Tyres and sidewall heights
Discussion
What width is your front wheels Daz 7.5 ?
". ". ". " Rear wheels 7.5 or 8 inch.
Goimg by the calculator I'm using and assuming a 7.5 front wheel
Your 205/50/16 are 611.4 mm outside diameter so only 4.9 mm larger than standard 205/55/15 tyre size
Your rears are 643.3 mm so 11.9 mm bigger than the standard 225/50/16 with a 631.4 mm outside Dia.
A very good set up
It's the high 99 rating that put me off the 245 tyre Daz, it's a big old tyre normally holding up a heavier car,
Bigger is always better on track cos you can lean allover them but for everyday use I think the 235 is more suited. And yours looked the boolox + you did a blinding time on them there babies. Can't wait
I've got to get under 13 seconds on the strip
". ". ". " Rear wheels 7.5 or 8 inch.
Goimg by the calculator I'm using and assuming a 7.5 front wheel
Your 205/50/16 are 611.4 mm outside diameter so only 4.9 mm larger than standard 205/55/15 tyre size
Your rears are 643.3 mm so 11.9 mm bigger than the standard 225/50/16 with a 631.4 mm outside Dia.
A very good set up
It's the high 99 rating that put me off the 245 tyre Daz, it's a big old tyre normally holding up a heavier car,
Bigger is always better on track cos you can lean allover them but for everyday use I think the 235 is more suited. And yours looked the boolox + you did a blinding time on them there babies. Can't wait
I've got to get under 13 seconds on the strip
Edited by ClassicChimaera on Friday 30th December 21:20
I am not sure why you are worrying about buckling wheels.
My Saab 9-5 runs on 235/45 17 tyres (Rainsprout 3s) and nobody has suggested I will buckle the wheels - they are standard fit on these cars, and Saab are /werevery safety and build quality conscious.
I have been on 40 or 45 profile tyres for the last 30,000 miles on 17 inch rims with no problems.
My Saab 9-5 runs on 235/45 17 tyres (Rainsprout 3s) and nobody has suggested I will buckle the wheels - they are standard fit on these cars, and Saab are /werevery safety and build quality conscious.
I have been on 40 or 45 profile tyres for the last 30,000 miles on 17 inch rims with no problems.
QBee said:
I am not sure why you are worrying about buckling wheels.
My Saab 9-5 runs on 235/45 17 tyres (Rainsprout 3s) and nobody has suggested I will buckle the wheels - they are standard fit on these cars, and Saab are /werevery safety and build quality conscious.
I have been on 40 or 45 profile tyres for the last 30,000 miles on 17 inch rims with no problems.
It might have something to do with the buckled wheels I've had, one pot hole on Peters old rims flat spotted and cracked the rim, needed serious repair and was almost scrap, 205 width mind! Pothole was a big one though! etc etc. Ffs My Saab 9-5 runs on 235/45 17 tyres (Rainsprout 3s) and nobody has suggested I will buckle the wheels - they are standard fit on these cars, and Saab are /werevery safety and build quality conscious.
I have been on 40 or 45 profile tyres for the last 30,000 miles on 17 inch rims with no problems.
Even these Azev wheels on Toyo T1R tyres with a 215 width and 40 height I've had similar experience.
The tyre looks stretched over the wheel and my rim is almost wider than the tyre. Easy to scrape on a Cerb for instance.
I've noticed on one site it says you shouldn't fit bigger than 235 on a 7.5 inch rim, I've got 245 at the mo, to be honest it looks like it fits better than the fronts do.
It's not hard to see when looking at pictures by having 17 in rims on the front and a tyre size that mimics the original outside Dia it will be a very shallow tyre.
I've never got on with low profiles, ok there more stable at speed etc but everything else they just ruin your comfort and ride.
I like big old tyres, I think it also suits the car better, I just hope by taking the front size up by 18.8 mm from the standard 606.5 mm Dia to 625.3 mm I won't induce to much understeer.
The front wheels are going to be turning slower so will it effect the brakes and how much the tyre heats up.
I'm getting all F1 on it
If I have a higher rude height I could make a bigger splitter
I'm not worrying Anthony, just over thinking it a bit, keeps me out of trouble and my mind free.
Tvr changes and upgrades are a bit of a joy in difficult times.
Gives me motorvation,
Having looked at others cars as maybe a replacement for the Tvr during the summer and realised I've got the best car for the buck,,,, on the planet it's easy to commit to its continued path of hopefully improvements.
I realise more and more how lucky I am to have a car so worthy of such things.
Tvr rock like few others
SILICONEKID345HP said:
I allso have the 308 diff ratio.
Yeah and your really funny !! I forgot to mention, you better watch your speed through cameras
As if I've got this right you've got a lower reading at 30 mph on your Speedo, more like 27 mph with all your changes considered.
The circumference of your rear tyre is 37.4 mm bigger than a standard tyre. That's if my math is correct.
That's a long distance per turn of the wheel when you think about it so adding to your higher gearing
You star you
RobXjcoupe said:
Above looks a bit blurred but option front tyre size is a 225 50 15 on a 7" front rim. People are forgetting to mention wheel offsets play a big part if wheel and tyre combinations will rub or not
Now your taking me into a whole new level of hurt! Offsets, my brains just fused!
Ok to try and narrow mine down a bit I'm using
17 inch AZEV rims allround with markings as thus
7.5J X 17 H2
Help!
I'm off to bed as I'm up early,
Can anyone confirm what my offsets are and what standard should be please.
2OOM said:
I think on std wheels it's 15 inch 7j et25 front and 16 inch 7.5j et 33 rear .. I've put 16 inch imola wheels on the front and I have 205/50R16 on the front and 225/55R16 on the rear ..
Excellent cheers for that Graham. I'll do some re calcs as I've mainly been talking about tyre diameters it shouldn't make a difference with 1/2 inch difference. Offset yes but I'm not far from standard so it should just work, famous last words.
If anything I'll either just need to raise ride height a tad or use some spacers if I have wishbone or body rubbing, full lock there's a risk they will contact the inner wing so we'll just have to wait and see.
ClassicChimaera said:
Excellent cheers for that Graham.
I'll do some re calcs as I've mainly been talking about tyre diameters it shouldn't make a difference with 1/2 inch difference. Offset yes but I'm not far from standard so it should just work, famous last words.
If anything I'll either just need to raise ride height a tad or use some spacers if I have wishbone or body rubbing, full lock there's a risk they will contact the inner wing so we'll just have to wait and see.
I used Mr Gasbag's suggestion for tyre sizes and they have worked well for me,the taller profile has smoothed out the ride a little. I'll do some re calcs as I've mainly been talking about tyre diameters it shouldn't make a difference with 1/2 inch difference. Offset yes but I'm not far from standard so it should just work, famous last words.
If anything I'll either just need to raise ride height a tad or use some spacers if I have wishbone or body rubbing, full lock there's a risk they will contact the inner wing so we'll just have to wait and see.
I am probably staring at the wrong end of the stick with this thought but when you have a 20mm larger diameter, I've always thought of it as 10mm at the top and 10mm at the bottom of the tyre so to speak .. so the tyre will be 10mm higher into the wheel arch ..
2OOM said:
I used Mr Gasbag's suggestion for tyre sizes and they have worked well for me,the taller profile has smoothed out the ride a little.
I am probably staring at the wrong end of the stick with this thought but when you have a 20mm larger diameter, I've always thought of it as 10mm at the top and 10mm at the bottom of the tyre so to speak .. so the tyre will be 10mm higher into the wheel arch ..
I worked out the size then used my tape measure across the tyre, and yes it's about 10mm wider than the 40 profile tyre per side I am probably staring at the wrong end of the stick with this thought but when you have a 20mm larger diameter, I've always thought of it as 10mm at the top and 10mm at the bottom of the tyre so to speak .. so the tyre will be 10mm higher into the wheel arch ..
Nice pics guys, that's more like it.
RobXjcoupe said:
TVR original spec sizes for wheels and tyres is the bit for people to view. Note the front tyre size option if power steering is fitted
Oh yeah,,, Pas 225/50
It's the 225 that's interesting as you say.
That's thrown me!
I Better no try calculating it now mind,,,,
ClassicChimaera said:
Yeah and your really funny !!
I forgot to mention, you better watch your speed through cameras
As if I've got this right you've got a lower reading at 30 mph on your Speedo, more like 27 mph with all your changes considered.
The circumference of your rear tyre is 37.4 mm bigger than a standard tyre. That's if my math is correct.
That's a long distance per turn of the wheel when you think about it so adding to your higher gearing
You star you
I forgot to mention, you better watch your speed through cameras
As if I've got this right you've got a lower reading at 30 mph on your Speedo, more like 27 mph with all your changes considered.
The circumference of your rear tyre is 37.4 mm bigger than a standard tyre. That's if my math is correct.
That's a long distance per turn of the wheel when you think about it so adding to your higher gearing
You star you
SILICONEKID345HP said:
ClassicChimaera said:
Yeah and your really funny !!
I forgot to mention, you better watch your speed through cameras
As if I've got this right you've got a lower reading at 30 mph on your Speedo, more like 27 mph with all your changes considered.
The circumference of your rear tyre is 37.4 mm bigger than a standard tyre. That's if my math is correct.
That's a long distance per turn of the wheel when you think about it so adding to your higher gearing
You star you
I forgot to mention, you better watch your speed through cameras
As if I've got this right you've got a lower reading at 30 mph on your Speedo, more like 27 mph with all your changes considered.
The circumference of your rear tyre is 37.4 mm bigger than a standard tyre. That's if my math is correct.
That's a long distance per turn of the wheel when you think about it so adding to your higher gearing
You star you
225/50 16 is 631mm diameter
So 12 mm bigger, 6 mm bigger radius
Yes correct, where did I pull the 15.5 larger Dia from!
I've got a piece of paper with so many numbers scribbled allover it you'd think it was my accounts...
If I wanted to keep the tyre size in proportion to each other id be going fo something like
215/45/17 = 625.3
245/45/17 = 652.3
These are both about 20 mm bigger than a standard tyre front and rear so theoretically my ride height wouldn't need agjusting but then the Y rating is higher so I'd assume a firmer tyre wall, I don't want that!
I've got a piece of paper with so many numbers scribbled allover it you'd think it was my accounts...
If I wanted to keep the tyre size in proportion to each other id be going fo something like
215/45/17 = 625.3
245/45/17 = 652.3
These are both about 20 mm bigger than a standard tyre front and rear so theoretically my ride height wouldn't need agjusting but then the Y rating is higher so I'd assume a firmer tyre wall, I don't want that!
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