odd handling

A

AndyC

K10 1.2L
New KYB oil dampers
about 1 deg Ghetto camber
about 1mm toe out per side
standard springs
rear antiroll bar - looks like a straightened out coat hanger
14" wheels and tyres off my GTiR

Now to the story, not had the Micra very long, but soon tired of it's 18yr old dampers and fitted the KYBs nice improvement, but it has a really strange trait when pushing on. If you ease it gently into a corner everything is Ok, but throw it at a corner and it kind of bounces back and jumps off line. This is when hooning around on B roads btw. I'm thinking that maybe it's smashing through to the bumpstops.

Any suggestions where to go from here gratefully received, I don't want to lower it.. Should I be looking for stiffer std height springs, roll bars, or trim the bump rubbers?

thanks
Andy
 
It sounds like you need new springs, if they are the original springs they will be old and saggy, that will make the handling bad if you suddenly change direction.
 
sonic said:
It sounds like you need new springs, if they are the original springs they will be old and saggy, that will make the handling bad if you suddenly change direction.
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It certainly doesn't 'look' to have sagged, maybe it has. I'm a bit concerned about shelling out for new lowered springs and finding out that they aren't stiff enough to keep me off the bump rubbers. I'm listening though, so any suggestions for springs that will be OK? Do you cut the bump rubbers down when fitting shorter springs?

I like the idea of anti-roll bars, the rear one is so thin it's not even funny, I'm sure I could rig up something better. Can you graft a front bar off a K11 onto the front?

Andy
 
When i say saggy i dont mean that they have shortened any, with age springs soften and take less pressure to compress, this will cause wallowing and bottoming out, new standard springs will improve the handling, but lowering springs will improve handling no end without the need to do any cutting of bump stops or anything.
 
how can a spring get softer without the car getting lower?

Assume for example that the standard spring is 100lb/in and it is supporting 400lb of unsprung mass. That spring will compress 4" (400/100)to give the normal static ride height. If the same spring then softened to 80lb/in it would comprress 5" (400/80) meaning that the car is sitting 1" lower than standard.

My concern about lowered springs not being stiff enough may also be valid. I'm guessing that there is about 3" of travel on the standard car before hitting the bump stop. Assume the same 100lb spring, it would take 300lb to make the car hit the bump stop (on the 1 corner). If I lower the car by 1" I now only have 2" of travel, but the same 300lb of load, I'd need 150lb/in springs (50% uprated) to hit the bump stops in the same way I do now, stiffer again to keep it off the stops. The uprated springs I've seen are only 30% uprated.

Sounding a bit like a keyboard warrior here, so have a quick look at my (self built) toy..

http://www.youtube.com/user/andyfandango

Andy
 
Yes springs can get softer with out significantly lowering the car, plus you have not actually compared your current road height to that of new OE standard srpings and shocks so don't cross the possibility off straight away.
Secondl 1mm out on tracking does seem a little too twitchy to me, mines currently set at 10mins out and i can't legaly say how good.

What size tyres you got on?? The KYB oil shocks honestly aren't that much of an improvement over standard shocks, your be better off with the kyb gas shocks as there isn't much difference in price, along with new OE springs, front k11 camber kit, strut brace and very low profile tyres (mine are 185/50/14 yokohamas) should see you about right.

When i lowered mine i fitted longer bump stops and never had a problem.
 
Wrenchable said:
Yes springs can get softer with out significantly lowering the car, plus you have not actually compared your current road height to that of new OE standard srpings and shocks so don't cross the possibility off straight away.
Secondl 1mm out on tracking does seem a little too twitchy to me, mines currently set at 10mins out and i can't legaly say how good.

What size tyres you got on?? The KYB oil shocks honestly aren't that much of an improvement over standard shocks, your be better off with the kyb gas shocks as there isn't much difference in price, along with new OE springs, front k11 camber kit, strut brace and very low profile tyres (mine are 185/50/14 yokohamas) should see you about right.

When i lowered mine i fitted longer bump stops and never had a problem.
Click to expand...

I've not crossed anything off.
By my calculations 10mins is 1mm on a 14" wheel (per side, or do you mean total?). Plus more camber will require more toe. I'm certainly going to play with toe as the corner entry is generally a bit 'nervy'. I don't think a bit of toe change will have the vicious effect I'm feeling.
Tyres are 195/60/14 Dunlop Formula R.

The particular corner that gives a real problem is 60mph over a crest into an anti cambered right. As you enter the right it rolls, boings back, and jumps off line. Unfortunately it pretty cold and wet most mornings to it isn't sensible to play.

Which springs did you get? if I get the same we will be speaking the same language. With regards to the KYBs, I read a fair bit on the site before buying and the opinions seemed pretty split over which work best.
 
put it simply standard shocks are oil, kyb's are just better built. gas does give a smoother ride than oil shocks, its just how its designed.
just a set of spax from demon tweaks, will drop it 35mm. think you may have some rubbing as i did with with 185\60 14 which still has a lower profile than yours.
yeah tracking i mean total, steering can get twitchy if to far out although very responsive. how did you adjust your camber?

put it simply standard shocks are oil, kyb's are just better built. gas does give a smoother ride than oil shocks, its just how its designed.
just a set of spax from demon tweaks, will drop it 35mm. think you may have some rubbing as i did with with 185\60 14 which still has a lower profile than yours.
yeah tracking i mean total, steering can get twitchy if to far out although very responsive. how did you adjust your camber? wishbones ok?
 
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