18inch wheels

[jsr]

As my rear tyres are now almost completely worn and i appear to have a tack in the tread of one of the fronts and also as my standard wheels are fairly scuffed and the paint flaking from some of the spokes, i'm now looking to upgrade to 18inch wheels... though possibly only at the rear - i may only fit 17 at the front.

I'm gonna fit rims and tyres that overall do not change the height of the wheels so the car doesn't end up looking like it's on stilts - a look that so many of the 'nova' drivers seem to achieve! I'm also trying to keep the tyre widths as close to standard.

In case anyone else is considering a change of wheels and as a future point of reference, the standard wheels and tyres on my 94 Chimaera are:

Front: 205/55x15, 7" rim width, offset ET25; overall height 607 mm
Rear: 225/50x16, 7.5" rim width, offset ET33; overall height 631 mm

Toyo have a very good tyre size calculator on their website and using this i've found my various tyre options to be:

Front:
205/40/17 - 597 mm height
215/40x17 - 606 mm (*)
215/35x18 - 607 mm

Rear:
225/45x17 - 636 mm
235/40x17 - 620 mm
245/40x17 - 628 mm
245/35x18 - 629 mm (*)

I'll probably go for the ones marked (*) which keep the overall height almost the same and only increases the widths slightly (and still only to those of the later power assisted cars). The small front rim will mean that the tyre sidewall height is the same front and rear.

Whilst some of the wheels i'm looking at come in 7x17 and 7.5x18, others only do a 8x18 at the rear so i'll need to work out the correct offset.

Is anyone using an 8 inch rear rim? I presume there are no problems with the width. What is the maximum size rim width that could be fitted at the rear?

[petros]

be aware that fitting 17 or 18" rims will most likely lead to a lot of tramlining and will certainly lead to a harsh if not downright unpleasantly bumpy ride.

[jsr]

I am preparing myself for the possible side effects, though other people have said they haven't noticed too much difference with bigger wheels.

The upgrade is mainly for style. My wheels are in such a state, they let the car down. I also don't like the fronts being so small. Despite the body design being 12 or so years old i think the Chimaera still looks a very fresh design. Unfortunately, the small wheels date it a bit - a set of big wheels will give the car a much more modern look. (IMO of course)

Some of the wheels i'm considering are also lightweight racing rims so there may be some benefits there.

[nztrev]

Have you thought about 40/17" for the fronts,unless you've got a good suspension set up,I say good luck to you with a 35/18 front.

ps: you can go far wider than standard if you do yor homework,,215FR 225R will look like bicycle wheels.

[19560]

jsr said:

Front: 205/55x15, 7" rim width, offset ET25; overall height 607 mm Rear: 225/50x16, 7.5" rim width, offset ET33; overall height 631 mm Front: 215/40x17 - 606 mm (*) Rear: 245/35x18 - 629 mm (*) I'll probably go for the ones marked (*) which keep the overall height almost the same and only increases the widths slightly (and still only to those of the later power assisted cars). The small front rim will mean that the tyre sidewall height is the same front and rear. Whilst some of the wheels i'm looking at come in 7x17 and 7.5x18, others only do a 8x18 at the rear so i'll need to work out the correct offset.

You've done a nice piece of homework there. NB that the standard rims are generally considered to be too small at the rear: an 8.5" rim would be ideal but 8" is fine for a 245 wide tyre. Because the ET (or offset) is measured from the centreline then you can leave it unaltered although it's usual to increase the track by half the width increase of the inside (which would give an ET30 for the rear) but I wouldn't bother.

[jsr]

You've got a point Gazboy. The 245/40x17 rear does sound like a more sensible option. Would also save quite a bit of cash too - the difference between 17 and 18 inch wheels is quite surprising!

One other thing i've though of - it's gonna make my brakes look absolutely pathetic!!!

[petros]

was at tvr central in stourbridge the other day and they,d got a tvr power 5.3 chim in with 18" alloys on and the mechanic said that the ride was VERY harsh, all bumps could be felt.

[Graham]

I've got 17's all round on mine, and you need to match the dampers to make things work properly, which they do on mine, but even then it can be a bit harsh on bumpy roads...


i think with 18's you'd struggle to see never mind keep it pointing in a straight line on some roads.

if your doing it for looks you will need to upgrade the front brakres as well... which isnt a bad idea any way ( i only put the 17's on as my caliper clearance was a bit tight at the front...

G

[Corin Denton]

I use 215/40x17 front and 235/40x17 rear on mine and the ride is fine with the Toyos and I don't expect it to really change once the new suspension goes on next month.
I did get a bit of tramlining with the Avon ZZ3s in 17" on the old Chimaera once the AVOs and polybushes were on there

You really need to look at fitting Nitrons if going to 18"

[shpub]

jsr said:

I am preparing myself for the possible side effects, though other people have said they haven't noticed too much difference with bigger wheels.

Depends on who you talk to.

jsr said:

Some of the wheels i'm considering are also lightweight racing rims so there may be some benefits there.

Usually it is for the wheel supplier as these type of rims can easily deform and go egg shaped if the wheel hits a pothole or something like that. The lower profile tyre means that something has to give and whereas it would normally be the tyre flexing, this is not the case. The next weak point is either the rim or suspension.

Also bear in mind that some of the pressures needed to seat the tyres on these rims is often far higher than a TVR normally experiences and this causes a bit of dilemma: either run at a lower pressure to get some tyre compliance and preserve teeth fillings or run at the recommended pressure and make block bookings at the dentist.

[Corin Denton]

I personally found that when I changed from the stock wheels with Bridgestones on to an aftermarket wheel without Bridgestones that the pressures didn't need to be altered too much due to most manufacturers having softer sidewalls than the old 'S.O.' tyres.

By the way, I spoke to Bridgestone U.K. this week and have completely run out of the standard Chim/Griff sizes now for good! When I asked them what would be the next move for a customer they are actually reccomending Toyo now!

[19560]

jsr said:

The 245/40x17 rear does sound like a more sensible option.

Remember that Chims were launched with the 630/654 rr but switched to the 608/630 Griff set up. 215/45/17 front (626) with 245/45/17 rear (654) would give the comfort compliance and rim/car protection althoug the 215/40/17f (607), 245/40/17r (629) is very tempting.

[tahiti450]

petros said:

be aware that fitting 17 or 18" rims will most likely lead to a lot of tramlining and will certainly lead to a harsh if not downright unpleasantly bumpy ride .

Certainly not my experience on 17" (f) 18" (r) running T1-S .
But I've wittered on about my views on wheel/ tyre mods at length on other threads. See my profile.

>> Edited by tahiti450 on Sunday 27th March 15:45

[jsr]

Tahiti450 - you're wheels look absolutely stunning on your car, a perfect match for the paint colour imo.

Not a style i'm considering though - don't think i could be bothered with the effort to keep them clean.

Will definitely be running Toyos - used them on my previous car and think they are a superb tyre, especially in the wet. Tread pattern is very cool too!

shpub - i might be ok with the lager wheels... i don't have any fillings

It's not easy trying to find a set of wheels that suit the car and come in the sizes (and don't cost a fortune either).

[markh]

tahiti450 said:

petros said: be aware that fitting 17 or 18" rims will most likely lead to a lot of tramlining and will certainly lead to a harsh if not downright unpleasantly bumpy ride . Certainly not my experience on 17" (f) 18" (r) running T1-S . But I've wittered on about my views on wheel/ tyre mods at length on other threads. See my profile. >> Edited by tahiti450 on Sunday 27th March 15:45

[markh]

tahiti450 said:

petros said: be aware that fitting 17 or 18" rims will most likely lead to a lot of tramlining and will certainly lead to a harsh if not downright unpleasantly bumpy ride . Certainly not my experience on 17" (f) 18" (r) running T1-S . But I've wittered on about my views on wheel/ tyre mods at length on other threads. See my profile. >> Edited by tahiti450 on Sunday 27th March 15:45

I agree have 17's all round and Nitrons and find the ride spot for me






>> Edited by markh on Tuesday 29th March 14:21

[jsr]

Nitrons are on my 'to do' list, but won't be getting them in the near future.

[Chimart4L]

I'm looking as well, would be interested in what the car looks like when competed.
I agree the standard wheels do date the car........

[petros]

i,ve just had a new set of wheels, they,re on the post i can,t believe you kiss your car goodnight. mine,s the green chim V8 OOF. for details of where i got the wheels e mail me at [e-mail] petros

[spend]

V8 OOF, must cost a fortune to keep clean!