Quote:
Originally Posted by Problemchild1976
Well firstly the wheels are made/designed for the car
Offset is ET6 and they are 18” ocean mk18
The tyres they are designed to use is 205 35 R18 but those are the tyres they came with from a non lowered volvo.
Fronts are close but I’ve had closer 
I want the arch gap to be the bit that matches better as this looks like it’s collapsed a bit at the back
I may still need to change the tyres but let’s see
JJ |
There isn't a need to be so defensive - I'm trying to help.
If the wheels are designed for a 240 then they should fit, but they don't - why not?
205/35R18 tyres would give a rolling diameter of 23.7", whereas with the 225/40R18 tyres it is 25.2", so the difference in radius is only 0.7", which still wouldn't give enough clearance for suspension travel. The 205 tyre would be 10mm narrower (inside and out) so that might work.
The offset is 6mm, so 14mm less than standard, I suppose that is to get enough clearance at the front between the inside of the tyre and the suspension strut. On the outside it will mean that the tyre sticks out 14mm+15mm = 29mm further than standard. I've just measured out 30mm on the RB and can see that would put the edge of the tyre under the wheel arch. If I measure up to the wheel arch from that imaginary point where a 225 tyre would be then there is 45mm of clearance. I reckon the RB has about 75mm of suspension movement at the back, but the wheel has 180mm of clearance up inside the wheel arch. Now, you have lowered the motor car by 40mm (near enough to 45mm for government work) at the rear, which explains why the wheel/tyre/suspension combination won't work at the mo.
Have you seen this set up (40mm lowered suspension, ET6 and 225/40R18 tyres) working on someone else's motor car, or has the manufacturer claimed it will work? If so then something (suspension) isn't quite right. On the other hand if not then the options would seem to be to raise the suspension (quite a bit I should think - you have zero clearance at the moment and need at least 75mm (in my estimation) of suspension movement, so to about 40mm higher than standard (that might make it look a bit too dragster?). fitting a bit smaller tyres might work, particularly if 10mm narrower bought it inside the wheel arch. You can't increase the offset of the wheels, so if you want to keep the Ocean wheels then those are the options.
From what you say I'm guessing you have actually tried steering the car on full lock and suspension travel, and there are no clearance problems at the front? If you haven't actually done that yet it might be a good idea to try full lock and bounce the suspension just to make sure it fits before spending too much money on fixes.
I recall us having a similar discussion when you were thinking of banding some steel wheels a few months ago; I think we discussed similar numbers then. There is a much more radical third option: flaring the wheel arches (Eeeeek! this is the Volvo 240 corner)!
Anyway, I'm sure you will solve this one, you have come too far with this project not to. I admit the motor car would not be my cup of tea (which is in no way significant), but the work you have done so far has been first class.
This is a really interesting thread,
Alan
PS. I've just looked up: Ocean MK18 Silver 8,5x18 5x108 ET6 HUB 65,1 on some supplier's website. For a Volvo 140/240/740/940 they come with 205/35R18 tyres and there is no mention of them fitting with lowered suspension. I found this photo of the wheels fitted to a 740 with 205/35 tyres on the dealer's website (credit to TH Pettersson AB):
... the tyres do look a bit stretched for 8.5J rims, but they do fit (just!). It may be that you have to fit the 205/35 tyres and revert to standard length springs (at least at the back) to make them work on your motor car JJ.
PPS. If it were me (and I know, it isn't), I try the free option first and revert to the standard springs at the back. You have just taken it all apart, so the bolts should come undone easily, probably only a morning's work. If the wheels don't rub then I'd put on the clear coat and call it a job - it might make the motor car look less awkward at the same time. If it still rubs you would have lost nothing before you lay out £400 on new 205/35 tyres. That is what I'd try - but then I'm a tightwad.