The DC2 Castor Thread

[szymonsta]

interesting reading..im guessing you could net similar results by using more negative camber and leaving the caster alone? (since the main advantage of increased caster is increased dynamic negative camber during the turn).

[freakygeek]

szy, you're basically spot on. We would be better off using more static camber than trying to achieve levels of caster that would net us any useful gains (in terms of dynamic camber), whilst at the same time throwing away Honda's hard work to achieve zero bump steer.

Even with the UCA swap you still only have less than half the caster than a standard BMW 3-series runs from factory, for instance...

[mugsee]

The reason why castor is at times more desirable than camber is because of its dynamic nature.

If you were just to add, for example, -4.5degrees of camber, your tyre contact patch will be significantly affected, thus reducing your acceleration and braking capacities.

That being said, a certain amount of camber is healthy but too much or too little can also be detrimental.

[tinkerbell]

interesting reading..im guessing you could net similar results by using more negative camber and leaving the caster alone? (since the main advantage of increased caster is increased dynamic negative camber during the turn).

yes, very similar results indeed...

however, static camber increases tyre wear - that is why castor increase is seen as "free" camber increase.

see...

the negatives of bump steer changes are felt most on a bumpy straight road or while braking/booting suddenly during a corner... i thought? in rapid comp/rebound

however, the positives of increased castor is the increased dynamic camber that increases as steering input increases... isn't it? like szy says...

yes, *marginal* performance increase at most on the dc2, but the principle is sound. it improves the immediacy of the chassis, so why not?

i guess my experience with this swap that relates only to aggressive track prepped cars, my perspective must certainly be tainted...

so i apologise for going on about it, but i really am interested in all this might even do the measures tomorrow...

[tinkerbell]

The reason why castor is at times more desirable than camber is because of its dynamic nature.

took wayy too long to edit my post, lol, you beat me

[freakygeek]

The reason why castor is at times more desirable than camber is because of its dynamic nature.

If you were just to add, for example, -4.5degrees of camber, your tyre contact patch will be significantly affected, thus reducing your acceleration and braking capacities.

That being said, a certain amount of camber is healthy but too much or too little can also be detrimental.

You're right in principle,

but do you know how much actual camber is added with +5deg of caster at normal steering angles on the track? It is about 1/5th of f**k all. Especially in high speed corners where the actual amount of steering lock is minimal - ie EC turn 1...

[tinkerbell]

and do you know what it is like in a round-about or a 15 km/h u turn?

[ChargeR]

The reason why castor is at times more desirable than camber is because of its dynamic nature.

If you were just to add, for example, -4.5degrees of camber, your tyre contact patch will be significantly affected, thus reducing your acceleration and braking capacities.

This man is factually correct. Camber does get you the ladies though.

You're right in principle,

but do you know how much actual camber is added with +5deg of caster at normal steering angles on the track? It is about 1/5th of f**k all. Especially in high speed corners where the actual amount of steering lock is minimal - ie EC turn 1...

However I think that this man truly knows the score.

The camber gained from the amounts of castor you are going to be able to achieve on a DC2 Integra is negligible. Tinkerbell, any improvements you felt in steering feel or turn in could have been caused by damn well anything, even the strange toe changes during compression from you swapping the upper control arms, because you certainly did not gain any significant amount of outside wheel negative camber at the levels of steering movement you would have been using.

szy, you're basically spot on. We would be better off using more static camber than trying to achieve levels of caster that would net us any useful gains (in terms of dynamic camber), whilst at the same time throwing away Honda's hard work to achieve zero bump steer.

I agree. Especially considering that you DC2 guys can get away with much less static camber since you have much more favourable camber gain under suspension compression.

[tinkerbell]

Tinkerbell, any improvements you felt in steering feel or turn in could have been caused by damn well anything, even the strange toe changes during compression from you swapping the upper control arms, because you certainly did not gain any significant amount of outside wheel negative camber at the levels of steering movement you would have been using..

could be placebo effect too?

[ChargeR]

could be placebo effect too?

Yeah. And if the swap felt better and you went faster who cares? The race track does not lie, people merely misinterpret it.

[szymonsta]

The reason why castor is at times more desirable than camber is because of its dynamic nature.

If you were just to add, for example, -4.5degrees of camber, your tyre contact patch will be significantly affected, thus reducing your acceleration and braking capacities.

That being said, a certain amount of camber is healthy but too much or too little can also be detrimental.

absolutely i agree. like tinks said the caster alows, if you like, 'extra camber but only when you need it like when youre turning' effect, without the negatives of negative camber in streight-line stability, streight line traction and braking (though with less than 3.5deg negative i personally think these side-effects are near-negligeable. although with my setup the front does 'wander' a bit under hard-braking eg from 180km/h+ to 40-ish, but thats in part the toe-out, as well as the camber).

i would say that in the case of the dc2R, my personal preference is to dial in a little extra negative camber and leave the minimal caster as standard.

[szymonsta]

....Especially considering that you DC2 guys can get away with much less static camber since you have much more favourable camber gain under suspension compression....

i wonder about excessive lowering and this statement..

im sure that in standard-suspension, or well-set-up coilover instance you are absolutely correct, and under compression there is favourable camber gain.
however i wonder if excessive lowering can cause reversal of this? as well as a rise in the roll-center?
anyone care to explain this to me?

ps very interesting topic! its nice to be able to discuss stuff like this on a forum. not many places out there like clubITR. feel the love.

[bennjamin]

my 2 cents.


i have EG civic , with the upper control arms swapped L/R.
I also have power steering removed , a LSD powered by a b18c7. car is lowered on n+ and straight alignment front/rear.
Car goes thru various forms of road , i am a learning driver but i havent experienced any bump steer in normal or excess conditions. Perhaps a sudded dip into a l/r corner may unsettle the car but overall its still quite predictable even on the limit.
All i know is swapping hte upper arms combined with the rest has improved handling.

I had the whiteline kit on a previous car , felt a fair chunk better than the above but like all things whiteline it failed and snapped one large bolt

[mugsee]

You're right in principle,

but do you know how much actual camber is added with +5deg of caster at normal steering angles on the track? It is about 1/5th of f**k all. Especially in high speed corners where the actual amount of steering lock is minimal - ie EC turn 1...

I completely agree that a couple of degrees of castor equates to sfa camber during your average corner on the track (DC2 and DC5), however every little bit helps. Also, Tinkerbells comment "it improves the immediacy of the chassis" strikes a chime with me and also adds to why camber is desirable.

Yeah. And if the swap felt better and you went faster who cares? The race track does not lie, people merely misinterpret it.

QFT. IMO, even if the change doesn't make you any faster but you like the way the car feels, then it is still a worth while modification.

[tinkerbell]

Also, Tinkerbells comment "it improves the immediacy of the chassis" strikes a chime with me and also adds to why camber is desirable.

yes, my comment was an elaborate and less blokey way of saying "oversteer"

which is a slightly quicker way around a race track than via an understeering car...