Megane RS Brembos and custom brakets

[reverend_sean]

I moved this thread from the For Sale section just to put the continued discussion in the correct location.

Hey all - these did arrive and I am in the process of installing them. I have done a few test fits and they seem to bolt up nicely. The caliper sticks out 33mm from then hub face so Austins definitely won't fit. My summer wheels are BBS SRs in 18x8 35et and they don't fit either. They are SUPER close, and if I run a 5mm spacer I think they will work fine for a daily. For the track I am going to run 18x8.5 32et TSWs and they should clear no problem at all with that offset and wheel design. Pad choices are near endless as these take the same pad as 4 piston STI Brembos and LOTS of other performance cars.

Concerns:
1) These calipers come from the Renault Megane RS 275 (really any Megane RS from like '08-'16 I believe). That car's front rotors are 340x28mm and the opening for the rotor in the caliper is only 32mm wide. It doesn't touch anywhere, but obviously that only leaves 1mm on either side for the GTI's 30mm wide rotor. We shall see how they work! Those pics showing how close the caliper is to the rotor are a little misleading. I didn't have the caliper bolted on tightly and there is a little play as far as the positioning of the caliper. I just need to get them centered perfectly before torquing them down.

2) I don't know what torque value I can use for the bolts that thread into the aluminum bracket. The stock caliper mounting torque is 200Nm, but I have to think that is too much for the new aluminum brackets. I guess if they strip they will be good candidates for steel helicoils, lol. If anyone knows more about aluminum (it is supposedly to be d16t aluminum if that means anything to you - U.S. equivalent is 2024-T6) and how I might determine a torque value for the bolts, feel free to chime in. EDIT - found a site called futek.com that will help me calculate the torque values.

Once I get them mounted and working I will let you all know how it is going. I have 2 track days planned before May, so it may be a while till I have a solid opinion. If they work out well, I'd be happy to have the brackets recreated for anyone interested. I am not sure if other US market Brembos mount the same way, but if so, it could be a nice brake upgrade option for MK7 cars.

 

[Navi]

Wow that’s close. I’m sure the rotor will hit the caliper from multiple difference forces and changes in tolerance. BUT, I do also think that that part of the caliper will be shaved 1-2mm by the rotor and then it will never rub again after, and I don’t think it will affect caliper function or structure.

 

[2015WhiteGTI]

I cannot for the life of me understand why someone would want to cobble together a BBK to save a few dollars. You do understand that it's not only your life you're taking into your hands, but other people as well. These calipers are not designed for your car. They do not have the proper piston size for your car to give you the proper braking balance front to rear.

I had a 2006 BMW 330 (e90) that I installed a Stoptech BBK on (6-piston, 355mm). I wanted to try to part the car out prior to selling it and contacted Stoptech to see if there was an issue with someone having a 335 of the same model (e90). They have different piston sizes to balance the car properly. I refused to sell the BBK to someone that wanted them.

A Stoptech BBK with 4-pistons and 328mm two-piece rotors is PLENTY of braking power for these little cars. Plus you won't have wheel fitment issues. This is the same kit that I have and it's just over $2000. You have a TON of brake pad options and you know they fit the caliper and rotor combination without having to guess. Plus, they take about 5 minutes to change each side.
https://www.urotuning.com/products/83-895-4300?variant=12298689249335

I have my comp license and have been driving on the track for over 12 years. I would never get in a car that has a braking system that is cobbled together. Not worth the risk. There are issues with braking systems that come from the factory if they're not vented well enough or don't have the proper fluid.

Think about what you're doing with this. In the end - is your or someone else's life worth it?
You plan on using these for the track. That is the toughest, most critical environment to have a good working braking system.

 

[burgerkong]

I cannot for the life of me understand why someone would want to cobble together a BBK to save a few dollars. You do understand that it's not only your life you're taking into your hands, but other people as well. These calipers are not designed for your car. They do not have the proper piston size for your car to give you the proper braking balance front to rear.

I had a 2006 BMW 330 (e90) that I installed a Stoptech BBK on (6-piston, 355mm). I wanted to try to part the car out prior to selling it and contacted Stoptech to see if there was an issue with someone having a 335 of the same model (e90). They have different piston sizes to balance the car properly. I refused to sell the BBK to someone that wanted them.

A Stoptech BBK with 4-pistons and 328mm two-piece rotors is PLENTY of braking power for these little cars. Plus you won't have wheel fitment issues. This is the same kit that I have and it's just over $2000. You have a TON of brake pad options and you know they fit the caliper and rotor combination without having to guess. Plus, they take about 5 minutes to change each side.
https://www.urotuning.com/products/83-895-4300?variant=12298689249335

I have my comp license and have been driving on the track for over 12 years. I would never get in a car that has a braking system that is cobbled together. Not worth the risk. There are issues with braking systems that come from the factory if they're not vented well enough or don't have the proper fluid.

Think about what you're doing with this. In the end - is your or someone else's life worth it?
You plan on using these for the track. That is the toughest, most critical environment to have a good working braking system.

That's...a little harsh. How do you know the piston area isn't the same? If it is, or similar enough, why would this be an issue? Proper bolts used, it should function identical to stock. This isn't a BBK, this is just a caliper swap from another similar platform.

Before looking like an idiot, these Brembos have top loading pads too, soooo you can also change the pads in 5 minutes or less. These are identical to the TT-RS Brembos, as well as the Aston Martin DB7.

 

[2015WhiteGTI]

That's...a little harsh. How do you know the piston area isn't the same? If it is, or similar enough, why would this be an issue? Proper bolts used, it should function identical to stock. This isn't a BBK, this is just a caliper swap from another similar platform.

Before looking like an idiot, these Brembos have top loading pads too, soooo you can also change the pads in 5 minutes or less. These are identical to the TT-RS Brembos, as well as the Aston Martin DB7.

Sorry, but I disagree. Probably the single most important item on your car is the brakes. These BBK systems are designed and tested on the specific vehicle that they're installed on.

How does he know that piston diameters are the same? He's already having an issue because there isn't very much room for the brake pads.
Plus, I'm sure he did all the strength analyses on the custom brackets he's using.

I was comparing the stock VW BBK vs. the Stoptech for ease of pad change. I know this caliper is similar to the Stoptech.

See the attached pic with the glowing red disc. That's me, running a full 12 hours on one set of brakes (pads included). We came in 5th overall after starting dead last (49th). I never once thought about my brakes.

In the end, I'm just stating that you should be EXTREMELY cautious when playing with your braking system.
If any hardware is made up to fit this caliper (i.e. mounting brackets) then it hasn't been tested to be safe and could fail. The fact that he wants to take this car onto the track makes it even more critical that everything is working properly and is designed properly. He could end up throwing his car away over this, unless he buys track insurance. If they do their due diligence and see that he cobbled together a BBK, I'm sure the claim will be denied.

 

[reverend_sean]

In the end, I'm just stating that you should be EXTREMELY cautious when playing with your braking system.

This is some really sound advice (not just this quote, but all of your feedback here). I can't tell you how much I appreciate it.

I am not an engineer. I don't know if the brackets are truly 2024-T6 equivalent, and even if I did, I don't know enough about that aluminum alloy to accurately deduce if the brackets are strong enough. I haven't done my due diligence with comparing piston sizes. I just jumped at what I hoped would be a cost effective way of reducing/eliminating the brake fade that keeps hampering my driving events. Last thing I would ever want to do is put other people or myself in harms way.

I have some research and thinking to do...thanks.

 

[Navi]

are these the same calipers as the TTRS calipers? Also, this bolt holding the caliper to the bracket doesn't look like the correct bolt to me. I've never seen bolts like this to mount the caliper. Looks more like a bolt to mount the caliper bracket to the knuckle.

usually it's a bolt that looks like this (in every bbk I've seen, ap racing, brembo, stopech, rotora, etc):

could be why your caliper doesn't look like it's sitting flush. Maybe it will help with the rotor clearance issues.

Also, AP Racing uses aluminum caliper mounting brackets. I have a feeling all the BBK companies use aluminum for brackets. I forgot the torque spec, but it was not the factory torque spec.

 

[2015WhiteGTI]

This is some really sound advice (not just this quote, but all of your feedback here). I can't tell you how much I appreciate it.

I am not an engineer. I don't know if the brackets are truly 2420-T6 equivalent, and even if I did, I don't know enough about that aluminum alloy to accurately deduce if the brackets are strong enough. I haven't done my due diligence with comparing piston sizes. I just jumped at what I hoped would be a cost effective way of reducing/eliminating the brake fade that keeps hampering my driving events. Last thing I would ever want to do is put other people or myself in harms way.

I have some research and thinking to do...thanks.

I am literally just concerned for your safety.

I've driven on the track for years and the first thing that everyone upgrades is their brakes because, while going fast is optional, stopping is mandatory

I'd hate to see you ball up your car over something like this. Like I said, Stoptech makes a very nice kit that is wheel friendly and a good upgrade for the standard GTI (non-PP). It's a 4-piston, 328mm two-piece rotor with a ton of pad options. The VW TCR race car actually runs the solid 312mm discs that we run on our non-PP cars! There is very little braking done with the rears.

See the pics of my car for the brake upgrade I'm talking about. The wheels are 17" Volks. The stock Austins fit over these brakes without a problem. Just a 5mm spacer is needed.

 

[reverend_sean]

I am literally just concerned for your safety.

That's exactly how I read it!

 

[DAS_STIG]

Aside from the weird bolts and crazy close clearance, this looks like a great kit! Now if we could just get autozone to stock these calipers in the states lol.

Quick maths says these are a pretty close match for non PP GTIs/Golfs! These should have 4 40mm pistons per caliper. They appear to be undersized for a PP.
4 40mm pistons fixed caliper = 5024 mm^2
1 57mm piston floating caliper = 5100mm^2
1 60mm piston floating caliper= 5652mm^2

The Megane caliper is actually a better match for the Mk7 than the NQSBBK which uses a 986 caliper with 36mm and 40mm pistons. The NQSBBK was great on Mk5/6s that came with a 54mm front piston, but they are a little undersized for the Mk7.
2 36mm pistons 2 40 mm pistons fixed caliper = 4546mm^2
1 54mm piston floating caliper = 4578mm^2

Don't the PP/non-PP use the same master cylinder on the MK7? What would make it "undersized" for the PP if the only real difference in the braking system in the piston size at the caliper?

 

[reverend_sean]

It's been 1.5 years so I figured I would update this just to 'put a bow on' the discussion.

I have about 10 track days on the brakes and never once got signs of fade or long pedal. I have been running Winmax W6 pads, but am switching to Pagid RSL19s as we speak. Always RBF600.

If you followed the discussion before then you know that there was some general concern that the brake piston surface area was too mismatched to the master cylinder. I do believe it is not a perfect match, but the mismatch only produces a slightly stiffer (and only marginally stiffer) pedal than stock. I don't notice the stiffer pedal, either does my wife who drives the car all the time.

Things to think about:

1. They look very similar but these are not the same calipers as TTRS ones. I bought a set of Vagbremtechnic caliper mounts to test fit and they do not work.
2. You'll need regular GTI (the ones for 312mm caliper) stainless steel or custom made lines as the 340mm caliper banjo bolt doesn't fit.
3. You will need to have a machine shop (our yourself I guess) widen the area in between the calipers where the rotor goes (see #1 concern in OP). Megane front discs are only 28mm wide, the 340mm VAG rotors are 30mm. They actually fit without doing this, but the tolerance was way to tight IMO for tracking driving stresses. You could probably get away without doing it for street driving.
4. 40mm StopTech pressure and dust seals work perfectly in these.
5. I could not find a grade 8 or 10 cap head bolt for the caliper mounts in the needed dimensions. Custom machining them was like $120 (oh hell no). So I still use regular hex head bolts (found some coated, grade 8 ones that work just fine).

Would I do it again? Hard to say.

The brakes have been fantastic for me, but all the extra work I put into making them "right" in my mind, I probably could have picked up a used set of StopTech ST-40s for the same amount. I paid $800 for the calipers, mounts, and a set of ceramic TRW pads. I spent $100 on brake lines. I spent $240 on having a machine shop, 1) remove material to make room for the wider VAG rotor, and 2) to have them install steel thread inserts into the aluminum caliper brackets so that I was comfortably torquing the mounting bolts to VAG specs. I spent $40 on the new grade 8 mounting bolts.

So all in I am at around $1180 USD.

Also, the calipers are wider than the ST-40 calipers by about 6-7mm, so it makes wheel fitment even more of a struggle.

https://freakyparts.co.uk/collections/seat-leon-cupra-mk3-brakes
Another forum member showed me this site. Looks like a UK based company is selling it as a kit. Just an FYI if someone feels so inclined. The Seat MK3 is MQB based too.

Again, you can probably find a second-hand ST-40 kit for similar money, and (I assume, but have never driven a car with ST-40 brakes) the piston size match and pedal feel should be just a little better. But since I have this setup and it's working great for me, I won't be changing it anytime soon.

 

[golfdave]

You had an idea & tried it which is good....

However most people are now doing the straight bolt on Audi TT-S (ATE 4pots) or Porsche Macan rear calliper (Brembo 4 pots)...neither require brackets

 

[toothofwar]

Also for the non pp folks, there is the b9 a4 4 pot calipers also. They are direct bolt on also.

 

[yakev724]

Very happy with this setup so far. Some additional resources as it took me a few iterations to assemble everything I needed:

Spacers: I need 5mm spacers to clear my stock S3 wheels and 7mm spacers to clear 18x8.5 Enkei RS05RR. My calipers came with the inner front edge very slightly shaved off which helps with clearance.
Brackets: reach out to https://freakyparts.co.uk/ and ask for "VW Golf Mk7 Brembo RS3 adaptors to 345mm discs". Mine came with the caliper mounting bolts (he has them available separately) but not bracket mounting bolts. 195GBP + shipping
Bracket mounting bolts: https://www.boltdepot.com/Metric_he...ss_10.9_steel_14mm_x_2.0mm.aspx?Selected=6785
Lines: I ordered a custom set from HEL and they were perfect, all hardware/clips fit in the factory locations. Can ask them to clone fronts from order 211215. 100GBP shipped for set of 4, 60GBP for just fronts.
Banjo bolts: If your calipers didn't come with these can order from HEL as well for example, they are M10x1.0mm, different to stock Mk7 thread.
Pads: Ferodo DS2500 part no. FCP1334H (~$250 shipped from FCP Euro). Original brembo pads are cheap, ~$50 from freakyparts if you need a set to get by.

 

[BillGaytes]

Reading this tread with great interest. I am currently doing a brake upgrade on my TVR Tuscan mk1. The original discs are 289mm and this has lead to some butt clenching moments so I have ebayed some upgraded discs from a Tuscan mk2 which are 322mm. Now I need calipers to go with them. The TVR ones are ridiculously expensive so I am looking at some alternatives and I think the Renault calipers in this thread may do the job. The disc diameter and thickness are in the same ball park and the caliper mounting type is the same. Questions: what is the distance (mm) between centres of the mounting holes ? What is the distance from the mounting hole line to the centre of the disc cavity, i.e. the offset ? 3rd has anyone got some of these calipers for sale ?