Slick Tyres Rubbing On Skirts

[nj1]

I have just put on some slick tyres on the front of my skyline, the tyres are kumho s700 245/645/R18.

On qtr lock the tyres grab the skirts, and rip them out

Based on the pics, the coilovers need to be raised, before I go about doing this, do you think it's going to fix the rubbing or am I wasting my time? Looks like a fairly significant ride height change is necessary.

Or is there something else I can do?

Thanks

[GTSBoy]

Wheels look to be a hell of a long way back in the arches. What sort of caster are you running?

[nj1]

Wheels look to be a hell of a long way back in the arches. What sort of caster are you running?

Not too sure, it's been like that since I got the car, I thought it was unusual.

In terms of suspension the only thing aftermarket is coilovers and adjustable camber arms as I am aware....but I maybe wrong

What should I be looking for?

[james32gtr]

What profile tyres were you running before?

[nj1]

What profile tyres were you running before?

Achilles 235/45r18 but they also rubbed and wore down the inside of the side skirts

[GTSBoy]

That last picture still makes me think that you need to wind on some more caster - the wheels are a long way back in the openings. You will need adjustable caster rods to be able to do it though.

On the actual tyre size issue - your tyres are too big. Standard size for an R32 is 205/55-16. Next most standard size is the GTR size, which is 225/50-16. Those are almost the same rolling diameter. The best matching bigger size is 235/45-17 (which is also the V-Spec size).

The standard rolling diameter is 632mm. The 235/45-17 size comes out to be 643mm, which is close enough to standard to be OK and also it's about the same size as the slicks advertised rolling diameter of 645mm. The Achilles 18s that you were running should have a rolling diameter of 669mm, which is far too large and not surprising that they rubbed.

So we have a problem. The way the current slicks sit looks like they are similar in size to the Achilles, which were too big......but the sizing of the slick shouldn't be too big.

Next question is.....what is the wheel offset? Looks kinda low. That won't help.

[KiwiRS4T]

Like GTSBoy says you need to get some adjustable castor rods and wind on about 6 or 7 degrees. But that might not fix your problem. I got a set of slicks exactly the same size and type as yours and they are too big for my Stagea. I will have to go back to the 17s I had before. For comparison below is a pic of my car with 17in slicks and below that my previous Stagea with 16in semi-slicks (on GTR wheels):

[nj1]

That last picture still makes me think that you need to wind on some more caster - the wheels are a long way back in the openings. You will need adjustable caster rods to be able to do it though.

On the actual tyre size issue - your tyres are too big. Standard size for an R32 is 205/55-16. Next most standard size is the GTR size, which is 225/50-16. Those are almost the same rolling diameter. The best matching bigger size is 235/45-17 (which is also the V-Spec size).

The standard rolling diameter is 632mm. The 235/45-17 size comes out to be 643mm, which is close enough to standard to be OK and also it's about the same size as the slicks advertised rolling diameter of 645mm. The Achilles 18s that you were running should have a rolling diameter of 669mm, which is far too large and not surprising that they rubbed.

So we have a problem. The way the current slicks sit looks like they are similar in size to the Achilles, which were too big......but the sizing of the slick shouldn't be too big.

Next question is.....what is the wheel offset? Looks kinda low. That won't help.

I think the maths might have been slightly off...

235/35r18 should have a diameter of 622 mm

245/645/R18 has a diameter of 643 mm

I now have a 10.5 mm radius difference, hence the rubbing

So now with adjustable castor rods, any specific brand I should be looking at or go cheap on a pair?

[nj1]

Like GTSBoy says you need to get some adjustable castor rods and wind on about 6 or 7 degrees. But that might not fix your problem. I got a set of slicks exactly the same size and type as yours and they are too big for my Stagea. I will have to go back to the 17s I had before. For comparison below is a pic of my car with 17in slicks and below that my previous Stagea with 16in semi-slicks (on GTR wheels):

When you say may not fix the problem, I am assuming even with xx degrees of castor I will never get full lock without rubbing?

[GTSBoy]

I think the maths might have been slightly off...

235/35r18 should have a diameter of 622 mm

245/645/R18 has a diameter of 643 mm

I now have a 10.5 mm radius difference, hence the rubbing

Um......no problem with the maths. At no point in the thread prior to your post quoted above, had anyone, you or me, said anything about a tyre that was 235/35. You said 235/45-18 and I worked out the numbers on that.

The 245/645 slick has an advertised diameter of 645. It's in the number. No point quibbling over the difference between the 645 in its identifying number and the 643 that may be written on its actual spec sheet.

So. Caster rods. NEVER BUY CHEAP SUSPENSION COMPONENTS. Tein, Cusco, Nismo, etc etc are good. Hardrace are probably good. Any of the Hu-flug-dung brands should be viewed with suspicion.

And what is the offset on the wheels you are running?

[nj1]

Um......no problem with the maths. At no point in the thread prior to your post quoted above, had anyone, you or me, said anything about a tyre that was 235/35. You said 235/45-18 and I worked out the numbers on that.

The 245/645 slick has an advertised diameter of 645. It's in the number. No point quibbling over the difference between the 645 in its identifying number and the 643 that may be written on its actual spec sheet.

So. Caster rods. NEVER BUY CHEAP SUSPENSION COMPONENTS. Tein, Cusco, Nismo, etc etc are good. Hardrace are probably good. Any of the Hu-flug-dung brands should be viewed with suspicion.

And what is the offset on the wheels you are running?

+20 offset on the fronts,

Taking a closer look the wheel alignment is way out

[GTSBoy]

+20 offset on a GTSt is asking for trouble. You want to be +30 or more.

Your wheel alignment does look uneven, which is bad, but the toe and camber that we can see in those photos has nothing to do with the caster.

[nj1]

I'll give the castor rods a go and get an alignment done.

Just looked on the hard race website, which of the below is best?

[GTSBoy]

The rubber ones are legal, the rose jointed ones are illegal.

I recommend the rose jointed ones. Much less compliance than the rubber ones. Much nicer. Unlikely to get defected for them.

[PN-Mad]

GTSBoy nailed it.

Just looking at your pics, it looks like it needs a butt load more castor. When you get them to align it, just ask them to screw in everything they can.

I run 240/68/17 michie slicks on my 180. They scrub the inner guard on full lock, but don't scrub anywhere else. That's on a 17x8.5 +22.

I suspect castor will solve your issues.