Front Tension Strut / Thrust Bearing

[m4forum]

I am looking for feedback on front tension strut / thrust bearing monoball on street and track performance. Can get them from BW or Turner.

Does it really make any difference at the track which is noticeable / yield better laptimes? I know would be stiffer but wonder if the gain is measurable.

Appreciate your feedback.

[m4forum]

any feedback! seems like this change is not popular.

[M 4 FUN]

Originally Posted by m4forum

any feedback! seems like this change is not popular.

Hi! Do you mean the eccentric front castor bushings?

[m4forum]

this is the part



[IMG][/IMG]

[jfritz27]

It's one of those things that's an incremental benefit -- are you likely to see better laptimes with this alone? Probably not. It definitely increases steering feel to some degree, and can reduce the tendency of the front end to dance under hard braking by keeping the geometry more stable. But that dancing will also be influenced by the rest of your suspension setup/dampers (how much forward weight transfer) as well as your alignment (toe). So laptime gain could come from increased confidence with braking, allowing you to go harder/later, assuming other factors align to permit that.

[RSXDC5]

The gain is that it makes the front of the car feel normal/stable at the limit in corners & under heavy braking/decel (the oem bushing deflects with added g force…if you run a 100tw tire, you will have enough deflection to warrant this upgrade…a 200tw tire would also benefit).

Upon getting these installed, I don't even notice them, ever, which is a great thing…but to answer your question an ultra small amount of additional directness is felt.

In terms of lap times, these monoball upgrades inspire confidence at the limit and/or when pushing. That is enough to shave a few tenths off depending on the track layout and whether you can ride the limit of tire adhesion well when pushing in corners or braking.

I would also recommend the rear SPL tie rods which pair well with these monoballs!

[M 4 FUN]

Originally Posted by m4forum

this is the part



[IMG][/IMG]

Ok, then we are talking about the same bushing. I have changed that one on my car to a SPL eccentric solid aluminium bushing. It's the only thing i've changed in the front suspension except Öhlins road&track coilovers.
These bushings makes a big different in feel but they also increase road noise. The benefit is steering feel and another good thing is that you can increase Caster angle. This makes the steering response better as Camber increases once you start turning your wheels into a corner. Stability under hard breaking also increases with a bit more Caster angle. For road use there is no idea to have a lot of Camber when driving straight as wear on the tires increases and braking performance will be worse.
Another alternative is to use Powerflex polyurethane bushings. They have a set of bushings that are eccentric and increase castor 0.5 degrees and are 18% harder than the stock ones.

[m4forum]

Hello all. thank you for the updates. Looks like the change can yield some improvement on steering fell and as consequence increase confidence and potential some gain in laptime. The change on itself doesn't see to provide a substantial gain.
As right now I am confident in pushing the car. My main focus now is to reduce understeer and get a more even tire wear between front and rear as I use staggered setup.

[M 4 FUN]

Originally Posted by m4forum

Hello all. thank you for the updates. Looks like the change can yield some improvement on steering fell and as consequence increase confidence and potential some gain in laptime. The change on itself doesn't see to provide a substantial gain.
As right now I am confident in pushing the car. My main focus now is to reduce understeer and get a more even tire wear between front and rear as I use staggered setup.

The a bit more Camber on turn-in should help and you will get that with more Caster angle.

[m4forum]

Originally Posted by M 4 FUN

The a bit more Camber on turn-in should help and you will get that with more Caster angle.

is that noticeable? can you feel the additional camber?

[M 4 FUN]

Originally Posted by m4forum

is that noticeable? can you feel the additional camber?

Yes, clearly. Steering response is clearly increased and you feel that the front end wants to steer in better. The solid bushings i use does increase roadnoise and the car feels more harsch over rail road crossings and such but at the same time they give a better feel through the steeringwheel. It doesn't feel as numb as before.

[m4forum]

thank you for the feedback. The numbness on steering is something I want to improve. Will look into it.

[stevehifi]

get the turner motorsports bushing, he uses a BMW OEM sealed unit and it's only ~$300 or so.

[bimmerboyE92]

Yes, monoballs are worth the upgrade for tracking.