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#1 215 rear 185 front ?
Posted: Fri Aug 18, 2023 5:28 am
by Paul bow
Hi guys at present im enjoying my freshly restored ots s2
After 20 months of slog and toil, along with keeping me skint!
I’m running PIRELLI CINTURATO 185 all around. However I’m considering putting 6.5” on the rear and 215 tyres.
Why u may well ask, well this car probably not going to be for the purists, it’s had a lot of mods, and regrettably I have a heavy right foot!
It can be easy to feel the back end break away.
The engine big valve inlets, fuel injected, lightweight rods/flywheel etc etc. makes a reasonable BHP.
My thinking was to keep the front on 185 so easy on the steering and beef up the rubber on the back for greater traction similar to what you’ll see on the E types racing at goodwood.
I know it’s not for everyone this kind of modification just trying to find out if anyone else’s has used this set up?
Thanks guys

#2 Re: 215 rear 185 front ?
Posted: Fri Aug 18, 2023 6:36 am
by chrisfell
215s in the rear wheel arches? Hmmmm. Here's what I know from when a friend turned up on a long tour with 215s on his 3.8 coupe.
Problems:-
1 Bump stop.
2 wheel arch rim.
3 mounting and dismounting the wheel.
1 Remove. But remember it is there for a reason.
2 Fold flat. Perfect rust trap.
3 Requires suspension to be fully extended and enough clearance to angle the wheel in before engaging on the hub. And off is just as tortuous. Try this on the side of the road with a scissor jack.
Otherwise, go for it.
Oh. I forgot. Two sizes of wheel/tyre, which do you carry as a spare? A modern space saver and its 50 kph speed limit?
#3 Re: 215 rear 185 front ?
Posted: Fri Aug 18, 2023 6:53 am
by paydase
205/70 on the rear would already be ample enough and would decrease the cons mentioned by chrisfell.
But sure the handling will be seriously affected
#4 Re: 215 rear 185 front ?
Posted: Fri Aug 18, 2023 10:37 am
by christopher storey
The E is predominantly an understeerer . If anything is going to breakaway ( other than deliberate rear end breakaway - probably in the wet - provoked with excessive throttle and steering input) it is more likely to be the front . And as already stated there are major snags to very wide rear wheels / tyres . Furthermore, if you increase the rear grip in the way you propose you will upset the handling balance of the car , possibly in an unpredictable fashion, and ( although there are others much better qualified than me to offer an opinion) it may be that you will increase the understeering tendency
#5 Re: 215 rear 185 front ?
Posted: Fri Aug 18, 2023 5:57 pm
by Paul bow
Yes thanks guys.. I thought about the under steer and it would most likely increase with a wider tyre.. but I didn’t give thought to the problems getting it off and on very good point I overlooked.
I suppose when u watch them racing the E’s they slide around corners in a perfect fashion so steering the car with a bit of throttle (slide), yes I’ve answered my own question.. that’s not going to go down well with the local constabulary !!
Cheers guys I will leave it as it was intended

#6 Re: 215 rear 185 front ?
Posted: Fri Aug 18, 2023 9:44 pm
by chrisfell
I have another car, a Honda S2000. It has 240 real horses, but all at the top end of the rev range, and that goes to 9000rpm. And it has fat rear tyres 245, thiner front tyres 215. When the grip goes it goes suddenly. This is the reason there are so few cars left and even fewer that are unmolested Crashes tend to be serious. Fat rear tyres do not give any warning when the grip threshold is passed. No slides or drifting, just goodbye tarmac, hello scenery.
#7 Re: 215 rear 185 front ?
Posted: Thu Aug 24, 2023 6:13 pm
by Paul bow
#8 Re: 215 rear 185 front ?
Posted: Thu Aug 24, 2023 6:30 pm
by Heuer
Ahh yes, the world of 911 ownership!
#9 Re: 215 rear 185 front ?
Posted: Fri Aug 25, 2023 6:02 pm
by politeperson
On the subject of E types and 215s, I have 215s fitted to this S1. All I will say is that they clear and it drives fine. Even the steering is OK! I needed some tyres to move this car around and happend to have the Michelins XWXs off an old Ferrari. They are fitted to 6.5 inch center laced wheels and I think I will keep them.
I will admit I only have a few miles, but so far, even on full lock, it seems OK. I can get my fingers between the wheel and the rear wheel arch just.
On the subject of 911s, you doubt will not get the back end to break away in the newer 992s. I cannot imagine how you could come close on a public road. I did get the front end to wash out once on a roundabout with worn Goodyears, but that was it. I have seen 1.6g in corners, that is so much, you risk neck strain. I have 50,000 miles on mine now. I had an SC and also 930 Turbo once, and they definitely could be made to break away much easier.
Not sure how 185s at the front with 215s at the rear would work!
#10 Re: 215 rear 185 front ?
Posted: Fri Aug 25, 2023 10:32 pm
by bitsobrits
1.6G in corners with a street 911? I think your G meter needs calibration.
#11 Re: 215 rear 185 front ?
Posted: Sat Aug 26, 2023 8:39 am
by malcolm
bitsobrits wrote: ↑Fri Aug 25, 2023 10:32 pm
1.6G in corners with a street 911? I think your G meter needs calibration.
Maybe not - I've got a street F type (V6 S) and at Goodwood, I record 1.2 G, and I'm not a super fast racer
#12 Re: 215 rear 185 front ?
Posted: Sun Aug 27, 2023 1:32 pm
by lowact
Also need to know the wheel offset (b/w the rim and the hub). Aftermarket wheels are not all the same, is why a wider tyre might fit ok on one car but rub on another. And if u want to corner like a race car you don't want the tyres to be too wide for the rims. Most references say 205 would be ideal for 6.5" rims.