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Author Topic: AP Racing BBK technical inquiry  (Read 3262 times)

Offline fuscobal

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AP Racing BBK technical inquiry
« on: June 24, 2011, 10:33:23 am »
Hello guys,

Just bought the ApRacing Pro 5000+ kit from my friend TEFF (he's also a member here) and would like your opinion on the following problem. The caliper carriers had to be thinned in order to clear the swivel/hub on the lower side. Here's what Ap Racing said :

"CP5060-1001NP was competition kit originally devised for the VW Scirroco that is based on the Mk5 Golf Gti / TDi PQ5 platform
We haven’t detailed a kit for the Mk6 Golf R20…………..

This model would appear to uses a different lower arm from the Mk5. From the photo The R20 uses an aluminium lower control arm that’s possibly wider than the Mk5 steel type; hence the Scirocco bracket fouls on full lock and droop by the looks of it. And It looks like the R20 knuckle & lower arm are from the current Audi S3 model (see 20091021.jpg).

 

To overcome this foul condition the customer has cut away the bracket to provide clearance. We can’t really condone this mod because it has not had FEA applied to it, although on a race application it would most likely be OK if the wall thickness between the cut out and the mounting lug hole is +10mm. With this caliper mounted as leading the brake torque is acting downwards on the bracket in the i.e. loads are being applied in the opposite direction to the modification.

 

AP Racing would handle this foul issue by rotating the bracket upwards away from the lower arm i.e. the calipers would be approx 10°/15° above the centreline. This would require a new designed of handed brackets with the cross sectional strength maintained.

 

Question: - Apart from that anomaly does this kit mount correctly to this model? If the answer is yes then I can ask design to consider a new bracket to alleviate the problem…………"


This was my answer to them :

Hello,

 
I'm the new owner of this brake kit (bought it from the guy with Golf 6 R20). The kit will be installed on a Golf 5 GTI wich sees 2-3 hard track days/year. My GTI also has Audi TT lower arms (give additional negative camber) and Audi S3 swivels (hubs) wich lower the weight/corner. Having these mods I might also encounter the same problems with the caliper brackets. I will install them today with the brackets that have been thinned by the other guy in order to avoid touching the swivel on the lower side. I'm attaching you 4 pics with the 2 brackets. One of them has 10-12mm from the outer edge to the mounting lug hole so I wouldn't worry about this one. However, the other one has only 4-5mm wich is too little. I will also make you some pics with them installed on the car in order to help you design new brackets that will clear the swivel/hub.

   Another question would be if these calipers require any kind of maintenance knowing they will also be used on street (the car may occasionally see snow or dirt) and the pistons don't have any protective rubber seals like road brakes. Thanks in advance for your help !

What do you think about this ?



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Mk5 GTI 6MT - Revo stage 3

Offline fuscobal

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Re: AP Racing BBK technical inquiry
« Reply #1 on: June 24, 2011, 09:39:58 pm »
Ok, today I've tried installing the kit and couldn't do it because it seems having the S3 hubs will require a new custom caliper bracket + longer bolts >

Difference between hubs >



Uploaded with ImageShack.us > haven't measured the OEM GTI one yet but will do it monday

Because the S3 hub is thicker, the bolts need to be 10mm longer (just like the ones used on the OEM S3/R32 brakes >



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Burnished the bracket in order to avoid touching the hub while the wheel turned at the maximum (plenty of material around the hole so nothing to worry about) >



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Uploaded with ImageShack.us > on the white board you can see how much material has been removed from the bracket

The final problem is, because of the thicker hub, the bracket needs to be extended by approx. 16mm in order to be able to mount the caliper on it >



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Uploaded with ImageShack.us > measurement wasn't very precise but should be within +/-1mm



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Mk5 GTI 6MT - Revo stage 3

Offline fuscobal

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Re: AP Racing BBK technical inquiry
« Reply #2 on: June 27, 2011, 09:26:08 pm »
Ok guys, just measured the OEM spindle today and it has 17mm as opposed to the 33mm of the S3 spindle. 33-17 = 16mm wich is exactly the distance measured by me between the 2 holes. Under these circomstances, I've designed a new carrier in Autocad. Now...if I can only find out the exact material they've used (seems a little heavier than simple aluminium so maybe it's some diferent & stronger alloy). Also...it has some kind of a chemical treatment (the graphite grey colour on the surface > I guess it's what they call FEA on the first post with the reply from Ap Racing but don't know what's that) ! Any of you care to enlighten me in these 2 respects ?



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« Last Edit: June 27, 2011, 09:28:14 pm by fuscobal »
Mk5 GTI 6MT - Revo stage 3

Offline danishmkvgti

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Re: AP Racing BBK technical inquiry
« Reply #3 on: July 05, 2011, 07:23:43 am »
As i see it then your adaptor sits between the hub and disc right?
I have run in to sort of a similar problem with my Tarox 10pots just my adaptor has to be sitting to the hub on the opposite side of the disc.
I'll have to measure if my spacer has to be the 16mm as well.
Regarding the surface treatment, you just have too have them anodized, which is an elektrochemical surface treatment that hardens the material and makes it less prone to corrosion.
Let us know how you get on with this  :happy2:

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Offline danishmkvgti

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Re: AP Racing BBK technical inquiry
« Reply #4 on: July 05, 2011, 07:28:59 am »
Correct that, your adaptor also sits on the side opposing the disc so i need to get 16mm adaptors made as well. I'm a bit more lucky than you as mine is not radial mounted meaning i can reuse the adaptor and just get 2 spacers made.

BTW i believe that they use aluminium grade 6064 but DaveB should be able to confirm if that's true.  :drinking:

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Offline fuscobal

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Re: AP Racing BBK technical inquiry
« Reply #5 on: July 05, 2011, 04:52:08 pm »
Don't know what they're using but I gave these Autocad drawings to DaveB for production. Yesterday he sent me the final 3D drawings made in solid works and they should be made this week. I'll let you know how this turn out !
Mk5 GTI 6MT - Revo stage 3

Offline danishmkvgti

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Re: AP Racing BBK technical inquiry
« Reply #6 on: July 10, 2011, 11:18:15 am »
Just been out measuring and looking at how my adaptors for the Tarox should be made. Looks like your problem with the corner needing to be cut away is due to the bolt distance of the AP calipers being wider than the distance between the original bolts, so hopefully i will not encounter this as the bolt distance of my calipers is the same as original

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