General max width alloys that fit on uno mk2??

[unoracer]

I need to get some 15" alloys for my race car, to 'up' the gearing a bit on longer circuits. Can anyone tell me what width I should be able to get under the arches? (I am allowed to curl arch lips back and use turbo arch spats to help clearance, and also running with at least 1.5 degrees neg camber which will help! I was hoping that I may get away with 6.5 or 7x15" rims with circa 205/55/15 slicks, but unsure what offset and width/diameter I should get away with! I am not allowed to use hormann arch kit etc in my particular class. Any pointers wheelie appreciated!

 

[circolo]

7x15" rims will fit.

But it's very, very tight at the back. The front isn't so much of an issue tbh.

The rear problem is getting the wheel to not foul against the rear swinging arm, and the outer arch lip. Move one way and it'll rub on the arm, move a mil the other way and it'll hit the arch lip.

But it can be done.

Ideals would be

Rim: 7x15, with an offset of 35-38
Tyre size: 195/45 r15

With that combination, you may just get away without having to alter the arch lip.

On the front, sometimes you have to remove the plastic arch lining for full lock.

 

[circolo]

Just noticed you're looking at 205/55 rubber. This is won't fit. Particularly on the rears, unless you're look at extensive arch lip work, and possible inner arch and swinging arm work too.

195 is really the widest tyre for the rears, and at 45 profile too.

The fronts will take a slight wider tyre, so 205 should be okay, but then at 15", I'd like to see the profile to be 45, perhaps 50 at the most.

 

[Jai]

do mk2 owners have the same rub issues onto the gearbox, with the front nearside tyre on full right lock with any wheel/tyre combo over 5.5inches wide?

 

[oldskoolmk1unoturbo]

i use spacers on the front of my mk1 and no clearence issues

 

[antsuno2]

When i bought the alloys on the mk2 (£500) there was a very limited choice for all fiats due to the funny offset, but luckily i stumbled on these, 195 45 15's and they dont rub at all, not on the gearbox and not even with passengers in the back and its lowered slightly, (spax adjustables 40mm) the place i bought them said out of all those shiny wheels, i only had the pic of around 5 so ended up with these I also bought wheels for the golf at the same time and they are 205 40 17 and they were only an extra £95, seemed a bit strange the golf wheels were not much more expensive? and he gave me the locking nuts for both free. Nice blokes at wheelbase in oldham! Ant!

 

[unoracer]

Thanks for the replies, I will have a play with gearing calculator to see how much I will gain by using 45 or 50 x15" profile. I don't want to go too low on profile as I will defeat object of increasing rolling radius for the odd long straights etc, and also want to keep rims well away from kerb strips! I will curl the arches up anyway to maximise room. I would look at using 14" but slicks tend not to be available for them.

 

[circolo]

If you're prepared to do some work to the arch lips, then you'll have more choice.

In the Uno Turbo owners club (UK), I knew someone who was running 16" rims, with 195/45 profile rubber - effectively increasing the overall rolling radius a little.

If you're prepare to forego the correct offset and go for a lower number, say, et 30. The front arches can be (relatively) easily played around with, some of the old members of the UT club used to put a longer stress bar, replacing the OE one that sits between the edge of the front wing and the inner wing. You can, this effectively added a cm or so of extra width on the front arches - doesn't sound much, but that could be enough to accomodate what you're looking for.

On the rears, you could completely remove the arch lip, and add UT plastic trim instead. But other than major bodywork mods, you're very limited on the rears.

Incidentally we worked out previously that a fair amount of the strength of the arch and wing area is reduced, if the complete arch lip is removed.

 

[alexGS]

Thanks for the replies, I will have a play with gearing calculator to see how much I will gain by using 45 or 50 x15" profile. I don't want to go too low on profile as I will defeat object of increasing rolling radius for the odd long straights etc, and also want to keep rims well away from kerb strips! I will curl the arches up anyway to maximise room. I would look at using 14" but slicks tend not to be available for them.

Exactly. I use 195/45s myself and as the others said, they're a good fit - BUT you have very little extra diameter over standard! So for your aim, I think you're better off changing the gearbox. Basically, 195/45/15s are an extra 3% over 175/60/13s, which serves to make the speedometer more accurate in my Uno Turbo - only over-reads by 5% now

It seems that if you go up in overall diameter, you hit the gearbox. And as far as going up in width, you hit the rear beam or the wheelarch. You could of course make up some limits for the steering rack (I thought of a plastic collar inside the rack at each end, but I was told this was risky from a seizing-point of view).

One car I had (Alfa Romeo 164) had some metal tabs welded to the suspension arms - the hub carrier came to rest against these to limit the steering lock - this is with standard wheels and tyres as a way to solve the tyre rub on the gearbox...

See also http://www.carbibles.com/tyre_bible.html which is my source for calculators etc. It's an excellent page, though now very large - scroll down a long way, past the Tweels and coloured dot/line mark explanations, and you get to the Tyre Size Calculator.

-Alex

 

[oldskoolmk1unoturbo]

I plan to fit a set of OZ ultra leggeras with 195/40/16's to my black mk1 ;-)

 

[unoracer]

Thanks again for responses: I am not allowed to start removing any metal from the arches, only curling up of the arch lips. I like the idea of a longer stress bar to front wings to give a little extra width.

Alex, I can't change my box as I need the current box set-up together with 13" rims for most of Uk short/medium straight circuits. Its just the odd longer circuits where I could use a bit more top end speed potentially. The other option I have is to remove the endcap off the delta/mk1 turbo type box I have and replace the 5th gear cogs only, resulting in 'higher gearing' in top! ( a very easy job to do Im reliably told!?)

I may just buy a cheap set of 15" rims to experiment with on test days etc. I suppose its the only way to see what works and what doesn't work!

 

[SteveNZ]

Thanks again for responses: I am not allowed to start removing any metal from the arches, only curling up of the arch lips. I like the idea of a longer stress bar to front wings to give a little extra width.

Alex, I can't change my box as I need the current box set-up together with 13" rims for most of Uk short/medium straight circuits. Its just the odd longer circuits where I could use a bit more top end speed potentially. The other option I have is to remove the endcap off the delta/mk1 turbo type box I have and replace the 5th gear cogs only, resulting in 'higher gearing' in top! ( a very easy job to do Im reliably told!?)

I may just buy a cheap set of 15" rims to experiment with on test days etc. I suppose its the only way to see what works and what doesn't work!

You could change just 5th gear. This can be done with the gearbox in the car too.

 

[circolo]

Just one other quick point. I'm not sure what you're allowed to do and not do with regarding to body mods.

But you could beat out the rear arches wider, if your any good with bodywork. It'll ruin the lines of the Uno, but you'll be able to get bigger wheels on the car.

Or you could run bigger wheels at the front - I'd say easier to accomodated the larger radius you're after but standard size at the back, put lower springs at the front to balance the cars height, and then you'd achieve the better gearing your after, without too much hassle with the rear wheel fittment.