Tyre choices

For you flat four Porsche 912 fanatics

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Spit Nolan
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Tyre choices

Post by Spit Nolan »

Hi all,
I’m trying to figure out tyre choice for my 67 912. I really want a period looking tyre with the right characteristics to suit a Porsche, such as the Pirelli CN36’s or Blockleys, but I have a set of 7” American racing Torq thrusts and the manufacturer’s both don’t recommend their 185/70 R15’s on a 7” rim.

Anyone have any other suggestions of something that will suit? I can’t go too big as the wheels will be a squeeze on a SWB car anyway. A 205 would be too wide without going to a low profile modern tyre.

Cheers
Gareth
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
Lightweight_911
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Re: Tyre choices

Post by Lightweight_911 »

.

I wouldn't have thought there would be a problem with the Pirellis - they were fitted (in the 185/70 size) to the front 7in Fuchs wheels on '73 2.7RS models when the optional 7's & 8's were fitted.

.
Andy

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- subtracting weight makes you faster everywhere”
Spit Nolan
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Re: Tyre choices

Post by Spit Nolan »

Thanks Andy, I had been told that but wasn’t sure. I think may just have to go for it, but lot of money if it doesn’t work.
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
Lightweight_911
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Re: Tyre choices

Post by Lightweight_911 »

.
Maybe just buy one & try that first ?

Or see if anyone has a used/worn) one going cheap ?

Also might be worth asking in the 'General' section if anyone is running 7in wheels with 185/70 Pirelli CN36 tyres ?

.
Andy

“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
neilbardsley
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Re: Tyre choices

Post by neilbardsley »

7inch on s 912? I thought 5.5 was standard

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Spit Nolan
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Re: Tyre choices

Post by Spit Nolan »

I now have some scrap ones, I’ll get one swapped over and see what it’s like. Cheers
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
Spit Nolan
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Re: Tyre choices

Post by Spit Nolan »

neilbardsley wrote:7inch on s 912? I thought 5.5 was standard

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I’m not running stock wheels, Torq Thrusts.
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
Boydyrs
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Re: Tyre choices

Post by Boydyrs »

I’m running Nexen Blu Eco on my hotrod and I’m quite impressed.
They get a B rating for rain but haven’t tested them as always sunny in JockLand presently.
In dry nice ride, plenty grip and get warm quick so keep TP lower.
They are great value also and realise not a Big Brand tyre but neither was Yokohama 10 years
Hope this helps.
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100702mark
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Re: Tyre choices

Post by 100702mark »

I swapped mine on to Vredestein Sprint Classics a few years ago and it transformed the handling over the more square section modern tyres. They are shaped traditionally but with modern tech but reasonable affordable. I run 185/70 14 on Fuchs 5.5 rims and 175/70 15 on some 6 inch minilites. The latter pretty much fill my swb arches without mods.
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Re: Tyre choices

Post by Lightweight_911 »

.

I hadn't noticed that your 912 was a '67 (swb) model - do you know what offset the Torq Thrusts are ?

For reference a 911R 7" Fuchs wheel (offset 49mm) will fit on the rear of a swb but a later 7" Fuchs (offset 23.3mm) won't ... at least not without extensive mods.
.
Last edited by Lightweight_911 on Wed Jul 22, 2020 10:18 pm, edited 1 time in total.
Andy

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- subtracting weight makes you faster everywhere”
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Re: Tyre choices

Post by 912Flyer »

neilbardsley wrote:7inch on s 912? I thought 5.5 was standard

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100702mark
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Re: Tyre choices

Post by 100702mark »

This is the clearance of 175/70/15 Vredestein Sprint Classic on a 6 inch minilite if it helps.
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Re: Tyre choices

Post by 912Flyer »

Spit Nolan wrote:Hi all,
I’m trying to figure out tyre choice for my 67 912. I really want a period looking tyre with the right characteristics to suit a Porsche, such as the Pirelli CN36’s or Blockleys, but I have a set of 7” American racing Torq thrusts and the manufacturer’s both don’t recommend their 185/70 R15’s on a 7” rim.

Anyone have any other suggestions of something that will suit? I can’t go too big as the wheels will be a squeeze on a SWB car anyway. A 205 would be too wide without going to a low profile modern tyre.

Cheers
Gareth
Hi Gareth I have a 67 912 SWB and it will soon have a Polo engine in putting out around 210hp with about 175 lb-ft of torque at around 5300 rpm and the largest width wheel that I would contemplate would be 6J.

You have a nimble car in a 67 912 and I have just replaced my 185 Conti Sports for CN36 165x15 on Fuchs 15x5.5J as Longstone were selling them off at £100 a tyre and the car has gone from tram lining and feeling slightly wooden to an extremely nimble handling car with quicker windup and unlimited chuckabilkity on the road. I have pushed the 912 to its limits to make it breakaway and it's beautifully controllable over the limit. Coming from a Lotus Elan Sprint I would echo the words of Tony Thompson a well known racer and his view was always "The car is like a beautiful ballerina why would you want to put pit boots on her" he was rights and Michelin XAS FF (Formula France compound) were a perfect choice for the Lotus. However if I could get 165 or 185 Mich XAS with the FF compound I would buy them over anything else but you cannot get them in a 165 or 185x15".

Admittedly with the greater HP I will probably go back to 185's on 6J Fuchs as the power may be overwhelming for the 165's but I will try them first and use possibly the 185 CN36 but I am tempted by the Avon CRZZ which are an amazing tyre but also amazingly priced :shock: :shock: :shock: :shock: :shock:

Another point Gareth to consider which I am going through on a completely different car to a 912 is a 993 and the increased width and size of the tyres and what affect that will have on your suspension and steering - do you have a cross brace on the front to take the additional stress that width of tyre will place on the S&S? Im pretty sure at the rear the driveshafts can take it but when I got my car and it had 6J wheels with 195 on the rears it has munched through wheel bearings and I am sure that is why the rear diff has worn so badly but then i'm only a home mechanic and what do I know.

I have learnt a lot through Mike Champion on the 912 and Centre Gravity on the 993 and I personally would be tempted to call Mike who is on this forum and have a chat as he has tested all sorts on the SWB 911's and 912's and Mike will be setting up my 912 when it comes back with its Polo engine.

Picture of mine with current CN36'S on.

Image
Image

Mike
1967 912
1994 993
2006 987 S
Mini Cooper S
Cooper MK9
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Alfa Romeo GTA-R
Spit Nolan
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Re: Tyre choices

Post by Spit Nolan »

That’s some great info thank you guys! I’m determined to get the 7” ones on, but worse case I have been tempted by some Group 4 Torq’s especially as they are going to be doing 5’s and 5.5’s soon, so could then go with a 165 CN36. But I already have my genuine Torq’s, oh the choices haha
‘67 912 “Scruffy B*stard”
‘68 VW Bay Westy Campmobile - very original family camper.
912Flyer
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Re: Tyre choices

Post by 912Flyer »

Spit Nolan wrote:That’s some great info thank you guys! I’m determined to get the 7” ones on, but worse case I have been tempted by some Group 4 Torq’s especially as they are going to be doing 5’s and 5.5’s soon, so could then go with a 165 CN36. But I already have my genuine Torq’s, oh the choices haha
It’s your car so do what you feel is right. If you have a chance to try a car on 165’s though you will be amazed how much quicker your car feels steering wise and the feedback is spot on.

Let us know how you get on.

Cheers

Mike
1967 912
1994 993
2006 987 S
Mini Cooper S
Cooper MK9
Lotus Elan Sprint
Alfa Romeo GTA-R
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