[Vital Velocity]

Ok im going to change my wheels on my 92 3000gt (16's) to the 17" chrome that are also wider.......what is the wieght difference and am i going to lose any performance?..... im planning on taking out my spare tire and jack once i get the new wheels on it.......will this make up for any weight difference?........could these new wheels maybe help my performance at least off the line, because when i floor it off the line i get some decent wheel spin because my tires are cheap ass tires.......when i change the wheels im gaining .... .5 of an inch in width and the tires that im gonna get are going to be z-rated.....so basically what im wondering is am i going to be losing performance or gaining it?

 

[Johnny99VR4]

Im pretty sure that the heavier the wheel, the worse. And taking out the jack and the spare tire wont be the same as taking weight off your rims mainly because unsprung weight is very important when it comes to many performance stats. I think it improves steering response, braking, acceleration and some others maybe? help me out guys. This is just what I think.
Johnny

 

[edge]

Your right - unsprung weight of the wheel is important for handling and the rotational inertia for accel and braking. A few members that have gone to the lightest wheels have noticed a difference. I seem to remember that a SSR 16 inch forged wheel at 15 lbs compared the OE wheel at 45 lbs.

 

[Vital Velocity]

ok well does anyone know the difference in the 16' from a 93 to the 17 chromes from a 93 vr-4?

 

[VIN_DIESEL]

I suggest not getting chrome rims. Chrome looks good but its pretty heavy.

 

[rt turbo]

my 18's are only 20 lbs a piece.

 

[VIN_DIESEL]

Chrome 18's at 20lbs each?! I find that really hard to believe. What brand are they?

 

[rt turbo]

they are enkie rpo1's NON-crome. they are some sorta shiny silver finish, and believe me they are only 20 lbs a piece, i weighed them myself. the tires weighed more than the rims did!

 

[VIN_DIESEL]

oh , ok. I thought you meant you had chrome 18's. Yeah , RPO's are light and desent looking

 

[rt turbo]

naw, crome is heavy. get polished rims if you want shiny and semi light weight

 

[DOCRADLEY]

My 19x9 AVS model 5's weigh in at 22 lbs. each. They are silver, not chrome. AVS supposedly has a chrome version that is nearly as light.

Just as important as the static weight of the wheel is the effect of moving the rotational mass further from the center line (the axle). This increases the moment of inertia of the wheel which results in greater energy being required to accelerate the load (your car) and brake the load (it does not effect the steady state operation of the car since once you put the energy into the rotating mass there it stays until you try to change the cars speed, up or down, I'm ignoring friction losses here). So if you effectively increase the net rotational mass (regardless of whether this is just the static weight or the effect of moving the weight from center line or both) you will make the car accelerate more slowly or need more power to accelerate it at the same rate as it currently has. Likewise you will need more braking distance from a given speed or changes to the braking system that increase stopping power.

Assumming that you increase the contact patch with a larger tire and that this tire has equal or better characteristics to the one it replaced you would see traction and handling benefits.

I was able to go from a 17x8.5 to the 19x9 with very little change in the net rotational mass because both the tire and the wheel were lighter and just as importantly the wheel geometry also changed such that I was placing less of the composite mass away from the center line.

The tires are a big factor in the rotational mass equation because they typically weigh more than a lightweight wheel and are further from the center line than the wheel.

Hopefully this explanation also makes clear that you would need to drop significant static weight (unsprung) from the car to offset the effects of increases in the rotational mass.

Chris
1994 VR4

 

[ECM3500GT]

wheel weights

i have 18x9 volk racing te37s (forged magnesium) and they only weight 13lbs each. these are the untimate wheel for reducing rotational weight

 

[VIN_DIESEL]

wow , only 13 lbs. Thats amazing. My rims are forged as well but they weigh about 25lbs , I never put them on a scale but i picked them up when they had no tires and that was my estimate.

 

[ECM3500GT]

te37s

yeah, before i put them on the car, i actually put them on a scale and they weighed like 13 1/2 lbs (without tires obviously)

 

[VIN_DIESEL]

BTW , where in NY are you?

 

[ECM3500GT]

location, location, location

i live on long island, about 20 min. from dpa (deer park ave.) if you are local, or feel like driving, i think there is a meeting on dpa either fri. or sat. but i'm not sure which one.

 

[pokey]

if u email me. i will send ya a pretty big list of wheel weights, manu, sizes etc. im not at that puter right now.

 

[Trevor]

Forged magnesium TE-37's huh? That's strange...I thought they're only availiable in forged aluminum. They're not on Volk Racing's japanese website. So where did you get them, how long did they take to arrive, and how much did you end up paying for them?

 

[Trevor]

TTT...I want some info about these magnesium rims.

 

[ECM3500GT]

te 37s

yeah, they come in forged magnesium, just look in any current issue turbo mag. they are used specifically for the jgtcc (japanese grand touring car championship). they took about 4 months to get here, i got them through east coast motorsports in ny (631)736-3852, and they cost me about $3000 w/o tires. i'll be happy to answer any other ?s about my car, i'm very proud of it. peace