Hello,
I have always been one for fitting the biggest brakes possible at the front and never really considered the upgrading rears until now which got me thinking, how big can I go on the back? Yeah, I could upgrade to the 310mm setup which has been done to death but I wanted to be a little different. I had already purchased a 310mm setup to go on so I had the correct callipers & carriers for what I needed.
I saw a for sale post for some 356mm discs and a VBT fitting kit to suit MQB cars. I went onto the VBT website to see what platform they fitted and could only see them fitting the newer MQB/RS3 which stopped me in my tracks a bit. After doing some thinking I knew the rear subframe from a Cupra 280 will fit an Mk2 Leon it made sense that other parts might fit too.
After doing some digging I found that the rear brake calliper/carrier setup from a Leon Cupra 280 (None electric handbrake) is in fact the same as the S3 8P/R32 calliper/carrier setup. I did some more digging and you can in fact upgrade a Cupra 280 to an electric handbrake so the bolt holes must be the same which they are!!! The only minor difference is the lower bolt hole for the carrier on the PQ35 which leads me on to this guide.
With a bit of modification, the 356mm setup will fit the cast iron rear hubs (front wheel drive) PQ35 cars. I do believe this kit will fit the alloy hub (S3 ED30/35) etc with the same small modification.
The Guide - ** I take no responsibility for anyone following this guide whatsoever **
To fit 356mm rear discs to a PQ35 platform car you will need to have S3/R32 310mm callipers and carriers. This is a very common upgrade if your car does not already have this from the factory - oe part numbers below;
2x Rear Left and Right callipers: 1K0615423G 1K0615424G
2x Rear Left And Right calliper carriers: 1K0615425T 1K0615426H.
You can use: Audi S6 & S7 discs even the Rs7 Wavy discs if you want to be fancy but I picked up some second-hand lightly used 356x22mm CHook discs to use.
OE Part no: 4H0615601P
You can purchase the adaptor kit from VagBremTechnic Here.
You can also upgrade this kit on the VBT website to include the discs/pads etc should you wish.
The kit that I got consisted of;
4x Caliper to carrier bolts
4x Spring washers for calliper to carrier bolts
2x Centre bore adapters for the discs
They list this kit only for the MQB/e-brake only but to get this kit to work you have to make some modifications to the lower bolt that secures the carrier to the adaptor.
I have marked on the below picture where the lower cap head bolt that comes with the VBT kit makes contact with the hub.
You could shave where the white mark is but I did not want to potentially weaken the rear hub with it being on the bend another option was to modify the bracket but I did not want to potentially weaken that too. This is the way I did it but you can choose to do it another way if you wish.
There is a local machine shop that I use for various stuff so I took the bracket, bolts and hub to see what they come up with and £20 later, I am very happy with the results.
They modified one of the cap head bolts by shortening the top and also added a large chamfered edge while keeping the integrity of the bolt intact.
Looking at the photos below you can see the modified bolt to the right and the standard one to the left. (I need to paint the modified one so it does not rust).
*** EDIT ***
The machined bolts did not work because as soon as you put any torque on them they mush up. I did suspect they would but hoped they would not. After many swear words I managed to extract both of the machined bolts and threw them across the garage in disgust!!!
Back to the drawing board with the bolt situation and what I come up with should have been the first iteration really.
If I removed the spring washer that comes with the VBT kit it gives me an extra 2 mm of room to play with when the bolt is torqued up.
That gives us another problem though as we have no spring washer to stop it from undoing itself.
The solution was to get some m12x1.5 12.9 tensile strength 35mm cap head bolts and some half nuts from the local nuts and bolts shop. I apply some Loctite to the thread of the bolts and added the nut on the other end for added tightness.
See below how close it is to not using the spring washer and using the standard bolt which was not shaven down at this point. This now means that we have to take approx 1mm off the top of the lower cap head bolt to clear the rear hub. I did this with my die grinder pretty quickly and painted it up.
With it all bolting up on my test bench it was time to actually try and fit it to my K1 to see if the theory would pay off.
The callipers are a tight fit on my Comp's but I think they sit rather well IMO!
As you can see they bolted up perfectly and look like dinner plates compared to the standard rear discs I had on my K1 lol!!
Onto the brake lines - I ordered some standard HEL replacements for my K1 and they seem to be a little tight for my liking.
I spoke to the lads over at AKS tuning and they have supplied me with a 230mm HEL line which fits perfectly!
Everything else bolts up like normal such as the brake lines and handbrake cable.
I hope this guide helps other people fit the 356mm upgrade
Cheeky pic of my K1 with everything all buttoned up.
Thanks.
I have always been one for fitting the biggest brakes possible at the front and never really considered the upgrading rears until now which got me thinking, how big can I go on the back? Yeah, I could upgrade to the 310mm setup which has been done to death but I wanted to be a little different. I had already purchased a 310mm setup to go on so I had the correct callipers & carriers for what I needed.
I saw a for sale post for some 356mm discs and a VBT fitting kit to suit MQB cars. I went onto the VBT website to see what platform they fitted and could only see them fitting the newer MQB/RS3 which stopped me in my tracks a bit. After doing some thinking I knew the rear subframe from a Cupra 280 will fit an Mk2 Leon it made sense that other parts might fit too.
After doing some digging I found that the rear brake calliper/carrier setup from a Leon Cupra 280 (None electric handbrake) is in fact the same as the S3 8P/R32 calliper/carrier setup. I did some more digging and you can in fact upgrade a Cupra 280 to an electric handbrake so the bolt holes must be the same which they are!!! The only minor difference is the lower bolt hole for the carrier on the PQ35 which leads me on to this guide.
With a bit of modification, the 356mm setup will fit the cast iron rear hubs (front wheel drive) PQ35 cars. I do believe this kit will fit the alloy hub (S3 ED30/35) etc with the same small modification.
The Guide - ** I take no responsibility for anyone following this guide whatsoever **
To fit 356mm rear discs to a PQ35 platform car you will need to have S3/R32 310mm callipers and carriers. This is a very common upgrade if your car does not already have this from the factory - oe part numbers below;
2x Rear Left and Right callipers: 1K0615423G 1K0615424G
2x Rear Left And Right calliper carriers: 1K0615425T 1K0615426H.
You can use: Audi S6 & S7 discs even the Rs7 Wavy discs if you want to be fancy but I picked up some second-hand lightly used 356x22mm CHook discs to use.
OE Part no: 4H0615601P
You can purchase the adaptor kit from VagBremTechnic Here.
You can also upgrade this kit on the VBT website to include the discs/pads etc should you wish.
The kit that I got consisted of;
4x Caliper to carrier bolts
4x Spring washers for calliper to carrier bolts
2x Centre bore adapters for the discs
They list this kit only for the MQB/e-brake only but to get this kit to work you have to make some modifications to the lower bolt that secures the carrier to the adaptor.
I have marked on the below picture where the lower cap head bolt that comes with the VBT kit makes contact with the hub.
You could shave where the white mark is but I did not want to potentially weaken the rear hub with it being on the bend another option was to modify the bracket but I did not want to potentially weaken that too. This is the way I did it but you can choose to do it another way if you wish.
There is a local machine shop that I use for various stuff so I took the bracket, bolts and hub to see what they come up with and £20 later, I am very happy with the results.
They modified one of the cap head bolts by shortening the top and also added a large chamfered edge while keeping the integrity of the bolt intact.
Looking at the photos below you can see the modified bolt to the right and the standard one to the left. (I need to paint the modified one so it does not rust).
*** EDIT ***
The machined bolts did not work because as soon as you put any torque on them they mush up. I did suspect they would but hoped they would not. After many swear words I managed to extract both of the machined bolts and threw them across the garage in disgust!!!
Back to the drawing board with the bolt situation and what I come up with should have been the first iteration really.
If I removed the spring washer that comes with the VBT kit it gives me an extra 2 mm of room to play with when the bolt is torqued up.
That gives us another problem though as we have no spring washer to stop it from undoing itself.
The solution was to get some m12x1.5 12.9 tensile strength 35mm cap head bolts and some half nuts from the local nuts and bolts shop. I apply some Loctite to the thread of the bolts and added the nut on the other end for added tightness.
See below how close it is to not using the spring washer and using the standard bolt which was not shaven down at this point. This now means that we have to take approx 1mm off the top of the lower cap head bolt to clear the rear hub. I did this with my die grinder pretty quickly and painted it up.
With it all bolting up on my test bench it was time to actually try and fit it to my K1 to see if the theory would pay off.
The callipers are a tight fit on my Comp's but I think they sit rather well IMO!
As you can see they bolted up perfectly and look like dinner plates compared to the standard rear discs I had on my K1 lol!!
Onto the brake lines - I ordered some standard HEL replacements for my K1 and they seem to be a little tight for my liking.
I spoke to the lads over at AKS tuning and they have supplied me with a 230mm HEL line which fits perfectly!
Everything else bolts up like normal such as the brake lines and handbrake cable.
I hope this guide helps other people fit the 356mm upgrade
Cheeky pic of my K1 with everything all buttoned up.
Thanks.
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