Power & Tires

[NickF]

23" front is not to small diameter? CR6ZZ offers a taller tire approx. just under 26"

 

[Jack Dunn]

23" front is not to small diameter? CR6ZZ offers a taller tire approx. just under 26"

I ordered the car new from the factory. It went straight to Dennis Olthoff's shop to benefit from his expertise, and he chose the wheel/tire sizes I've listed. (BTW, the 17" Michelin Pilot Sports on the front are 245/40ZR17, which are about same diameter as the 15" Avons, about 23.5").


I'm merely reporting how my car was done, and I'm happy with it. You may want to do yours differently.


Jack

 

[Terry Oxandale]

Yep, running 245/45ZR16s on the front of my project with wider/taller in back. Works very well. Would not want to go any taller in front.

 

[NickF]

Thank you for all the information.

 

[thomas haak]

Can these cars handle 600=hp? Trans, half axles, frame? I have a 2005 CAV. Looking at 13" wide rear tires. What can break if not equipped correctly?

i have in my Tornado 430hp and i cant give full power until the 3 gear. at the 4 gear ist okay, but it goes like hell

 

[NickF]

From what I gather gearing, and tires make a huge diff. on these cars, especially tires. I am going with Avon 14" rears. nice and soft with a nice tread. I am not one to do burners, but more of a controlled fast acceleration. Street tires just wont grab.

 

[Takis M.]

Sorry for resurrecting such an old thread but does anyone know how the Avon CR6ZZ’s compare to the Avon Historic all weather tyres with regards to grip in the dry????

 

[Larry L.]

No, they were treaded from the factory. "Historic all weather pattern tires" (the section width is 15.25" in case you were wondering). This info is off the Avon site here:


15" Historic all weather | Avon Motorsport


Jack

'Tread pattern looks identical to the Micky Thompson design that's been around since the Earth cooled!

 

[Mark Winton]

Sorry for resurrecting such an old thread but does anyone know how the Avon CR6ZZ’s compare to the Avon Historic all weather tyres with regards to grip in the dry????

Hi ... A good question, because the 15" Historic All Weather Tires are available for Rim Widths up to 16". I have 15" Diameter * 14" Wide Rear Wheels (5.30/15.00-15 Dunlop Racing Tires on my build - but cannot use on the street.
Does anyone know if the Avon Historic All Weather would be street legal ?
I am not interested in the Avon CR677 because is only available up to 295/50R15 - which is pretty skinny for the rear of a GT40.

 

[Randy V]

In the USA, the tires must be DOT branded in order to be legal for highway use. I’ve not heard of anyone being pulled over by the Police for running a tire that has visible tread, but have seen them pulled over for running slicks.

 

[Mark Winton]

In the USA, the tires must be DOT branded in order to be legal for highway use. I’ve not heard of anyone being pulled over by the Police for running a tire that has visible tread, but have seen them pulled over for running slicks.

Hi Randy ... Thanks for comments ... I would expect equivalent rules to those you described (DOT Approved) would apply in Australia. Your comments regarding running slicks are also my experience.

 

[Ian Anderson]

Also check hat your regulators and insurance say.
in the UK you have to have a speed rated tyre that matches the potential of the car.
In my case a V rated which means a constant speed in excess of 150 mph for,over an hour. fair enough you say for a GT40 but we all know that you could not achieve that .... perhaps get there for a few seconds at the end,of a straight on a track.

So people are tempted to put on a cheaper tyre.

This happens all the time in daily drivers. Have a bump and the insurers check the tyre speed rating and if incorrect refuse to pay any claim.

I believe the CR6 Avon’s are the only ones that are road legal, even if perhaps not as wide as you would desire.

ian

 

[Takis M.]

Ian, (and others), are the non-speed rated tyres (such as the CR82’s and others) weaker than the speed rated, street legal tyres In some way? So for instance if you fitted CR82’s and went on a three hour, motorway road trip will such tyres risk failure by crusing at say about 80-90mph for a couple of hours? Is this where the difference in construction lies between treaded race tyres and speed rated street legal tyres? Are the racing tyres not made to stand up to hours of cruising at motorway speeds or to the differences/weaknesses lie elsewhere?

 

[DaveM]

Ian, (and others), are the non-speed rated tyres (such as the CR82’s and others) weaker than the speed rated, street legal tyres In some way? So for instance if you fitted CR82’s and went on a three hour, motorway road trip will such tyres risk failure by crusing at say about 80-90mph for a couple of hours? Is this where the difference in construction lies between treaded race tyres and speed rated street legal tyres? Are the racing tyres not made to stand up to hours of cruising at motorway speeds or to the differences/weaknesses lie elsewhere?

Treaded racing tires should stand up to high speeds at extended times. I ran Dunlop CR65 tires on a street Lotus Europa. No problems, good wet grip, just wore them down in about 4000 miles. One weakness of race tires is the sidewalls are very thin and may puncture easier with nails, etc. Another weakness is they are more porous and some need more air added every week or two.

 

[Takis M.]

Hey DaveM, thanks for getting back to me on this. I guess that makes sense about the tyre wall because fact is that race tyres are under much higher stresses than road tyres on a motorway. So the main issue with treaded race tyres is only sidewall puncture resistance?

 

[DaveM]

Hey DaveM, thanks for getting back to me on this. I guess that makes sense about the tyre wall because fact is that race tyres are under much higher stresses than road tyres on a motorway. So the main issue with treaded race tyres is only sidewall puncture resistance?

Yes. I should have added that treaded rain tires are not suitable for everyday use as they're way too soft. I assume we're not talking rain tires though.

 

[Takis M.]

That’s right DaveM. I was referring specifically to the Dunlop cr82’s (and not the likes of Avon historic rain tyres which start life as slicks and are cut to a pattern for rain use. Thanks again.

 

[Neil]

No, the tread is very thin on race tires to dissipate the heat built up in the rubber from hysteresis. It doesn't take much to puncture the tread.

 

[Takis M.]

Hi Neil. ’Hysteresis’ you mean the movement and changes of direction of the blocks of rubber tread as the car exerts forces on them due to acceleration, braking, turning, etc.?
is there any way of strengthening the puncture resistance of a race tyre tread using an insert (bearing in mind balancing must be bang on)?

 

[Neil]

Yes, it is the stretching of the rubber that generates heat because it is absorbing energy. No, there is no good way to make race tires work on the street; If you do, consider then sacrificial.