ian 993gt2

all nine of my brain cells are marching in the same direction but is it the right one
i know:
1 rubber is bad
2 flex is bad
3 changeable alinment angles is bad
but after looking at the rear subframe all the suspention pickups are to the rear subframe not to the body so locking one to the other dose nothing
the rubber bushing is just insulating vibration from the road wheels

rs bushings monoball or rose joints in the rear control links i understand this would stiffen the rear no end but subframe bushes...... what am i missing

ps i just orderd them to keep my ocd under control and waste somemore money

Jean

Ian, it is not the rubber only, the mounts change the tilt angle and geometry of the rear subframe.

Bill Verburg

It also moves the subframe up into the chassis to help alleviate unwanted geometry issues(rear bump steer) which arise when the car is lowered, think of it like the RS uprights & tie rods used front to compensate for geometry issues that arise when the car is lowered

ian 993gt2

dont the kinematic arm sort that out by intruducing toe out?

ian 993gt2

i read what jean wrote which is correct ir you have the gt2 eco bushes which drop the nose of the box down a few degrees my point was is it woth doing the sumbframe bushes without doing all the controderl arm bushes aswell i think the rs has monoballs if not much harder control arm bushes

pstoppani

My opinion is that if you are going to bother with the subframe solid bushings, you should do the tilt kit version and monoball the whole suspension. Otherwise, you create an unintended imbalance in forces on the remaining rubber bushings.

Basically, if you go solid in one part of the suspension and leave the other bushings stock rubber, then the forces will be higher than intended on the remaining rubber.

Personally, I wouldn't bother with just the solid subframe bushings; I doubt you'll notice any difference.

pstoppani

Bill V -

I followed your suspension conversion very closely and it was your experiences that drove me to do the same for my 993TT. It completely transformed the car from a wallowing cruiser to a tight sports car. I'm amazed at how little noise/harshness is added to the car with the fully solid suspension!

Best modification for this car; hands down!

ian 993gt2

thats what i was thinking pete all or nothing

Bill Verburg

An RS has harder rubber bushes on the inner ends of the kinematic link and the rear arm of the lower A control arm. The leading lower A arm is the same monoball on all of them and the camber and toe links are the same on all of them
.

the harder RS bush KT reduces the amount of KT, a pure monoball end would be even more restrictive leaving only geometry as a factor in the amount of KT that would be evident.

the solid sub frame mounts are great as are the harder RS bushes(for a pure track car you would want all monoballs) the icing on the cake is monoball toe links


I can't comment on the tilt kit but I love mine w/ all RS arms solid flat subframe mounts and monoball toe links.

ian 993gt2

is that diagram wrong? camber kinematic viky verky

Bill Verburg

No

ian 993gt2

sorry bill i can see now (dont look at pics on a blackberry when you dont have your glasses)

Felix

Not sure I agree - the forces are basically a result of the car's dynamics (cornering, braking and/or accelerating) and just because deflection is removed in one area doesn't greatly increase or change the force in another. It may increase the stress on the other component because it has to provide all of the deflection but the actual force will be much the same.

ian 993gt2

thats a real head scratcher felix

mbb993

QUOTE=Bill Verburg;9169850]It also moves the subframe up into the chassis to help alleviate unwanted geometry issues(rear bump steer) which arise when the car is lowered, think of it like the RS uprights & tie rods used front to compensate for geometry issues that arise when the car is lowered[/QUOTE]

I am in the process of doing all this right now. I was just inspecting the subframe to body mounting and it appears that the solid mounts (without tilt kit) will move the subframe up a few millimeters after installation.

Has anyone found that this changes their ride height/corner balance significantly after the mounts are replaced? I suspect it may have some effect on this but hopefully not enought to need to redo the corner balance I just did last month!![