Whats the benefits 16" to 15"

[Jack 172]

Ok so i have heard that people with 16" wheels on there cup use 15" for track, what are the benefits i am currently running my standard speedlines on 195/45/16 and i have to chance to buy some o.z f1s on 195/50/15 is this going to be any use to me?

Thanks

 

[Stefan.]

cheap tyres.

 

[Jack 172]

is that all no effect to handling???

 

[GrahamS]

well there will be an effect on the handling due to the increased tyre wall if you have idential model tyres. 15" are good for much cheaper r888's, spec 2s etc. £35 a tyre for uniroyal rain sports on 15"

 

[MartinR]

cheap tyres.

This.

And it will look broke if you don't have it low enough.

 

[Chi]

I'd of thought 16's would be better due to lower profile.

 

[GrahamS]

profile difference is only 5% of width.

 

[Chi]

5% is considerable when your consider the lengths people go to for an extra couple bhp

 

[Jack 172]

so to sum up people use 15"s on track because there cheaper how much difference in price is there for r888 in 15 and 16"

 

[aucky]

I'd of thought 16's would be better due to lower profile.

15" track tyres have a stiffer sidewall though.

 

[Stefan.]

so to sum up people use 15"s on track because there cheaper how much difference in price is there for r888 in 15 and 16"

Surely you could google that?

 

[Chi]

15" track tyres have a stiffer sidewall though.

Would a stiffer 16" profile be better than a 15" profile.

 

[aucky]

Would a stiffer 16" profile be better than a 15" profile.

Couldn't say. Stiffer everything isn't always better. More sidewall gives you more progressive control IME

 

[Jekyll]

The car feels better to drive on 15" over 16" IMO.

 

[Jack 172]

The car feels better to drive on 15" over 16" IMO.

Hi mark
this is what i have been hearing but im just thinking that a ph1 is originally set up for 15" wheels, my ph2 has been set up for 16"

by going from 195/45/16 to 195/50/15 then surely i will be throwing out the speedo or something along them lines just cant put my finger on it.

 

[aucky]

By like 1-2mph at legal speeds.

Just do it, they really do feel better on 15"

 

[Jack 172]

By like 1-2mph at legal speeds.

Just do it, they really do feel better on 15"

aucky do you run 15s on your ph2 then if so what size tyres?

 

[Jekyll]

I ran 15s on my 182 from cup wheels and noticed the difference. It felt different when I went back to 16s again before I sold it. Just do it Jack

 

[GrahamS]

http://www.willtheyfit.com difference in rolling radius is less than 1%. The abs pump uses the same cali value for both tyre sizes

 

[Alex_X93]

15s are so much better overall weight handling improved gearing and acceleration cheap tyres too 16s are junk imo.8)

 

[Jack 172]

15s are so much better overall weight handling improved gearing and acceleration cheap tyres too 16s are junk imo.8)

ive just seen a thread, my 16s are 8.9k a corner and o.z f1s are 9k a corner i thought they would have been lighter?

 

[imprezaworks]

15s are so much better overall weight handling improved gearing and acceleration cheap tyres too 16s are junk imo.8)

Improved gearing and acceleration??? Educate me...

 

[Saamm93]

Would it be worth going from trophy turnis (205/45/16) over to the 15's?

 

[MartinR]

15s are so much better overall weight handling improved gearing and acceleration cheap tyres too 16s are junk imo.8)

?? Please explain

Also to those who say the cars loads better on 15's etc etc.

If that is the case then why did renault not fit that size to the mk2 ph2 then? Surely the cars was setup suspension wise and so on for 16's. And if the benefit was that good on 15's they would have fitted them as standard?

 

[Jack 172]

?? Please explain

Also to those who say the cars loads better on 15's etc etc.

If that is the case then why did renault not fit that size to the mk2 ph2 then? Surely the cars was setup suspension wise and so on for 16's. And if the benefit was that good on 15's they would have fitted them as standard?

this is what I have been thinking, but it seems so many people are going to 15s there must be some hidden secret !

 

[imprezaworks]

people go to 15's when tracking the car imo. My inferno had the standard 16's with cooksports and it looked spot on. If i had planned on doing more trackdays in the car i would have opted for 15's.

 

[twilliams6854]

Improved gearing and acceleration??? Educate me...

A smaller diameter wheel will have the same effect as a slightly lower ratio gearbox as the car will move forward slightly less for each revolution of the wheels due to their smaller circumference. Smaller wheel also means less unsprung weight which will improve handling.

 

[imprezaworks]

Right ok. Maybe I was wrong with my assumption of cheaper tyres being the reason people swap. You would never notice the difference on the road, ever.

 

[MarkCup]

I noticed zero difference if moving from 16s to 15s on my 172 Cup...well, there may have been a slight change, but certainly no different than switching from say a set of Continentals to Michelins.

Main reason for me...price and variety of rubber.

Track tyres are available in the 16 rim size, but, last time I looked, drop to 15 and there's much more choice out there.

 

[imprezaworks]

Forgot to edit my post. Just for clarity i was being a tad sarcastic with my opening line

 

[sidey]

A smaller diameter wheel will have the same effect as a slightly lower ratio gearbox as the car will move forward slightly less for each revolution of the wheels due to their smaller circumference. Smaller wheel also means less unsprung weight which will improve handling.

Yes IF you were using the same section tyre on each wheel size... 45/16 and 50/15 differ by less than 1% on the speedo, as stated above, so surely the acceleration/ gearing argument is moot.

The weight difference between my 182 cup wheels and my 15" TD pro race 1.2s is, however, ubdeniable. The car feels MUCH more agile on the pro race for losing about 4kg per corner. The standards feel like they're tramlining, especially when you overtake, used to occasionally feel only half in control.

Cheap tyres is a great reason for 15s. Massive handling improvement is another.
Don't pay much attention to anyone saying it'll look like a tractor without lowz, i'm perfectly happy with the way mine sits on Sportlines and 15's

 

[ed55j]

http://www.willtheyfit.com difference in rolling radius is less than 1%. The abs pump uses the same cali value for both tyre sizes

This. Barely a difference between the two options. So comes down to looks and the cost of tyres i would say.

 

[MartinR]

But renault spent loads of time and effort on suspension so it worked with a specific wheel from standard.

Yes i can understand that a lighter wheel (which i have fitted) does redhuce unsprung mass. But is the car not setup to carry that extra mass??

So it looks like unless you track your car its pointless

Surely then if going from 16-45's to 15- 50's it will work the same as going up to 17- 40's?? Wheel has to turn far less iirc.

 

[sidey]

Good point Martin... Better directed at those faffing with all their suspension/ steering geometry by lowering heaps?

I'm certainly no motorsport engineer so i'm not going to argue here. We both speak from experience that reducing unsprung weight improves handling... I'd be very interested to try back-to-back some similar weight 15" and 16" wheels (with appropriate tyres as described above). Maybe even 17"s :/
However the smaller version of any given wheel is necessarily lighter... i'm going to assume that the 15 would feel better every time. (assumption being the mother of all f*ck ups, i know!)

All's i know for sure is my car is far better to drive on the 15s

 

[sidey]

Also, did Renault not spend loads of time and effort mapping these cars? That we all know to run like a bag of bolts when cold and have a big ol' flat spot til that magic 5k kick?
Maybe they're not so perfect. Or running to cost/ time restrictions?

 

[imprezaworks]

They were mapped safely and tbh im yet to have one (owned four) where i would describe them as 'a bag of bolts' when cold. Yes they are improved with a decent map but i could probably say that about every car made would be improved by someone who doesnt have parameters to adjust the map etc.

 

[is1]

There is no one line generic answer to this.
The key issues are wheel weight (apparently every kilo saved on a wheel can be multiplied by 4 as it's both unsprung weight and rotated mass) and cheaper/greater variety of tyres.
If you go for one of the superlight type wheels (OZ Superleggera (5.2kg), OZ Ultraleggera (5.6kg), TD Pro Race (6.2kg)) the "real" weight saving can be around 50 kilos.
Bear in mind that those wheels are spinning on the end of the hubs, you are going to notice that weight saving under braking, turn in etc.
I still maintain it's the single most effective change you can make to a car with heavy wheels. The standard 182 wheels are over 10kgs each!

 

[sidey]

Yeah fair point, hyperbole may have got the better of me somewhat regarding the lumpiness!

 

[l33th3tr33]

Remember Renault have to map the car to pass emissions, so if that wasn't an issue then they'd run differently. Plus it's not an expensive car in the first place so they won't be having sleepless nights trying to perfect inlets and whatnot.

It's not a supercar so people need to stop expecting supercar performance. If they wanted it to have 200+ bhp it would have left the factory like that, just be happy with what you have, which is a brilliant car IMO.

 

[jumbo]

17's it is then........