Tuning Improving cornering

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Tuning Improving cornering

Steve145

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Ok, so now I've got my Uno 45 up and running, I'd like it to be able to take corners a bit faster.

Current tyres are the standard size 135/80R13, ditchfinder brand.

Firstly, I'm thinking that 135 is actually too narrow for the standard 4.5" rim (should really be on a 4" rim) and that I should upgrade to the "option" 155/70R13 size. Noticable difference? Should I go wider?

Second option is the set of 14" Alfa/Speedline pepperpot alloys I have lying around. Narrowest tyre I could run on these would be 165/60R14. If I fitted these, I could also fit a set of Alfa 145TD front brakes (254mm disc, non vented), not tested yet (and I would before investing in tyres), but hoping "Fiat parts bin" means the bolt spacings will be the same.

In either case, tyres will be Uniroyal RainExpert, for a good balance between price and performance, sadly they don't make the RainSport in small sizes. Unless anyone wants to suggest something else?


Strut-brace, antiroll bar are all under consideration, but it seems sensible to start with the tyres.

A full suspension refresh is also planned, not sure I want to lower it though.
 
To be honest, I don't remember the 55S we used to have with the slightly wider tyres cornering any better than the 45 we have now. I also owned a 1985 Uno SX 3 door which I think had 165/65 r 13 Pirellis and that seemed to corner much tighter. In fact, a lovely little car all round - would love another one now!
Agree with your assessment of the Uniroyal tyre. Just fitted a set with new steel wheels from Mytyres and very pleased so far.
 
Tyre's are great and all, and having a 155 tyres on my 45, and with my sister having 185s on her 45S, there isn't much of a difference. The biggest differnece is suspension in my opinion - Maybe a strut bar, some new shocks and maybe an anti roll bar or lower/stiffer springs would help?
 
Not sure if this applies (as I don't know what sizes the driveshafts are & if they'd fit into the gearbox), but if the larger models have longer driveshafts, using those gives you a cornering advantage cause of the wider track.

(a not so recommended version is to use spacers on the wheels, I wouldn't do so purely cause it's weaker and can break more easily, it's more for looks that kind of mod)
Then you'd need to get the longer control arms too. This may make it lowered also, as the struts stay the same length.
And it'd affect the steering rack ( tie rods ) cause they're also fixed to the uprights. Might not be a good idea to just unscrew them a bit more, makes them that bit less secure & puts extra pressure on them - I'm not sure if there's other models that have the same size tie rods screw threads, and you can just swap longer tie rods onto the existing rack.
Otherwise it'd be best to use the steering rack from the other models.

(Not sure if this'd affect you - but for road legal purposes you then have the thing with the wheels not being fully arch covered. Plus clearance, so you need to change the arches anyway.)

Then your rear wheels are tapered in compared to the fronts, if undesired then - wider wheels and tyres? If you can, play about with different settings, eg use alloys on the rears and see if that works with steels upfront - do the rears follow the fronts better, or do they follow better as steels. That kind of thing.

An ARB properly set up should help. That should keep the car body level with the road more. As would stiffer springs. Adjustable dampers. Lowering works as it lowers the centre of gravity - but that changes the wheel alignment (static and dynamic).
Stiffer springs are going to be more jumpy and not as comfortable - if you use adjustable dampers you can kind of cheat and keep softer springs, stop them reacting as much - then when you use the car for 'normal' driving set them back to road use again.

When you change anything in regards to all that, you need to re-do the wheel alignment - and that can mean recalculating from the original settings. Not sure if you can adjust the front struts at the turrent mount, if so then that helps.


Another in-theory (I'm not sure what's available etc) - different CV joints, as when you're taking a corner you'll get weight shifting to the outside wheel so this is going to affect how the angles and plunge amounts react.

Stickier (softer) tyres, lower tyre pressures, for grippiness.

Maybe try different wheels for different backspacing.

Not easy to change castor, you'd need like different uprights or to modify them. With struts & the single control arm, the easiest way I think is via the strut mount at the turret. The more 'upright' the castor is the less scrub you get, it should be more stable as it's more direct, but as it gets more upright it gets harder to steer it in terms of effort required.

Again, more in the major mods and money dept this - but a limited slip diff. There's some manufacturers make an ATB that fits the Punto (it may even be the entire transaxle, I forget) so that should fit Unos as - as far as I know - their various transaxle units are interchangeable. The ATB responds directly to the road so unlike the ramp types and other statically weighted types, it's more like an active differential.
 
Swap it to hydragas suspension! (like the original DS - you could lose a wheel on those and the car still drives right)
 
Thanks, but for legal reasons, the suspension will be remaining fairly standard.

P.S. Hydragas was the Metro, Citroen was Hydro-Pneumatic, no?

Nice idea though, somewhere around here is a Willys Jeep with retrofitted Citroen suspension, very cool, but not really road legal (it gets away with it due to age).
 
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A decent set of 135s should be fine if you want to prove a point that the original design was fine, but going to 155/70s would be a decent and legitimate upgrade. You'd have more grip when you need it and the walls would probably be less flexy, steering might be a bit heavier but not by much.

Don't go wider, and I'd say forget the Alfa alloys etc. Fiat rims or trims always look the best on these original unmodified cars.
 
Sorry for the late reply.

Based on my experience with my Uno SX (over 6K track miles) I ran

FIAT O.Z. Alloy wheels - Type 01B7 B, 5J * 13 H2 ET45
Tyres - Pirelli P6 185/60 R13 80H

Unless you change the rim ET offset value then the biggest tyre you can use on the Uno is a 185/60 R13 80H.

The rolling/speedometer values are consistent with the OE fit tyre size.

The limitation on this tyre size is NOT with wheel arch and front wheel turning fouling but actually with the clearance of the tyre inside wall with the rear suspension trailing arm clearance.

I think you will find this tyre upgrade a huge improvement. If you want to go a step further then SACHS (as did Koni) did an Uno Turbo spring and damper upgrade kit for the Uno Turbo which worked wonders on my Uno SX despite not having the Uno Turbo's anti-rollbar.

When I was running this car it was renown for being a "killer" at various tracks despite only having the stock 68BHP engine.

You may have to adjust the toe-in a little (out as opposed to in) with 185 tyres but if you a purely "road" bases then standard values should be OK.
 
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Thank you for the very informative post, in the end I went with the 155 tyres (ordered just before reading your post), but I've filed it away along with all the other Uno tuning tips I've come across.
 
If you want to make it corner /turn in better then the front ARB is not the answer... (maybe if you mean a rear ARB). don't get me wrong a medium one will do wonders.. just don't think a bigger one will translate in better cornering.. it will actually under-steer more.

I would start with the basics: bushes, shocks, top mounts, a wheel allignment..etc

All i can say is that a pair of Bilstein shocks did wonders for my car.
 
Thanks, I was beginning to think the same after reading up a bit more on the subject.

Essentially, my current issue is understeer, limiting my cornering speed, with only 999 ccs, keeping the speed up in the corners is important ;)

I'll see what difference the new boots make, I wonder if the current "Tigar" tyres are so named for the stripes they leave on the road...


Then a full suspension refresh is in order, standard, but "better than OEM" quality parts, unless there are any reccomendations for specific kits? I've seen elsewhere that Uno Turbo springs won't work on a 999 cc, as the car is some 200 kg lighter, though the kit suppliers appear to suggest otherwise.
 
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I have changed my rims for my 96 uno with 15" rims & tyres with 195/50
a little bit scratching with the rear fenders which I had to wide it a little bit to fit from front it's perfect looks aggressive and handling is super


but I still have to change the suspension to grip more on corners.












Ok, so now I've got my Uno 45 up and running, I'd like it to be able to take corners a bit faster.

Current tyres are the standard size 135/80R13, ditchfinder brand.

Firstly, I'm thinking that 135 is actually too narrow for the standard 4.5" rim (should really be on a 4" rim) and that I should upgrade to the "option" 155/70R13 size. Noticable difference? Should I go wider?

Second option is the set of 14" Alfa/Speedline pepperpot alloys I have lying around. Narrowest tyre I could run on these would be 165/60R14. If I fitted these, I could also fit a set of Alfa 145TD front brakes (254mm disc, non vented), not tested yet (and I would before investing in tyres), but hoping "Fiat parts bin" means the bolt spacings will be the same.

In either case, tyres will be Uniroyal RainExpert, for a good balance between price and performance, sadly they don't make the RainSport in small sizes. Unless anyone wants to suggest something else?


Strut-brace, antiroll bar are all under consideration, but it seems sensible to start with the tyres.

A full suspension refresh is also planned, not sure I want to lower it though.
 
Turbo driveshafts will make no difference to the non-Turbo as the track is controlled by the wishbones & subframe, & they are the same width on all Unos, Turbo or not. If you want to increase the track, it can only be done at the wheel, either by fitting deeper offset wheels or by adding spacers.

I corner hard 80% of the time in my main Uno, its not unusual for me to be up on 3 wheels, and sometimes 2, so I think I can offer some advice!

Tyre choice is critical on any car, and 135 tyres in my experience (on Uno`s & Panda`s) are useless for serious handling no matter what brand, I've even managed to roll a 135 completely off the rim during hard cornering in a Panda 750L! If you want handling, you need a good brand 165 or 175 tyre on an Uno, and to reduce wet weather understeer (which Uno`s do suffer from), you need a tyre with a wet grip bias.

I have 14" Alfasud Sprint/33 alloys on my main Uno, & have found both Pirelli P3000`s & Goodyear Duragrip (175/65x14) suit it perfectly, both reducing wheelspin when accelerating out of corners & both makes providing good cornering limits with good feedback & a gentle, controllable breakaway on the limit.

175/65x14`s also make the speedo 99% accurate.

I wouldn't recommend 185/60x14 without fitting spacers/having deeper rims, as they foul the inner wings (rubbing approaching full lock at the front, & rubbing during hard cornering at the rear).

I run them at 32psi pressure front & rear, but you may find you prefers a different balance to suit your driving style & front/rear weights, you have to experiment to find out!

I wouldn't recommend fitting an anti-roll bar, as, although breakaway is marginally higher, its much more sudden & is often impossible to control when it does break away.

There's no point fitting a rear ARB because the Uno`s rear axle is designed to act as an ARB. Some people have boxed/welded the back axle pressing to stiffen up the rear, but, its designed to flex, & when welded up, they've been known to crack as well as spoiling the fluidity & natural balance.

It is worth fitting a front strut brace, its also worth making sure there's no significant rust in the rear arches, and, if its had any rust repairs to them, the reinforcement panels on the underside have also been replaced (& ideally, extended).

I wouldn't recommend uprated springs, they make the ride bone jarringly uncomfortable, uprated shocks are generally good though, & adjustable ones mean you can get the handling perfect, but they usually cost as much as a reasonable standard Uno! (£4-500)

I've not tried polybushes, I just change my wishbones & rear shock mounts every 3-4 years, they can be had for around £40 on ebay.

I live somewhere where there are a lot of speed humps, so I don't lower my cars either.
 
Thanks, good to hear from people with experience with the car.

I've gone with the 155 tyres, on the standard rim, so we'll see how she behaves. I'm not expecting miracles, but an improvement over the standard 135 would be welcome.

I'll keep the Alfa rims (mine are the later 145 rims with a slightly different offset), maybe try them another year, though a 200€ investment in tyres is an awful lot for just trying.

Will lookout for a strut brace. My shell is sound, no rust.
 
Fair enough, although a 155 will be an improvement, especially if you go for a highy rated tyre, I`d still say go for a 165 or 175. Auto Express have some good older tyre tests online which`ll give you an idea.

My Alfa rims are 5 1/2x14 et 39 if it helps.
 
I wouldn't recommend 185/60x14 without fitting spacers/having deeper rims, as they foul the inner wings (rubbing approaching full lock at the front, & rubbing during hard cornering at the rear).

Pirelli P6 185/60 R13 80H were absolutely fine. 185/60x14 you mention would be completely wrong as in going to 14 inch from 13 inch would require a profile drop. Not researched but 185/50 or 185/55 on a 14 inch rim would be more appropriate.
 
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