ;)
dynos are for tuning, not getting accurate 'readings' of your power.

as long as you keep using the same one to measure changes that you make to your engine, then accuracy doesnt matter at all... (as long as the dyno is kept to spec)

engine dyno is most accurate of all...

[strafe]

Was looking for info on tyre pressures, came accross this thread....

Bigger wheels require more energy to turn than smaller wheels, this is because there is more weight towards the outer edge of a larger wheel and tyre combination.

Larger Brakes also require more energy to turn.

The weight of wheels and tyres, as well drivetrain losses, have less of an effect on a car that makes 500kw over a car that makes 100kw. This is because the drivetrain, wheels and tyres only consume a certain amount of energy.

[J_Mech]

Different tyre and wheel combos will come up with different power/torque figures on inertia type dynos, where you need to measure the change in speed (acceleration) to get your power figure. But on controlled dynos where you can hold speed/rpm constant under load then there shouldnt be any difference. Things like tyre pressure will have an effect because your changing the rolling radius of the tyre/wheel so the speed will change with the same rpm.

J_Mech

[type one]

yes. I run a 5kg rim at the front and a 4kg rim at the rear.

I have run a 4kg rim at the front and the difference is amazing...mind blowing... hehehe... maybe if i cbf i will try it on a dyno for you guys...

[Jus-10]

A guy I know ran his current shape BMW M3 with 20inch chromies (what a waste of an M3!) on a dyno. It managed a pitiful 130-odd kws at the wheels. Now think about the factory claimed 230-odd at the fly and that's a serious loss of power!

Weight, rolling diameter, it all as an effect on the readings...

[bumography]

i think a car with high torque
wheel weights wouldnt be much of an issue.