BIGGER WHEELS = SLOWER CAR???, can you say INERTIA??? Options

[pflau]

just wondering.... do bigger wheels make the car accelerate slower and stop longer because of the greater rotational inertia??? yes I know big wheels make steering more responsive.. so maybe going from 15 to 16 makes sense.. but 17 and 18???? do some people sacrifice performance for look???

phil

[hata]

in my opinon..

what u said in ur paragraph was correct. I belive that having over 16" wheelz can decelerate our cars at the get go...not too bad but you can feel it since our cars have a weak motor (talkin ST...not sure about the GT).

[boosted_K2]

remember weight is a big factor in that equation too, and where the weight is centerally located on the rim, whether it be on the outer diameter or centered more in the middle of the rim... but your overall assumption is correct.

[Neipas09]

I've heard that you can go up to 17s without sacrificing exceleration.

[boosted_K2]

QUOTE (Neipas09 @ Apr 13, 2003 - 12:38 AM)

I've heard that you can go up to 17s without sacrificing exceleration.

if you are willing to do the math and figure out what setup would relate to the ideal rim diameter/width/centripital force and acceleration/ tangential force and acceleration/ any other relivant equation and find a rim that matches the specs you are looking for then yes, you can go up to 17s w/o sacrificing performance... but to flat out say that you can go to 17s without sacrificing performance is false. i know first hand, i lost alot of acceleration when i went to my 17" enkeis.

[No0bOne]

There's an explanation for bigger wheels=slower cars that i've discussed with a shellow(female car enthusiast). I'll find it and post here if it's still there. gimme a moment

[jontechie]

QUOTE (K2_Celica @ Apr 12, 2003 - 10:45 PM)

QUOTE (Neipas09 @ Apr 13, 2003 - 12:38 AM) I've heard that you can go up to 17s without sacrificing exceleration. if you are willing to do the math and figure out what setup would relate to the ideal rim diameter/width/centripital force and acceleration/ tangential force and acceleration/ any other relivant equation and find a rim that matches the specs you are looking for then yes, you can go up to 17s w/o sacrificing performance... but to flat out say that you can go to 17s without sacrificing performance is false. i know first hand, i lost alot of acceleration when i went to my 17" enkeis.

Man you sound like an extra from "star trek".

I'm wearing 17"s and I think my standing starts would
be compromised even more if it wasn't for my 4 wheel drive...

This post has been edited by jontechie: Apr 13, 2003 - 9:18 AM

[95STCelica]

Our cars don't have enough torque to sufficiently push 17, 18 and 19 inch wheels...so it slows us down..(talkin about STs here)

[pflau]

hey maybe I worry too much...

let me think about it again.. that little extra inertia at the perimeter of the wheel would be nothing comparing to the inertia of the 2700lb car acting on the tire..

just think about it... if you were to cruise down the road and drop the clutch.. what keeps the wheels spining is the inertia of the car acting on the tires acting on the wheels.. so what is that extra 20lbs for a beefier set of wheels??? you can compensate for that by losing weight.. (or picking a skinnier rider.. )

phil

[Silver94CelicaOw...]

QUOTE (pflau @ Apr 13, 2003 - 11:21 AM)

hey maybe I worry too much... let me think about it again.. that little extra inertia at the perimeter of the wheel would be nothing comparing to the inertia of the 2700lb car acting on the tire.. just think about it... if you were to cruise down the road and drop the clutch.. what keeps the wheels spining is the inertia of the car acting on the tires acting on the wheels.. so what is that extra 20lbs for a beefier set of wheels??? you can compensate for that by losing weight.. (or picking a skinnier rider.. ) phil

hahahaha, youre right about a skinnier rider....when i have 1 or 2 people in the car, i can feel the thing fighting like hell to speed up It's so much quicker feeling when its just me- im only 150 pounds.

[sirrahtap]

QUOTE (pflau @ Apr 13, 2003 - 11:21 AM)

hey maybe I worry too much... let me think about it again.. that little extra inertia at the perimeter of the wheel would be nothing comparing to the inertia of the 2700lb car acting on the tire.. just think about it... if you were to cruise down the road and drop the clutch.. what keeps the wheels spining is the inertia of the car acting on the tires acting on the wheels.. so what is that extra 20lbs for a beefier set of wheels??? you can compensate for that by losing weight.. (or picking a skinnier rider.. ) phil

i disagree. the best place to save weight is in moving parts on your car. so take wheels. your car will be faster if you lose 20 lbs in the wheels vs. 20 lbs in the hood, fenders, seats, gut, etc.
reason: if you jacked up your car and had no restriction on your wheels they would spin slower with heavier wheel that with lighter ones. the moment of interia increases with a heavier wheel. it also increases when the weight is concentrated farther from the center of the wheel. so not only does a heavy wheel slow you down just like a heavy hood or a heavy you does, but it also robs power straight from the engine.

[97GTinKC]

But its not the wheel diameter that matters, its the overall height (and weight) of the tire/wheel package, an 18" wheel with a 35 series tire could be the same overall height as a stock 205-55-15 and might weigh more or less, depending on brand, as long as the weight and overall diameter are the same, it should make no difference in acceleration. (other than maybe better traction with a hi-perf tire) there is a lot of variation in weight between brands of both tires and wheels. thats how Centerline got so popular in the streetrod market, they had one of the lightest, strongest wheels available, (ugly though),,,The old original Cragar Mags looked good, but they were HEAVY!
You also need to remember, the wheels are UNSPRUNG weight, vs the body/eng/trans being SPRUNG weight (meaning they sit ON the springs), the less UNSPRUNG weight the better. Say you hit a bump, if the wheel/tire/spindle assembly weighs 50lbs rather than 40, more of the energy from the bump will be tranferred to the body thru the spring, giving a rougher ride, worse handling. with lighter wheel/tire setup, the shocks and springs can control the bumps better since there is less moving mass. (this is actually where drilling the rotors started, they were looking for less unsprung weight)

[94celicaguy]

i have tenzoR's apex-5 18's and i cant really tell a difference besides in my handling. i did have 15's b4.

[hioctane]

What about 16s ?? I have the gts rims. I used the miata calculator thing and i only have a 1.3% difference in the speedometer. I'm just curious; would getting 17s or 18s make the car handle differently?

[pflau]

QUOTE (97GTinKC @ Apr 18, 2003 - 9:40 PM)

(this is actually where drilling the rotors started, they were looking for less unsprung weight)

what are you talking about.. drilled rotors are for heat dissipation.

[boosted_K2]

QUOTE (97GTinKC @ Apr 18, 2003 - 11:40 PM)

But its not the wheel diameter that matters, its the overall height (and weight) of the tire/wheel package, an 18" wheel with a 35 series tire could be the same overall height as a stock 205-55-15 and might weigh more or less, depending on brand, as long as the weight and overall diameter are the same, it should make no difference in acceleration. (other than maybe better traction with a hi-perf tire) there is a lot of variation in weight between brands of both tires and wheels. thats how Centerline got so popular in the streetrod market, they had one of the lightest, strongest wheels available, (ugly though),,,The old original Cragar Mags looked good, but they were HEAVY! You also need to remember, the wheels are UNSPRUNG weight, vs the body/eng/trans being SPRUNG weight (meaning they sit ON the springs), the less UNSPRUNG weight the better. Say you hit a bump, if the wheel/tire/spindle assembly weighs 50lbs rather than 40, more of the energy from the bump will be tranferred to the body thru the spring, giving a rougher ride, worse handling. with lighter wheel/tire setup, the shocks and springs can control the bumps better since there is less moving mass. (this is actually where drilling the rotors started, they were looking for less unsprung weight)

very true, except the crossdrilled/slotted rotor part.

[boosted_K2]

QUOTE (hioctane @ Apr 19, 2003 - 1:01 AM)

What about 16s ?? I have the gts rims. I used the miata calculator thing and i only have a 1.3% difference in the speedometer. I'm just curious; would getting 17s or 18s make the car handle differently?

it all depends what kinda rubber you get, and what the change in width is.

This has to be the best tech discussion 6gc has ever had! hahaha!

[ghostdog]

QUOTE (K2_Celica @ Apr 19, 2003 - 7:47 AM)

This has to be the best tech discussion 6gc has ever had! hahaha!

LOL. I had the same thought while reading this thread.

[macavely]

just remeber that if change you wheel you have to get a tire that make the wheelandtire the same height as your stock tire and wheels. cause if you don't your speedomiter will be off.

[hioctane]

QUOTE (K2_Celica @ Apr 19, 2003 - 7:47 AM)

QUOTE (hioctane @ Apr 19, 2003 - 1:01 AM) What about 16s ?? I have the gts rims. I used the miata calculator thing and i only have a 1.3% difference in the speedometer. I'm just curious; would getting 17s or 18s make the car handle differently? it all depends what kinda rubber you get, and what the change in width is. This has to be the best tech discussion 6gc has ever had! hahaha!

Yeah i put in the width, wheel size and everything in the calculatator thing.