True effect of rims??

pagan · Post by **pagan** » Mon Jul 05, 2004 7:51 pm

Howdy people

i was wondering lately about rims and what effect they have, since i don't know a great deal about them aside from what looks good maybe you folk can help.

when i bought my FTO it already had the ROH international ADRENALIN set on the car. recently i had my brakes and disks machined to get rid of an annoying squeel when braking. (the brake pads and the disks were glazed and so rubbed together like glass) anyhoo when the wheels where taken off i noticed that it had a respectable amount of wieght in each wheel. this abviously adds wieght to the car and lowers performance, but does it also mean that the rims are stronger and less likely to snap under high cornering pressure. or are there very strong light wieght rims out there. basically what i wish to know is, can you have the best of both worlds. (obviously money is a factor but taking that away) a light wieght rim that effects the cars wieght mnimally and is unlikely to snap.

Slither · Post by **Slither** » Mon Jul 05, 2004 7:58 pm

Sure the weights rnt just normal wheel weights??
thats what they do when they do a wheel balance, place weights on the rims until theyu r weighted correctly

As for your wheels snappin, can't say ive ever heard of it done before, sure its possible but id think other things would give way first before your wheel would snap!!!

mrx · Post by **mrx** » Mon Jul 05, 2004 10:59 pm

Wheel weight does detract from performance. Rotational mass is the enemy of acceleration, and to a certain extent, top speed. The less weight that the engine has to try and turn, the faster it will do so.

As for the wheels breaking, it is not something that I have ever heard of. There would have to a major defect in the construction of the wheel, and hit something extremely hard for that to happen.

Best of both worlds? It depends on whether you want you car to look as good as possible, or be as fast as possible. As you spend most of your time either a) parked; b) in traffic, or c) doing the speed limit, I would say that the asthetics are more important than the pure function.

And really, invest the money you don't spend on the ultra lightmeight magnesiuym wheels on some good tyres. This will make more difference during breaking and cornering, making you car both safer and quicker.

ruchi · Post by **ruchi** » Mon Jul 05, 2004 11:57 pm

pagan wrote:i noticed that it had a respectable amount of wieght in each wheel. this abviously adds wieght to the car and lowers performance

Do you mean each wheel was heavy or that each wheel had a lot of wheel balancing weights on them?

If it has a lot of wheel balancing weights on it, it means that the wheel and tyre combo is quite unbalanced. One or both has been made with uneven weight distribution. This is a sign of a lower quality product, but not a major issue, as the wheel balancing weights will help.

mrx wrote:Wheel weight does detract from performance. Rotational mass is the enemy of acceleration, and to a certain extent, top speed. The less weight that the engine has to try and turn, the faster it will do so.

While it is true that heavier wheels will increase inertia (make it harder for the engine to turn the wheels), this is not the big issue, in fact it is quite minimal.

The big issue is suspension and handling.

In simple terms the weight of all those items that are supported by the suspension are said to be "sprung weight" while all those things which sit below the suspension are "unsprung weight". To simplifly this even further, the body of the car and everthing in it is "sprung weight" i.e. it rests on top of the suspension, while the wheels are "unsprung weight" i.e. they have no suspension.

Why does this matter? Because the heavier the wheels are (the unsprung weight) the more inertia there will be with the suspension (i.e. the suspension will not be able to react as quickly). This means your handling will decrease especially on bumpy roads or around corners.

So while your performance will decrease, it is not so much speed performance, the big issue is suspension and handling performance.

FTO338 · Post by **FTO338** » Tue Jul 06, 2004 1:12 am

In all reality, it depends how much power you putting through your wheels.

When i had my 300zx, i was running 19psi, & with standard wheels, they spin like house on fire, so therefore i lost a lot of performance on acceleration. And then for look i put on some 19" 'bing bling', because they are heavy, i didn't have any wheel spin & able to accelerate much faster then the 16".

So the lesson here is to find the right balance between wheels & KW, not the weight.

Reguarding the strenght of the wheels, its all depends on material & how many pieces it made from. The toughest and lightest are the single piece, which mean the whole wheel/rim is made out of one piece of metal/material. The weakest & usually heaviest are those three pieces type (join by 3 pieces of metal/material, which what you get from lots of wheels & tyres place these days.

Those three pieces rims wheel will buckles if you go through lots of pot holes in a very short time.

pagan · Post by **pagan** » Tue Jul 06, 2004 8:57 am

yep to be honest i had never heard of a rim snapping (aside from maybe in an accident or something, i know of a guy who snapped his rims but he hit a gutter dead on at high speed, the rims were nothing compared to the car i bet!) maybe he ment buckling the rims. my rims are one piece, and from what i hear ROH is a pretty good mark so i doubt they are cheap. then again what would i know. oh and yeah each wheel seemed heavy, compared to the rims i had on my vl which for memory didnt have so much wieght and they were also 17". maybe its nothing and i was just taken by surprise, maybe all the newer rims are heavy.
and by heavy i dont mean you cant pick them up, just that you can certainly feel the wieght when you do.
oh well, if anything i learnt from your posts on what effect they have. thanks guys

G1 · Post by G1 » Tue Jul 06, 2004 11:20 am

the stock rims are very light weight weight actually, i went from 17" bling blings to 16" stockies, coz i think they look good anyway and they will definitely handle better

but in the end we're not driving race cars here (well most of us)... for normal street use youre not really gonna notice much difference if at all

MADFTO · Post by **MADFTO** » Tue Jul 06, 2004 5:25 pm

*edit* =)

Anyways, what ruchi said =P There's also a tire stability thing at high speeds with lower profile tyres (less amount of flex) but that's got to do with sizes not weight.

pagan · Post by **pagan** » Tue Jul 06, 2004 8:48 pm

runner? what runner?

payaya · Post by **payaya** » Sat Jul 10, 2004 10:29 pm

FTO338 wrote:In all reality, it depends how much power you putting through your wheels.

When i had my 300zx, i was running 19psi, & with standard wheels, they spin like house on fire, so therefore i lost a lot of performance on acceleration. And then for look i put on some 19" 'bing bling', because they are heavy, i didn't have any wheel spin & able to accelerate much faster then the 16".

So the lesson here is to find the right balance between wheels & KW, not the weight.

Reguarding the strenght of the wheels, its all depends on material & how many pieces it made from. The toughest and lightest are the single piece, which mean the whole wheel/rim is made out of one piece of metal/material. The weakest & usually heaviest are those three pieces type (join by 3 pieces of metal/material, which what you get from lots of wheels & tyres place these days.

Those three pieces rims wheel will buckles if you go through lots of pot holes in a very short time.

you do know running tyres at low PSI sometimes reduces grip level? 19PSI is really low, and i know in my falcon 19PSI would decrease my grip levels.

Slither · Post by **Slither** » Sun Jul 11, 2004 1:29 pm

I think Kev was reffering to his boost level

RallyMad · Post by **RallyMad** » Tue Jul 20, 2004 2:49 pm

Yeah I think the most important thing here is that if your not using your car regularly as a hard core race car expensive light weight wheels aren't really worth it. You wouldn't be driving the car hard enough to gain the benefits, at least I'd hope not.

From memory some of these wheels can start at $1000 or more each.

I've seen wheels buckle and break, but that is from driving really hard in rallies and the like. FOr the road really only crashing should damage a rim. As for the strenght thing. I would have thought that some three peice wheels would be stronger than some cheap one peice rims. No arguements though that forged one peice rims are both strong and light, but I've seen most race cars using two or three peice rims I think, so I would think they would still be very strong, especially for events like Targa Tasmania.

FTO AUSTRALIA

True effect of rims??

True effect of rims??

Re: True effect of rims??