ride height bias

[JUST CUSTARD PLC]

What is the general rule of thumb for 4wd cars, front lower than rear ?
and by what amount ?
At what point (i.e. how much lower) would having the rear lower than the front affect braking bias ??

[Duncan_cox]

Ride height effects corner weight....if you lower the front it has a lbigger corner weight than the back....this is what race cars do to balance the weight distribution of the car for particular tracks. So if you want to keep the babnce of the car the same keep the ratios of front and rear ride height the same, unless you want to track race it...then you need to start measuring the corner weights can be expensive!

Ride height does not effect the breaking bias, you nee a brake bias valve to do that, it just effects the weight distribution, thus under steer, over streer, bump compression, tyre pressure the list goes on:)
have you got coil overs or straight struts with different spings?

Dunc

[JUST CUSTARD PLC]

leda coilovers
450 front
325 rear

front slightly lower than rear ????
or should rear be lower as rwd cars ?

[Duncan_cox]

As the engine is in the front, I would lower the back more than the front (or raise the front) so that more of the weight is on the rear tyres. Ideal is 50:50 front to rear side to side. It is difficult to guess the distribution with trial and error. Much better to take the car to someone with a set of scale and get your C-spanner out, fuel tank, and you sat in the drivers seat (plus passenger if you like scaring people ona regular basis :D )

Dont forget that the tyre pressure will be different to standard with a different height / weight distribution.

BMW rave on about 50:50 front to back weight distribution and they are all RWD front engined. a mid engined car it doing it even better with most of the mass in the middle.

Dunc

[Blade]

Custardo - corner weight it. Not only do you have to get the weights balanced, but also you want some preload on the springs too.

Can only be properly done with corner weights. My garage could do it for you if you are stuck.

[JUST CUSTARD PLC]

i understand preload , as in bike dampers,
but do you need preload on the spring when the car is off the ground ?, or is it ok to have huge free travel to get the ride height where you want it ?

wishing id left it alone !!!!
sod this,
i am buying a skyline, evos had its day, old hat now !

[Blade]

I believe the preload is only possible when the car is on the ground! The spring is pushing against the weight of the car, so the whole point of corner weighting it is to balance the different forces (as the weight varies) and get the right amount of preload (which depends on the type of damper you have).

Remember you need to corner weight with you in the driving seat!

It doesnt cost much to do it properly. Do you want the guys number or not?

[JUST CUSTARD PLC]

"It doesnt cost much to do it properly. Do you want the guys number or not?"

maybe doesnt cost much in money terms, but time is my enemy

no, but my titanium spring retainers have not come in this mornings post ??????

!
stuart

[Blade]

Sorry to hijack, but I haven't ordered them..

why not?

Well having spoken to various big knob tuners (e.g. Prospeed) they say there is no point if you don't rev above 8krpm.

Well, as max power at high boost always seems to be no higher than 6.5k or 7k, then what's the point? However, I have found some in the US for $180...


On the other subject, why is time your enemy?

[JUST CUSTARD PLC]

the big knobs are wrong
the real big knobs, use titanium valves ,springs and retainers on KTM engines that only rev to 8k

they just rev quicker,
so get some, and get me some

i do not have any spare time, thats all.

[Blade]

Don't get me wrong, I will get some... but I am in no hurry. I presume it is head off to change these - so I will have to do other things to warrant it, e.g. solid lifters, thinner head gasket, possibly different cams again.

Expensive.... should have done them first time round really :(