What is your take on rake?

[BlackSupra]

I have been trying to find more information about suspension rake and haven't been coming up with alot of results.

Over the weekend i decieded to give my soarer 'a bit' of positive rake ( a bit due to the fact i never measured it). I didnt touch the rear and left it as it was and dropped the front around 20mm. Now it looks great, however what are the real world results of creating positive rake?

Does it decrease lift as a few sources claim?

Will it result in a lightened rear end?

How does this effect weight transfer under braking and individual corner weights?

What are peoples real world results with this?

Fire away.

[oldcorollas]

depends more on the actual geometry of the arms involved?
and the newly changed CG with respect the the new roll centres?

some cars handle better with neg rake, although it looks liek arse

[Disturbed1]

not that im educated enough to know the real answer but im gonna guess that it will;

decrease lift and increase downforce and drag
will put less wait over the back wheels
will decrease the amount of weight that will transfer over the rear wheels when launching (ever so slightly)
will make little difference in breaking performance
and lastly, going to guess that it will promote understeer

overall, doubt u will notice any difference at all apart from how it will effect turning corners

[craigsimon]

without modifying your suspension pickup points it will mess with your roll centers and camber curves because you are moving into a different point of the curve.
if you only raise the rear it will raise your CG which will increase front weight transfer during braking.
by dropping front only you have lowered the CG which will decrease front weight transfer
there is an increase in downforce generation up to about 3 deg angle (front down) but you will only really see any useful downforce with a smooth underbody as the whole underside of the car will work as a gently diffuser.
neg lift (downforce) will reverse sharply as you approach a front ground clearance of around 2-3 cm (boundry layer starts to interfere with air flow under car) but as you approach 2-3cm front ground clearance neg lift is increasing so it is a balance act and the reason F1 front suspension is practically solid so downforce doesn't suddenly go away and also why thy rear is now fairly soft so that as the cars speed up they get closer to zero rake and have a little less drag at top speeds

cheers
Craig

[oldcorollas]

re corner weights, the CG is not moved much, and only 10mm down.. but buggerall in terms of front/rear, so why would corner weights change (edit) "much"?

re lift.. CG is 10mm (roughly) lower, so that decreases the (effective) moment arm of CG around the rear axle?? and the rear lower arms are pointing down more (by whatever amount.. about 0.5deg at a guess), so there should be a bit less anti-squat??

whether it will feel lighter at rear will be the result of changed roll centers no?

carroll smiths guide suggests increased oversteer

[merc-blue]

Any adjustment to hide height will affect corner weights, its not till you spend 6-10 hours trying to corner weight a car do you realise how fiddly they are