wheels, tyres and grip
Discussion
Having searched the pages i've read a bit about wheels... and there are many opinions, i'd like to open that one again if i may:
What is this experience of drivers who have moved from 15 and 16 to 16's all round? how does it affect the already (in my eyes) poised handling, does the steering become heavier with a bigger wheel up front? and what about going all the way to asethetic 17's do they destroy the comfort? and one last thing; tyres; i need a new set and i want as much grip as possible... what do i get for the corners?
What is this experience of drivers who have moved from 15 and 16 to 16's all round? how does it affect the already (in my eyes) poised handling, does the steering become heavier with a bigger wheel up front? and what about going all the way to asethetic 17's do they destroy the comfort? and one last thing; tyres; i need a new set and i want as much grip as possible... what do i get for the corners?
I made the move to 16's all round 18 15 months ago. Tyre width change from 205/225 to 225/245. I detected no change in the weight of the steering, mine has power steering. It is difficult to give an opinion on grip and handling because I changed from Bridgestone to Toyo at the same time. The car is better in a very subtle way, it just feels generally more planted on the road and I feel that I can push the limits better. The oversteer/understeer is about the same. Perhaps a little more understeer on the track when tyre pressures are significantly higher. The ability to catch and control oversteer is far better on the track.
backslide said:
what is UHP rubber?
Ultra High Performance; the industry name for the top of the range sports car rubber. eg www.dunloptyres.co.uk/ourTyres/car/searchResults/SPSportMaxx/
I'm currently running on A539s that came with the alloys (17",) perhaps not the top recommendation, lol.
For example, in your Q 16s at the front would allow the use of 205/50(or 45)/16s in F1 GSD3. There is a lot more choice with 17s. (Ironically my runaround has a set of D3s.)
Assuming that you keep the rolling radius the same then larger wheels will: Downside: - cost more, have more expensive tyres, perform worse in the wet, perform worse on bumpy roads, be more susceptible to tram lining, increase the weight of the car, increase the unsprung weight, produce a harsher ride, increase the rotating unsprung weight (second moment of inertia) and be more liable to scuffing on kerbs when parking. On the plus side they should: - prevent the tyre from distorting thus giving greater cornering grip in the dry and on smooth roads, be more direct giving greater steering feel and control, have less tyre wall flex (thus reducing both heat and fatigue and be better for long high speed journeys) and they should look good. Perhaps most of all they allow you to use top quality (UHP) rubber.
Note that larger wheels will effectively increase the spring rates.
Also note that fitting lower section tyres with less sidewall flex can make the car more sensitive to suspension geometry changes. Lowering the car can adversely affect the handling by throwing the static geometry out, and giving you too much camber correction and bump steer.
>> Edited by JR on Wednesday 15th March 19:06
For example, in your Q 16s at the front would allow the use of 205/50(or 45)/16s in F1 GSD3. There is a lot more choice with 17s. (Ironically my runaround has a set of D3s.)
Assuming that you keep the rolling radius the same then larger wheels will: Downside: - cost more, have more expensive tyres, perform worse in the wet, perform worse on bumpy roads, be more susceptible to tram lining, increase the weight of the car, increase the unsprung weight, produce a harsher ride, increase the rotating unsprung weight (second moment of inertia) and be more liable to scuffing on kerbs when parking. On the plus side they should: - prevent the tyre from distorting thus giving greater cornering grip in the dry and on smooth roads, be more direct giving greater steering feel and control, have less tyre wall flex (thus reducing both heat and fatigue and be better for long high speed journeys) and they should look good. Perhaps most of all they allow you to use top quality (UHP) rubber.
Note that larger wheels will effectively increase the spring rates.
Also note that fitting lower section tyres with less sidewall flex can make the car more sensitive to suspension geometry changes. Lowering the car can adversely affect the handling by throwing the static geometry out, and giving you too much camber correction and bump steer.
>> Edited by JR on Wednesday 15th March 19:06
thankyou, confirms many of my fears, i certainly don't want any more weight, or a less comfortable ride, and i drive in all weathers, i'll take 16's all round.. that's what the grif estoril's are, right? so is anyone running 16's all round, that, as pref, are lighter than the standard wheels... and can anyone recommend anything stickier than the bridgestone SO3's?
For the road only or road and track? If the latter then you might consider Toyo R888. They have a slighly softer sidewall than SO3s so give a better ride on road. They are stiffer and therefore more harsh than normal road Toyos. They grip very well in the dry and OK in the wet providing there is no standing water. They only come with 5mm tread and are a soft compound so they don't last long. Noisy on the road too. Fantastic on track! Very noticeably more grippy than SO3s.
This isn't an easy question to answer. If you need all weather grip then you will need to compromise. For dry weather you will find it hard to better the Toyo R888. I think Toyo 16s stop at 225 so if you're planning 245's hard luck. As for all weather tyres I think the Toyo T1-S and R is better than SO2pp and 3pp and is available in 205, 225 & 245. There may well be others out there but I wouldn't like to comment outside of my own experience. I personally think the T1-S is the best all rounder. Don't forget that more grip will transfer more energy, and thereby harm, back into the drive train and will speed up the deterioration of your engine mounts. This I do have experience of.
tvrbob said:
This isn't an easy question to answer. If you need all weather grip then you will need to compromise. For dry weather you will find it hard to better the Toyo R888. I think Toyo 16s stop at 225 so if you're planning 245's hard luck.
Yes, that's the problem. You'd have to run R888 215/50/16 (slightly too big) at the front and 225/50/16 (slightly too small) at the rear. F1 available as earlier post.
ohh that sounds harsh! still it's a compromise i'm prepared to make for the enormous smile i get whilst driving the beasty!
245's the width isn't it? if the r888's only get to 225 does that mean i'll get more skippy... skinnier tyres with more grip sounds like i'll almost break even....thoughts? i'll check your all rounder option now...
245's the width isn't it? if the r888's only get to 225 does that mean i'll get more skippy... skinnier tyres with more grip sounds like i'll almost break even....thoughts? i'll check your all rounder option now...
backslide said:
ohh that sounds harsh! still it's a compromise i'm prepared to make for the enormous smile i get whilst driving the beasty!
245's the width isn't it? if the r888's only get to 225 does that mean i'll get more skippy... skinnier tyres with more grip sounds like i'll almost break even....thoughts?
Probably more grip despite reduced width. Main drawback is low tyre life. I was a passenger to a chim around Oulton Park last year which had 17" 235 R888s - very impressive.
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