V-Sport AP ARacing 296mm 4 Piston NA/NB Front Brake Setup

[Magpie]

I just can't believe I cannot get these Winmax W7's to fade. They must be made out of magic or similar.

I use W6.5's in a NB8B setup and have only had them fade twice and both times it was pad knock back!

I get about 3 sets of pads to a set of rotors on the front. I could go through my note bonk and tally up the laps and wear for the past 3 years if needed.

I have been measuring rotor wear before every sprint event and pad thickness on change, however I will be starting to grease the slider pins more often as well as swapping the pads inside for outside so I will be taking more measurements

[Hoolio]

Just had a quick read through the whole tread and hear are some comments about points which stick in my mind:

I am using the V8 Roadsters 11,75" Dynapro Radial kit. The disk is mounted further inboard than some of the other kits for maximum wheel clearance. 6ULs fit easily, as do some other 7" and 8" wheels I have tried.

All Dynapro radial calipers use 16 mm thick pads. All Dynapro lug use 12 mm.

Wilwood has recently expanded the caliper range and many of them are now available with dust seals. You should be able to substitute a different caliper in any of the US sourced kits – just ask the vendor. I did this (because I wanted a different piston size to the standard kit) and it was no problem at all.

The AP kit uses 28 mm thick disks – that's a lot of extra weight which you don't need.

The Stoptech kit which V8 Roadsters sells looks good for the money and the calipers are reputedly stiffer than the Wilwood ones (and a bit more money). The AP calipers will certainly be much better again, but $$$.

Regarding the Clio RS. It's a road car: the brakes will be dictated by marketing desires, not performance requirements, so don't use it to judge the braking requirements of an MX-5 track car. And don't forget that there are Brembo calipers and there are Brembo calipers (i.e. cheap OE calipers and race calipers are not the same thing).

And the most important bit for the OP: What cooling duct arrangement have you got? Sorry if I missed it, but I don't remember any mention of it. Before you do anything else get some Singular Motorsports or similar backing plates and some 3" ducting and get some air in there. Lower temp = much longer life.

[Luke]

The AP kit uses 28 mm thick disks – that's a lot of extra weight which you don't need.

And the most important bit for the OP: What cooling duct arrangement have you got? Sorry if I missed it, but I don't remember any mention of it. Before you do anything else get some Singular Motorsports or similar backing plates and some 3" ducting and get some air in there. Lower temp = much longer life.

Slow reply post by me but yes I have brake cooling ducts, TSE ones from when they used to make them many years ago before everyone started going to Singular. Straight to the fog light holes.

And grr, Wilwood suggestions just keep coming up even though what I wanted to know from the start was who has this AP kit on their car.
I have now talked to the owner of probably one of the most serious setup MX-5's in Australia that I know has a TSE 11.75 inch Willwood based brake kit. That would be Beavis.
I noticed that he has not really done much of a review of the kit since he has gone for Turbo power so I asked him at NSW vs VIC Interstate Challenge what he thinks about the setup.
He confirmed what my thoughts have been.
The rotors wear through quickly, likely due to the low thermal capacity due to being thin. Pads also wear as a consequence as the heat has to go somewhere plus they are thin as well. He sounded very interested in this AP kit as well as he is running 15x9 Storms and would like to stay with 15's.
I've also have discussed with MX-5 Cups guys on YSR 287x26mm setups and they have experienced fade when racing hard. They would have more thermal capacity than the Wilwoods. These are the same people that directed me to the AP Kit in the 1st place.

Just based on those people I have talked to at the track alone, I would say 28mm thick rotors do have a case going for them.


Now far more importantly NEWS NEWS NEWS.

This afternoon I have met up with the person who had the V-Sport AP Kit developed.
Conveniently he had them fitted to a SE as well. Of course I worked out that I have met him before on a few occasions at various track events, yet it took me this long to track him down, go figure.

So the kit did include:
Callipers, Pads, Rotors, Hats, Dog Bones, Brake lines, mounting hardware and because it was the development car, fitting.
He believes the rotors are Skyline GT-R rotors but was not 100% sure. From what I've researched only early R32's had 296mm fronts, but they were 32mm thick so I don't think they are it.
My guess would be VT to VZ Commodore as they were 296x28 and are available in DBA 5000's. Oh and cheap cause Commodore, so hopefully I'm right.
Will double check that detail with V-Sport on my next visit to them.


More importantly I can now confirm some 15 inch rim fitments.
He runs Buddyclub P1's 15x8 +32. Needs a 10mm spacer. Not because the spokes hit, but because the barrel of the wheel gets tighter, the closer you get to the spokes and the calliper rubs the barrel without the spacer. Bugger, because I have those rims as well, but don't want to do spacers.

Factory SE 17inch Racing Harts fit no problem, little surprise as there are people that have had them over massive 6 piston kits with 330x32mm rotors.

I took my 15 inch rim collection over as well to try out.
I can confirm that Advanti Storm 15x8 +25 fits with no spacers. YAY, as I have 2 sets of these. That was the main thing I wanted to know.
And these 2 do not fit as I expected.
Avid AV-12 15x8 +25. Wheel barrel will not fit over calliper so not even spacers are an option.
6UL 15x7.5 +42. (Not sure what Generation they are) Spokes hit calliper, I have a bad memory, but I think it worked with spacers, can't remember if the barrel of the rim fitted over calliper sufficiently as all I cared about was the Storms fitting. I gather not many people will care about this size 6UL anyway as its a bit of a rubbish offset for a track car.


So with knowing that, from my research in the past, Advanti Storm 15x9+35 are supposed to have more room than the 8's so may fit as well.
The owner of the car is interested in that's size and knows someone who has that size Storms so will be trying them out one day as well.

I would be interested to know if 6UL's in 15x8 and 15x9 would fit. I gather Gen 2 won't but 1, 3 and 4 may.

If someone has the above mentioned rims or another 15 that has a bit of room and is also interested in these brakes, PM me and I can get you in contact.


There is one thing I did note visually.
I believe that the offset may be increased a fair few mm over the stock brake setup as the hat looks like it is thicker, ie sits further outwards. His car also had custom knuckles, upper arms and Bosnjak hubs, so it is hard to say that with full confidence as there are way to many variables.
I should be able to confirm this easily by taking one of my spare NB8B rotors and OEM hubs to V-Sport to compare to the Bosnjak hat. Will have to see where I have my next weekday off from work to do this.

At least I now have enough information to talk further with V-Sport regarding pricing as I know how much he payed. The only real part affected by currency would be the callipers as everything else is Australian.
Definitely a serious proposition since I know they fit within my Advanti Storms. I don't mind paying a bit extra for something I know is of higher quality and should have a longer service life and less maintenance.

[plohl]

Can't remember if I posted this or not, but when I spoke to vsport, the guy said there was a 12mm spacer built into the rotor hat.

If you find zoomzoom's build thread, he used gtst calipers and 26mm discs from a lotus. He would kill them with his turbo 5.

[greenMachine]

Good work Luke! Was that car registered, and did he say anything about engineering?

Good news about the Storms, I have one set, but not so good about the 6ULs. Are your Storms S1 or S2?

If there is already a 12mm 'spacer' built into the hat, running another spacer to get wheels to fit would raise a couple of issues, one being steering geometry (scrub radius?), the other the length of the studs required. If you add a say 10mm spacer, that is a total of 22mm that has been 'lost'.

In other news, the radio has just told me the $Aussie is back over USD$0.70c!

[Luke]

Can't remember if I posted this or not, but when I spoke to vsport, the guy said there was a 12mm spacer built into the rotor hat.

If you find zoomzoom's build thread, he used gtst calipers and 26mm discs from a lotus. He would kill them with his turbo 5.

Hmm. Wonder if VSport and Bosnjak can reduce that 12mm down a bit. I though it looked more outward.
I am sure I would have a guard clearance issue as I get slight rubs with the 225 a050s now.
My way round it would be to with ISC racing Delrin Offset bushes in the upper arms and back to stock lower ball joints to keep the same camber while making the wheel sit more in.

Yes I can see that was a great setup that zoomzoom created. Awesome rear as well.
Here is whatzoomzoom said about them.

These calipers are from an R32 GTST. The Nissan calipers are all virtually the same with the major differences being that some were cast iron and some were alloy depending on what they came off, whether they were JDM vs. ADM and the length of the mounting ears also differs slightly from one model to another. There is also the difference of most of them being to suit a 30mm disc and some being to suit a 32mm disc.

These calipers being from a R32 GTST are of the alloy variety and are made to suit a 30mm disc. These were chosen due to the length of the mounts being most suitable for how I wanted to mount them. While I had them apart to rebuild them I had them modified a little so they now suit the 26mm disc. The Nissan calipers are quite thick through the piston housing so despite being alloy they are known to be quite stiff.

The brackets are all custom made. The rears retain the OEM handbrake cables which I have not had a chance to try out yet as I have not bled the brakes.

All Here
http://www.aus-cartalk.com/forum/viewtopic.php?f=57&t=59941&start=90

He also had to then upgrade to a 1inch master cylinder as well, which re retro-fitted from a mystery model Subaru.

But for the average punter there are a few issues with doing so custom like this.
1. Getting the correct Nissan caliper as there are so many. There is even variances within them. Unless you know exactly what your are looking for I can se it going wrong.
2.Modifying the callipers to suit a narrower disc as they were for 30mm discs. How the do you even do that? I gather longer pistons???
3. Custom brackets to make it fit. Easy for him as he made them but I would need to find someone to do it.
Same will then go for brake lines.
4. Use of 288x26mm 1 piece rotor probably heavier than larger 2 piece ap kit due to heavier hat.
5. What wheels will it even fit. He had 6ul 9's.

What makes this V Sport kit appealing is the hard engineering and design work is done. It should just be bolt on and go.

Good work Luke! Was that car registered, and did he say anything about engineering?

Good news about the Storms, I have one set, but not so good about the 6ULs. Are your Storms S1 or S2?

If there is already a 12mm 'spacer' built into the hat, running another spacer to get wheels to fit would raise a couple of issues, one being steering geometry (scrub radius?), the other the length of the studs required. If you add a say 10mm spacer, that is a total of 22mm that has been 'lost'.

In other news, the radio has just told me the $Aussie is back over USD$0.70c!

Remember the 6UL's I have are the useless 7.5 +42 ones that don't have much room compared to other models.
The more relevant 8's or 9's may have the room.

Car used to be registered. It is sort of turning into a time attack car, so no longer registered.
Didn't get into any talks about engineering.

[Luke]

Bugger, missed a point in the edit time.
Yes my Storms are S1's.

Now that I think about the 12mm increase of offset due to the the hat, it is even more relevant to find out if 6UL 8's or 9's fit because of their +36 offset. Same goes for Storm S1's 15x9 +35.
That will be a far easier fit in the guards than the S1 8's or anything that is +30 offset or less.

[greenMachine]

Just been out adjusting ride height, and had the tape measure on hand.

The AP studs I have in the front are 45mm of thread between the hat and the start of the lead-in. It looks like the cast iron SE disk is around 5mm thick on the face of the hat section, call it a total of around 50mm of thread from the outside face of the hub. My S1s have about minimum 5mm thickness at the bottom of the taper. The 949 nuts when tightened are showing just about all the lead-in, so pretty much 40mm of thread engagement - important data point!

If the V-Sport hats are 12mm thick (an extra 7mm), that still leaves around 33mm of thread engagement.

If the V-Sport hats are an extra 12mm thick over say a base thickness of 10mm (5mm thicker than cast iron because alloy), total 22mm thick, that is an extra 17mm thickness, taking thread engagement down to 23mm (40-17).

I'll leave it to the Mech Eng types to provide a definitive answer, but my understanding is that max strength is at thread engagement of diameter plus 50%.

It also means that the wheel/tyre is 7mm or 23mm further outboard (based on the above assumptions).

Luke, if you (or anyone) can get the thickness of these hats at the hub face, that would help nail down these dimensions and the implications for steering geometry and/or stud length.

Grist for the mill.

[Luke]

How thick is the spacer they are using on the e30 BMW MX-5 Hubs you have in your hands???
May be an option running those hubs with these brakes and no, or a smaller spacer to correct things???

Just been out adjusting ride height, and had the tape measure on hand.

The AP studs I have in the front are 45mm of thread between the hat and the start of the lead-in. It looks like the cast iron SE disk is around 5mm thick on the face of the hat section, call it a total of around 50mm of thread from the outside face of the hub. My S1s have about minimum 5mm thickness at the bottom of the taper. The 949 nuts when tightened are showing just about all the lead-in, so pretty much 40mm of thread engagement - important data point!

If the V-Sport hats are 12mm thick (an extra 7mm), that still leaves around 33mm of thread engagement.

If the V-Sport hats are an extra 12mm thick over say a base thickness of 10mm (5mm thicker than cast iron because alloy), total 22mm thick, that is an extra 17mm thickness, taking thread engagement down to 23mm (40-17).

I'll leave it to the Mech Eng types to provide a definitive answer, but my understanding is that max strength is at thread engagement of diameter plus 50%.

It also means that the wheel/tyre is 7mm or 23mm further outboard (based on the above assumptions).

Luke, if you (or anyone) can get the thickness of these hats at the hub face, that would help nail down these dimensions and the implications for steering geometry and/or stud length.

Grist for the mill.

When you run factory nuts on factory studs there is stuff all thread engagement. I know more is better, but I ran the previous SE for many years with standard studs with 225 tyres without an issue.

[greenMachine]

I don't have them yet Luke. I would have to sit down with pencil and paper, but I don't think that will work unless you use a different hat. The calliper location seems to dictate hat 'offset', so if you change one you would have to change the other - hat offset/calliper location (dogbone/mounting bracket).

Do we know why they were made this way - was it a function of the suspension mods the OP made, that required the calliper to move, or perhaps just the size/layout of that calliper? Who owns the IP - V-Sport or Bosnjack? If the reason for this unique offset is the Bosnjack hubs (likely), what would the issues/cost be to rework the CAD, re-run the FEA, for moving the caliper/rotor back 12mm(?) to where the stockers are? That will not alter fitment issues, but will address steering geometry and guard clearance.

In the meantime, and assuming that is not a viable option, I think that the better solution might be to identify a more appropriate wheel offset for common sizes, assuming the barrel is parallel and not tapered. That could move the wheel back into the arch, getting back to (or closer to) the original position. That would mean new wheels (it's only money ), unless the adverse effects on steering geometry were tolerable. Maybe we need a guinea pig ...

[Luke]

When I put my Storm on with my 949 Nut, I could not see the end of the stud poking out like I can on my stock brake setup with ARP studs.
But because the car in question had Bosnjak hubs, I have no idea if the studs are actually the same length as the ARP ones that go into the stock hubs.
This just blew any visual reference I could make unfortunately.

I don't think that the Bonjak Hub itself changes offset. Should be the same as other hubs for MX-5's, other wise how would people run them with existing brake setups.


I don't live to far away from V-Sport, so trying stuff out may be an option now that I know the whole kit fits within the Storms.
What I'm hoping is that when I approach V-Sport they will kindly lend me a hat. I can then test fit that to my car to see how it sits.
Won't really need the calliper and rotor since, I know that is not an issue in the Storm.


And yes, I was alluding to using the modified BMW hubs just with re-engineered different dog bones/brackets on this kit. Although I suspect the Hubs may need further modifying or maybe just a smaller spacer.
Keep the same hat, rotor and calliper.

From my understanding, he went to V-Sport, and said build something. My guess would be that V-Sport would have likely outsourced some of the Engineering work to Terry (Bosnjak).

[torsospeed]

Please call this number I have a set up you may be interested in Rod Wiggins 0418608561
He has DBA 5000 series discs and hats
328 mm cheers

[Luke]

Please call this number I have a set up you may be interested in Rod Wiggins 0418608561
He has DBA 5000 series discs and hats
328 mm cheers

And how would that exactly fit under 15inch wheels???

[torsospeed]

They don’t

[greenMachine]

They don’t

Not helpful then. Did you read the discussion?