Best way to cut the castor blocks?

Cassp0nk · #1 12-01-2009

Hi guys, whats the best tool/approach for cutting the castor blocks?

Cassp0nk · #2 12-01-2009

ok did it

Dremel cutting disk and 2mm drill bit for extending the pilot hole through. Bit of a faff given no one wants 3mm but I guess its not cost effective for schumacher to fix the molds?

BlackedOutMugen · #3 12-01-2009

Cutting the caster blocks? Havent heard of this one lol. Whats it do?

jayst · #4 12-01-2009

i was suffering major oversteer . cut it level and it cured it for me

Gnarly Old Dog · #5 12-01-2009

It enables you to lower the front outer pivot ball height by approx 3mm - by skimming the shoulder and grinding it flat with the remainder of the block.

On high grip tracks like many of the ones over here, this helps reduce some of the front end bite (a reversal of lowering the inner pivot if you like).

You can always shim the pivot ball back up to standard height but you may need longer threaded balls to do this since 3mm of the material they otherwise screw into has been removed.

Hope this helps

Cassp0nk · #6 12-01-2009

Quote:

Originally Posted by BlackedOutMugen

Cutting the caster blocks? Havent heard of this one lol. Whats it do?

All the team drivers here do it, so I felt I must follow sheep like

My setup is probably going to be a mess though as I can't go the whole hog on all their options as Schumacher are too tight to include enough spare shims to play with setup out the box. GRRRRRR

Cassp0nk · #7 12-01-2009

Quote:

Originally Posted by Gnarly Old Dog

It enables you to lower the front outer pivot ball height by approx 3mm - by skimming the shoulder and grinding it flat with the remainder of the block.

On high grip tracks like many of the ones over here, this helps reduce some of the front end bite (a reversal of lowering the inner pivot if you like).

You can always shim the pivot ball back up to standard height but you may need longer threaded balls to do this since 3mm of the material they otherwise screw into has been removed.

Hope this helps

Which inner pivot is being lowered? The upper camber link?

Gnarly Old Dog · #8 12-01-2009

Yes - I mean the inner pivot ball of the upper camber links.
Lowering it tends to make that end of the car more aggressive and increases bite. Raising it does the opposite and takes away some of the bite.

The reverse happens at the outer pivot.

Come and find us at EPR and we'll work it through.

Cassp0nk · #9 12-01-2009

So why do people bother dropping it if the outside machining is cancelling out a change on the inside?

p.s. I see your technique to lure me to EPR

Gnarly Old Dog · #10 12-01-2009

I think we'll need Elvo for this one but here goes.

It doesn't quite cancel itself out. My understanding is that it affects the roll centre and both inner and outer pivot heights have subtly different effects on that - although both can be characterised by the feel on the track as I previously described.

But don't forget that you'll want to work on both ends of the car independently and in some cases, you'll want to reduce the front end and maybe also increase the rear end grip. Since the rear hub carriers do not allow for vertical ball height adjustment, you are forced into using the inner only (which you would lower to increase bite) whereas on the front end, you can use both inner and outer.

Cassp0nk · #11 13-01-2009

Ah, so none of its going to be relevant to me bashing into the side of the track until I break the car?

Chrislong · #12 13-01-2009

Lowering the inner front camber link increases bite, as does raising the outer. By cutting the hub you are lowering the outer ballstud to decrease bite, but we also raise the inner to 0mm shims to further increase the same effect given by cutting the and lowering that ballstud. This does not cancel each other out.

If you do one side at a time, you will see the drastic change in the angle of the camber link. From kit the angle is very severe in relation to the wishbone, whereas what we are aiming to achieve is that camber link to be much closer to parallel to the wishbone.

Chris

Northy · #13 13-01-2009

Quoted from Elvo's awesome site:

Parallel Link (Parallel to lower arm)

A parallel link gives a little more roll than an angled one.
It feels very smooth, and consistent as the body rolls in turns.

Angled Link (Distance between arm and link is smaller on the inside)

An angled link makes it feel as if the car has a tendency to center itself (level, no roll), other than through the springs or anti-roll bar.
It gives a little more initial grip, steering into corners. It makes it very easy to 'throw' the car.
The body rolls a little less than with parallel links.
On bumpy tracks, it could be possible to use softer settings for damping and spring rate than with parallel links, without destabilising the car.

I think from my tests the link angle effects 'turn-in' more than anything else, but on a 4wd car that generally feels like overall steering to me. You might need this turn in depending upon the rest of your set up. For example I ran our 24 hour S1 SX on Saturday night (fixed 4wd) and increased the front link angle to gain turn in (the outer hub wasn't cut down either).

Elvo's site can be found here:

http://users.telenet.be/elvo/

G