Spacers or no spacers, that is the question
Discussion
New wheels shod and fitted to the car at the weekend; RS Diamond Cuts, which IMHO look fantastic. The mut's nuts! Opinion will always remain divided but I think these wheels suit the Chimaera better than any other – Imolas included! (Running for cover now.)
The rear 17” rims have the same offset as the Imolas they replace so no problem here. The fronts however have 10mm greater offset, which means they sit 10mm further towards the centre of the car.
I conducted much research on this and finally decided on 5mm spacers. The original studs are long enough for the nuts so no problem there. The spacers are sold as ‘hubcentric’ (although they don’t have hub extensions) and fit snugly over the hubs and studs, so again no problem.
The 16" front wheels, however, while sitting over the remainder of the hub do not ‘locate’ on the hub. Instead, the wheel nuts centre the wheel. Now I’m pretty sure this is how the wheels on my old MGB V8 work (centred by the nuts – so to speak!) but it’s not the way the original Imolas were centred on the TVR.
If I take the spacers off and bolt the wheels directly and snugly onto the hubs the track width will be 20mm less than the originals. This could give rise to some over steer issues when pressing on. If I leave the spacers on, the wheels are centred on the hubs by the nuts alone.
Interested in opinions/logic/experiences…
The rear 17” rims have the same offset as the Imolas they replace so no problem here. The fronts however have 10mm greater offset, which means they sit 10mm further towards the centre of the car.
I conducted much research on this and finally decided on 5mm spacers. The original studs are long enough for the nuts so no problem there. The spacers are sold as ‘hubcentric’ (although they don’t have hub extensions) and fit snugly over the hubs and studs, so again no problem.
The 16" front wheels, however, while sitting over the remainder of the hub do not ‘locate’ on the hub. Instead, the wheel nuts centre the wheel. Now I’m pretty sure this is how the wheels on my old MGB V8 work (centred by the nuts – so to speak!) but it’s not the way the original Imolas were centred on the TVR.
If I take the spacers off and bolt the wheels directly and snugly onto the hubs the track width will be 20mm less than the originals. This could give rise to some over steer issues when pressing on. If I leave the spacers on, the wheels are centred on the hubs by the nuts alone.
Interested in opinions/logic/experiences…
Centred on the nuts is fine. The original cerbs came with wheels that didn't centre on the spigots, the bulletin from the factory just said to take care bolting them up to make sure you seated each nut and torqued them up in stages.
The spigot is only there to centre the wheel for balance purposes, it isn't there to support the weight of the car as most people think. It is purely the face to face frictional forces that provide the accel / braking forces etc. Neither the bolts nor the spigot should carry any bending loads on a correctly fitted wheel, the bolts only provide the clamp load on the face to face hub / wheel fit.
The spigot is only there to centre the wheel for balance purposes, it isn't there to support the weight of the car as most people think. It is purely the face to face frictional forces that provide the accel / braking forces etc. Neither the bolts nor the spigot should carry any bending loads on a correctly fitted wheel, the bolts only provide the clamp load on the face to face hub / wheel fit.
So if I read this correctly, the Ford wheels have an ET35 (35mm) offset?
The late Griffs had a 33mm front offset, IIRC.
I have run ET40 and then ET38 Ford fit wheels with 5mm spacers for some time now, and have noticed no bad handling whatsoever, even though the car was aligned with ET25 front wheels on. And I do track days and sprint days, as well as fast road driving.
My advice to you, if you have ET33 or ET35 wheels, is suck it and see, ie try without the spacers first. And then stick the 5mm spacers on if you need to. I have done the best part of 10,000 miles with 5mm spacers on with no noticeable adverse effects.
The late Griffs had a 33mm front offset, IIRC.
I have run ET40 and then ET38 Ford fit wheels with 5mm spacers for some time now, and have noticed no bad handling whatsoever, even though the car was aligned with ET25 front wheels on. And I do track days and sprint days, as well as fast road driving.
My advice to you, if you have ET33 or ET35 wheels, is suck it and see, ie try without the spacers first. And then stick the 5mm spacers on if you need to. I have done the best part of 10,000 miles with 5mm spacers on with no noticeable adverse effects.
Thanks very much spitfire4v8. This is pretty much as I thought but your confirmation is good to hear.
Thanks also Anthony and you have read completely correctly. ET35 for the RS front wheels. If you've run 5mm spacers on your fronts then you are the proof. I know you do a relatively high mileage and do track days so this is good enough for me. I shall leave as is with the spacers in for now and suck it and see.
Rubbish picture but you get the idea with the new look.
I may even be tempted into a track day or two with the old Imolas which I shall keep.
Any places in the southeast?
Thanks also Anthony and you have read completely correctly. ET35 for the RS front wheels. If you've run 5mm spacers on your fronts then you are the proof. I know you do a relatively high mileage and do track days so this is good enough for me. I shall leave as is with the spacers in for now and suck it and see.
Rubbish picture but you get the idea with the new look.
I may even be tempted into a track day or two with the old Imolas which I shall keep.
Any places in the southeast?Woodbridge near Ipswich is good.. 102db limit.. http://www.trackdays.co.uk/tracks/woodbridge.htm
The couple of times I've tried to out at Brands they've had a stupid 95db limit
The couple of times I've tried to out at Brands they've had a stupid 95db limit
I had the very same wheels on mine once and they look fab'. But I would fit spacers of correct thickness by changing the studs also. [like wot a did] 
Why exagerrate oversteer on these cars?
PS; they are painted diamond cuts, but still look better than softline.
Why exagerrate oversteer on these cars?
PS; they are painted diamond cuts, but still look better than softline.
Edited by macdeb on Monday 18th August 20:42
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