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Author Topic: 312mm J-Hook discs on a VRS  (Read 14983 times)

Offline muckipup

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312mm J-Hook discs on a VRS
« on: September 10, 2010, 05:45:17 pm »
A shameless copy & paste from my post over on the Briskoda website but wanted to share over on this forum for info....


This is a bit of a follow-on to my review / 'how-to' on the Porsche 986 calipers :  http://briskoda.net/forums/topic/169744-not-so-big-brake-kit-porsche-brembo-4-pot-calipers-on-vrs/

I remain delighted with this brake set-up and the improvement over the standard brakes even with OEM discs was great.  However....

DaveB waved a picture of 312mm J-hook discs in front of my nose a while back. I resisted at first as the brake set-up was giving me what I needed but the discs that I had started rusting very early on due to lack of any protection on the metal in the bell area or the unswept area of the braking surface (which was wider than with the stock VRS brakes).  This, combined with the kind of curiousity that has cost me £££s already and the good reports that AP and Alcon have had over the J-hook design on different discs made me give in to temptation. This is what turned up:



You will notice that DaveB had kindly powdercoated the bell and outside edges of these discs in addition to the unswept area with my calipers (which wouldn't be an issue with stock brakes). To the left you will notice the old 312mm discs...when I say "old", these were 4 weeks old!!  :doh:

Here they are on the car



I guess the aesthetic looks of these things are about personal taste. Personally, I liked them although my main driver for buying these was to squeeze a bit extra braking performance...and lose the non-aesthetics of the existing rusting discs. On to the performance....

It is difficult to comment on braking performancewith respect to standard GTI/VRS brakes as I have never tried this and the jump-up with the new calipers would make further improvements a little bit more difficult to distinguish.  Generally, I think that they are a tad better in low/medium speed conditions and in the dry. However, where I have felt a more notable difference is when hooning it and in the wet - these seem to react with notably better initial bite and braking thereafter. I guess this is not surprising when you look at the design which is intended to eject water, dust and heat.

Another thing that made me hesitate before buying them was a fear that these things would be noisy - not the case! In fact I can hardly tell the difference from the normal discs. With the window down and some hard breaking, I can make out a very faint 'zipping' sound coming from these discs but only when I am deliberately listening for it.

I think these would be well-worth considering for anyone looking to get some improvement out of the stock VRS brakes particularly with braking in the wet or at speed but for those looking at getting some decent capability out of their 312mm set-up, I think you will still need to be looking at better aftermarket pads or uprated calipers (imho, the standard pads/calipers have no right being on a remapped VRS, MkV GTI and especially a Golf ED30)

Offline vRS Carl

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Re: 312mm J-Hook discs on a VRS
« Reply #1 on: September 10, 2010, 09:32:49 pm »
Looking good Dave  :happy2:

Not sure about the Kerbed alloy though  :surprised: :laugh:

Offline muckipup

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Re: 312mm J-Hook discs on a VRS
« Reply #2 on: September 11, 2010, 11:04:45 am »
you might want to get the mods to shift this and your other review into the product review section :happy2: :happy2:

Good point - that would be a better place if a kindly mod would like to do that  :happy2:

Offline muckipup

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Re: 312mm J-Hook discs on a VRS
« Reply #3 on: September 11, 2010, 11:06:44 am »
Looking good Dave  :happy2:

Not sure about the Kerbed alloy though  :surprised: :laugh:

Yeah, I did that three weeks ago on a granite kerb in Glasgow so need to take full credit for that one  :ashamed: I should have taken the photo from  the other side  :signLOL:

Offline Rob GTI

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Re: 312mm J-Hook discs on a VRS
« Reply #4 on: September 11, 2010, 11:46:08 am »
I like the look, a bit different from the usual drilled and grooved look. - thats why I bought some too :laugh:

Can't wait to get them fitted especially like the comments about the wet weather initial bite.

Glad they got a good review cos I ordered some for the rear last night as well  :P
GTI Edition 30 No. 907, 3 door, Black. (Now Sold)

Offline muckipup

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Re: 312mm J-Hook discs on a VRS
« Reply #5 on: September 11, 2010, 07:07:03 pm »
You won't regret it Rob - I can't / don't hoon it on my daily commute but the weather last week was a good test when I experienced some awful driving conditions. They skim off the water very well.

Like fitting new pads, give them a couple of weeks before you make up your mind  :happy2:

Offline Rob GTI

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Re: 312mm J-Hook discs on a VRS
« Reply #6 on: September 11, 2010, 07:25:24 pm »
The only thing that concerns me about these is aesthetically do you get rust forming in the cut out of the J hook?

I waiting on Dave B to recommend me a solution if it is an issue.
GTI Edition 30 No. 907, 3 door, Black. (Now Sold)

Offline DaveB@Vagbremtechnic

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Re: 312mm J-Hook discs on a VRS
« Reply #7 on: September 11, 2010, 08:53:39 pm »
Rob sorry mate thought I'd dropped you an email about that straight away, you'll find the grooves will just go black and fill with a bit of pad material. If you leave them standing for a week or so you'll get some surface rust as normal but they wont go rust brown if thats what you're thinking may happen.

They'll just be contrast black.

No issue at all mate

Offline Rob GTI

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Re: 312mm J-Hook discs on a VRS
« Reply #8 on: September 11, 2010, 11:59:05 pm »
Nice one, was thinking hoping/ thinking the answer was along those lines. Tough luck for you boys todat against Burnley. Dropped you and email yesterday with payment for the rears.

Rob
GTI Edition 30 No. 907, 3 door, Black. (Now Sold)

Offline Rob GTI

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Re: 312mm J-Hook discs on a VRS
« Reply #9 on: October 17, 2010, 05:03:03 pm »
Here are mine
Front:-

Rear:-
GTI Edition 30 No. 907, 3 door, Black. (Now Sold)

Offline phelan77

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Re: 312mm J-Hook discs on a VRS
« Reply #10 on: February 15, 2014, 10:10:02 am »
Are these J Hook rotors lighter than stock rotors?

Offline bacillus

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Re: 312mm J-Hook discs on a VRS
« Reply #11 on: February 15, 2014, 11:13:48 am »
Are these J Hook rotors lighter than stock rotors?

Not really! Dave machines the oem Brembo discs to produce the J shapes.
Without traction power is nothing!

Offline Pikey Motorsports

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Re: 312mm J-Hook discs on a VRS
« Reply #12 on: February 15, 2014, 01:10:48 pm »
can you do different designs
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Offline bacillus

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Re: 312mm J-Hook discs on a VRS
« Reply #13 on: February 15, 2014, 10:51:02 pm »
can you do different designs

I'm pretty sure Dave can but the machining costs are large in comparison with the price of the original disc and not worth doing for just a small batch.
Without traction power is nothing!

Offline phelan77

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Re: 312mm J-Hook discs on a VRS
« Reply #14 on: February 17, 2014, 06:38:24 am »
Are these J Hook rotors lighter than stock rotors?

Not really! Dave machines the oem Brembo discs to produce the J shapes.

Thanks for the info... :happy2: