21 replies to this topic

[subseamac]

I have read through the countless threads on the subject and I think it would be very helpful to have a definitive pros/cons view of various wheel and tyre sizes combinations including: (1) rear wheels on front, 5-10mm spacers all round, 205 tyres upfront. cons: without the spacers will rub inside of front wheel arches. Increases weight upfront pro/con (depending) will probably provoke oversteer given increased adhesion upfront. pros does not increase arch gap upfront (esthetics) and will not need lowering - overall sounds like a viable option but mostly esthetically pleasing, questionable improvement in dynamics and by far the cheapest option. cost approx £400 (2) the continental approach - most german tuners - 17" all round sometimes quite light e.g. rial nogaro or rial GTR, etc. fitted in sizes up to 215 fromt 245 rear. Pros are: much lighter than OEM (approx 8Kg), esthetically fills the front arch i.e no need for lowering etc. cons: 245 at rear sounds like it definitely would -rub at max suspension travel? cost wise still manageable at approx £1k (3) the UK approach: 17"/16" combo with TD 1.2. Great dynamics and handling, but gaping space in arches often forces lowering the front. for most other cars done by using lowering springs, but in the UK mostly associated with fitting ££ Nitrons all round. Wheels + tyres + Nitrons will not leave any change from £2-2.5k (4) the ultimate (or is it given hassle?): 17"/16" magnesium speedlines + tyres + nitrons. Will not leave much change from £3.5k Given the extremely wide range of benefits/issues and the massive variance in price could we have some debate from proponents of each option, and come up with 2-3 viable recommendations out of: -rears on front -geman 17"s all round -TD 17/16 but with lowering springs -TD 17/16 with nitrons -Mag speedlines 17/16 with nitrons We could also have a tyre recommendation for each viable option eg 048/R888 for track or dry road, R1s for road and mild track use etc etc who wants to start?

[snoopstah]

There's no real benefit to rears on the front over the other methods you list unless you're a cheapskate like me

They're also quite hard to find, you end up buying the second-hand so they might be buckled/kerbed, and if you've got an NA you need to make sure they're heat-treated. Although I guess you could buy them from Vauxhall directly, but I think they're about 280 quid each.

Worth pointing out that all the options will reduce understeer/increase oversteer, as you're reducing the differential between front and rear tyre sizes. Also, if you have an NA, you could consider Spax instead of Nitrons - about 550 quid instead of 1000+ quid, and they're still leaps and bounds ahead of the stock shocks/springs, by all accounts.

[slindborg]

for the tyre aspects you will always get random answers as some like certain tyres while other loath them... My personal preference... Eagle F1 DSG2's (if you get 3's make sure its a europe batch) Dunlop sports (top end ones) as they rock Not a huge fan of T1's BUT they are good vfm (ish) Ill be trying hankook rs2's with my new 16/17 combo, since i dont know of anyone to have tried them on the vx.... might aswell do a decent tyre test lol. 048's and 888's are great but if you do more than about 20 miles a year they are totaly impractical... id be replaceing them evey 6-8weeks by all accounts :s

[subseamac]

for every day use the standard suspension seems just fine and I'm reluctant to change it because of 16" wheels fitted upfront. There must be a solution to end up with 195 or at most 205 upfront and change nothing else. 195 on 5.5" rims doesn't quite work hence my question about 195/205-shod rears upfront with 5mm spacers, which avoids the need to change all 4 wheels. 195s should dial out some understeer, be more pleasing on the eye than the standard bycicle tyres while keeping the car controllable.

[dw1]

Great thread and I'm avidly watching for more replies as I'm currently going through this dilema. Out of interest why are the magnesium speedlines the ultimate over the TDs? And if they are better, what makes them a grand better?

[mandarinvx]

Great thread and I'm avidly watching for more replies as I'm currently going through this dilema.

Out of interest why are the magnesium speedlines the ultimate over the TDs? And if they are better, what makes them a grand better?

Very very light - I held one at Plans, you can literally hold it on one finger

Unfortunately not entirely practical, as any scratches/scuffs will react! (then again I don't take my Compomotives anywhere near curbs, and I'd keep even further away if I'd spent that much on rims ) Presumably the lack of weight also means they won't be as strong as their counterparts too

[slindborg]

magnesium alloys are used in motorsport a lot to keep unsprung weight down and also reduced intertia on the drive train so the engine isnt having to work as hard to accelerate (steady state remains the same), and the same goes for breaking too. they are possibly stronger than std alloys sicne they are able to take rallying/BTCC abuse etc... but then they have big budgets to keep a huge stash of wheels lol. in our world there is really very little need for mag wheels, unless you just want to add that wikkid line to your max powa spec sheet lol

[subseamac]

All continental tuners go for wider tyre combinations like 215-245. A lot of people on here argue that this is due to the fact that continental driving - specially germany - involves a lot more motorway miles vs here in the UK where a lot of "feel" is lost with wider front combinations. Some tuners offer 8" and 9" wheels in 17" sizes that are roughly the same weight as the 16/17 team dynamics combo, so unsprung weight can't be the only issue. Presumably, increasing grip upfront without a corresponding increase at the rear is a recipe for oversteer, but I've lived with several rwd cars with a tendency to oversteer and as long as you are careful that is usually manageable. My current thinking so far (and it's evolving) is for rears on front shod in 205/40/17 potenzas r040 and rears standard, or perhaps 205/45/17 on fronts to maintain exactly the same diameter as rears, but with 5mm spacers all round for clearance. potentially 235/45/17s on rear after I have finished off my current 225's to maintain the difference in grip front/rear. The 7.5" rear rims will take tyres in the 205-235 range. downside according to some on the continental forums is that the tyres will work less efficiently at the boundaries of standard fitment i.e 205/235 will not be as good as 225 on 7.5" rims? My next favourite combo would be for Thorneys TD 17/16" on "civilian" rubber vs 048/r888 but without the mandatory nitrons. There was a thread recently about lowering springs. I am certain that Eibach or equivalent produces springs that could be used as a replacement with the standard bilstein dampers to lower the car 20-30mm at the front and fill the gap resulting from the 16" upfront rears on front is a £350 job all in, TDs/tyres and lowering springs probably £1.5k given the need to remove existing springs + replace. Either way a much cheaper option than the £2.5 to £3.5k 16/17 + Nitrons. I would love to have a ride in (1) 16/17 TD with no Nitrons (2) 16/17 + Nitrons (3) rears on front - rare but a few brave souls still using that combo? (R1chy?)

[slindborg]

i dont think there is a "need" to replace the shocks/springs to lower the car for 16" fronts... it just looks a bit nicer (and would give mild handling improvements but nothing major) and for the record205/45/17's will NOT have the same diameter as 225/45/17's the profile number is a %age of the tread width. Myself and RobNA shall soon have 16/17's on normal tyres and normal suspension (well mine wont be std suspension for long since my spring platforms ahve corroded and will get spax or something to replace it all but set at nearly std settings)

Edited by slindborg, 29 May 2007 - 07:51 AM.

[subseamac]

thanks, what fronts would give the nearest diameter to the standard rears: 205/40/17?

[slindborg]

205/50/17 is a ffraction bigger (2mm) than the rears... you can have a difference in sizes its not the end of the world.... just not a huge one. iirc 5-10% is about the limits of difference 205/50/16's (which ill be running) are 3.6% different to the std sized rears... no big deal there imho.

[snoopstah]

thanks, what fronts would give the nearest diameter to the standard rears: 205/40/17?

205/40/17 on the front will cause the ABS to enter ice mode (do a search) more often than is ideal, especially if the front tyres are worn and the rear tyres are unworn (as that's when the rolling radius is most different). They also don't look great cosmetically, if that bothers you (they have that 'stretched tyre' look).

205/45/17 would be ideal, but your tyre range is reduced accordingly (i.e. no R888 option, which you do get with 205/40/17s). You'd also probably have to run 5mm spacers (which you, or at least I, get away without needing with 205/40/17s).

Also, remember you should be comparing tyre sizes with the standard front tyres (175/55/17s), not with the rears, as that's what the ABS module is calibrated to - and there's a 1.6% size difference between the standard rears and fronts. This means that 205/40/17s are 4.6% out, 205/45/17s are 1.3% out, and 205/50/17s are 2.0% out.

[subseamac]

sounds like 205/45/17 then. You're the second to have tried/lived with that combo successfully. Have you tried 235's rears? On the 5mm spacers any particular source or just Demon T? Re bolts which are already prone to failure standard, have you fitted longer bolts to compensate for the spacers and increased bolt strength? sorry for all the Qs

[snoopstah]

sounds like 205/45/17 then. You're the second to have tried/lived with that combo successfully. Have you tried 235's rears?

On the 5mm spacers any particular source or just Demon T? Re bolts which are already prone to failure standard, have you fitted longer bolts to compensate for the spacers and increased bolt strength?

sorry for all the Qs

Unfortunately I can't help with any of that, as I'm running 205/40/17s without spacers, even with the ABS problems (which are fine as long as you're used to it).

About the only thing I can say is that I don't feel the need for 235-width rears with the 205-width fronts - there is one downhill off-camber exit from a roundabout to a motorway slip-road where it can feel very slightly unsettled if you're really shifting, but otherwise it's a very neutral drive - and to be honest I think it would feel unsettled regardless of the tyres, just because of the profile of the corner.

Edited by snoopstah, 29 May 2007 - 09:20 AM.

[PaulS]

subseamac, I have the 16/17 TD wheels with Toyos T1-Rs and standard suspension. Im in N London if you wanted a run out give me a PM. Also Im doing the Abingdon track on the 15th June which would probably tell you more if you want a pax ride.

[ChazUwe]

in our world there is really very little need for mag wheels, unless you just want to add that wikkid line to your max powa spec sheet lol

Lol, I am not sure I agree with the Max Power spec sheet comment

I have the Plans Magnesium Alloy speedlines and I can honestly say they have been the best money I have spent on the car. I can't compare with TD's or any other wheels but the difference in feel and general plantedness on the road is fantastic. I can't stand switching back to OEM's (which i have currently as off to the alps in a few weeks). Whilst on the road general drive is much improved, on the track the difference is even further highlighted.

Yes they are expensive and at the time it was a bit of a snap decision (like most decisions I make while visiting plans ) but I don't feel that they are particularly over priced. Personally I am not a massive fan of the multi spoke wheel types such as the Oz's/TD's so it didn't really leave me with much choice, and as second hand sets of standard VXR speedlines fetch upto £1000 on ebay (and weigh twice as much) I thought what the hell!

In addition I knew that in the future I would either be going for a VXR or keep my N/A and get it TB'd or S/C'd. Either way a set of wheels is a nice easily transferable mod dependent on what I ultimately decide to do. Which at the moment is keep the N/A and turn it into a track monster

I do love the look of them too

[RichH]

Surely which of the four options is best is simply down to why you would want to change from the standard set up? Going through the four: 1) Personally I'd rather not have the extra weight up front for the sake of a little bit more grip. If it's for track use then you can pretty much drive around the lack of natural front end grip by altering your driving style, and on the road you can't/shouldn't really be getting that close to the limits of grip. I'd suggest that a decent geo setup would be a better option if you prefer a more tail happy car. 2) Similar to option one, just with non-standard wheels. This is purely asthetic and does rely on actually finding some decent looking wheels. So far I've never seen a set of aftermarket 17" wheels on a VX that look nicer than the standard NA ones. Some have come close the the VXT ones though Beauty is in the eye of the beholder though 3) If track days are what you like doing then this is a good solution, but remember that on the road the ride in a car equiped with standard Nitrons is really quite horrible as it's too hard (IMO). If you don't do track days you won't really be able to stretch the car enough to take full advantage of them either so I'd steer clear of this option. Obviously you could always try to get different springs fitted (extra £?). Of course there are other alternatives such as Spax (as previously mentioned) for the NA, or the Sach's ones being sold by Plans, or even a standard set of VXR suspension for a VXT. Of course there is also Ohlins which in my mind is the best solution (but also the most expensive) and I can't fault them on my VXR. Using Spax or Sachs you'd also save at least £500 on the prices you've quoted, maybe more. 4) As others have said you'd have to be very careful everywhere and if you're racing or tracking a lot this might be the perfect setup, but for mostly road, the nitrons are still too hard and the speedlines too expensive to risk getting curbed etc. As for alternatives, what about getting some of the VXR speedlines? Many people on here have bought them. You might also come across some of the OZ wheels that TMS were selling a while ago, or there's always the option of swapping to lotus hubs and then having access to all the elise/exige wheels. One thing though, is it still possible to buy lowering springs? The only ones' I've ever heard of were the eibach ones but I'm sure they only existed for the NA and were discontinued about a year or so ago.

[slindborg]

erm surely you can get the relevant ID coilover springs in the appropriate rate and length from the likes of tweeks to lower the car.... they arent that expensive either

[MartinS]

What about td 1.2 17 inch front, with 17 rears, they do make them. Might be a balanced compromise? Martins

[RichH]

erm surely you can get the relevant ID coilover springs in the appropriate rate and length from the likes of tweeks to lower the car.... they arent that expensive either

Quite possibly. TBH I've never looked into it, I just remember when the eibach ones were available that other people that were buying them were saying that they were the only options and there was a bit of a rush to get the last available sets.