Gt6 Mk3 15" Wheels

[Jimmmy0_0]

I am about to start rebuilding a Mk3 with a 2.5 pi. I was thinking about wheels and tyres. I would like to fit 15" by 5.5 using 195/50/15 tyres.

Does anyone know if they will fit and if any body work mod's will need doing? Or has anyone done his before?

Thanks James

[Nick Jones]

Well, people fit MGF 15 x 6" to Spitfires - seems to work

Nick

[GT6 M]

Jimmmmmmmm,  me thinks  51/2 inch for 195/50,s is far far tooooooo  narra a wheel

you looking at 6 min preff 6  1/2 s ideally  7,s

you will be hard pushed too find many you like, too, :-/ :-/

as Nick says, there are alot of Mgf wheels about, in 15, 16 inch

I my self was thinking of 16,s but I thought that there was too much camber change,

for that wide and low a wheel,

so opted for 15 inch and a 50 series tyre [ 7 x 15 ]

it all depends on the inset / off set of the wheel for the way it sits,

back end seems as though it will tek it, but fornt end looks a bit  ..wide..

due to the way the wheel arch goes to nothing, either side,


one thing you will need is 600lb springs, min, and possibly a thicker roll bar too,.

and depending what you got, one on the rear too,

  as the amount of body roll you going to get, by the xtra grip,

is going to play havoc with the handling  of the car, and the grip of the tyres  , if you no get it right,.

tyres will be constantly working away on the ..edges.., so you need to limit travel a bit,

to keep the cmber changes , to a minimum,

the fatter and lower the tyre, the less camber change ye want,.

dont get it right, and you will be no better off with fatties, as you are with a decent set of ..skinnys.. :-/ :-/


regards

Marcus

[jango]

I have 14" 6" with AO48 on

[cook1e]

My Mate Colin has got 15" 5 Spoke Revolutions on his GT6 as below.

Car is rather modified and not sure what rear hubs he's got fitted as he's got rear discs (Sierra Cossie LSD, custom built coil over shock rear end)but the front hubs are defintly standard GT6 PCD so you can certainly get 15" revolutions to fit the GT6 PCD.

[Jimmmy0_0]

Ok so 15's should fit ok but Marcus you said 5.5's are to narrow if I was to order 6.0 or 6.5 what tyres should I fit?

[AndreGT6]

[Jimmmy0_0]

AndreGT6 what width are your wheels and what tyre size.

James

[GT6 M]

Jim, if you go to a narrow wheel with tyres that are big,

then the actual tyre sticks to the road, ....BUT... the rim moves aboot ont wheel,

so making it feel like you driving with ..flat tyres..  every time you want to change direction

and it all depends on how stiff the side walls are too,

eg, 1 ply side wall on me MX, and it was  a little vague, going into corners,

just put some 2 ply ones on, and its like  being on rails , no bend at all in the side walls

but then , they a motor sport tyre,

sizes,

195,  50, 6 min  up to 7
205   50  6.5 min to 7 +

plenty of info aboot on this subject


just seen a MGF today, with some   lurvvly  6 spokes on it,  MGs own brand ,

see if ye can find them on a site, some where, it was a newish car too,.

a 195 will give just under the gearing,

a 205 will give just over,

regards Marcus

[Tim Bancroft]

James,

Have a chat with Mike Bestard about fitting MGF 15'' wheels to a mk3-not sure its such a great idea?

Paul Michelmore has 14'' Revs on his Mk3, think he rates that combination-however 14'' Revs are unobtainable at present!

Personally speaking MGF wheels on a Triumph-er, no thanks!

[DoZ]

Can't find a better photo at the moment but I have 15" MGFs on mine and like the look.

I went down from the MGF standard 195 fronts and 205 rears to Toyo proxes, 185/55R15 and it seems to work well.

BTW mine is a rotoflex model which might sort out some camber issues with larger wheels.

[Jimmmy0_0]

Thanks all

I was looking at 15" minilights. Doz mine is a rotoflex to but will have the c.v conv carried out when I get around to doing the machining bits.

First things first the new panels and welding need doing.

I think 15" by 7 with 195/50s will be the way to go?

[AndreGT6]

http://www.gt6.ca/06/0127/index.html

[DoZ]

Jimmmy the reason I went 185 was because I thought the thinner tyres would be softer, due to the ratio of width to heigh being larger.

Not sure if the difference between 185/55 and 195/50 would be that noticable.

[GT6 Mike]

MGF 16 x 7's will fit on a non roto car.

Currently fitted with 215/40 which are great in the dry but too wide for wet conditions.

I will try some 195/45 next.

Handling on my car is very good but the ride quality suffers a bit  :)

[Royboy66]

reckon these are 15", or even 16" ?  8)

[Jimmmy0_0]

Ok I know I shouldnt say this but that looks great. What pcd are they or what hubs?

[CharlieB]

To me that looks SO wrong!

[Nick Moore]

I think the idea is that the wider the tyre, the lower the weight on the road per square inch. In the dry this is OK, but in the wet a tyre not pushing down hard enough onto the road can aquaplane - the water under the tyre isn't expelled and the car rides on a layer of water rather than road.

[Nick Jones]

Iain,

Even if you are right about the size of the contact patch being the same (not sure about that), you have already answered your own question - the contact patch is wider and therefore encounters more water which has to be displaced to prevent aquaplaning.  Small, light cars with wide tyres can get very frisky in the wet when the tread depth is low - I remember a certain Golf GTI...... puddle-hop or what :o

Nick

[Deleted User]

The tyre contact area for any tyre is calculated by dividing the single wheel load by the tyre inflation pressure.
If the load is expressed in pounds, and the tyre pressure in pounds per square inch, then the area is in inches squared. The same thing works with kilograms and kg/cm2 - the result will then be in square centimeters.

So if you fit wider tyres and keep the pressure the same, the contact patch will have the same area - but will be a different shape !

[Deleted User]

Wet grip, and the point of aqua planing is all about how quickly the tyre can expell the water.

Basically, the wider the tyre, the further the water has to travel to be expelled, so the easier the tyre will loose grip in the wet.

A good tread design can expell more water, so will loose grip at a higher speed.
Likewise a good tread depth that gives the water somewhere to go also helps, and is why the Police change their tyres when the tread depth is down to 4mm.

The other thing that needs to be remembered is that the contact patch area for each tyre changes as one corners, as the individual wheel loads change, and that fitting wider or narrower or bigger or smaller wheels will change the suspension geometrty (camber) and thus change the rate at which each wheel load varies.

[DaveKent]

no, mike bestard has a mk3 gt6, same ish as the spit 1500

[DaveKent]

pic of his sexy car

[Tim Bancroft]

I hope Mike will not mind me saying, but on the 2007 10CR his car had loads of grip when the roads were dry, but I think he suffered abit in the wet. Howver his car is abit nippy so trying to get decent horsepower down onto the road was an issue. Not so sure now as he has done some mods and probably softened the car up abit.

Mike did comment about his wet weather grip earler in this thread. Great car or what.

I'm a fan of smaller tyres in these cars-my fear is increased grip will make a spin speed to high to catch, I'd rather run out of grip at a slower speed, but be able to catch-these cars are not particulary good at letting the driver know what the wheels are doing though!

I think in James' case I'd go for a set of 14'' Comp MLs and fit nothing wider than 185.