Wheel spacers and understeer?

[CUPRACAR]

I dislike a car that understeers so I tried to induce a degree of oversteer with the following mods

I have set up my LCR with the following.

KW matched springs and shocks lowered about 30mm from stock
S3 front strut brace
R32 front ARB
28mm rear ARB set on the stiffest setting
Polly front suspension bushes
New ball joints and top mounts and full geo alignment.

I took the car to the Ring and I was more than pleased with the results, this set up seemed to be spot on.
This weekend I decided to fit 12mm spacers to the rear.
I went out on a spirited drive only to find once again I have understeer ?

Has anyone else experienced this or can anyone offer an explanation to this change in handling?

I am running on 2 thirds worn GSD F1’s.
I think I will leave them on to do Cadwell and take them off for the afternoon session to assess the difference.

Any thoughts?

 

[Fl@pper]

This weekend I decided to fit 12mm spacers to the rear.

I went out on a spirited drive only to find once again I have understeer ?

sort of explains itself really - wider rear track has gained a rise in rear grip bringing on understeer

not forgetting it's a higher powered front wheel drive of course

put the spacers on the front instead

 

[CUPRACAR]

I take your point, but I wouldn’t have thought that a 24mm increase in rear track would have improved grip to such a degree.

It felt to be more of a loss of front-end grip rather than an increase in rear grip if that makes sense.

I note that the LCR has a narrower rear track than front as stock, is this maybe an attempt to dial out oversteer.

 

[DOLBY]

i have a similar set up to yours bud but i have V3s and a rear strut brace and i get NO understeer even when im pushing it on rounabouts.....mine is well planted, dont know how your still getting understeer buddy

widening out the rear wont promote more understeer at all the more you even out the rear track the more neutral the car will become surely

 

[DannyC87]

You only have a certain amount of grip available in theory, mods just move it around. The ratio of rear track to front track can have a massive effect on understeer/oversteer. I have recently moved my 15mm spacers from the back to the front and what can I say, it looks a little weird, but it handles superbly; no understeer, much better turn in, backend that follows the front nicely - ideal! I also have front and rear strut braces, r32 arb on the front and nuespeed 25mm on the back at stiffest setting; weitec coilies.

 

[Fl@pper]

I take your point, but I wouldn’t have thought that a 24mm increase in rear track would have improved grip to such a degree.

just thinking back to the Ibiza Cupra R, Seat sport altered whole track as they fitted wheels with a different offset and a few have fitted rear spacers (15mm) to just the rear to positive results

old skool days used to fit Spax Gas to Mk2 Xr2's but once you stripped the rears out and caged up and braced em they were so hard/light at the rear and would oversteer majorly but keep the spriings and change the gas shocks back to standard oil and they used to ride so sweet it was a joy i've been tempted to go back too many times

just shows how a small tweak can make a lot of difference though mind

 

[csd_19]

Narrower rear track than front will bring a more mobile rear. Put the spacers on the front

 

[GREY 225]

Ive got a similar set up but with weitec coilovers and have 15mm spacers just on the back,the rear neuspeed arb is set to its softest setting, before i got the coilovers the rear spacers made a fair bit of difference to the handling, i was surprised what a difference they made,especially under hard braking, were the back end use to feel a bit loose, with the spacers on the rear it felt so much better, as it is now i would say understeer would come first but only when at a silly speed, ive thought about getting some 10mm spacers for front to see what difference that makes if any.

 

[6th.replicant]

A wider rear-track will always increase undertseer, especially during turn-in, whether on a kart, a F1 car or a LCR. It's why most performance cars have a wider front-track as standard.

For example, Lotus offers a narrower front wheel/tyre option on the Elise/Exige for customers who find the standard setup too 'pointy'.

I have set up my LCR with the following.

S3 front strut brace ...

Plus, if you haven't also fitted a rear strut-brace, I'd guess that you're getting on-the-limit mid-corner & corner-exit understeer? This is because, since fitting the front strut-brace, the front-end of your LCR's bodyshell in now much stiffer than the rear. You can get a rear (removable bar-type) strut-brace for LCRs, it fits across the rear seat:
http://www.seatcupra.net/index.php?option=com_content&task=view&id=510&Itemid=6

But if you really, really want a car with almost nil understeer, try a Mk1 Honda S2000, they just keep on turning & turning, & turning, & turning, & turning, & turning, & turning...

 

[Willie]

I have very similar mods to you and even on the track in maximum attack mode I find it very difficult to induce either under or over steer, this is with F1 Asymmetrics. Perhaps your tyres have gone off.
Even @ 80MPH on a very sharp right with a big down hill the rear end is VERY planed