CN36 and P7

[Dougal Cawley]

OE Cinturato CN36 and P7 tyres are in stock.

I 'm assuming you guys are all aware that Pirelli are making the original equipment tyres in all the right sizes, tread designs, but most importantly the correct carcass strctures.

so if you going for the early stuff. (pre 1968) then this is what Porsche fitted.

https://www.longstonetyres.co.uk/165-r1 ... -ca67.html

165HR15 Cinturato CA67 FULL 700x700.jpg

then in 1968 pirelli developed the CN36, some cars like the 912 stuck with the 165 section tyres, because cars are nicer to drive on a thinner tyre. But on the mopre race cars like the 911 they used the new low profile tyre technology to fit 185/70VR15 Cinturato CN36 and then in the early 1970s Pirelli went a little further and invented 60% profile tyres and the back of the RS ended up with a 215/60R15 Cinturato CN36 on the back.

https://www.longstonetyres.co.uk/pirell ... -cn36.html

as time moved on Porsche developed more of their models to be suited to these new wide tyres.

Pirelli Cinturato 18570R15 FULL 600x600.jpg

But don't just assume a wider tyre makes your car better, often the opposite is true.

But as Porsche developed its suspension to be able to keep a wider flatter tyre foot print on the road, and cars moved away from the need for progressive handling, ultra low profile tyres were developed for ultimate grip and of course Pirelli led the way again with the P7

https://www.longstonetyres.co.uk/pirell ... to-p7.html

again cars of this period suit the handling characteristics of these period tyres.

The P7 is also the tyre that Porsche moved onto 16" wheels with. if you look at the bottom of the page it shows which tyres are suited to which rims.

Pirelli Cinturato P7 285-40x15 - FULL 600x600 (1).jpg

[Darren65]

We’re in desperate need of a CN36 in a 235/60 R 15 profile if you have any influence Dougal

[CraigB]

Don’t suppose you have any information on the Dunlop tyres?

My CoA indicates that the car was fitted with Dunlop radial 185/70 VR 15" tyres. Would like to know whether Dunlop still produce a “period” tyre in a similar way to Pirelli.

[Dougal Cawley]

We’re in desperate need of a CN36 in a 235/60 R 15 profile if you have any influence Dougal

Hi

Are you completely sure that is actually a proper fitment for definite set in stone?

all i have is this page from a book

3.0RS.jpg

I have been down a rabbit hole before based on a book like that where it is actually a mistake or something taken as fact that wasnt nesecarily fact. so i also have this

"Bagged and Been saving these since the late eighties. I bought these from Parr at the time just to use the 216/60 CN36 for my RS. They had pulled them from a very early 75’ turbo.
These are Very early turbo Fuchs 7” and 8x15”.
Rare 235/60 CN36 still on the 8” rims. I believe this tire was also used on the 74’ 3.0RS.
Still Very soft and usable for the show, display or concours car. They have been coated, bagged and stored since I bought them.
The 7” are dated 9/74 and the 8” are 12/73.
Inquire with pm for any other details.
$4500"

which i found maybe on here. but again, it isn't actually black and white proof, and this and the book thing could be the cause of each other if you see what i mean.

Look i'm not calling anyone a liar, it just doesnt make sense to have a tyre that tall on the vback in this period. here are the tyres Porsch fitted with their dimensions and rim sizes

CN36
https://www.longstonetyres.co.uk/pirell ... -cn36.html
15" PIRELLI CINTURATO CN36 Dimensions
Tyre Size Load Index Section Width Overall Diameter Recommended Rim Width
165 VR 15 PIRELLI CINTURATO CN36 N 87 = 545 kgs 165 mm / 6.49" 645 mm / 25.39" 4.0" - 5.5"
185/70VR15 PIRELLI CINTURATO CN36 N 89 = 580 kgs 196 mm / 7.72" 637 mm / 25.07" 5.0" - 6.5"
215/60 VR15 PIRELLI CINTURATO CN36 N 94 = 670 kgs 228 mm / 8.97" 639 mm / 25.16" 6.0" - 7.5"

Then P7 that came out in 1974
https://www.longstonetyres.co.uk/pirell ... to-p7.html
15" PIRELLI CINTURATO ™ P7 Dimensions
Tire Size Load Index Section Width Overall Diameter Recommended Rim Width
205/50 VR 15 PIRELLI CINTURATO P7 86 210 mm / 8.27" 585 mm / 23.03" 5.5" - 7.5"
225/50 VR 15 PIRELLI CINTURATO P7 91 229 mm / 9.01" 608 mm / 23.94" 6.0" - 8.0"
285/40 VR 15 PIRELLI CINTURATO P7 92 288 mm / 11.33" 609 mm / 23.98" 9.5" - 11"

my point is, i cannot understand why they would put such a hugely taller tyre on the rear all of a sudden. it doesn't make sense.

Oh no i've just found this

1.jpg

[stretch]

Wow... those large one's are as expensive as the Michelin TB15's.

[Dougal Cawley]

Well unfortunately not enough people fit tyres that size and shape, so they can only make small batches.

https://www.longstonetyres.co.uk/vintag ... tyres.html

But yep the TB make the Pirelli look cheap don't they. specially when you consider they will return multiples of the mileage, and really are a much better road tyre. Oo and actually DOT marked, so road legal in the States.

[stretch]

It there an alternative not so expensive tyre for the 7 + 9 x 15 Fuch wheels ?

[Darren65]

Are you completely sure that is actually a proper fitment for definite set in stone?

...also in the homologation documents plus other sources and is correct.

I went with CR6ZZ's which you supplied, 215/60 front and 245/60 at the rear although these give a tad more rake than I'd like...



...I might try 225/60's at the front to compensate so both front and rear are a touch wider and taller?

[Dougal Cawley]

It there an alternative not so expensive tyre for the 7 + 9 x 15 Fuch wheels ?

there are cheap tyres out there in these sizes but really they do last a while so it is worth fittting the good stuff

07219C7F-71FB-44CD-98BD-AC63EDDE3167-762x456.jpg

this car has 7's on the front with 225/50R15 P7

https://www.longstonetyres.co.uk/225-50 ... to-p7.html

then 9's on the rear

https://www.longstonetyres.co.uk/285-40 ... to-p7.html

(i would add more pictures but the system wont let me up load larger pictures. if you want m,ore email Longstone and i can send you some.

The rears are a similar price to the Michelin TB tyres, but the fronts are a lot cheaper. in all fairness you arent going to get a rear tyre that size without it costing a lot. they are a weird size and, even at that price they are difficult to justify making. The front tyres also arent exactly being given away, but they are prettty specuial things. Just don't look at your credit card bill.

I guess yes the Avon CR6ZZS are a bit cheaper, but not enough to make you consider a modern race tyre that doesnt work as well on the road on your car as the P7, or work anywhere near as well as a tarmac rally tyre as the TB. for me it would be P7 or TB. sorry. i can justify the price, but we cannot get away from the fact it amouts to a large credit card bill

[Darren65]

Oh no i've just found this

Just realised I'd photographed the same page when I was Centre Gravity at couple of weeks ago!

[Dougal Cawley]

Hi

A 9" rim might sound too wide for a 215 section tyres (215mm is 8.5") the recomended rim for this tyre size for this tyre is 6" to 7.5" however the actual width of the tyre is 228mm at its widest point while fitted on an optimum rim. So to stretch it onto a 9" rim is feasible.

One of the tricky things is i beleive the original wheels on these cars were tube type wheels. And the first Pirelli 215/60R15 tyres were also tube type tyres. However what i also know is that very soon after that, no tyre manufacturer made a 60% tube type tyre again, and they are all now tubeless 60% profile tyres. I think these original tube type wheels built to put that 215/60R15 tyre on are a bit of a concern.

[Darren65]

I think these original tube type wheels built to put that 215/60R15 tyre on are a bit of a concern.

I've used 215/60 CR6ZZ's with my original 7R's on the rear of my Mongrel for many years and thousands of miles. On track, Alps tours, Welsh roads north and south, always pushed hard and often going sideways - never had an issue!

[Dougal Cawley]

Hi

Well the CR6ZZ range of tyres are good tyres. They dont look right but they do have the right kind of carcass for your cars, as does the CN36 which makes them handle so well. However they are a racing tyre, so the rubber is racing rubber so they will get really sticky when they get warm and start picking up pebbles and flicking them all over the pleace, and as they go through these heat cycles that rubber will be loosing its oils and becomeing less good. so if yiou fit a set and use them up quick then they are great,and as a trck tyre they are great, but as a standard road tyre the CN36 is a much better all rounder. it is a shame no one has done a back to back test on them with the CN36. it would be very interesting how well the CN36 does. yes it has a road compound, but it does also have a lighter carcass and return amazing results in all the tyre tests it has been put through. And of course it looks great.

[Darren65]

I've now switched my rear 9's over to 225's ....



....the 245's were too large imo....



...whilst the 225's, although visually much better and in keeping with the original RS, maybe a tad narrow.....



...TB15's were also a consideration and look ok and would provide some extra width although quite a smaller difference in diameter plus a lower profile.

A CN36 235/60 would most certainly be the sweet spot and what RS owners the world over are crying out for....have a word with Pirelli Dougal and see if you can work some magic!

Cheers,

[Dougal Cawley]

Hi

I dont think there is much hope of that. we very rarely get asked. Also i am having enough trouble getting the P600 made which was actuallyOE on loads of Jag XJS.

how many cars do you think would fit the 235/60R15 CN36?