Quote:
Originally Posted by cv129
There's a next to brand new SPL front arms for sale right now, if op is considering that.
Question for the gurus: would increasing front positive caster and negative camber simultaneously be better than increasing just front camber? My simple understanding is increasing positive caster helps create negative camber when the wheels turn. I ask because, in my mind, wouldn't severe negative camber (like a -3 or even more) reduce straight line braking performance?
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If you go high on neg camber, then you can't be low on ride height because camber gain in bump (eg: dive under braking) will really screw with the contact patch.
I put 10 degrees of caster into my race car (70's historic Pommy sports car) so I could pull back the camber a bit and still get camber gain with steering input to help with turn and not kill the inside of the tyre under braking, but I have to install stealth power steer (actually electric power hook - hidden up under the dash).
This "sort of" translates to the Z34, keep neg camber around 3 or 3.5 (max) and push caster up a degree or two - this will help with turn and power steer will deal with increased steering effort with increased caster.
With the Z34, camber gain in bump (as the car dives under braking) can be significant if the car is low (real low). The rate of camber increase grows with bump. The only way to counter this is really stiff front spring which will kill grip which is not desirable.
It is all about finding the sweet spot and it can be very small ... BJ from Doran Racing noted on this form somewhere where a 1mm change in ride height "transformed" to Z34 RC they were running at the time, and finding the right compromise "at the limit" can involve small changes.
It is all a trade-off and the more adjustable and less compliant the suspension becomes, the less "daily-capable" a vehicle becomes.
SWMBO will not get into my car now because it is simply too harsh for her !! but that has its own benefits as well
To answer the OP question, increasing front caster can actually reduce the level of camber required to get the car to "turn". For me, I started at 3 neg camber when I installed SPL FUCA and then played with caster to get the level of turn I wanted - I am using 265/35R18 r-specs because I could not see the need to go bigger at present.