14 replies to this topic

[Jonny dhr]

I know there are tonnes of topics on wider tires, especially focusing in front options. What I can't find anywhere though is whether there is a certain ratio of front width compared to rear width that works the best? E.g does 195 front work best with 225 or 235 rear? If you go 205 front do you stay 225 rear? Ultimate goal of course- less under steer/ sharper turn in! Cheers, Jonny

[Ormes]

All I can tell is what people tend to go for which is 195 or 205 with 225 or 215 with 235.

[Nev]

The ratio is important, but so is the geo (camber) as both of these determine how the car "slides". I have 245mm width on the fronts and 285mm width on the rears with -0.5 camber on front and -1.5 camber on the rears. With this setup the other night when on a very slippery roundabout (with 3 lanes width), I was happy to note that the car broke away on all 4 corner simultaneously and slid in a very controlled way. Bascially all I did was look at other mid engine cars for a clue on ratios. HTH.

[Tonie Pettersson]

I´m running 205/50-16" front and 235/40-17" rear on TD´s 7x16/8x17, ride height 123/128 with this geo

 

Total toe-out front: 0°03' Camber front left: 0.9° (max camber for my OEM uprights) Camber front right: 0.85° (max camber for my OEM uprights) Toe in rear left: 0°13' Toe in rear right: 0°13' Camber rear left: 2.5° Camber rear right: 2.6°

 

The car felt really good with this setup, very well balanced and got rid of most of the under steer.

[TheRealVXed]

The factory geo is designed to be more biased to understeer as this is "safer"

 

Go and get a decent geo, a more track focussed one should dial a lot of that out.

 

ETA: I have a 340R geo on mine with 195 fronts, 225 rears.  It over steers much more readily than understeers suits me

Edited by TheRealVXed, 27 February 2015 - 11:05 AM.

[Jonny dhr]

Do you have to have modified uprights to achieve 340r geo?

 

I have a basic geo done already, but nowhere near as much camber on the front as the 340r, which is -1.5 right?

 

I currently have 195 front and 235 rear. I was going to go 205 front, but wasn't sure to stick to 235 rear or go 225. If I'm able to get more camber on standard uprights then I will do as well  

[james_ly]

Do you have to have modified uprights to achieve 340r geo?

 

I have a basic geo done already, but nowhere near as much camber on the front as the 340r, which is -1.5 right?

 

I currently have 195 front and 235 rear. I was going to go 205 front, but wasn't sure to stick to 235 rear or go 225. If I'm able to get more camber on standard uprights then I will do as well 

 

http://wiki.seloc.org/a/Geo_Setups

 

340R road geo requires no special mods. 340R track might well do...  

[Jonny dhr]

thanks for this... guess I will try and aim for the max. negative camber I can go to on the front on standard uprights with whoever ends up doing the geo

[P11 COV]

Matt Bentley  https://www.facebook...acing?pnref=lhc  will do you a good geo and advice on the best set up wheels tyres wise. He knows his Vx's and Elises. He's a good guy to chat to about it and is only an hour from you.

 

Steve at http://www.guglielmi...eguglielmi.html    also does a good geo on these cars and is not to far also.

 

I have used both several times over the last ten years. Personally I'd go for Matt out of the two at the moment.

[Jonny dhr]

Nice one.. Steve is where I got my first geo done, but it was a very basic one as the car was pulling to one side under braking, so he didn't put anything aggressive on there. Geometry aside, I'm still un decided between 205/235, 205/225 or stick with 195/225. I may well give Matt a call and ask his opinion

[Georgeralph43]

Any specialists in Hertfordshire that can do the geo?

[scw02102]

Personally I'm surprised path at 10mm us gonna make a noticeable difference I wouldn't worry one bit When I did the car limits day It was driving input and how aggressively u turn in made the most difference not the width of tyres

[Nev]

Any specialists in Hertfordshire that can do the geo?

 

Try doing it yourself (look online for video), it's quite easy, just takes a bit of time.

 

If you do it yourself, you can fiddle with settings back and forth with test drives in between and then come up with a geo that suits you, rather than what someone else infers you might want.

 

BTW, if you drive on road you will not be wanting max front negative camber (as your post mentions above), I wouldn't go above -0.5 degree camber on the front TBH, or you will get excessive inner barrel wear and also the car wont dig in reliably on variable road cambers (particularly in the wet).

Edited by Nev, 28 February 2015 - 10:19 AM.

[slindborg]

Just having the toe setup properly made mine massively more stable even with odd cambers. When I say more stable, it would oversteer easier but it was controllable and recoverable whereas before it would oversteer and then spin

[Smashf15c]

Johnny I did 195/225 winter setup and I have 205/235 summer/track tyres - standard geo settings and have tracked the car & wouldn't change a thing. Hmmm, of course, the Elise's kept up with me on track, maybe I should fiddle with it some more Smash