What is a good street tyre

[400TT]

Originally Posted by stephen low

15" tyre what would be a normally tread width for this sized tyre?

I bought some Yokohama AVID S/T 15" tyres from Tirerack. A significantly better tyre than the old choices we have here - TA's & 325's. Plus heaps cheaper of course.

Front: 245/60/15 (673mm diameter)
Rear: 295/50/15 (678mm diameter)

I went with these sizes so they would bag nicely on original sized 7.5" & 9.5" rims. And it's a compromise against width and diameter.

If you want a bigger diameter you could go with:

Front: 225/70/15 (696mm)
Rear: 275/60/15 (708mm) Lots of Cobras run this size.

If you want an original look, then go with Goodyear vintage bluestreaks(not approved):

Front: 26.5x8.0-15 (665mm)
Rear: 26.5x10.0-15 (678mm)


With larger diameter rims you actually struggle with rear tyre diameter. e.g. 315/35/17(Sumitomo's etc) are just over 650mm in diameter. You would do better with 335/35/17's, but still fall short of diameters of 15" tyres. 18" it is basically worse.

The bigger the diameter the tyre, the lower the car will look as you are filling the wheel arches and gaining clearance underneath.

The downsides of 15" rubber is performance and brake size availability. You can only squeeze in a maximum of 310mm rotors using the slimest of calipers.

At least with tyres like AVID S/T street performance is at least respectable.

Also something like 315/35/17 would not appear any wider from the rear of the vehicle than say my 295/50/15 tyres. My 295's have a overall width of 315mm when mounted on 9.5" rims. A 315/35/17 on a 11" rim would have an overall width of 320mm from memory...amazing hey. But the 315 has a massive 35mm more tread width.

315/17 Sumi's are fantastic value and a good option for wide 17" rubber.

Check the wheel arch sizes on the G-Force, if they are anything like the original Cobra's, you will always struggle to fill them.

[Aussie Mike]

I'm running 315/35/17 Sumitomos on the rear 17"x11" rims. Since there isn't much sidewall you need a wider rim as they pull in on a smaller rim. I've seen them installed on 10" rims and they look OK but are starting to pull in.

Tyre widths are measured from side wall to side wall and since the 315 has basically straight sidewalls with little or no bulge this translates to a fairly huge tread contact patch.

The fronts are 235/45/17 on 17"x8" rims. They are both similar rolling diameters and whilst they don't fill up the guards like a 15" tyre you can always lower the suspension a bit to get that look.

They may not be the stickiest tyre available but they are great value for money and will probably hang on better than any 15" tyre apart from race compound tyres.

My theory is they will do fine for the street and I'll keep a set of dedicated race rubber for the track. It's only about $80 to get them swapped over at my local tyre shop. I plan to buy a spare set of rims eventually though.

Initially I was thinking about using race rubber for the street but from talking to people who have used them, race rubber on the street is just dangerous. They don't seem to work till they get warm and they only have a limited number of heat cycles till they are stuffed.

[Beejay]

Craig,

What rubber are you going for on the GT40?

Ben

[400TT]

Originally Posted by Beejay

Craig,

What rubber are you going for on the GT40?

Ben

I have Michelin Pilots:

Front: 225/45/18
Rear: 335/30/18

18's to clear the brakes I have for it.

[Cameron Parsons]

Everyone has their own ideas, it's part of what makes these toys so much fun. I have 15's and run the 352's on the Road and BFG TA/R on the Track. (I did use the 352's on the track a few years back, but the panel work bill got way too high too fast! ).



Cameron

[acecob]

Yokohama ADVAN
zr rated, H compound
I have 17's on mine and they stick .

Dont know who has them in Melb, only 1 guy up here, he's out at Penrith

[sambo]

Guys, I find this classic vs. modern wheel size 'debate' gives me headaches. It's interesting and mystifying at the same time... anyway, do you guys use some sort of calculator to determine final tyre width/diameter for a given wheel size or is it trial and error?

Nobody has mentioned 16" wheels yet. 15" is better looking to me but I'm sure 17" tyres perform better (comfort aside). But why no go for 16s? What would be the ideal width/profile/diameter for that size?

Thanks

[hsv300]

Try this site Sambo
http://www.tyresite.com/tyrecalc.asp

[400TT]

Plenty of online wheel/tyre size calculators. Just Google "tire calculator" etc. They do vary slightly between manufacturers though, so for the exact spec's see the manufacturers web site.

16" tyres are really limited in sizes(especially wide sizes) & pricing is often poor, that's the downside. But they are a great compromise for looks and performance. A lot of Cobras are fitted with 16" wheels. My GT40 originally had 16" wheels.

[sambo]

Thanks guys I'll check out those calculators. For those with 16" wheels, what tyres are you running?

[400TT]

In 16" sizing, the most popular choice seems to be:

Front: 225/50/16
Rear: 255/50/16

You can squeeze those tyres onto 16x8" & 16x10" rims if you want.


Check out 07cob's Gallery for photos of 225/50 & 255/50 16" tyres on 8 & 10" rims on a Harrison.

http://www.clubcobra.com/photopost/s...=24838&cat=500

[sambo]

Thanks Craig. Are they Millaz 'champagne glass' wheels? The rubber looks to me like it could go a little wider too.

[400TT]

Yes, they are Millaz champagne glass(wine) wheels.

It's hard to find much in 16" in the wider sizes, well anything that is suitable for street use on a Cobra anyway.

[PCC]

As Craig says, 16" dia Wheels used to result in a relatively poor choice.

Saying that I have noticed a recent improvement in this area.

As already said I cannot fault the Toyo T1R - Exceptional!

I have 225/50 on the front and 245/45 on the back.

$200 fitted and balanced for the front (each); and
$250 for the back.

Not forecasted to last long, but for my mileage not an issue

[Beejay]

MHT makes the wheels for Foose, and they make no mention of custom fitments?

http://www.mhtwheels.com/default.cfm?brand=4

Ben

[CHANMADD]

Summit Racing has just added 315/45/16 , 27.2 inch Diameter Mickey Thompson ET street radial ,with a 11.2 Tread width for $179-95 each.I have 16's and could never find any bigger than 255, until now.My car does sit low but drives really smooth on these wheels.I have Kuhmo Exsta Supra ZR's with 255 rear and 225 front,and these tyres perform better than a set of Yokahama AVS100's that I had ,which also did'nt last very long.

[BigBlockRob]

I'm gonna wack 335's on 18 inch rims on mine for the rear. !!!
I'm gonna use the same tyres those ferarri boys use!!

[400TT]

Rob, something like this. 335/30/18's on a Harrison.





Don't limit yourself to Pirelli. You can get some really good deals from US Viper dealers on 335/30/18 Michelins. I bought mine from a Viper dealer through eBay US. They were very, very cheap, brand new with sticker on the tread. From memory around AU$350ea landed. Just make sure you shop around and are patient.

[BigBlockRob]

yeah looks sweet dont it??