Larger wheels

[Dutchone]

I am thinking about putting larger wheels on my Griff purely for reasons of appearance and not chasing 'improvements' to handling etc, but don't want to go below /45/ tyre section as I feel this may compromise ride comfort too much.
I have read various earlier threads on the subject which suggest it can be done OK albeit with lower profile tyres but they don't give much technical detail.

I have read section 16 in the Bible including Richard Branches attached article and have also decided to maintain ride attitude of the car with lower front by going 17" front and 18" rear.
When compared to SatNav my speedometer is currently reading consistently high by 9mph so the increase in tyre circumference on the rear will go some way to correcting this.

I intend to keep the hubs, brakes and suspension parts as standard but don't know how to check that a front tyre/wheel combination of say 225/45/17 with the standard 25mm offset will fit without interference or for that matter the same question on the rear for a 245/45/18 with 38mm offset (offset figures from Bible quoted but unchecked at the time of writing).
If I cannot confirm beforehand that the tyre/wheel mods will physically fit and cope with full lock and suspension/body travel then I won't spend the money.

Can anyone help who knows (empirical data is good) what wheel/tyre size combinations will fit in arches with standard suspension i.e. "bolt n go".

Thanks for any experiences, Paul

[B19 RUS]

Hi, I am no expert but I went 215*40*17 on the front. You must use a reinforced tyre though (apparently) and at the rear I went 235*45*17. I perhaps could have gone a bit wider on the rear but offsets and stuff limited my choice of wheel, plus I knew what I wanted. See my profile and my lovely wheels thread. This has given me a car that looks soooooo much better and the handling although not better is still very good.

[Dutchone]

RUS, Thanks for reply. Having fitted yours do you think a slightly wider and deeper tyre ie. 225/45 on a 17" wheel would give adequate clearance for the front or are you already tight for space.
Same question for the rear - do you think there is room for the 18" wheel.
Lastly - what offset did you ask for front and back.

Cheers, Paul
PS: I think your car looks good infact it was your earlier thread that made me think more seriously about the change.

[richb]

To be honest I think you will have trouble fitting an 18" 45 profile tyre inside the rear arch. Also I can't see you getting a 225 45x17 in the front arches and still being able to turn the wheels. Look at the standard tyres fitted to the Griff and use the tyre size calculator www.shpub.co.uk/tvrbooks/faq_tyre2.html on Steve Heath's web site to see how much bigger your suggested tyres are. Standard tyres on the Griffith 500 are 225 45x15 for PAS cars and 205 55x15 for non PAS cars at the front and 245 50x16 rear. The ones you are suggesting are 4% & 7% bigger. Rich...

[JR]

With richb on this one. You need to fit smaller dia tyres. Try 245/35/18 or 255/35/18 on the rear and 215/40/17s at the front.

[groucho]

I would love 17"s on my car. It's a pity they don't do the original estorils in that size. I've got 205x55x15 front and 245x45x16 rear.
Anybody got a cheap pair of 16" estorils to fit my front?

[pete500]

I use AZEV type E, 7 1/2 x 16 ET25 front and 8 1/2 x 17 ET 40 rear. Rubber is 225/45ZR16 front and 255/40ZR17 rear. Less than 40mm ET rear will give you a clearance problem to wheel-arc with 255's as its close to zero clearance on mine. The setup changed the car in a very positiv direction - speaking handling. pt

[Dutchone]

To RichB,
Rich perhaps I misinterpreted the chart in the Bible and the information it gives me.
I read it as giving me an overall diameter for the wheel including tyre having taken the rim diameter and tyre section into account. I think it also gives me the % increase in circumference from 'standard', but I don't think it tells me the max width of a particular tyre section which is what I'm looking for to try and estimate wing clearances on the back and steering clearances on the front - but maybe this information is implicit in the chart and I haven't understood it.

Cheers Paul

>> Edited by Dutchone on Thursday 17th November 08:37

[apache]

I had 215/40 x 17 on the front and 245/45 x 17 on the back with my racelines. It needed 2 x 3mm spacers on the front but, as testified by others, handled like a beaut

[bagpuss 996r]

Just went for it put 18" on f+r 215/35/18 235/40/18 adj for
nose down with gaz adj, backed off dampers by one with the 18"
for ride was a bit jumpy mind you this is on back lanes much
better now but would go for 40 on front but dont do any in 215,
dont know if 225/40/18 would rub or not. Mine is non p/s is
easyer to turn and turns in rearly well grips like F---.

>> Edited by bagpuss 996r on Friday 18th November 06:37

[richb]

Dutchone said:

To RichB, Rich perhaps I misinterpreted the chart in the Bible and the information it gives me. I read it as giving me an overall diameter for the wheel including tyre having taken the rim diameter and tyre section into account. I think it also gives me the % increase in circumference from 'standard', but I don't think it tells me the max width of a particular tyre section which is what I'm looking for to try and estimate wing clearances on the back and steering clearances on the front - but maybe this information is implicit in the chart and I haven't understood it. Cheers Paul

Paul,... ok you 've got the idea. Look at the size for your particular standard tyres, read off teh circumference inches and enter that figure in the box at the top. You can then compare the % difference in rolling-diameter against any size tyre on the list. No it doesn't say much about widths but to be honest you are limited by the width of the rim. i.e. 8.5" rim = 235/245 tyre 9" rim = 255 tyres. Rich...

[richb]

bagpuss 996r said:

Just went for it put 18" on f+r

Looks nice Dave...

[richb]

apache said:

I had 215/40 x 17 on the front and 245/45 x 17 on the back with my racelines. It needed 2 x 3mm spacers on the front but, as testified by others, handled like a beaut

Do ypu still have it Pete? Nice picture...

[apache]

richb said:

apache said: I had 215/40 x 17 on the front and 245/45 x 17 on the back with my racelines. It needed 2 x 3mm spacers on the front but, as testified by others, handled like a beaut Do ypu still have it Pete? Nice picture...

nope sold it on ages ago

[b19 rus]

Dutchone said:

RUS, Thanks for reply. Having fitted yours do you think a slightly wider and deeper tyre ie. 225/45 on a 17" wheel would give adequate clearance for the front or are you already tight for space. Same question for the rear - do you think there is room for the 18" wheel. Lastly - what offset did you ask for front and back. Cheers, Paul PS: I think your car looks good infact it was your earlier thread that made me think more seriously about the change.

Hi pal I have just seen ure thread (i have also had 12 cans of carlsberg) and must say that I thik if you give your griff the carrotts as I am sure u do the front may bind. this is all dependndent on car and heights etc. I am not an engineeer , see www.torquecars.co.uk/Tuning/alloy-wheels.php but I do have an EX tvr power engineer working me. call me if you want to chat 07766515559

[b19 rus]

Drunken update, my car now is the the dogs it really has 30% more grip at both ends but it does tram alot more.