V rated tyres

cameron02 · #1 (**permalink**) 11-05-2004, 06:25 PM

To pass ADR I must have V rated tyres.

I purchased Adrains old rims (wire spoke). 7 X 15 & 8 X 15.

I was going to put Yokahama 352's on but they are only H rated.

Seems to be very difficult/impossible to get V rated tyres in the 255/60/15 range.

So I'm in the market for new 17 inch rims (I'm assuming that there is a better selection of wide V rated tyres) and tyres. With new rims I will be able to fit 265 width on the back.

Can anybody make any recomendations for a street tyre?

PS. Anybody want to buy nice spoke wheels?

Rebel1 · #2 (**permalink**) 11-05-2004, 06:31 PM

Cameron, I don't know if this still applies.

Not too long back the shortage of V rated tyres was recognised by the authorities and also tyre manufacturers.

Queensland Transport would accept lower rated tyres...(yoko 352 etc) as long as a sticker was applied to the windscreen warning potential passengers that the car was not fitted with the recommended tyre. ( would you F$%#ing believe).

They accepted Yoko's, BFG's etc. in place.

EDIT: Forgot to mention..This must not be an unusual situation as the tyre outlets have stocks of such stickers.

Cheers

REPTYL · #3 (**permalink**) 11-05-2004, 09:52 PM

call Andrew on 59401669. (Packenham tyres)
mention reptyl and your problems will be solved.

Jack21 · #4 (**permalink**) 11-05-2004, 10:49 PM

"Z" rated tires are what you should be looking for in a 17" tire. And you won't believe the performance improvement over your 15"s.

I'm using Falken FK451"s. Jap made, they should be available in Downundaland. 235/45ZR17 on 8" wide fronts (25.2" tall), and 275/40ZR17 on 9 1/2, or 10" wide rears (25.8" tall). For wheels, I'm using Team III's, but they're all good, depends on the size of your wallet.

cobra427mnsi · #5 (**permalink**) 11-06-2004, 08:57 AM

Jack21

What backspacing are you using on the 17" Team III's ?
Sorry, didn't want to hijack the thread but I need to know this info.
Paul

Jack21 · #6 (**permalink**) 11-06-2004, 02:29 PM

Paul, you're not hijacking the thread. Backspacing is an important consideration, but it depends on what you're using for a front and rear suspension and brakes.

With a CR, assuming you're using the MII front or aftermarket derivative, and a mid 80's 8.8 diff, my backspacing was 4" front for the 8" wheels, and 5" rear for the 9 1/2" wheels. With a different suspension, you have to measure it, and baseline your backspacing on the original factory wheel.

And you might want to get Don Scott's opinion on this also.

My brakes were installed already and were setup for 15" wheels. I can upgrade to bigger brakes with the 17's. Anyway, fronts are 11" Grenada rotors with '66 Mustang GT, 4 piston calipers. They are newly minted copies of the Kelsey-Hayes calipers from Stainless Steel Brakes. Rears and master cylinder are off '87-'89 Tbird Turbo Coupe from Ford Racing Mustang rear disk brake conversion. Rotors are 10" with single piston caliper.

Backspacing - front. The stock CR wheels were 15 x 8, used a 235 tire, and had a 4" backspacing. It fit fine, so I copied it to the 17".

Backspacing - rear. Going from an 8" to a 9 1/2" wheel was a tight call. I was tempted to split the backspacing like the fronts, and use 4 3/4". For insurance, it's easier to shim a wheel out, than in, so I went with 5" backspacing.

The 17" tires are a lot smaller than their 15" counterparts! There is no sidewall bulge like the 15's. You have a lot more fenderwell clearance. The overall height is the same, about 25 1/2". But these guys are all tread, and perfectly flat! The car looks "All Business", like a Porche, or M class Beemer, not like a '60's hot rod.

They don't break loose and spin like the 15's either if you get tires with the "AA" traction rating. No smoke, all go. My 275's are almost a foot wide.

One more thing. Wide tire - light car = hockey puck on a wet road. Totally untrue with these 17's. They're designed for wet roads (just not ice and snow). On the way to DVSFIII in '02, it was rain and thunderstorms through the twisty, winding roads of Western PA, and WVA. Car tracked straight and true, passing trucks, keeping speed 75 - 85 all the way.

So good luck with your wheel and tire upgrade.

cobra427mnsi · #7 (**permalink**) 11-06-2004, 10:20 PM

Thanks Jack21, You have provided alot of good info. Very useful. I appreciate it !!

Paul

David Hodgson · #8 (**permalink**) 11-07-2004, 07:31 PM

Cameron

Is it your engineer or rego authorities that have asked for "V" rated tyres? Your engineer should have done a top speed calculation based on installed gearing, tyre dia and engine out put and if that figure is below 210kph you should only need "H" rated, based on the factory spec's for a stock 5l efi it should come close.

Although you will find as you go up in quality of tyre, the speed rating also goes up. I know of only a few tyres that are available in two speed ratings, for the same tyre.

If your really keen on 15" Bridgestone have RE 710 in 255/60-15 and RE 711 in 225/06-15 both V rated. These are exceptional tyres in wet and dry. The 255/60's are brought in by a bridgestone dealer in Adelaide, and should able to be shipped to your local dealer. Also reasonably priced.

cameron02 · #9 (**permalink**) 11-08-2004, 07:42 PM

Thanks for the help guys,

It seems that every tyre dealer recommends a different tyre.

Thanks to David Hodgson it looks like we have the solution.

I called my local Bridgestone dealer. The 710 & 711's have been discontinued. Replaced by G3. The G3's only go up to 225 width.

However my dealer has discovered some 710's 255 width in NSW. He is double checking to ensure they are in physically in stock, if they are then I will order them today.

My next door neighbour also had a good idea. He suggested putting 225 width all around and then getting H rated 255 after registration. Then keep the 2nd set of 225 tyres for when the front ones wear out.

My car is back at the auto electricians. Hopefully my car will be ready for rego in a couple of weeks.

David Hodgson · #10 (**permalink**) 11-08-2004, 08:48 PM

[quote]Originally posted by cameron02

[My next door neighbour also had a good idea. He suggested putting 225 width all around and then getting H rated 255 after registration. Then keep the 2nd set of 225 tyres for when the front ones wear out.

Cameron

The 2nd set of 225's would be hard as hell before you wore out the first set of fronts.

Someone at the Nats was telling me that some 255's were recently brought in as Bridgestone did a run of these after requests from several countries. So keep on your dealers back.

David Hodgson · #11 (**permalink**) 11-09-2004, 02:12 PM

Cameron

It appears I was telling porky's about the 255/60 710 potenzas being V rated. I had a look at mine last night and they are H rated. Best check with the Bridgestone guy before ordering.

Sorry if I've given you a bum steer.

These speed ratings are for maximum sustained speeds (not if surpassed briefly) at the max load rating i.e. H rating is max "sustained" speed of 210kph at 710 kg per tyre for a 225/60 and about 750 kg per tyre for a 255/60. So thats a total allowable wieght of 2,920 kg. Your DRB would wiegh about 1150 kg? and you wouldn't be sustaining 210kph very often let alone 230kph for a V rated tyre.

As I said previously, your engineer should also do a theorietical top speed calc. This is done by using installed gearing ratio's, tyre circumfrence and the most critical is the rpm at which either the max HP or Torque is produced (can't remember which). Try and convince them its a stock 5.0 efi, about 175kw.

Also ask them where is it that you can drive at these speeds.

Don't let them pull the wool over your eyes, ask them why they want V rated tyres.

Dave

cameron02 · #12 (**permalink**) 11-09-2004, 10:06 PM

Thanks for the heads up David.

My top speed in 3 should be 191 kmh (3.9 diff ratio)

Hovever in over drive it could get to 281 kmh

I might have a case but time is running out. I think I'll just get the 225 v rated all round and replace the rear tyres later.