172 cup - suspension setup

[JJ172]

OK, just popped into Toomey Renault at the weekend (in Essex) and they are getting a 172 Cup in a fortnight, for demo The salesman handed me a 172 Cup brochure which led me to wonder....

* 20mm increased front offset
10mm increased rear offset

This sounds like it has been achieved through nothing other than the alloy wheel offset. Is this so? If it is the case, then getting a new set of wheels (or fitting the Cup wheels) would effect the same suspension improvement.

* Revised castor angles
Improved damping

Could you use the 172 Cup dampers on the 172 Mk2 to effect the same changes?

* 3mm lower

Any idea how we find out the revised spring rates?

 

[JJ172]

Just checked the std 172 16" alloys and they are 7x16 ET48.5

48.5mm offset - is this correct? If so, that means the Cup wheels are 68.5mm front and 58.5mm rear. Surely this isnt right?

 

[sandys]

the brochure says that the alloys have chnaged offsets to increase the track, wouldnt be as much as you reckon though as you added 40mm to front and 20mm to rear, the track is measured from the width between the two tyres.

 

[sandys]

in fact I think I got that wrong by adding to the offset you would reduce the track to increase the track you would reduce the offset soe front would be 38.5 and rear 43.5. feel free to correct me.

Cheers

 

[sandys]

course wheel spacers (10mm/5mm) could do this for you on standard alloys and obviously dont have a detrimental effect on the handling as that is effectively what Renault are doing.

The increased castor I couldnt say how they sorted it but could just happen from lowering maybe as that can increase negative camber on some cars not sure about clio(although I doubt its that easy as you would get it whilst going straight ahead which is not good, twitchy car), but by increasing castor I think that means that you increase negative camber whilst cornering giving you better ability.

Again dont know much about this just what I picked up modding my Coupe

Cheers

 

[sandys]

In fact I doubt lowering would have any effect on castor, god an edit function would be nice, so I could edit the bollox I just wrote

Thinking out aloud and just typing it....Doh

Cheers

 

[GR7]

The Captain and BenR will soon let you know the correct figures!

 

[RSTDL]

Read the cup brochure - its there in black and white - 3mm lower, 20mm/40mm wider, incr4eased castor/camber - nuff said - Renault engineers obviously did it, how doesnt really matter!

 

[M.C.]

Im no genius, but Ill tell you what I know.

If you look at the car side on, castor is the angle that the shock leans back. Increased castor helps with steering self centering, and possibly gives a sharper feel to turn in. The only ways to do this are to either move the top mount towards the back of the car, or move the bottom forward.

Camber everyone probably knows about.

Lowering the car by 3mm is unlikely to have any real noticeable effects on either of these. And 3mm is probably more than the car falls and rises by with petrol and passenger weight.

I doubt very much that the offset refered to is simply wheel offset, as that is a great deal. More than likely they are refering to track width. The offset might be different, and adding 40mm to your offset will actually bring the wheels in a long way.

 

[sandys]

I realize that with the cambor/castor as I said I typed it then wanted to slap myself as I realized what a dumbass I was being.

but the increased track is definately from wheel offsets front track is increased but 20mm (10 per side) and rear is 10mm (5 per side) at no point did I mention 40mm.

To quote the brochure new wheel rim offset couldnt be any clearer

 

[sandys]

Perhaps I am not remembering the brochure correctly but I am sure it mentions increase track by 20/10mm not offset? Dont have it with me to check.

Cheers

 

[M.C.]

I suppose that sounds feasible.

If you change offset by -10mm the track would be 20mm wider. So youd be running 38.5ish rather than 48.5ish.

 

[RSTDL]

Is 38.5 not the standard offset for clios?? My RSi 1999 is 37.5

 

[sandys]

Thats what I said at the top of the thread MC, sounds right to me so it could be done on normal 172 with spacers, again the castor not sure about you might be able to use shims to chnage but not having a clio yet I dont know whats possible, besides Ill have a cup so couldnt give a monkeys

As for the RSi, dunno, its a different model probably a smaller wheel to the Mk2 as offset chnages with wheel width too so if you change to 6Jx16 from the 172 7x16 the offset would no longer be 48.5.

 

[JJ172]

Thanks for the replies. I am hoping to see a Clio Cup in the flesh and see what offset is stamped on the Speedline alloys on it. It may then be worth sourcing some alloys of the same offset to achieve the same track as a Clio Cup on a std 172.

The geometry change on the front dampers is quite easy to achieve, so I am told (by a Clio Cup racer).

I intend to use AVO springs for lowering the car - 3mm is bugger all!

 

[sandys]

so how do they change the geometry then?

dont know if I would go to the expense of new alloys (unless you want new alloys of course ) just to get the cups offset you should be able to get custom made spacers match to your hub for about £50 that would give you the 10mm additional of the front and 5 mm on the rear, wouldnt be suprised if they already exist for a Clio.

Cheers

 

[RSTDL]

tHE WIDER TRACK ON THE CUP IS NOT JUST DOWN TO SLAPPING DIFFERENT ALLOYS ON THE CAR - I THINK THERE WOULD ALOT OF CRITICISM BECOMING OF RENAULT IF THEY MARKETED A CAR AS IN THE BROCHURE AND IT WAS DISCOVERED THAT A DIFFERENT WHEEL HAD CHANGED THE GEOMETRY???!!! iD LIKE TO HOPE THAT THERES BEEN A BIT MORE THOUGHT AND CALCULATIONS PUT IN TO THIS CAR THAN A DIFFERENT SET OF WHEELS AND IM VERY SURE THERE HAS BEEN!!

 

[sandys]

Its not just down to the alloys, the original question was how to give the standard 172 some of the Cups attributes, there has obviously been some thought put as the chnage of the castor and the offset matched with the lower suspension will change the way the car loads up in to corners etc. not something you can do willy nilly as you can screw up a cars handling, some of these mods on the Cup can be done to the standard 172, far as I remember Renualt have made no false claims in their brochure under the bit where it mentions widen track it does state new wheel rim offsets but there are the other changes to that compliment the car, suspension mods, weight reduction, quite the enthusiasts motor. Just changing alloys doesnt give you a Cup so relax CUPSIZE mate but may improve the 172 handling further.

Cheers

 

[JJ172]

Well said sandys!

CUPSIZE? STOP SHOUTING!! TAKE YOUR FRIGGIN CAPS LOCK OFF!

If you re-read the post, youll see that I never suggested that just changing the wheels would give a std 172 the handling of a Cup car! I was merely assessing what has been uprated on the Cup and how you might modify a 172 to achieve a similar result i.e. 1) lower the car, 2)wider track, 3) more camber/castor at the front.

I used to run a Mk2 XR2 with Koni/Slick50-racer suspension and 2.5 degrees -ve camber on the front. The handling was bloody amazing, partly due to the lowered/stiffer springs but also due to the revised geometry!

 

[RSTDL]

IS THAT IT OFF NOW!!OOPS LOOKS LIKE MY COMPUTERS A CAPS ONLY ONE!!

 

[Captain Slarty]

wooooooooooh...

who SAYS the poor mans 172 (aka Cup) handles better than a 172 ??... thats the first question...

aome of you guys make me chuckle sometimes.. ya cant wait to change anything unboltable asap... yet.. when a cheapo model comes along .. ya want to change to model the cheapo... ??

hello ????



fit a spacer if it really concerns ya...

fit a camber bolt in the strut if ya want more negative c.. and the cup AINT got enough NC to qualify as anything but a granny mobile.. same as the 172... lotsa lotsa safe understeer etc...

the changes are minimal... dont worry about it..

lol..

Joe..

 

[JJ172]

Joe - as vocal as ever...we like that! *LOL* Im not about to change anything on my 172 just yet....Ill be testing a Cup car in the next week or so and gauging the difference in the handling dept. The handling of the 172 is good, but it can be improved, and I fully intend to find out how best to do that, with the help of someone whos been tuning suspension setups professionally for over 20 years

 

[JonC]

I recently took my car out for a blast one night and thought the handling was a bit sqidgy and not as sharp as I thought it used to. Checked my tyre pressures and they were down by about 4psi all round. set them to the correct pressure and Im happy to say the handling is alot sharper and no more tyre scrubbing on turns. Amazing what a few psis can do to the handling...

 

[RSTDL]

Captain - its not a cheapo mate!! Its an improvement on the then unimproveable!! Its a refined and 172!!! The 172 got slayed by the cooper S and now renault have reclaimed the title with the cup!!! Thats good news to me and a nice comfort to be one of the few who gets to actually own and drive one of these cars and relish in that knowledge!

If I wanted gay comforts Id have bought a cooper S or a beetle, but I already have them in my 1999 RSi with full 172 interior!!!

 

[sandys]

Out of interest I dropped a mail to Speedline about the Cup alloys and specifically getting them larger what the offsets were and what the wieght penalties were etc. heres the response which puts my idea of the offsets out abit in they they only mention 38mm which is what you expect the front to be but nothing on the rear?

I would probably replace with forged alloys from team dynamics though as there 18" wiegh 7.5kg so the 17" can only be ligther

Hi Alexander, thanks for your enquiry.
The are quite right, Renault are now using the Turini in 7x16 as an official Renault approved and supplied wheel for the new Clio RS.
The offset for this wheel is ET38.
The wheel supplied to Renault is different to the 17" version of Turini, apart from the obvious size difference, in that the Renault wheel is not "flowformed", the 17" aftermarket version is flowformed. The Speedline flowforming prcess is a highly advanced production method that allows the wheel to be made very light without compromising the wheels strength. For this reason if you use the 17" version you are unlikely to increase the weight of the wheel ! The 7x17" Turini weighs just 8.5Kg. We have these wheels in stock, in silver colour in offset ET35. These wheels are £188-00 each inclusive of VAT.

Sounds interesting ?
Kind regards
David Williams

 

[Captain Slarty]

Hi Cupsize, glad you like the 172 interier.. will u be putting one in the cup ???

Joe..