Tyre sizes again..........

[markcoopers]

I believe the PAS equipped cars ran a 225/50 on a 15" x7" wheel which i think gives me dimensions of 606mm diameter and 225mm wide. I am thinking of fitting 16" fronts and running a 225/45 16" wheel on the same 7" width and et25 offset. This should give me a 609mm diameter and 225mm width. I assume this should fit with no rubbing as it is is virtually the same or is the 3mm on TVR's a critical issue?

Cheers,

Mark

[QBee]

markcoopers said:

I believe the PAS equipped cars ran a 225/50 on a 15" x7" wheel which i think gives me dimensions of 606mm diameter and 225mm wide. I am thinking of fitting 16" fronts and running a 225/45 16" wheel on the same 7" width and et25 offset. This should give me a 609mm diameter and 225mm width. I assume this should fit with no rubbing as it is is virtually the same or is the 3mm on TVR's a critical issue?

Cheers,

Mark

All I can tell you is that 225/45 17s rub on my car, 215/45 17s don't. Over to you on the maths front, I am an accountant, but am off duty.

[SILICONEKID 345HP 12.03]

225s rubbed on mine ,I prefer 205/50/16

[RobXjcoupe]

The 3mm extra on the diameter is in effect 1.5mm closer to the wheel arch.
Personally I can’t see that being an issue. 225 on a 7j rim will not give a good steering response. 7.5j or 8j would be a better width wheel for a 225 tyre.
As mentioned already, a 205 50 r16 or 215 45 r16 on a 7j rim would be better.
Just my opinion though

[SILICONEKID 345HP 12.03]

Go for it .

[markcoopers]

This gets more and more confusing.

225/50/15 is a diameter of 606
225/45/16 is a diameter of 608.9 (but owners have had issues of rubbing)
215/45/17 is a diameter of 625.3 (this does not rub)

Did TVR change the shape/arches for PAS equipped cars?

Also currious how the feel is changed on a different width rim.....not picking a fight, just really interested to know the theory behind this.

cheers.

[QBee]

markcoopers said:

This gets more and more confusing.

225/50/15 is a diameter of 606
225/45/16 is a diameter of 608.9 (but owners have had issues of rubbing)
215/45/17 is a diameter of 625.3 (this does not rub)

Did TVR change the shape/arches for PAS equipped cars?

Also currious how the feel is changed on a different width rim.....not picking a fight, just really interested to know the theory behind this.

cheers.

Mine rub with 225/45/17. They rub on the back of the headlight port, when the wheel is on full lock inwards. So what is causing it is the diameter measured diagonally across the wheel, ie from the back left to the front right, or vice versa, which is far bigger than the diameter of the wheel as you have calculated it

[markcoopers]

Mr Bee,

225/45/17 has a diameter of 634.3, which is the largest of all possibilities so not a surprise that it rubs. I am however only looking at 16" so not really a concern in this cortex. If i was going for 17" wheels i think i would be at a 215/40/17 and a diameter of 604......but at this lower profile i suspect harshness to become more apparent.

I did want to fit the 225/45/16 which is only 3mm out with the same width so really should fit.........but advice about feel on a 7" width and someone else saying a 225 on a 16 rubbed is something not to ignore. This would also allow me to fit the OEM 225 and 245 widths for PAS cars. More reading needed i think.

Chaps with 225/45/16 that rubbed, are they on 16" imola or estrils ie running a set of rear wheels on the fronts? I ask as this might be an offset issue as essentially they are now 10mm further inbord so likley to foul the wishbones.

Edited by markcoopers on Tuesday 10th July 15:33

[markcoopers]

Decision made, thank you for the help.

7x16 et 25 fronts with 205/50/16
8x17 et33 rears with 225/45/17

probably proxs T1-r as a balance as this is where it gets very personal.

[SILICONEKID 345HP 12.03]

I have 205/50/16 and 235/45/17 ,both have a good wall height and look balanced with no rubbing .
I will never change those sizes .

[RobXjcoupe]

markcoopers said:

Decision made, thank you for the help.

7x16 et 25 fronts with 205/50/16
8x17 et33 rears with 225/45/17

probably proxs T1-r as a balance as this is where it gets very personal.

Good choice. You won’t have any rubbing issues with those sizes and offsets

[QBee]

RobXjcoupe said:

markcoopers said:

Decision made, thank you for the help.

7x16 et 25 fronts with 205/50/16
8x17 et33 rears with 225/45/17

probably proxs T1-r as a balance as this is where it gets very personal.

Good choice. You won’t have any rubbing issues with those sizes and offsets

....and you can always try your rears on the fronts with 5mm spacers to test for catching for future reference..... It is only at full lock, especially in reverse, that they catch on my car.

I have to add that my 225/45/17s are Toyo R1Rs, which are probably a tad squarer-shouldered than many a road tyre. This may be the reason for the rubbing.

[SILICONEKID 345HP 12.03]

RobXjcoupe said:

Good choice. You won’t have any rubbing issues with those sizes and offsets

Good choice ,wall heights are exactly the same .

[markcoopers]

And the car arrived yesterday with a different owners handbook saying different OEM sizes that matched the car. 215/50/15 fronts 235/50/16 rear. To match these in 16-17 combo you get a 215/45/16 which is best described as an odd size with little to no suitable tyres. So we now have 205/50/16 and 235/45/17 in Tokyo T1-Rs to fit 7x16 et25 and 8x17et33 wheels. Same as recommended above I think.

Got to love TVR random stuff.

[RobXjcoupe]

If you could put a picture up please of your new wheel and tyre combo

[markcoopers]

Here you go

Edited by markcoopers on Saturday 14th July 14:21

[mk1fan]

Tyres rub on TVRs mainly because the body has been fitted off square, with fewer packing rubbers, have had extra grp added during construction or a combo of all three.

Plus the suspension =has been changed for coilovers and the ride height set for 'looks' [low] rather than performance - nose down generally.

[RobXjcoupe]

markcoopers said:

Here you go

Edited by markcoopers on Saturday 14th July 14:21

You can’t really beat that wheel design from who ever that makes them, but
I have to admit the fronts don’t really look noticeably a size smaller in diameter.