just spun 360 on a wet round about

[wongy008]

now as the title says this just happened to me on a wet RA.this has left me filled with adrenaline so i had to post straight away, the last time i did this was 5 years ago in a crap handling mk 3 fiesta not a good handling lowered clio.

earlier today i swapped my 17s for 15 phase 2. i was hoping to get a faster accelerating better handling car back on 15" but my honest opinion is its a myth, if anything clio handled 1000s times better on 17s, it broke away the same when pushed hard but it broke away at speed 15s cannot think of cornering at. the phase 2 have good tyres although crap make but on 10 mintues of driving on them i notcied they totally transformed the car. i could not get the power down no matter what and the front end broke away at speed much lower then i couold take on 17s

anyway i was driving around all night testing how far i could push before they would let go and yes i managed it eventually. it was on a RA i used literally 1000s and 1000s of times and it really suprised me to say the least as i was not even trying to provoke it to break away,the conditionswere damp but drying. decided to hit the apex and just go round casually and slow but to my suprise the back end gave way and so i corrected, however i did not correct enough so the rear kept on swinging round. luckily my car control aint too bad and i stop it well before hitting th kerb. stop to a standstill i was a bit giddy and just drove off smiling at what just happened, this was until i realised ive taken the exact same RA in worse conditions at speeds well in excess of 50 mph on my 17s

well ive had my clio for about 2 years and driven on 15s for about a year and 17s for about a year and i can honstly say 17s handle better.


ive found 15 break away to quick
traction is crap
less out right grip
well im gonna be driving slow on these till i get my new 17 i just dont trust them,

can we have a constructive discussion on this topic as it comes up a lot of time, i think thst when people say 15 handle better they are actually lying to themselves and never driven a car on 17s. ive never actually spun my clio till tonight,

what do u boys think,i will accept a car will accelerate faster on 15s but they don t handle better, i just cant see how,i really dont like 15s. could the crap make tyre make that much difference could tyre pressure affect the car that much,. dont think i can go fast again till i get my 17s back

wongy

 

[matt_arundale]

i always thought bigger wheels handled better? or am i confused, mabye. how wide are the 17s compared to the 15s? and what profile?

Matt

 

[wongy008]

17x 7 on 205,40,17

15x 6 think 185.55.15

i really really dont rate 15 at all.

wongy

 

[matt_arundale]

well i think thats maybe why u noticed a huge difference, 205 compared to 185. but hey im no expert, just givin my view, and thats its nearly 2 am, heh

Matt

 

[inf1d3l]

my 15s are 195/50/15 actually, and they came stock on the car. we dont get the 16" option here.
are the 15s and 17s youre using the same tyre or different brands? the difference in grip levels could be due to this as well.
i guess the 17s would offer improved grip, but handling? guess ill have to try it. personally, i get my kicks from the tailhappy nature of the car on 15s, especially in the wet. in the dry, its just amazing how much you can adjust your cornering line with the throttle.

regards,
inf1d3l

 

[BenR]

LOL mate...adrenaline eh!

funny how it was after i told you i almost lost it on a damp corner 2 nights ago!! HAHA

anyway, i think your idea of 17s being better than 15 is pure grip. You have more rubber and more ultimate grip with 17s over thinner 15s (espesh the oddball 185/55s) and if theya re not good tyres, they will affect it alot on such a thin tyre.

anyway, the way people talk about handling leads to much confusion with all out grip and corner speeds.

Handling of teh actual chassis, if they were on the same tyres, 2 differently setup chassis would handle differently. But your car with the same suspension and diff tyres merely reacts with the ground differently through a larger and gripper contact patch. I would say, ultimate corner speed will he higher DOH, but on a track, though a tricy sequence where setting up the car on a fine balance into the corner so you can take a specific line through the next corner will be harder on 17s as the breakaway is more violent and snappy, staying on teh limit is a different world to 15s. I take it your 15s gently slid away with you watching the entire slide.

I have no idea where im goin except personal preference and driving style/ability will lead you to fin a setup more comfortable for you.

Saying all this though, theres the debate to where toca cars etc use alrge wheels for grip or merely to fit larger brakes under. But F1 cope with 13", and in the toca kit, the brake kit fits just as well under 17s as they do 19s........so....the debate will rage on, what best for YOU is all that matters.

 

[Jeff XSi]

I think the tyre pressures will have a lot to do with it... the handling the 206 was halved when the tyres were a few psi down...

 

[miltage2]

i had standard 13" rims changed to 16" alloys and lowered and sticks to the road like a porsche i love it!!

 

[Jonathan]

What make / model of tyres on both sets of rims ? Tyre touches the road = most important part of the equation !

 

[Roamer]

Well mate, I wondered what was going on late last night when you changed your msn profile, hehe

Ok, your 17s had a sidewall height of 82mm and the 15s have a sidewall height of 101.75mm, now this nearly a 25% increase in sidewall height, this gives more flex in the tyre which will affect the handling (imho itll be affected badly) and of course your width reducing from 205 down to 185 had reduced your road contact patch by about 10% thus less rubber to the road. Now, with the sidewall increase means that the car (under lateral force) will move laterally more away from true over the contact patch, this also means that the trailing side of the tyre loses more grip as the sidewall distorts from true, correction of this needs to be more due to you first needing to correct the flex in the sidewall before you start correcting the traveling path of the car, due to this though there is less likelyhood of you overcorrecting, as any minor overcorrection will be taken up in sidewall flex first (I think) - the smaller the sidewall the more snappy the handling will be.

So, the contact patch of the tyre to the road is imperative to grip, but sidewall height has a major role to play in the grips and handling (and has a minor impact of the contact patch), (obviously as well the tyre compound, tread pattern etc have a great impact on this as well, but I was only thinking about the size change on the same make/model of tyres, and the same tyre pressures too)

So, the moral of the story is, lower profile and greater width = Better grip, but to do this without having to re-calibrate your speedo you have to upsize your wheels, increasing (generally) the unsprung weight, thus reducing straight-line acceleration (in general)

Please, shoot me down in flames if Ive got this wrong, Im going on some very old thoughts and may have got completely the wrong end of the stick

 

[Ben j]

yea id ave thought more rubber more grip, but bigger wheels less acceleration.. maybe if u could get some 205 15s vs 205 17s itd make a good test

 

[Ben H]

I changed my old 16" wheels with 205/45/16 rubber for some 15" Phase IIs a month ago (with four brand new tyres).

I reckon that the car is much better on the original 15s!!!

The grip is a little less on 195/50/15 tyres, but the car breaks away more progressively and controllably, the "handling" down a good B-road is better and its slightly more comfortable.

As always, its a case of trade-offs. The original 15s will please some eyes, not others, some prefer the grip of larger wheels and some the comfort and predictability of the originals.

If youre after better performace, Id take a poo before driving or lose the spare wheel.

 

[Adams_16v]

Hmmmm, im gonna wait untill my 17s are back on before I make my mind up for sure. But I swapped to 15s the other week and I have to agree with Ben H. More spin but feels more comfortable with the 15s on when it comes to corners. I nearly lost the arse end 3 times over the past 3 months with the 17s when it should have gone round nicely. Maybe its just my car or something.

Although the phase 1s look a bit shiite compared to 17" gold monzas :-(

 

[Matty]

Happened to me ages ago when the spare steel wheel with crap tyre was deflating itself and lost grip due to the tyre pressure.

I would say 15s handle better from what Ive heard but you would have to make sure tyres are good quality just like you would 17s. Crap 15s against good 17s would always be inferior.

Using Bridgestones S03s Ive never spun and scared myself at some of the speeds you can corner.

 

[Clart]

Wongy read my post on liftoff oversteer too!!! I cacked me pants so doing a 360 must have messed urs big time!

 

[BRUN]

try a higher pressure, my car handles like crap IMO on any pressure lower than 35 all round

usually have 36 all round

 

[BenR]

holy cow, thay must be a harsh ride............

 

[cse]

well, ive had 2 clios, a phase 1 and a phase 2, but i presume the differences are bugger all, but my phase1 with 15" wheels it was much better than my current one with 17". with the 15" u could throw it into corners, it would hardly slide, grip well and gone, with 17" it feels like i am skating across the road, i turn and nothing seems to happen at times. its prolly 2 things thou

1. tyres - ive got to get some new ones. as the 15" were brand new pirellis, and these are a bit worn, so hopefully this will make up for it

2. suspension - i reckon that 17" without lowering doesnt do it justice, and this buggers the handling up, which makes sense.

and 3. (ive just thought of this ) - the phase 2 steering is slightly ligher, with less feedback thru the wheel, if anything the larger tyre should make it heavier, but it isnt, and because of the larger tyre, u have to move the wheel slightly more for the same turning, or thats the way it feels.

last thing, what tyre pressures does everyone else run then ? especially on 17", ive got 35ish all round, was like that when i bought it, any other opinions to whats best on this ?

 

[Adams_16v]

I usually have just over 30 all round.

 

[BRUN]

dunno how you even drive mate with that pressure, i tried it once and it was horrendous, drove straight back to the petrol station to put some more air in

 

[clean16v]

ive tried this the whole 17 13 thing in my old RT, in the wet 17s are better.....much much better simply because of surface area but there is absoloutely no denying that in the dry the 13s rocked..the car is set up around the standard wheeels and although i had stiffened suspension things like offsets, wieght, rolling diamater etc change so its always best to use standard IMO

 

[derv]

ive been wondering about this too, i would like 17s on my car but always worried about affected handling, to be honest i think the standard 15"s aint that good, i took my mate to a notoriously slippy island and i understeered all the way round at 20mph, (its a big island) i have practically brand new pirellies on the front and they seem good in stopping strait line wheelspin but not so good round corners. i wonder if larger wheels would help. funnily enough as i came back to the island later i saw a escort cossie come round the island, only slowly, spin a 180!

 

[Matty]

I used to run 30 but now 32 psi and find that good enough without having to harsh a ride.

On the subject of new front tyres. Drven did a test months ago on channel 4 where they tried fitting new tyres either to the front or the rear of the car. Car only broke away and spun on a wet corner when old tyres rather than new were on the back as they became unweighted and lost grip easier.

 

[Leigh]

Wongy

Have you changed your driving style then ???????

Coz last time i saw you, u wouldnt go above the legal speed limit !! HAHHAHHAHAHAHHAHAHHAHAHHAHAHAHAHAHAHAHAHAHAHAHHHAAA. Or is it that you have found that speed limiter, that I fitted when we last went to the pod !!!

Just kidding mate !! I take it you sold your 17s then !! When do you get your new ones ???

 

[petes]

Wongy - are you running the same make & model tyre on both sets of rims?

The theory about greater contact patch = more grip isnt quite correct (sorry, going to Slarty mode). Wider tyres = more contact patch = the ability to make the tyre from a softer compund without excessive wear. If you could get a tyre made from the same compund as your 205s youd get exactly the amount of traction (smaller contact patch but more weight applied through that patch) but theyd last about 50 miles.

Air put in the tyre to maintain its profile. This means keeping the sidewall reasonably stiff, and keeping the optimum amount of rubber in contact with the tarmac. In the dry this is generally all of the tread, but when there is standing water you generally INCREASE (yes) your pressures to give your tyre a convex profile, thus allowing water to disperse from the centre of the tread. The other positive factor here is more pressure - higher tyre temperature which generally = more grip (up to a point). The negative side is that it increases the effective spring rate, so the car is stiffer, NOT what you want in the wet.

Also, take a look at your tread blocks. You need SHARP edges to give you good grip in the wet. As soon as the edges wear off, your grip will reduce dramatically.

I believe smaller wheels should give better handling (for reasons such as lower unsprung weight, lower gyroscopic forces etc.). Larger wheels are part fashion and part necessity. Touring Cars need large rims so that they can be fitted with bigger brakes. So people equate large rims with fast cars ...

Were not talking about handling, though, we are talking about grip. It will be down to tyre construction, compound, condition, tyre wall flex and air pressures more than the rim size (as several people have pointed out already).

(Slarty mode now off)

Oh, forgot to say - IMO applied to all of the above

 

[Ben H]

Ha ha! Told you all that 15s were better! Nuuuhhhh!

 

[Nick Read]

lol this old chestnut. BTW good work on the roundabout mate!

ANyway i can say with certainty that on mine the ride is 100 times better on 18s than it is on 15s, the *only* downside is that on very fast corners they can be snatchy, the grip is like an on /off switch, its either there or its not, which can be nasty if youre not expecting it.

Anyway, my 17s are coming soon so well see how they go.

 

[wongy008]

nick

looks like you will be getting 18s again, oz have been out of stock for ages now in your fitment

got my new rims ordered up to

got to drive my clio in dry and bloody hell it like a go kart now. totally different car in dry. and bloody hell it accelerates much much faster then on 17s

wongy

 

[BenR]

LOL

 

[wongy008]

cant decide what i like more

maybe i should get a pit crew at home to change my wheels for me depending on wether

wongy

 

[RobFenn]

You forget laws of physics, the circumference of 15s are less than 17s, so intial accleration is going to be better. You just mean grip, which obviously going to be better. The main difference would be in the quality of your tyres.

15s on track would be a good choice for many a reason IMO. First of all you can lower it more, and also provides minimal weight (plus less grip is more fun!). Thats why clio cups go to 15s instead of the road spec 16s.

 

[BenR]

hold on laddy, your getting ahead of yourself here.

actual acelerative times wont be hugely hampered by large wheels.......teh trade off in weight (which is easily accomodated for) is initial grip and less wheelspin.

FWD draggers use absolutelyufappin HUGE front wheels and tyres.

ref your lowering it more, you being a racer should of all people know slammed into the weeds severly affects static geometry. And your basically driving on bumpsteer setting, which means UNDERSTEER!!!!!

toe out, excess camber, TCAs completely inverse etc etc.....

15s on a track are good, but it depends on what car, and the cliocups use 15"wheels because they are actually MK1 s with new panels. They are using the old MK1 setups, which work fine so why change. Also, 15" tyres cost alot less then low profile 16 inchers....by a fair amount!

 

[RobFenn]

i didnt no that was the case with the racers, i still wouldnt mind having a go in them, theyre supposed to be a right handful according to EVO though i presume the car wasnt set up for the driver.

If you go off the track your f**ked anyway so who cares about the geometry ha ha. Anyway i dont go off I always have a very hard setup, its not as much fun but my cars always set up to understeer as im that bit faster, which is the point, hence why in another thread i told you i was crap in caterhams.

I think the accleration bit is a lot to do with torque, being the acclerative force. Say if i had 17s on my 1.2 the difference would be noticeable but on a torquier motor there wouldnt be a lot of difference.

I wont get anymore techinal as frankly i dont no enough! lol. Id just like to empahsis how much good tyres make so much difference to a cars handling though!

Whens the new clio v6 out btw??

 

[visceral]

Just got in from a tip out with the kids, coming round a medium sized round about the rear let go, I wasnt nailin it cos of the kids.

It was wet, and I had just come off the power due to volvo man infront slowing for the exit. Its a standard 172 with 195 45 16s - which have done 400 miles. Was able to correct, though it was a suprise.

Looking forward to experiment time round Trafford Parks roundabouts late one night in the wet.

 

[BenR]

like i said Rob......EVO = rock apes

and i care about geometry...you should too....its what stops us goin off the track.......and you like understeer....ergh, stange fetish mate......LOL

what happens in a tightning radius corner? ergh, cant bare to think how much youd have to slow down!

anyway, of course torque has lots to do with acceleration......, torque is the power of an engine and HP the rate of work done.

agree with tyres though, my prepped fezzy is a nightmare on anything except the best......

V6 out in early march.....cant wait!

Visceral....agree, std chassis is FAB for oversteer..........

 

[RobFenn]

Well i dont set them up for major understeer! Theres the fine line and i have mine understeering over oversteering as im quicker, i dont find it much fun but thats not the point. If i go on track day i usually swap front tyres for back so more grip and more oversteer..FWDs obviously. I leave set up to my dad. Id like to know more technically but times have changed and i dont race much now im working, and i have to be 18 to do trackdays (only a month now though!!). This means ill be doing more organised stuff as id expect ill stop proper balls out racing until i start earning a sh*t load of money!

Whats ur fezz pumping out?

Cant wait for the V6 either...anyone seen the 800bhp TT in EVO yet?

 

[BenR]

ah well, if you like it that way....

but i prefer a pointy car (and im not talking sideways mania) but just something that will hang the rear before the fronts. and it usually prooves faster........but i guess growing up in karting does that to most drivers, if you watch most F3, F3000, formula renault, its far more snappy than it used to be, as with karting the argressive driving has moved on with them.

anyway, agree racing prices are soaring!

im goin, hopefully, some time soon for a test with Meritus and met with Peter Thompson (owner creator and president, also desinged the Panoz racer) about a week ago to discuss. But prices are US$250,000 to get in F3 and even formula Renault is $175,000!!!!

I miss doin it free!!!

oh, me fezz....MK1 with heavy chassis mods, the crossflow is pumping out about 150 BHP on twin 40s and a 244 cam, head was ported by myself, and is of HUGE spec......i can go to twin 45s but i need a 1700 block to come and ill loose alot of tractability.....but not that i mind...its heavily track focused......

did many a cossie at coomb during the ford day......but did have a 2ltr turbo nova go past, only to spit flames at me on the braking area....LOL..embaressing and entertaining.

 

[RobFenn]

Must sound great with the webers though.

It is very expensive. I am considering getting a mini so i can enter their race series, they do hill climbs as well. With that sort of racing you can get small business sponsers 2, thats what i was hoping would happen with the cup..

 

[BenR]

getting the cup to spec would cost a fair bit!