Tfsi Mikes Money Pit :: AKS built Cupra :: TTE420 :: Rtech Tuned

[danishmkvgti]

Sorry i haven't got the pm from JonnyC anymore, but here's a bit about the subject:

http://www.mk5golfgti.co.uk/forum/index.php/topic,7823.msg222742.html#msg222742

[RedRobin]

^^^^
Ah! Understood 

Lower position of ball joint = higher centre of roll.

TT arms also do this?

[Tfsi_Mike]

How will the top mounts lower the roll centre, Jake? Cheers

[danishmkvgti]

How will the top mounts lower the roll centre, Jake? Cheers

actually, looking for the info from JonnyC i couldn't remember the argument for, but i'm sure the top mounts was bad compared to doing the tt lower arms. I'm just not sure why anymore 
Maybe Alex has some info on pro and cons for the top mounts??

[Janner_Sy]

it was something like top mounts pushed the roll centre away from the optimum level, but TT arms moved it towards it.  iirc he said something along the lines of having both allowed you to keep a good roll centre

[Top Cat]

This ^^^  Basically there is more benefit adding camber from the bottom than  the top. Wider track lower rolling centre, more contact patch bla bla. This being said i am guessing the differences would be minimal unless you could achieve lots of camber with both. Every little helps though when on track near the limit ( or your just a mad modder.  )

[RedRobin]

Every little helps though when on track near the limit ( or your just a mad modder.  )

....We don't know any mad modders on here though, do we.

Though there's a lad called Mike with a Cupra..................

He is going to enjoy himself when he gets the opportunity to do trackdays more 

[the bruce]

I need to assume Jake is right:



When increasing camber by adjustable top mounts you also change the 'strut angle'
'SAI' (unfortunately I only know the German word 'Spreizung') at the same time.
This is the angle you see on the right picture and it's in the 15° area on a Mk.V GTI.

The point is this angle also defines the position of the roll center as shown above.
For maximum cornering grip more camber is more important.

 

I wouldn't overestimate this, but it seems Jake has set an interesting point on this.

 

[vRSAlex]

Did myself a little drawing.  Too good to publish but it helped me write this answer:

There is very little, and I mean very little change to the roll centre by using adjustable top mounts.  You are only moving the mount approx 15mm inboard which wont cause any noticable change in handling to a negative effect.

You will have more or a negative effect by keeping the rubber mounts as the mount moves so much before the damper can function.  For example, with the stock rubber mounts on the vRS I could push down on the front of the car and it would 'bounce' due the flex in the rubber.  Now with the Ground Control mounts fitted it wont flex at all.

[Tfsi_Mike]

That satisfies me 

Plus with both the lower arms and top mounts I will always have the full options on adjustability in the future 

[the bruce]

For example, with the stock rubber mounts on the vRS I could push down on the front of the car and it would 'bounce' due the flex in the rubber.  Now with the Ground Control mounts fitted it wont flex at all.

Keep in mind Mike's Cupra already has the TT/Cupra mounts which are 30 % stiffer.

 

On a side note:

If you want to increase camber significiently you need to shift strut mount a bit more
than 3 mm.
Don't get me wrong, I still believe this is no reason to worry, it's just an interesting point.
Also there's no alternative. If you want more camber you also get an increase in 'SAI'.
Otherwise you'd need different swivels.

[vRSAlex]

I have edited so state its more like 15mm as I miss typed.

[Tfsi_Mike]

What are the Dunlops I might be selling my testicles to order Alex?

Thanks for the update on the battery tray! 

[vRSAlex]

What are the Dunlops I might be selling my testicles to order Alex?

Thanks for the update on the battery tray! 

Dunlop Direzza 03G tyres.  150 plus vat each iirc.

Go read some reviews.  I want some too.

[rich83]

Thats seems quite cheap... is that for 225 40 18?