i was wondering if anyone is running these or a similiar product and what ur pros and cons r

 

I am using the Special Project MS roll center adjusters. Installation was painless and the quality is great.

http://specialprojectsms.com/index.php?categoryID=39

 

there basically the same what did u notice handeling wise and do u have problems with the uca hitting the sock tower worse

 

It pushes the lower control arm down, it doesnt push the upper control arm up.

 

ok do u like them im on konis and gc 400 front and 450 rear rates with stock front sway bar and gsr rear would these make the car push or improve handeling im on r compounds

 

By lowering the front outer ball joint, this will raise the roll center. In addition, the roll center rate of change (the vertical displacement of the RC) with suspension movement also is reduced due the reduced angle relative to horizontal of the LCA. Both of these factors help to reduce the chassis roll angle in cornering. Thus, at the front of the car, the effect of raising the RC will reduce the tendency to understeer.

If the RC was above ground to begin with, then raising the roll center has one negative aspect: Jacking. When the RC distance above ground increases, there is a larger jacking force that acts vertically through the RC and tends to lift the chassis at the front. This also increases the suspension's droop and for double wishbone type suspensions the camber becomes more positive. This is why RC relocation needs to be done properly to get the best performance out of your car.

To do the RC relocation correctly, you will need to decide at what ride height will give the most benefit with consideration to the wheel rates (suspension spring rate and ARB rate) you're using.

 

Raising the RC reduces the roll moment (distance from the RC to CG height) which tends to increase understeer, not decrease it. Raising the RC also has the effect of increasing the rate of weight transfer upon turn in which could help improve corner entry balance on a naturally oversteering car. On a car that has too low a ride height and not very stiffly sprung it could also be a benefit by preventing the RC from going below the ground level during turn in while the car is still diving due to braking. Since the RC moves vertically with the chassis, dive under braking can result in the RC passing below ground which makes for some unusual handling feedback when the car begins to corner. most race cars are stiffly sprung enough that that isn't a large concern. The reduction in front view swing arm length also increases the camber gain but again, on a suspension that has only 2" of bump and droop travel, that's not likely to be that great of a difference to be noticable. So it really depends on one's particular setup to say if it is a benefit on double wishbone cars. On a lowered mac strut car, it's almost always a benefit.

 

It is not as simple as saying raising the RC at the front will tend to increase understeer. There are two major factors involving how the height of the RC will have on grip levels at one or both ends of the car.

A higher RC will result in a smaller roll couple resulting in a smaller chassis roll angle. With less chassis roll, the tire maintains more of it's static negative camber. Tires generally develope maximum grip at small amounts of negative camber of -2 to -4 degrees depending on the tire and it's construction. The amount of grip improvement depends on the static camber, the tire's grip verse camber curve, ect.

The jacking effects of a higher RC will tend to reduce grip and with stickier tires the worse the situation becomes. We generally want to minimize jacking and therefore we want a RC only a couple of inches above ground for more applications.

The other issue not directly related to the static RC is the lower control arm's angle with the horizontal. The larger the angle, the more the RC will migrate vertically downward during and after steady state cornering is achieved. This larger RC migration will result in more roll angle and thus more camber change resulting in more understeer.

So, it isn't simple to state that raising the RC will result in a more or less understeer.

 

Hm, so when you put on RCA's does it make the front wheels naturally loose negative camber? I literally just got my Mfactory RCA's in this morning.

I am a little confused on what to expect out of them. (don't mean to thread jack).

All I know is my car is not that low and my front LCA's are angled upwards a little bit and I just wanted to correct the geometry.

 

thanks guys a bunch for all the info i appriciate it alot ...this is my setup del sol si koni and gc 400 front 450 rear stock front sway bar gsr rear sway beaks bar stock motor r compound tires 225/45/15 with 5 mm spacers all the way around .....i have a pair of knuckles with new m factory roll center adjusters i auto x the car and a few track days should i put the other knuckles on or not ....i would like ur guys opinion on wht i should do put them on or leave them off

 

Put 'em on and try it. See if they work for you. Its not as easy as slaping them in tho. You may have to make some changes alignment wise. But do some testing with them and go from there.

 

If I'm not mistaken, this will also put the UCA further up into the wheel well, increasing the chance of the UCA making contact with the shock tower. Cars that are lowered more than a few inches should check for clearance problems.

 

Only because installing them will lower the static ride height.

If the ride height is corrected after install back to its previous height, the UCA will remain the same distance from the shock tower as before.

 

I got to use these for a full week before my car was stolen. They felt awesome for that one week, the front end was planted.

 

I love posts like these (and HT is full of them) that discuss the dynamics of the theory without ever answering the question or attempting to solve for a single answer by providing practical examples of the benefits or detriments of choosing one path over another.

It's like Parliament discussing the merits of law all day and then breaking for the pub without ever calling a vote.

Perhaps some sort of sliding scale should be introduced that helps assist consumers as to if a part should be considered given their suspension setup.

 

Unfortunately, I think there are too many variables in the equation.

The only way to actually answer "do I need them" is complex. People need to understand that there is simply no easy answer here.

If you are interested enough to want to improve how the car handles, be interested enough to learn how to achieve that. Once that understanding is in place, then you can decide if you need them for your driving style and your car's specific configuration for your car's specific uses.

 

By the way, installing roll center adjusters will give varying results depending on so many factors like, tire choice, c.g. height, track width, ride height, suspension roll stiffness and coupling, ect. So the answer you seek can only be described in the trends in a particular parameter (like roll center migration, or roll gradient, ect.) for a given setup.

To be sure, handling is not an easy exercise to nail down due to the multitude of possible permutations of each parameter involved and the compromises that are inevitable (e.g. how roll center height affects jacking and roll gradient is a good example of how one parameter causes opposite affects that need to be dealt with).

 

So would it reduce the angle in which the lower ball joint bolt nut protrudes toward the rotor?
Or does that angle remain static and the roll center adjust simply lowers it?

https://honda-tech.com/forums/tech-misc-15/lower-ball-joint-bolt-rubbing-rotor-1788276/

 

The balljoint and nut portrude the same amount. They are machined to seat like a factory balljoint.

 

I've had mine on for about 2 weeks now, and i'm not going to lie. I didn't feel any difference what so ever. Only thing I noticed was a little loss in negative camber about .5 a degree to be exact.

Although the lower control looks to be in a better position (flat) I didn't feel anything.

 

If you had a lot of front or rear roll stiffness, that would have cancelled out some of the benefits of the roll center adjusters anyway. At some point, I posted a link to some excel program that was originally designed for an STI, but has a section on calculating roll and roll couple and all that other stuff. If you reverse engineer his formulae, then you can sort of get an idea what is going on, and how much of a difference your roll center adjusters would have made.

 

Any chance of having a look at that spreadsheet beanbag?