Wheel Weight

[Marshan]

Looking to get new rims. Does anyone here have any experience with the weight of the wheel?

I'm currently running on stock 17" (no idea how much these weight) and looking to go 19". My mates telling me heavy rims can be felt to decrease performance.

I'm not too sure how it will affect our cars as we kinda have a bit of torque to play with. But looking at some Stance sc-5ive and i'm reading their about 29-31pounds (rim only) for the 19".

Is that too heavy?

Cheers guys.

[sonicii]

Spinning the wheels up to speed requires some power, heavier wheels will require more power, not sure how much you will actually feel this, but it is a factor.

The other issue is unsprung weight. heavier wheels add to unsprung weight and create more initeria in the suspension, meaning the suspension won't be able to react to changes in the road surface as quickly. Again, I am not sure how much you will actually feel this..

This is why people like the Rays 19s, as they are quite light.

[Marshan]

Spinning the wheels up to speed requires some power, heavier wheels will require more power, not sure how much you will actually feel this, but it is a factor.

The other issue is unsprung weight. heavier wheels add to unsprung weight and create more initeria in the suspension, meaning the suspension won't be able to react to changes in the road surface as quickly. Again, I am not sure how much you will actually feel this..

This is why people like the Rays 19s, as they are quite light.

Yeah i wonder if anyone has experienced this. Or whether or not we can feel the difference for a set that's 30 pound.

My mate's also saying that since our car has a bit of torque it won't matter that much. Might be something trivial.

[djr81]

Yeah i wonder if anyone has experienced this. Or whether or not we can feel the difference for a set that's 30 pound.

My mate's also saying that since our car has a bit of torque it won't matter that much. Might be something trivial.

As already stated it wont make a bit of difference to your acceleration - it is another 40lbs you are adding to the weight of the car - not a big figure given the thing will weigh over 3000lbs to start with.

What it will do is degrade the cars ride and its handling. The heavier the tyre/rim/brake/suspension arm set (refered to as unsprung weight) the harder the suspension has to work to keep the tyre on the road. So your 30lb wheel (which is thereabouts of 10lbs heavier than a good 17" rim) will have an effect.

[PN-Mad]

This is why good quality Jap rims are expensive, and knock offs are cheap- actually, just one of many reasons.

My 19" SSR rims are 8.7kgs each(or 19lbs). Even they are not the lightest option- some RAYS rims are even lighter.

Good question. What the other guys have said is correct- your increasing unsprung weight. Remember you have to fit a tyre too, which will be wider and heavier as well, compared to stock.

[Marshan]

This is why good quality Jap rims are expensive, and knock offs are cheap- actually, just one of many reasons.

My 19" SSR rims are 8.7kgs each(or 19lbs). Even they are not the lightest option- some RAYS rims are even lighter.

Good question. What the other guys have said is correct- your increasing unsprung weight. Remember you have to fit a tyre too, which will be wider and heavier as well, compared to stock.

I don't track, just daily driving. Not sure if the effect will be very noticeable in respect to ride stiffness or something very trivial....30 pounds are pretty heavy for a wheel imo.

Any idea what the OEM wheel weight are for our cars (i'm guessing 20-21pound for the 17" as mentioned above)?

Edited August 20, 2012 by Marshan

[PN-Mad]

Its not about tracking the car and looking for every last 1/10th of performance.

Upgrading wheels and tyres smartly means looking into a myriad of different areas. Unfortunately the "flat cappers" have turned it into looking at one area- "stance".

Things to think about in reality are weight both of wheel and tyre, clearance from suspension structures, Clearance from guards, clearance from brake callipers, Rolling diameter, tyre profile, and width. Plus availability of tyres in chosen size. And lastly Legality.

30lbs is heavy for a wheel, but not the heaviest by far. Imagine all the things the wheel is connected to- suspension, brakes, gearbox, engine, wheel bearings. Changing wheels effects all those parts in different ways. I'm not saying changing wheels will blow your engine up, but pointing out that if you chose a setup with a greatly increased rolling diameter, then expect a decrease in performance. Heavier wheels, your shock absorbers will work harder.

TL/DR;

do your research, going from 17s to 19s will effect the way your car does just about everything.

[sonicii]

As already stated it wont make a bit of difference to your acceleration - it is another 40lbs you are adding to the weight of the car - not a big figure given the thing will weigh over 3000lbs to start with.

It isn't just the additional weight to the car overall, it is a rotating mass the engine has to spin.

Similar to fitting a lighter flywheel, it is only a tiny difference in overall car weight, but the less mass the engine has to spin, the less power is consumed in doing just that.

But as said, I don't know how much you will notice heavier wheels, as they don't spin anywhere near as fast as a flywheel.

I would also suggest you ensure you select the correct size tyres so the overall wheel diameter is the same.. otherwise you will have all sorts of issues with your speedo..

[Marshan]

Yeah figured that one out. Anyone heard of Koya wheels or XXR's? good or bad?

Edited August 20, 2012 by Marshan

[t5iv]

Form>Function... Just sayin'

Seriously though, heavier wheels will cause more strain on components but it isn't a significant amount. You won't feel much difference and it comes down to what you want. As with anything, you will pay a premium for quality/brand name.

[n15m0]

http://www.wheelweights.net/

4000+ wheels with their relevant weight

[Marshan]

Quick question.

19" OEM rays? Which would weight lighter than the 17" i have now. Any decrease in performance?

I know that going from 17 to 19 is a big move and will have significant effect on performance and handling, but not sure how it will turn out if the larger wheels are lighter?

[iamhe77]

Why would there be a decrease in performance.

Assuming the rolling diameter is very close and the 19's are wider (usually the case with OEM), the main differences will be a greater rubber contact patch due to the wider rim-thus wider tyre (unless you are doing the stretched thing) and a harsher ride due to the lower profile tyres on the 19's.

Also you may notice a small decrease in fuel economy due to the larger contact area with the road (I lost around 0.5km/L).

Reference: I went from OEM 17's on my Stagea to Buddy Club 19's. Both weighed around the same but the BC have 245's on them (9" wide) where as the 17's have 215's on them (7" wide). Car handles much, much better with the new rims... but a lot of that comes down to the tyres.

[sonicii]

^^ this.. no reason for performance decrese.. just rougher ride, as the lower profile tyres will absorb less..

Although if you run the same tyre pressure, the contact patch size will be the same.. just wider and shorter for wider tyres. Fuel economy may come down to the type of tyre.. maybe also a slight difference in outside diameter??

[iamhe77]

hmm... I am curious as to how you come to the conclusion that a wider tyre on a larger diameter rim will have the same contact patch as a smaller narrower rim.

I just can't see how the contact patch would be shorter for the tyre on the larger rim. Wider, yes of course... but shorter? Explain?

[sonicii]

Contact patch size is direclty related to tyre pressure and weight on the tyre, not tyre width. A narrow tyre will have a narrow but longer contact patch, a wider tyre will have a wider but shorter contact patch, assuming the same pressure and weight. The contact patch area remains the same.

There are plently of articles about it.. but a quick search came up with this.

http://autospeed.com/cms/title_Tyres-Grip-and-All-That/A_108915/article.html

[Marshan]

Contact patch size is direclty related to tyre pressure and weight on the tyre, not tyre width. A narrow tyre will have a narrow but longer contact patch, a wider tyre will have a wider but shorter contact patch, assuming the same pressure and weight. The contact patch area remains the same.

There are plently of articles about it.. but a quick search came up with this.

http://autospeed.com...15/article.html

I've heard of something like that too. Kinda makes sense.

I remember reading a thread on one of the 350z forums where someone was explaining that the OEM 17" might have a slightly larger contact patch than light weight aftermarket 18" due to the weight and negated grip of the larger wheel. I think you are right on the tyre pressure and weight bit.

Edited August 23, 2012 by Marshan

[Marshan]

Does anyone know if any guards will be rolled if we went for an offset of 20 for the coupe?

Or should i just stick to the stock fr 30 and r33 (i think it's +33 or could be +35 for the rear)

[t5iv]

Does anyone know if any guards will be rolled if we went for an offset of 20 for the coupe?

Or should i just stick to the stock fr 30 and r33 (i think it's +33 or could be +35 for the rear)

Wheel width? Rim diameter?

[Marshan]

234/35R19 and 245/35R19 on stock suspension