Adjusting Bulkhead angle

[Mtbmatty]

We have a broken front bulkhead on our associated B6.4 the kit setup was zero degree. It came with an optional-2.5/+2.5 depending on how it is oriented on the car.
What will this angle adjustment accomplish?? Lower ride height or overall handling; both, neither or what

 

[bill_delong]

This is often called kick-up or caster:
https://www.teknorc.com/wp-content/uploads/2014/06/Set_Up_Guide.pdf

 

[Mtbmatty]

Thanks Bill, I think I will keep the car where it is and upgrade to the aluminum zero degree bulkhead.

 

[WickedFog]

0° caster will make the car less capable in the corners. The combination of camber and caster causes your front tires to lean into a corner like a motorcycle, lifting the tread and riding on the inside lip of the tire. No caster means the car will only be good at going in a straight line (drag cars are setup this way). Any camber you have with 0° caster will just cause the front tires to shovel into the dirt, and the car won't push into the corner as well.

On my 1:1 Mustang, which was setup for carving corners, I had every bit of caster I could get (the Mustang actually leaves you wanting more). It made the car take corners so good it really scared the hell out of people while entering corners way hotter than they thought the car could handle

 

[Mtbmatty]

I think he could use a bit more steering (at times). Still working on consistency on corner entry.
I’m also a bit gun shy to make adjustments, not knowing what follow up adjustments may be needed/necessary.
I think he’ll get used to pretty much anything at this point, he just wants to grip it and rip it.

 

[Lumikko]

0° caster will make the car less capable in the corners.

The 0-degree bulkhead in this case means that it doesn’t change the kick-up of the chassis which is already set to 22.5 degrees. The caster blocks used in the kit setup adds 5 degrees to this for a total of 27.5 degrees of caster.

———

Kick-up and caster are two different things.

Kick-up is the upward angle of the A-arm hinge pin relative to a horizontal axis.

Caster is the rearward angle of the steering knuckle kingpin, relative to a vertical axis. It changes along when you adjust kick-up but can be adjusted separately.

If your stock bulkhead is broken and you’re waiting for a spare or upgrade part, you can use the -2.5 option included with the kit if you ride mostly smooth tracks and want faster steering. For bumpy tracks, consider using the +2.5 orientation of the bulkhead and changing the +5 caster blocks to +2.5 blocks to get more kickup while maintaining the same caster angle as in the kit setup.

 

[WickedFog]

The 0-degree bulkhead in this case means that it doesn’t change the kick-up of the chassis which is already set to 22.5 degrees. The caster blocks used in the kit setup adds 5 degrees to this for a total of 27.5 degrees of caster.

———

Kick-up and caster are two different things.

Kick-up is the upward angle of the A-arm hinge pin relative to a horizontal axis.

Caster is the rearward angle of the steering knuckle kingpin, relative to a vertical axis. It changes along when you adjust kick-up but can be adjusted separately.

If your stock bulkhead is broken and you’re waiting for a spare or upgrade part, you can use the -2.5 option included with the kit if you ride mostly smooth tracks and want faster steering. For bumpy tracks, consider using the +2.5 orientation of the bulkhead and changing the +5 caster blocks to +2.5 blocks to get more kickup while maintaining the same caster angle as in the kit setup.

Ahh, ok. That makes sense then.

 

[Mtbmatty]

Great explanation thanks!!

I did try the -2.5 and it was a noticeable difference. The car was a bit twitchy but cornering seemed better…. He wasn’t stoked on it so we switched back to the zero degree but in aluminum.