Rear vented discs..

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Keg510

New Member
Hey guys, new member here and recently bought myself a gtir track car. A few brake ideas going thru my head ATM but havnt been able to find much info on anyone who's done a rear vented disc setup at all. The solid little factory rear 9mm? Disc cops a mass amount of heat on the track. Any members gone thru the trouble?

On another note, I have noticed a touch of play on the front right drive shaft where it enters the transfer box? About 1mm of play, left has zero. Much to worry about?

Fresh tune tomorrow then off to the track again sat, cant wait!

Keg
 
fubar andy

fubar andy

Moderator & N/W Rep
Staff member
Keg510 said:
Hey guys, new member here and recently bought myself a gtir track car. A few brake ideas going thru my head ATM but havnt been able to find much info on anyone who's done a rear vented disc setup at all. The solid little factory rear 9mm? Disc cops a mass amount of heat on the track. Any members gone thru the trouble?

On another note, I have noticed a touch of play on the front right drive shaft where it enters the transfer box? About 1mm of play, left has zero. Much to worry about?

Fresh tune tomorrow then off to the track again sat, cant wait!

Keg
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There are a number of options you can take:

Better pads and braided lines are a must as you mentioned the rears do/take a lot of work/heat and take a hammering.

Next is grooved discs: Black Diamond offer solid rear grooved discs (which I currently run). Great for keeping the pads glaze free and there is a noticeable improvement in performance, but still get rather hot.

Bigger discs: There are a number of members that have designed their own kits that offer 300mm plain/solid discs (I think there are grooved available) as away to help with braking and stability.

I find that rear grooved discs and good performance pads with braided lines works well enough for me, however speaking to other members with 300mm rears, find better stability and braking.

To my knowledge I've not seen any rear vented discs (but I could be proved wrong). :thumb:
 
K

Keg510

New Member
Cheers guys, the way I see it brakes and tyres will be my main consistent cost factor, over kill or not. Getting a decent setup asap means less time spent under the car and more time enjoying the ride. Ithink the gtr caliper and n16 front hub conversion will be my best bet, and try for some larger rear discs, at least it sounds like members are getting good results from that.

Haha and yeh it gets fn hot down here. Summer is coming up so the car will get a rest and a brake upgrade!
 
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pulsarboby

Guest
a fairly easy mod to do if you want rear vented discs is to swap the front calipers and discs and put them on the rear.
you will then need to buy a hydraulic handbrake though as youll have no handbrake, it will just be a case of diverting the lines to them and a brake bias valve if you wanna adjust braking

personally i cant see the point though unless your rallying
 
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skiddusmarkus

Active Member
Yeah Pobody that extra 15 degrees centigrade is a killer to rear brake discs I hear.His discs aren't going to get any hotter in Australia than they would here.

Rather than fitting vented discs that are going to need at the least different calipers and discs , you can just go for either new discs with a good pad or go for larger rear discs, still solid that retain the standard caliper but will require a spacer for it.
 
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Braveheart

Braveheart

New Member
I looked into this a while back but did not follow it up.
Here's what I came across..... I have other stuff on the subject somewhere. Think I even found a UK supplier for a similar setup but that was years ago...

 
K

Keg510

New Member
Awesome feedback guys, not really looking into buying any kits etc I'd rather do it all myself. Also had the idea as pulsar boby said and using the fronts and converting them to the rears, spacing the caliper would be easy enough! And would def need to run a bias valve. Has anyone actually measured the heat of their discs with track use. Either by a gun or temp paint?
 
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nex

Member
I put the 280mm solid read kit on my rear *i think its the one npulsar was selling*, I found the extra bite balanced out the wilwood 310 i put on the front and stopped the car diving so much. not sure about heat/vents as I dont track or just my R a huge amount, but really did help.
 
darkyGTI-R

darkyGTI-R

New Member
I have front and rear vented discs from a company on Ebay £200 posted with all pads included which were ebc:thumbsup:I have had no problems with them and were straight bolt on:-D
 
K

Keg510

New Member
yeh would love to know the details about the rear discs! did u use bigger calipers? space original calipers?
 
Braveheart

Braveheart

New Member
darkyGTI-R said:
I have front and rear vented discs from a company on Ebay £200 posted with all pads included which were ebc:thumbsup:I have had no problems with them and were straight bolt on:-D
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Might find that quality vented discs on the rear along with good functioning calipers and pads would fit the bill.... as above.
Maybe some cooler air into the discs could help ;-).
Talked myself into it. Interested in quality rear vented disks now..:lol:
 
S

skiddusmarkus

Active Member
You have to ask yourself why manufacturers use vented discs and its because they dissipate heat better as there is more metal to radiate it away and you get the airflow down the middle cooling it even more.Pretty much all modern cars have vented front discs.
Now look at the rears, they only do a very small percentage of the braking the fronts do so won't get anywhere near as hot.Further to that its a light car so even less work done by them so less heat.

Now, do you really think that 99 percent of R's out there need vented rear discs, or do you just want them because they look/sound cooler?

If you really want to do it, its your choice but unless its a dedicated track/race car that has problems with the rears overheating, what's the point?I usually like to plan ahead and have overkill on things which in this instance would be to fit rear vented "just in case" but then I also do research first and I don't think I have ever come across anyone complaining of rear brake overheating problems/wear.You just have to look at the specs of peoples cars and vented rears just don't come into it.

Edited to add, don't forget your handbrake.I'm not sure if a mechanical handbrake is part of the MOT but mine has saved me before when the hydraulic system failed and I would have crashed into standing traffic without it.You can add on those aftermarket ones but they just look like something to pass an MOT and stop you rolling down a hill to me, mine slowed me from 70mph to 0mph(albeit quite dramaticly).
 
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Braveheart

Braveheart

New Member
skiddusmarkus said:
Edited to add, don't forget your handbrake.I'm not sure if a mechanical handbrake is part of the MOT but mine has saved me before when the hydraulic system failed and I would have crashed into standing traffic without it.You can add on those aftermarket ones but they just look like something to pass an MOT and stop you rolling down a hill to me, mine slowed me from 70mph to 0mph(albeit quite dramaticly).
Click to expand...
Good point...... heaven forbit.
I have just fitted new discs, calipers and pads so hope to find out soon how much work they do. November.... Hope all corners shine in the dull light... :lol:
 
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pulsarboby

Guest
skiddusmarkus said:
You have to ask yourself why manufacturers use vented discs and its because they dissipate heat better as there is more metal to radiate it away and you get the airflow down the middle cooling it even more.Pretty much all modern cars have vented front discs.
Now look at the rears, they only do a very small percentage of the braking the fronts do so won't get anywhere near as hot.Further to that its a light car so even less work done by them so less heat.

Now, do you really think that 99 percent of R's out there need vented rear discs, or do you just want them because they look/sound cooler?

If you really want to do it, its your choice but unless its a dedicated track/race car that has problems with the rears overheating, what's the point?I usually like to plan ahead and have overkill on things which in this instance would be to fit rear vented "just in case" but then I also do research first and I don't think I have ever come across anyone complaining of rear brake overheating problems/wear.You just have to look at the specs of peoples cars and vented rears just don't come into it.
Click to expand...

totally agree with that....never had a prob with rears overheating.

unless you change the brake bias (which would be foolhardy unless you are rallying or off road driving) the only time the rears will cook is if you either have real poor quality pads fitted or your rear caliper is seizing and not functioning properly.
and that goes for track use too!
 
K

Keg510

New Member
Spent the day at the track yesterday and I am definitely going to fit some vented rears. My local track Mallala is considered the hardest track in aus on brakes, we were getting some serious heat coming from the brakes only after the first session, and brake fade soon to follow. Admittingly the brakes are one thing I havnt upgraded as the car is only new to me, but where times are important I don't think vented rears
on a track car could ever be an overkill. Plus if I do it right the first time I wont have to worry about it or waste more time n money re upgrading. Plus how many race cars do u know of that have solid rear discs?

Fairly set on the gtr front calipers n n16 hubs combo, and will try to utilize the original front vented discs and put on the rear. Just have to look at rear calipers to suit. Either space the originals if they can be split, or possibly adapt gtr rears again. That's why I'm keen to find out what rear calipers are on drakies setup :)
 
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