Imolas on a 500?

[Chris71]

Last tyre question I promise... Can someone confirm whether you'd be able to run 500-spec tyres (225f, 245r) on the Imola wheels usually fitted to the 400s?

And (well, okay second to last question) do you think they really need the 245 section rear?

I think with no traction control it's assumed you're going to be fairly sensible with your right foot anyway. And given that the real world power output figures between the two aren't as different as TVR would have liked to suggest, is it going to be a massive handful running an unmodified 500 on 400 spec tyres?

[SILICONE KID]

Check on this tyre calculator...Think you will find the rear imola as a wheel rim width (J) of 7.5 not sure if you can fit a 245 on that rim

http://www.alloywheels.com/tyrecalc.asp

[pwd95]

Had 225's on the back of the Griff 500.

[MK INDY]

And the Chimaera 450's have 225's and 245's fitted on Imola's

[BeastMaster]

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

[BeastMaster]

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

[Chimpafrolic]

BeastMaster said:

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

+ 1

Steering feel is so underestimated, in my opinion its a large part of the pleasure driving gives you.

Too many many fall into the trap of fitting unessesarily big tyres, all you end up with a nasty feeling over tyred car.

I have the same dislike for the ridiculous fashion for ultra low profile tyres, typically they just tramline and ruin your ride quality.

Show some restraint and your car will drive so much better.

[glow worm]

If you mean 16" wheels all round then 225/45 (Diam 608.9) front and 245/45 (Diam 626.9) rear , I think is the way to go. This what the factory installed on the very last cars when they couldn't get 15" tyres.
Maintains the same car profile as 15" 205/55 (Diam 606.5) front and 16" 225/50 (Diam 631.4) ... I prefer the ride with 245s on the rear.

[900T-R]

Chimpafrolic said:

BeastMaster said:

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

+ 1

Steering feel is so underestimated, in my opinion its a large part of the pleasure driving gives you.

Too many many fall into the trap of fitting unessesarily big tyres, all you end up with a nasty feeling over tyred car.

I have the same dislike for the ridiculous fashion for ultra low profile tyres, typically they just tramline and ruin your ride quality.

Show some restraint and your car will drive so much better.

Couldn't have said it better.

As an aside, my 430 makes as much power as a well tuned 500 (albeit without the torque 'hump' in the middle) and the only time I've come unstuck with the 205/225 combo (which is a better fit on the 7/7.5" wide OE wheels - Imolas and estoris are the same dimension-wise - anyway) is when they proved too wide for conditions i.e. on snow/ice

[Chris71]

900T-R said:

Chimpafrolic said:

BeastMaster said:

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

+ 1

Steering feel is so underestimated, in my opinion its a large part of the pleasure driving gives you.

Too many many fall into the trap of fitting unessesarily big tyres, all you end up with a nasty feeling over tyred car.

I have the same dislike for the ridiculous fashion for ultra low profile tyres, typically they just tramline and ruin your ride quality.

Show some restraint and your car will drive so much better.

Couldn't have said it better.

As an aside, my 430 makes as much power as a well tuned 500 (albeit without the torque 'hump' in the middle) and the only time I've come unstuck with the 205/225 combo (which is a better fit on the 7/7.5" wide OE wheels - Imolas and estoris are the same dimension-wise - anyway) is when they proved too wide for conditions i.e. on snow/ice

Thanks guys, that was very much what I was thinking on both counts.

I'm definitely a 'feel and balance over outright grip' sort of a person too, so it sounds like 205/245 is the way forward.

What I've basically decided to do, after a long and tortuous path, is retro-fit it back to OEM wheels (either Imolas or Estorils). For various (non-technical) reasons the aftermarket alloys I was looking aren't going to be as convenient as hoped and I like the standard look. Plus I'm happy to go with T1-Rs in a slightly lower speed rating and just back off when I get to 149mph.

Speaking of which, given they're softer tyres than the originals, do you think it's fair to drop 5% on the profile at each end? So, instead of 205/55 R15 front, 225/50 R16 rear it becomes 205/50 R15 front, 225/45 R16 rear?

[Chimpafrolic]

Goodyear Eagle F1 directionals & 16" Imolas all round for me.

Fronts: 205/50 ZR16 87Y

Rears: 225/50 ZR16 92Y

Seems to work very well and no annoying 15" tyre choice limitations.

You just need the lock stop washers in the rack to stop the inner edge of the front wheels fouling the lower wishbones.

Getting hold of a set of four 16" Imolas shouldn't be too hard, getting hold of a set of four 16" Estorils is another matter.

You could argue its a shame to put Imolas on a 5.0 litre Chim.

But I still think the car will look nice and factory with the Imolas and they are definitely a lot easier & cheaper to get hold of.

If you ever get that ego deflating comment "Nice 4.0 litre you got there" you can always flash your purple rocker covers

[450Nick]

Chris71 said:

900T-R said:

Chimpafrolic said:

BeastMaster said:

The wide'r tyres IMHO may give better traction, but introduce a lot of understeer. I have found 205 front tyres (even with PS) to give a much nicer feel to the fromt end. Andy

+ 1

Steering feel is so underestimated, in my opinion its a large part of the pleasure driving gives you.

Too many many fall into the trap of fitting unessesarily big tyres, all you end up with a nasty feeling over tyred car.

I have the same dislike for the ridiculous fashion for ultra low profile tyres, typically they just tramline and ruin your ride quality.

Show some restraint and your car will drive so much better.

Couldn't have said it better.

As an aside, my 430 makes as much power as a well tuned 500 (albeit without the torque 'hump' in the middle) and the only time I've come unstuck with the 205/225 combo (which is a better fit on the 7/7.5" wide OE wheels - Imolas and estoris are the same dimension-wise - anyway) is when they proved too wide for conditions i.e. on snow/ice

Thanks guys, that was very much what I was thinking on both counts.

I'm definitely a 'feel and balance over outright grip' sort of a person too, so it sounds like 205/245 is the way forward.

What I've basically decided to do, after a long and tortuous path, is retro-fit it back to OEM wheels (either Imolas or Estorils). For various (non-technical) reasons the aftermarket alloys I was looking aren't going to be as convenient as hoped and I like the standard look. Plus I'm happy to go with T1-Rs in a slightly lower speed rating and just back off when I get to 149mph.

Speaking of which, given they're softer tyres than the originals, do you think it's fair to drop 5% on the profile at each end? So, instead of 205/55 R15 front, 225/50 R16 rear it becomes 205/50 R15 front, 225/45 R16 rear?

Can't say I agree with all of that business about going for 205's to change the feel and understeer levels.

I run 225's all round on my car and my car does not understeer as I have had it geo'd to suit the tyres and my driving style. The 205 tyre works probably because it has been set up like that. I'd suggest that you go for as big a tyre as you can, but then have it set up by someone who knows their eggs (I used TVR Power) and explain how you want the car to drive.

For me, the change was ubelieveable and after throwing it round a good few tracks with a hell of a lot more horsepower than standard, I can confirm that it does not understeer, if you lean on it, it goes pretty much straight to 4-wheel drift and then oversteer in a wonderfully balanced manner.

[glow worm]

Chris71 said:

Speaking of which, given they're softer tyres than the originals, do you think it's fair to drop 5% on the profile at each end? So, instead of 205/55 R15 front, 225/50 R16 rear it becomes 205/50 R15 front, 225/45 R16 rear?

I would have thought your speedo may need adjusting with those rears... Not sure if a 3% change in circumference matters on a TVR speedometer.

Edited by glow worm on Thursday 27th January 14:44

[Chris71]

glow worm said:

Chris71 said:

Speaking of which, given they're softer tyres than the originals, do you think it's fair to drop 5% on the profile at each end? So, instead of 205/55 R15 front, 225/50 R16 rear it becomes 205/50 R15 front, 225/45 R16 rear?

I would have thought your speedo may need adjusting with those rears... Not sure if a 3% change in circumference matters on a TVR speedometer.

God knows if it was ever adjusted for the mammouth 18 inchers on there now... I just make sure I'm going slower than everyone else past the speed cameras.

[900T-R]

450Nick said:

I run 225's all round on my car and my car does not understeer as I have had it geo'd to suit the tyres and my driving style. The 205 tyre works probably because it has been set up like that.

No matter how you cut it, all else being equal c.q. optimised for the respective configuration, more rubber on the steering axle = less steering feel, which has nowt to do with over/understeer in itself. More rubber on the front wheels will ultimately mean less understeer, but also resists changes of direction more on initial steering application.

[450Nick]

Ah but I have power steering and didn't mention steering feel... I've never felt there was a problem with steering feel though, it goes where I point it, and it seems to change direction nicely enough. I did note though that the pointyness of the car could be massively changed by altering the front camber settings. When I first had it set up I had a fair bit of camber put on there, and it was blisteringly quick to change direction; but ultimately a pain in the arse to drive on the road so I had it backed off a little.

[BeastMaster]

900T-R said:

450Nick said:

I run 225's all round on my car and my car does not understeer as I have had it geo'd to suit the tyres and my driving style. The 205 tyre works probably because it has been set up like that.

No matter how you cut it, all else being equal c.q. optimised for the respective configuration, more rubber on the steering axle = less steering feel, which has nowt to do with over/understeer in itself. More rubber on the front wheels will ultimately mean less understeer, but also resists changes of direction more on initial steering application.

Think you will find - more rubber on the steering axle will give more understeer not less - because the extra grip will try and keep going in the same direction.

Another point I take into account when considering tyres for the road is standing water. The wide'r tyres are going to aquaplane far easier which I think is very relevent on a car which already has a dark side on wet surfaces.

All this is of course IMHO - I do not do track days, so am only interested in fast road use - my Chimaera is a 500 with some extra work - f205/60/15 r225/55/16 and at the sesible limit of what I would want to do on the road. Any more and I would get locked up.

[900T-R]

BeastMaster said:

Think you will find - more rubber on the steering axle will give more understeer not less - because the extra grip will try and keep going in the same direction.

That's what I said - initially you will get more understeer because the extra rubber will try and resist the change of direction; but ultimately the wider rubber will hang on longer before understeer happens while in the corner.

Standing water indeed is the other concern of note on a car as light as a TVR especially.

[2 sMoKiN bArReLs]

Just as a matter of interest, 500s were supplied new with Imolas as a factory option.

[Chris71]

Well, it's all sorted now!

I picked up a set of Estorils in the end, complete with fresh T1Rs - 205mm front and 235mm rear. Given I'm still relatively new to the car it's probably no bad thing that there's a little bit less tyre area on the front.

Hope to fit them over the weekend and then it's on to the suspension and a thurough service before Spain.