RB5_245

Eibach springs and bilstein dampers seems to be a good combo. I've never heard anyone say bad about them that's fitted them.

Whatever you do you want a progressively wound spring. If you're still on the 205's or even 215's you will be ok.

18's are still good for smooth roads from what I hear but get a bit out of shape when it gets bumpy.

Dropping it a small way on good springs will improve the handling.

As for F1 cars using small wheels... well what about - Touring cars, WRC tarmac, DTM, GT cars, Le Mans racers.... In fact everything that is not a single seater uses very large wheels on the track.

Gear Head

iTrader: (2)

Are you the love child of Pslewis and Bubba?

Damocell

iTrader: (1)

Well there are numerous reasons for that. For one, low profile tyres are designed to look good without compromising too much of the performance edge, but that is the key, they are more for looks, than they are a performance advantage. In truth, while they do provide a more stable cornering profile on certain surfaces do to the lack of sidewall sway, they also are less forgiving on certain surfaces, and are more likely to give up traction on bumpy surfaces due to thier harder sidewall and less absorbing nature. Low profile tyres also present a problem in something like F1. They have a higher lateral load limit on some surfaces, others they are less adaptive to, but on road cars or GT cars, the suspension is much much softer than that of an F1 car, and because of that, the low profile tyres work effectively because the suspension is absorbing much of the bumps and undulations on the surface, but in a formula one car, the suspensions are harder and aerodynamics are much more of a consideration and grip source. because of that, there is much more loading and demand on the tyres, and the higher profile does multiple things in that regard.

For one they are more stable on the limits of adhesion, the low profile tends to have a very sharp edge of when it gives up grip, it's OK, then gone, but the higher profile on an F1 tyre allows for a more gradual loss of grip, and makes the cars much more controllable and drivable on the limit. Also, the higher profile tyres allow for more play in the sidewall, which the manufacturers can use to gain more stability on bumpy surfaces as the tyre can better float and grab pavement on rougher surfaces. It also allows for more mechanical grip without the loss of durablity, as the sidewall is softer giving some qualitys of a softer compound tyre, but the actual surface layers of the tyre are harder which will last a little longer. Additionally heat is a consideration, lower profile tyres have a harder time getting rid of high heat quickly, and they are also closer to the rim and coupled with high brake heat, they do have a higher failure rate. The higher profile allows more material to disperse the heat and to allow more pressure build up without failure.

When it is all said and done, low profile could be used with design changes to the chassis, but with what is chosen to be used, it's just safer, more reliable and probably a bit quicker under the constant limits of stress an F1 car is under, no other race car has that limit of constant stress put on it, not at that speed and at that duration anyway, and for now atleast, that is what has been chosen. Ultra low profile tyres have been tested however, and they may be used in the future. Hope that helped answer your question, thanks.

chocolate_o_brian

iTrader: (22)

well this might sound sad or whatever but i had my ols scooby sport before my current wrx. it was on 15 standard wheels and 195/55/15 tyres. obviously not being a turbo wasnt the fastest car but the handling was good. then i popped on some lightweight 18" speedline turinis with toyo proxes 215/35/18 tyres and it did handle better even with standard springs etc. rond corners especially, maybe due to thicker tyres?? anyone think the same?

for the record on my wrx now i have the 16 gols speedline wheels as standard i think and they run on 205/50/16 tyres but obviously is m,uch faster round corners...

ben44

Sorry for not wanting the make of car I own to be chav'd up. As stated, lowering is a bit max power.

Or maybe you have a chip

RB5_245

Sidewall flex can make a car feel wobbly and unstable, so lower profile tires will make it feel better, mind you cars with high sidewalls are normally soft enough anyway.

RB5 and P1 were fitted with 17's as that is what prodrive considered the optimum tire size.

Ben, I think the chip comment was made in response to your saying in not so many word that you reckon the impreza handles rubbish. In which case i'm inclined to agree

ben44

I own an Impreza, and it handles better than an F1 car IMHO.

The comment made was taking the p!ss....

LEUVEN

Fitting larger wheels doesnt necessarily increase the radius.

If the step up/down in wheel size is not too big then the tyre profile compensates for the difference.

The larger wheels with the correct size tyres will have the same or very similar radius/circumference.
Going from 16" to 18" will result in minor differences, a couple of mm maybe.

Gear Head

iTrader: (2)

So was I!

GC8

If you re-read my post youll see that I havent stated that it does. The rolling radius is frequently increased though; and you dont need a tape measure to tell. Even a few milemetres will will increase the wheels leverage over the brake caliper and make a measurable difference though; this is very very simple physics and not even remotely subjective.

RB5_245

I wasn't... Now I look silly

RedScoob

17" and 18" do look cool, but to maintain the same or greater contact patch you need to be looking at profile, width and pressure. By going larger diameter and increasing width can actually reduce the contact area if the tyre pressure is incorrect, which is part of the reason that factory wheel and tyre combinations are chosen so carefully.
For my own preference only, the weight of the wheel is more important than an increased rim radius and lower profile tyre. Every kilo lost here is more beneficial than a kilo lost elsewhere.

GC8

RedScoob; this thread is no place for remarks like that! We have established that there is a direct correlation between the wickedness of a set of rims and their handling benefits. Its also accepted that a slammed car both looks cool and benefits from improved handling; the more the better (for both). No one either knows nor cares what 'unsprung weight' is so it cant be important.....

Hope this helps.


Simon

RB5_245

GC8 - Here: for your shoulder

powerwrx

iTrader: (11)

am after some suspension advice here and its turned into a debate between you all, im not bothered about the radius of my wheels,wether or not a subaru handles better than a f1 car or if bubba and pslewis have a love child.
Its impossible to get helpful answers to anything on here without some cr*p

Floyd

iTrader: (9)

Wrong forum surely?

F

N1gel 1970

my mate has got the same, except for having Toyo's instaed of the F1. the car grips the road like no-ones business. he also had the geomtary (sp) played with as well, it now has the Prodrive set-up

hth

chris25uk

i have 19's and lowered on my classic, yes its abit of a hard ride but if i wanted a soft one i would of bought a land rover. car corners and grips well enough on the roads, point being if ya wanna put 18's on it and lower it..go for it! dont take a blind bit of notice what some on here say

GC8

Ironically, in trying to show me up RB5 245; you make yourself look like a ****.

powerwrx

iTrader: (11)

GOOD LAD -CHEERS MATE

RB5_245

As said, with 18's you'll be fine. There are heaps of classics out there lowered with 18's and minimal complaints from people who've done this.

Quite a few that have gone to 19's changed back to 18 or 17 due to handling and ride, but then they do look good on 19s.

Need to keep the offset similar too, but any decent place you buy them from should sort that out

You have to read around the useless posts to get good info if you ask a question outside of technical unfortunately.

Dave (making a **** of myself apparantly )

n3 wrc

there are a few sad individuals on this forum ! !

nothing positive to say !