upright mushrooms

[degmwilliams]

I do not understand why the hole is off center on the mushrooms, surely if the hole is not in the center of the insert it could cause an issue if they were not perfectly in the same place in the upright as the other side?

[twinturbo]

It's called an eccentric top mount. Combined with the adjuser on the wishbone it allows for castor and camber adjustment.

TT

[Talonmotorsport]

The hole needs to go to the front of the strut clamp to give the correct caster other wise the car won't self centre as it should. You could put the hole in the middle of the mushroom but then you'd have to modify the front top wishbones to sit further back to give the correct caster. It might mean that the ball joint and track rod end that acts as the pivot might not last as long.

[degmwilliams]

so why do gts tuning sell them with the hole in the center for the haynes roadster?

[dogwood]

I bought mine from Rally Design, they were also center holed.
They fit but the off center ones are better.
It's hard enough to get these to self center with the correct mushrooms.

P.S no comment on GTS

[twinturbo]

Perhaps for their own chassis which is slightly different in many respects to teh Locost/Roadster. They may have dialed in the Castor into their suspension geometry using the wishbone locations.

The eccentric ones alow for fine tuning and for adjustment if you fancy setting your castor up differently to the norm.

TT

[Talonmotorsport]

I have lots of comments on GTS tuning and Darren George none of which I can put on this forum or any other! If it was my money that I was spending I would look at other suppliers even my immediate competion.

[HandyAndy]

i got my mushrooms from a car that was being "broken"..... £5 for the pair

and yes they are the "off center" type

andy ( renowned bargain hunter )

[3GE Components]

The reason they are offset is to align the top and bottom pivots with the axle centre line better, If you draw an imaginary line through the Sierra upright you will see that if the mushroom insert is concentric it will miss the centre line of the axle, requiring more effort to self centre.

The reason some suppliers mushrooms are concentric is cost, put plain and simple they are cheaper to make.

Hope that all make sense

Kind regards

John

[RAYLEE29]

This has all been done before you need offset mushrooms for the best geometry with sierra uprights.
gts will tell you anything to get a sale .
its all to do with kingpin inclination
there is a search tool on this forum
and yes you do want both sides the same thats why when i made my offset mushrooms i marked them with a file to show the position of max offset
Ray