Yoko A048r's with 180bhp - opinions please

[olij]

I have 185 60 13 Yoko A539s front and rear of my K-series 7 which has 180bhp/140lbft and a LSDiff. on airfield days, i really enjoy the low grip on the rears but find the understeer frustrating. I need new rear tyres and can't decide what to buy - two 539's or four 48r's?

 

I'm not after ultimate grip but would like to reduce the understeer whilst not over-tyre the car (i.e. keep the oversteer ), if you see what i mean......

 

I guess what I'd like to know is will the 48r's provide too much grip for the fun handling aspect or is it a case of learning to drive it differently? I've no experience of tyres grippier than 539s so not sure what to expect.

 

Suggestions welcome please - I can't decide

 

thanks

Oli

[Alias]

Hi Oli,

 

first thing to mention is that the understeer of your car is dependent on several items - not just tyres. The rating of your springs front and rear, and the flexibility of your anti-roll bars will all have an impact.

 

If you are after some oversteer fun, you could put A048s on the front of your car but keep the A539s on the rear. However, I would strongly recommend against doing this as the front end grip will be much better than the rear.

 

If you simply want to dial out the understeer, you could put some stiffer springs on the rear of the car, or some less stiff springs on the front. (Springs are pretty cheap).

 

A048s are pretty sticky, but with 180Bhp you should be able to overwhelm them. However their stickiness means that they will wear out quicker than A539s, and this might be an important consideration if you intend to hang the rear of the car out on frequent trackdays.

 

My personal opinion would be to put A048s all round, and set up the car so that it drifts (i.e there is a balance of oversteer and understeer). This is far more satisfying once you get the hang of it, and will enable you to drive quickly and more smoothly.

 

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1400 Supersport with 6 gears and clamshell wings

[olij]

Thanks for replying RobF - looks like there's no easy answer! Perhaps I'll replace the 539s and then work with the setup - I can always change tyres again later!

 

thanks again

Oli

[Mark Chilton]

Put a pair of Michelin Pile-Ups on the back 😳

 

Oversteer guaranteed 😬 😬

 

Mark

 

CATCH THE WIND

[Normans_Ghost]

Oli, I fitted a set of 48's a few weeks ago. They've done Knockhill and Anglesey plus about 1000 miles and they're down to the wear bars. I've got Curborough and Elvington and then I've got to decide what next.

 

£400 every 2 months is not funny.

 

Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here

[olij]

hmmmm, thanks Norman (and Mark ). i think I'll stick with the 539's for now - the geological timescales at which they seem to wear down suits me for the moment.

cheers, Oli

[Ben Willis]

I have about the same power as Norman and my rear 48s are at the wear bars after 2000 road miles and one day at Llandow. I might try CR500 next - too much of a pain ordering new tyres so often, sorting out delivery and convincing the grumpy local fitters to put them on (they swore like mad last time and said they were a total pain).

[murph7355]

It's a while since I played my stuck record, but try A021Rs.

 

They're about the cheapest of the Yokos (owing to the lack of trendy looking tread no doubt), very progressive tyres allowing you to play nicely, exceptional in the wet and remarkably effective in the dry. They also last very well IME (200bhp-ish K series driven with spirit).

 

On the downside, they're heavy (though probably no more so than 48Rs) and start to fal to bits on a hot track day when pushing (the rubber marks down the side of the car add a certain "patina" to a 7 though).

 

Well worth a try (I believe they're about 55 quid a corner these days).

 

With 180bhp I'd probably go with 185 fronts and 205 rears. 60 profile on 13" wheels, or if you want to save a bit of cash without too much downside, go with 70s.

[MJF]

A048's are available in two compounds - super soft and medium. Whcih are you using? I've just fitted mediums to mine but have yet to use them. On the other hand I have a Blade engine with about 130bhp - so it probably won't be as hard on them...

[murph7355]

PS I wouldn't be inclined to run different tyres front to rear. Not as much a no no as different ones across an axle, but I still wouldn't do it, having learned early on in my 7ing just how much of a difference tyres make.