Sams Polo 3.0

[simon k]

The lower control arm link is the superior solution. Is the inner most bolt on the ball joint too far outboard to use for the swaybar link? It doesn't have to be perfectly vertical with sphericals both ends.

If not tig would be OK on the lower control arm, easier to be gentle than a mig.

Cheers
Gary

here's a Subaru LCA with the swaybar link bracket...

[sambb]

RE the intercooler, I was hoping you'd say that. The existing turbo, a K04-001 is basically just what I've already had but with a slightly bigger exhaust wheel. So its a bit more midrange-ey but still undeniably small and boost limited. I'm going to swap in my ported exhaust mani to free things up a tad more and help cyl 3 which is really choked down on the stock mani, swap over my turbosmart wastegate and then i'll probably leave it that way for a while till I can get the Golf 6 Gti turbo in there. But even that is pretty small so I think the single pass is the way to go.

[sambb]

RE using the inner most ball joint bolt.....its a no go. Even with the Audi TT ball joints in there which put the inner most bolt further up the arm, its still too far outboard and at full lock the caliper would get in the way of a drop link running out to there.

the bar sits directly above here on the wishbone and the drop link would have to attach to the arm in a similar position as the driveshaft runs across the middle of the wishbone.
It'd be nice to just take a piece of squared channel and slide it over the front edge of the wishbone and bolt it up with crush tubes, but the surface of the wishbone is all contoured and it doesnt present any flat surfaces. I think it'd look like a dogs breakfast.
I like the pic that Simon put up of the Subi arm in the next post. Can you weld a tab on like that and the arm is strong enough to take the forces in that one position? What worries me is that the natural pick up point is half way along the arm.....on a 22mm bar it wouldnt be able to fold the arm in half would it?

[sambb]

and looking at it again, the only place you'd think you get a crush tube in, would be at the big hole in the wishbone. But that been sort of dimple die'd and there's not really any way that you could feed a crush tube in that could be used at the two holes just back from where the flange needs to be. I think it needs to be welded.

[sambb]

In other suspension news, I'm going to press out the super pro rear lower control arm (caster bushes) and press them back in in a different position. I'd previously run them in the outer most 9 O'clock max caster position because at the time the only way I could get max caster was at the subframes (bush position + subframe eccentric bolts). But now that I've got strut tops its not super important to get it all at the bottom and I need to be mindful that I need 225/45/16's to fit so cant run the tyre as far forward at the bottom as I had.

What I want to do is either press those bushes back in at the 6 o'clock position to reduce anti-dive/pro-lift or choose a 7/1/2 O'clock position that is a middle ground between the min anti-dive and max caster position. thoughts pleeease........

[sambb]

best pic I could get with the car on the ground. The convoluted tube of the brake ducting in the foreground sort of obscures the wishbone a bit but the bar end sits roughly half way along the wishbones span and actually is over the front edge of the wishbone too. Should be easy to get one of the horse shoe shaped droplinks around the driveshaft though.

[sambb]

Rear brakes

I believe the new car has Audi TT quattro vented (22mm wide) 256mm discs and 2WD 125Kw Bora V5 calipers. Standard is solid 9mm wide and 232mm diameter. Both Bora and Polo calipers are single piston.
I'd like to find out if their piston displacement is the same.

The stock Polo F:R weight bias is 66:34. The Audi TT quattro which had the 256mm vented rears is 60:40. (https://www.audiworld.com/model/tt/04/04tt.pdf)

Clay who did this rear stock --> vented conversion weighed the difference and it adds 1Kg per corner.

So is the 2kg unsprung weight saving off the rear beam justifiable enough to go back to standard brakes, considering that the Polo is far far lighter in the rear in relative terms compared to the TT quattro, and was never rear brake limited to begin with??

[Sydneykid]

In other suspension news, I'm going to press out the super pro rear lower control arm (caster bushes) and press them back in in a different position. I'd previously run them in the outer most 9 O'clock max caster position because at the time the only way I could get max caster was at the subframes (bush position + subframe eccentric bolts). But now that I've got strut tops its not super important to get it all at the bottom and I need to be mindful that I need 225/45/16's to fit so cant run the tyre as far forward at the bottom as I had.

What I want to do is either press those bushes back in at the 6 o'clock position to reduce anti-dive/pro-lift or choose a 7/1/2 O'clock position that is a middle ground between the min anti-dive and max caster position. thoughts pleeease........

I always go with the maximum caster I can get, particularly on a FWD car as it reduces the need for excessive camber, which helps with the straight line traction (more tyre contact patch). Try the strut top adjuster at max caster and see if the tyres clear then.

Cheers
Gary

[Sydneykid]

Rear brakes

I believe the new car has Audi TT quattro vented (22mm wide) 256mm discs and 2WD 125Kw Bora V5 calipers. Standard is solid 9mm wide and 232mm diameter. Both Bora and Polo calipers are single piston.
I'd like to find out if their piston displacement is the same.

The stock Polo F:R weight bias is 66:34. The Audi TT quattro which had the 256mm vented rears is 60:40. (https://www.audiworld.com/model/tt/04/04tt.pdf)

Clay who did this rear stock --> vented conversion weighed the difference and it adds 1Kg per corner.

So is the 2kg unsprung weight saving off the rear beam justifiable enough to go back to standard brakes, considering that the Polo is far far lighter in the rear in relative terms compared to the TT quattro, and was never rear brake limited to begin with??

If you go with a 2 piece rotor/hat sometime in the future you will easily save the 1 kg.

I assume the front brakes have had a substantial upgrade as well, which has relevance to the balance question?


Cheers
Gary

[Sydneykid]

RE using the inner most ball joint bolt.....its a no go. Even with the Audi TT ball joints in there which put the inner most bolt further up the arm, its still too far outboard and at full lock the caliper would get in the way of a drop link running out to there.

the bar sits directly above here on the wishbone and the drop link would have to attach to the arm in a similar position as the driveshaft runs across the middle of the wishbone.
It'd be nice to just take a piece of squared channel and slide it over the front edge of the wishbone and bolt it up with crush tubes, but the surface of the wishbone is all contoured and it doesnt present any flat surfaces. I think it'd look like a dogs breakfast.
I like the pic that Simon put up of the Subi arm in the next post. Can you weld a tab on like that and the arm is strong enough to take the forces in that one position? What worries me is that the natural pick up point is half way along the arm.....on a 22mm bar it wouldnt be able to fold the arm in half would it?

I have used the Subaru "C" links on other cars to get around the drive shaft. I always prefer to load the centre of the lower control arm, rather than apply a twisting motion to it from the swaybar. Loads up the bushes, wears them out and adds noticeable amount of friction to the up and down motion of the lower control arm.


The further outboard you can go the less anti roll you lose due to motion and leverage ratios. Mounted ~half way along the lower control arm you are going to lose ~75% of the anti roll.

Cheers
Gary