195/55/15 on track?

[trackerdave]

On my Williams 2 track car I usually use 195/50/15 tyres, but I've been offered 195/55/15 direzza full on track tyres at a great price, my question is will I be doing the wrong thing buying 55 series?
ive been told the tyres are a heavy belted slick type tyre and its the tyre that holds the nurburing track record,

 

[PBCup]

You'll gear the car up so it will accelarate slower.

 

[.GAZ.]

You'll gear the car up so it will accelarate slower.

He's never going to notice that in a million years.

Biggest factor is rubbing/clearance issues.

 

[PBCup]

He's never going to notice that in a million years.

Biggest factor is rubbing/clearance issues.

I bet it's more noticeable than using vpower or a remap.

 

[.GAZ.]

No chance.

 

[trackerdave]

I was a little worried about more side wall etc handling but I've heard the Dunlop's are a heavyish tyre and so therefore quite stiff side walls. Previously used toyo r888s.

Thanks for the replies.


Dave.

 

[Bluebeard]

Like Gaz said, i'd be worried about clearance. My valver has 195/50's and theres barely any room left in the arches! So much so I've had to trim the front bumper as it is!

 

[.GAZ.]

Yup, even with 50's, I'm contemplating 10-15mm spacers.

 

[trackerdave]

id love to try some just for size before I bought any but then I guess when the cars under load and compressed its a whole new ball game...

its just ive been offered some £50 cheaper than 50 series!!!! you can see why I ask guys..

Dave.

 

[Jay Payne]

Direzza's need plenty of heat to 'switch them on' and are useless in anything but bone dry conditions. Very good tyre tho. R888 is one of the best all round trackday tyres imo/ime as they work in almost all conditions.

 

[trackerdave]

How have you found ao48r compared, I may get some of them, I found 888s very soft and seemed to go off quite quickly, it may have been my hard driving.

Cheers.

 

[Jay Payne]

Only driven on them once so not as much experience as they others

 

[trackerdave]

Only driven on them once so not as much experience as they others

Ahh ok, well I guess I should give them a try then as I've have read many positive comments ref the ao48r, been offered some good clean part worns to play with.

 

[fuad]

I've got some of the 55 Dunlops on my clio, only issue i found was some scrubbing, probably not helped by the fact my Bilstein coilovers are far too soft. But at the price i got them for, i snapped them up.

 

[.GAZ.]

A048's are superb!

 

[trackerdave]

Good good thanks all.

 

[Willo]

I found 888s very soft and seemed to go off quite quickly, it may have been my hard driving.

Cheers.

What compound were you using? GGG will overheat very quickly.. Also will depend what track your on. Great for most tracks but short twisty stuff I find the sidewall is too soft.

 

[mike1pow]

I use 195 50 16 AO48's on track. Only had it rub a couple of times

 

[Hoofy]

We run the Direzza 55 profiles on our race car.... We switched to them when we found out the difference in cost!! £360 for a set of 4 versus £450!

After a bit of calculation, we determined that the top of the tyre would be ~9mm closer to the inner arch and that the speed difference was ~3%. Therefore, if before you were doing 100 mph at a set engine RPM, you would be doing 103 mph at the same rpm. When on track, we didn't notice much of a difference at all AND if you're going to increase the power of your track car, it helps with gearing too.

In terms of clearances, we've cut away some of the bumper to make sure. We've also added caster, so if you don't do that you'll have a fair bit more room. Practically, we haven't had any problems on track, the only time we heard anything touching was at the bottom of paddock hill at Brands. In that case, we saw the bit of rubber mark on the inner arch, but it was touching a flat surface and for only a fraction of a second, so it wasn't a problem at all.

I'd highly recommend using the larger profile tyres, especially if you haven't excessively lowered the car!

 

[trackerdave]

Thanks excellent advice...I will deffo get some of these then whilst there so cheap..

But for now Ive just sourced 2 full sets of ao48r 195/50/15 with an even 5mm throughout only used twice £300 which i thought was a bargain guys, they only just look scrubbed lol.

 

[imprezaworks]

That is a bargain

 

[Willo]

Really surprised the 55s dont rub. Im getting the front rubbing on high speed turn in using 205/45/16. You must be running quite a substantial ride height im assuming?

▲btw that is a bargain

 

[Hoofy]

Really surprised the 55s dont rub. Im getting the front rubbing on high speed turn in using 205/45/16. You must be running quite a substantial ride height im assuming?

▲btw that is a bargain

We're obviously running a fair bit stiffer springs than standard and hence we get a bit less travel. If you are using your car on track specifically, the standard springs and dampers aren't really up to the job (trust me, I've got a road going 172 we've put on the track back to back).

If you're not that serious about the outright performance and just wanna do a few trackdays for fun, you're unlikely to see the saving in all honesty 'cause you'll go for quite a while on 1 set of tyres. However, if you're like us and do about 8 to 10 events a year where performance matters, you soon get through tyres and the saving can be really noticeable.

 

[Willo]

I do 10 MSA sprints and arounf 5 track days a year so go through them quick enough. Used to be in a Subaru on 235/45/17 until August this year so the price of 205/45/16 was a little less than what i have been used to.

Had the Clio for 3 weeks and only done 1 competition in it so far. Got crappy raceland coilovers on at the moment but getting BCs with uprated spring rates fitted in a couple of weeks so hopefully the rubning will go. I will look into the difference in cost for 55 profile 15s but want to keep 205 for obvious reasons.

Cheers for the tip/ advice. Hopefully I can save a few quid