Please settle this argument!

[Dansta]

Me and matey at work are arguin over mods.
Please answer this.....
17s...........sometimes slow your car because:

A: Heavier
or
B: Bigger (rotation and stuff!)

GRrrrrrrr???!?

Cos im lookin to get 17s but he recks itll slow me down, but ive told him im lookin to get lighter ones than the existin cup ones!

 

[Tom]

Sometimes it can slow you down

but 17s on a cup wont make any diffrence (except less wheelspin)

 

[Zidan]

Higher top speed. Slower acceleration.

 

[RobFenn]

It will effect acceleration, but not noticeably. The main difference will be ride quality. But theyll look better!

What have you got in mind then?

 

[KDF]

I would go for secret option C

C: All of the above

If the wheel is heavier its gonna slow ya down, and the larger rotation can slow you down a bit aswell, but then there is the extra traction that your gonna get + less wheelspin, so it kinda evens out, and 17" looks the dogs dangles so ..... get the 17s man !!!

 

[Dansta]

but does it slow accelleration because of they are heavier or size, cos im gettin lighter ones?

 

[VX-Tony]

One thing you can do is make sure they are lighter, and then get a thiner tyre so that the actually radius stays the same. This is also a good idea so you dont screw your speedo some.

 

[Tom]

Paul the guy i bought my 16s (your current wheels) had the 17 inch versions on his he said he didnt notice a diffrence except less w\s

 

[RobFenn]

Its the size of the wheel, think about it, the circumference is larger so it will take longer to get it going round. They might also cause a bit of added transmission strain but nothing serious.

 

[clean16v]

some thing that everyone forgets is the diameter of tyre. 15x6 have a lot less rolling resistance then 17x7.5!! remember on push bikes, the racers had really thin tyres(for less resistance and higher speed/acceleration) but mountain bikes had big chunky tyres!!

 

[KDF]

I wondered why I was always knackered when I got on my mountain bike..

maybe it cause I am lazy though ?

 

[Dansta]

so lighter 17s wont make a huge diff on performance then!

i hope! gulp!

17s it is, i think, lets pay the insurance first shall we! lol!

 

[Zidan]

Like Tony says, just get a lower profile tyre so the circumference of the wheel stays the same. That will also keep things like your speedo accurate as well.

 

[Nick Read]

Theres a lot of different factors. Regardless of whether its 17 or not ( I dont know what youre comparing them to!), in general:

LARGER WHEEL/WIDER TYRE

Larger overall diameter gives longer gearing overall, making higher top speed theoretically possible but slowing acceleration.

Generally weighs more so is harder to accelerate; this also works in reverse- the wheel is more difficult to decelerate so braking is harder. Will have slightly more speed stability because the greater momentum of the wheel requires less power input to maintain speed (like a heavier flywheel).

Generally wider tyre gives more outright grip and greater heat carrying capacity (why you dont find many 135 tyres with a Z speed rating!). Wheelspin less likely with a wider tyre which almost counteracts the larger diameter hurting acceleration. More likely to aquaplane.

Lower profile allows less sidewall flex and reduces ride comfort. Up to a limit (beyond that of a normal profile tyre on a smaller rim) handling is better because the tyre maintains its shape more effectively. Breakaway at the limit can be less progressive and more snappy than a smaller wheel/higher profile tyre combination.

Does this sum it up?

 

[Nick Read]

BTW having a larger wheel/tyre doesnt automatically guarantee a higher top speed...you need enough power to be able to overcome wind resistance at higher speeds.

 

[Dansta]

Thanks Nick!! geeez you know about wheels!

i just want my cup to look diff! grrr but really dont wanna jeapodise performance!

Was looking at 17s like your nick, or some diff speedlines!

Grrr maybe some engine mods first..

 

[Frosty]

No - 17s will not increase top speed!

If you have 17 inch wheels, the tyres MUST be a lower profile to make the entire wheel size (rims + tyres) the same diameter. If you dont, the speedo will be wildly inaccurate.

No one has mentioned handling yet either. I know 1 guy who has a Pulsar GTi-R and he went from 14s (standard) to 16s to 17s and then back down to 16s again because 16s were the optimum for the car. They corner much better.

Its something you just have to try and see. The Clio may love 17s, or it may refuse to go round corners at anywhere near the usual speed.

DannyBoy - go for it and let us all know what happens.

 

[paul172cup]

Go for the 17s

My car feels much better. Handling is improved and a lot less wheelspin plus it looks so much better.

It has made the ride a bit harder but even though the car is lowered it drives ok.

 

[RobFenn]

I cant believe that Paul to be honest, the cup was designed for 16s, the chance of it performing better with different sized wheels is..well theres no chance! Its the suspension which has made it better.

The width of the wheel will effect top speed, this was magnified on the Smart L2B run where Smarts on standard wheels were 5mph faster (86mph!) top whack on the motorway compared to brabusd Smarts.

 

[The Monk]

volks racing or racing hart if you looking for top quality and light weight, although it come at a price

 

[Eddd]

The most important thing is the outside diameter or circumference of the tyre. There are tyre charts which show the different sizeds wheels and tyres so that you can match the original OD. Keep the OD the same and the gearing and speedo will be more or less spot on.

In an underpowered car, the greater drag of a wider tyre will slow the car. See the last of the "real" minis! The car will stick better in most conditions but aquaplane at lower speeds all other things like tread depth and tyre design being equal if the tyre is wider.

Unsprung weight is bad and you really want to keep this to a minimum. Look around and buy the lightest possible quality wheel. Think twice about going for the biggest possible diameter.

There is an optimal apect ratio for the street. Look at the rally cars for a bit of guidance here. They run a taller sidewall since they have to perform in real world conditions, just like our cars do. If they ran on race tyres, they wouldnt make it past the first pothole. What looks really great usually would fare better on a track than on a real road.

The same can be said for lowered suspensions. Too many are far too low for road use. Look at the ground clearance on the rally cars for guidance here as well.

 

[Dansta]

thanks evryone! im still stuck tho! lol!

i think ill drop her 30mm for now with some tints and engine bits! and have to get use to tryin for traction in 1st & 2nd! grrrrr

 

[RobFenn]

You could always try some expensive tyres. Dropping it 30mm will make the wheels look bigger anyway.

 

[Cord-172]

I didnt notice any change at all in the acceleration of my car when I put 17s on. It surely has to be a tiny percentage. Lose half a stone in weight and it will probably even out to exactly what it was!!!

 

[paul172cup]

Robfenn. The suspension did make a lot of diffenance to the handling as i still had the 16s on, but when i put the 17s on the steering feels more positive.

If the Cup was designed that well there would be no need for Renaultsport upgrades

The 17s have the same 7" wide rim as the 16s.

 

[steve_rt]

with my lowly RT on 15s, i havent gained any top speed, more like lost it (about 10-15mph), but i suppose thats becuase of the cack engine!

cant really add to what nick said, but in my experience with these i can certainly grip more round bends (and i certainly would have crashed on the a2 the other day when i started losing it coz of swerving out the way of a fox if it werent for the extra grip!), but in the wet they aquaplane like sh*t! have to be extra careful in the snow and ice aswell, no give there either!

go get the 17s man, theyll look the nuts

 

[Nick Read]

Generally the bad effects of big rims are felt more on underpowered cars that arent designed to be chucked around so much. The extra drag of an extra 10mm of tyre width on each corner might trouble a Smart, but its not much bother to a 172 Cup. Getting the same rolling radius as your factory wheel is a laudable aim, but at the end of the day, impossible. And before anyone compares one profile with another and says theyre the same, the differences in tolerance between tyre brands will take care of that argument. It is a fact that once you start to upsize your rims you might be able to stay close to your factory radius but it will always be at least a little bit taller than the wheel you started with.