WMS Brakes: 4 pot race / trackday brake upgrade kits
Posted: Mon Nov 21, 2011 3:41 pm
About time we had a thread here! 
There are quite a few options, each "kit" includes calipers/brackets+inserts/discs/bolts - pads and line are extra (to see if a kit will fit your wheels open it's PDF, print it out, check the scale....and offer it up to your wheel!).
When comparing WMS and other 4-pot kits it's well worth noting that EBC pads for the WMS calipers are about half the cost for the same size and material as to fit our main competitor's calipers, and that the WMS/Earls lines are a proper "E30 specific fit", where as the lines supplied with one competitor's kits in the UK are "not great" (do a search here on the zone)! Also the WMS-style of CNC brackets with stainless insterts are not found on competing E30 kits and neither are the WMS/E30 1.25" piston sizes.
Here are the WMS E30 kits (each includes calipers/brackets+inserts/bolts etc/discs):
4P025 - 280x22 size kit with best wheel clearance (printable clearance test profile: 280x22 kit PDF ) = (£439.75+vat RRP - 5% E30Zone member discount) = £417.76+vat, PRICE HELD AT 2013 RATE
4P028 - 298.5x24 size kit, normally for 16"+ wheels (printable clearance test profile: 298.5x24 kit PDF ) = (£490.32+vat RRP - 5% E30Zone member discount) = £465.80+vat
Wheel clearance:
4P025 (280x22, starts at "-2mm" due to thinner flange):
- 15" BBS (FPS and BBS versions)= no spacer needed (but adding 2mm will get the wheels EXACTLY back in the std position)
- 15" BBS (Alu version) = 2mm spacer, only back to std wheel position again though/
- 15" 4x4 (325ix) BBS = Doesn't fit due to different offset
- 16" Alpina replicas (rare!) = Needed a thin spacer
- 16" Alpinas (real) = No spacer I'm told
- 16x7.5j ET25 AC Schnitzer = No spacer I'm told
4P028 (298.5x24):
- 15" BBS (all versions probably, tested on FPS) = DOES FIT...but you will need a 20mm (maybe 22mm) wheel spacer!!
- 16" Hartge = 2mm spacer needed (maybe 3-4mm)
- 16" Hartge split-rim = 1mm spacer needed (so 2mm)
- 16" Alpinas (real) = 6mm spacer needed, but still "VERY tight"
- 16" Lenso's = No spacer I'm told
- 16" Keskin KT-4 = No spacer I'm told
- 16x7.5j ET25 AC Schnitzer = No spacer I'm told, but "tight"
- 16x9J ET15 Borbet B = "doesn't fit"
- 17" Alpina replicas = Fits, no spacers needed.
OPTIONS:
- Grooved discs are offered as a service, and add £40.00+vat/pr. (price lowered)
- EBC Red pads (fast road / "200bhp+") are £38.08+vat/pr
- EBC Yellow pads (fast road / track) are £44.01+vat/pr
- EBC Blue pads (race only) are £45.20+vat/pr
- EBC Orange pads (fast road / track) are £53.24+vat/pr
- Ferodo DS2500 (fast road) = £61.20+vat/set
- Ferodo DS3000 (race) = £62.22+vat/set
- Front Earls WMS-fit braided brake lines = £35.39+vat/pr
- WMS hub-centric 2.0mm G60 (280x22) disc offset-fix spacers = £19.20+vat/pr (these work on Wilwood 280mm kits as well)
- WMS hub-centric 4.0mm G60 (280x22) disc offset PLUS 2MM spacers = £25.82+vat/pr
- Rear discs = £33.15+vat/pr
- Rear EBC Reds = £46.21+vat/set
- Rear Ferodo DS2500s = £81.91+vat/set
- UK shipping = £FREE (if settled by bank transfer, £10+vat if by PayPal, applies to brake kits only)
SPARES:
- Replacement 280x22mm discs are £60.00+vat/pr
- Replacement 298.5x24mm discs are £87.14+vat/pr
We also do these "OEM Fit" bits if it helps:
E30 325i etc (vented front discs, rear discs not drums):
EBC Red front = £POA+vat
EBC Red rear = £POA+vat
EBC Yellow front = £POA+vat
EBC Yellow rear = £POA+vat
EBC Blue front = £POA+vat
EBC Blue rear = £POA+vat
Standard handbrake shoes = £POA+vat
260x22 front discs = £POA+vat/pr
258x10 rear disc/drum combo = £33.15+vat/pr
Earls braided hose kit (4 lines) = £POA+vat
E30 M3:
EBC Red front = £POA+vat
EBC Red rear = £POA+vat
EBC Yellow front = £POA+vat
EBC Yellow rear = £POA+vat
EBC Blue front = not available for some reason
EBC Blue rear = £POA+vat
Earls braided hose kit (6 lines) = £POA+vat
I've been working on bias a bit recently, ONLY as a simplified "brake setup vs brake setup" comparison, not an overall car study - so this ignores everything other than the caliper/pad/disc.
Here are four examples, interesting results I thought!
Standard E30 saloon (not Touring!)
...fitted with 280mm disc / 1.25" piston WMS kit:
...fitted with 298.5mm disc / 1.25" piston WMS kit:
...fitted with 280mm disc / 1.38" piston WMS kit, this is the earlier spec and is still available for people wanting more front bias inside the 15" BBS (due to running semi-slicks for instance):
---- photos ----
Here's the 280x22 4P025 fitting inside the 15" BBS (made for BMW by BBS) and the FPS-BBS (made for BMW by FPS), but the Alu-BBS (made for BMW by Alu) does NEED the 2.0mm spacer as it's tighter behind the spokes:
290mm vented 2-pot retaining the handbrake, one is already in Beta testing:
"Why do WMS use threaded inserts?"
They are about getting the best of both worlds. Aluminium brackets are easily strong enough to take the loads created during braking, but have a few issues:
- Aluminium is a bit soft to have threads in it if the bolt is taken in and out a lot.
- They are also at risk from people fitting extra washers and/or shorter bolts etc resulting in less engagement, or over-torquing, basic human error etc.
Steel/Stainless brackets on the other hand are fine for the threads, but also have issues:
- They are heavy.
- They are also very expensive to machine.
By fitting heavy duty stainless inserts into aluminium you get the lighter bracket, but with the stronger threads! In effect the aluminium "sees" a much larger bolt/thread so it has an easier life. Other things worth noting:
1 - The inserts are 431 or 303 Stainless Steel. 431 is a VERY high grade of steel, in fact its properties and tensile strength are similar to a Grade 12.9 bolt (think ARP rod bolts etc).
2 - The inserts are fixed into the bracket with a grade of Locktite retainer that can withstand high temperatures (the softening/"disassembly temperature" is 250 degrees C) and is fully resistant to motor oil, unleaded petrol, brake fluid and ethanol.
3 - In destruction-testing we tried to pull an M10 bolt/insert out of a bracket by over torquing it. It made it to 80FtLb (twice the 40FtLb suggested for use one the car) before the Grade 12.9 BOLT stretched.
4 - Lastly this is not an untested concept: Wilwood's own USA-market brackets are aluminium with threaded inserts as well.
Brackets before inserts are fitted:
"What's the lowdown on the G60-disc-correction spacers?"
- 2.0mm thick, use to get the offset exactly back to standard when using G60-based 280mm kits.
- 6082 Aluminium, water cut to avoid heat distortion/lumpy edges. Obviously far more accurate than stamped or cast versions...
- Very accurate thickness due to being cut from sheet.
- Hub-centric on the E30 when using the 5mm-flange 280mm disc (Wilwood and WMS).
- Full-contact to spread wheel loads properly (no wasted holes), also allows maximum heat passage from the disc to the wheel for cooling.
* Probably NOT hub-centric on cars with the 260mm disc as they have full-thickness 7.0mm flanges, thereby "covering" the centre of the hub.
If you want custom versions of these (thicker 280mm type, 260mm type, thicker 260mm type etc) please let me know and I'll be happy to quote. There's a price drop at 5pr, but I can do one-off pairs if badly needed for some reason!
Photos showing the advantage over normal wheel spacers:
WMS 2.0mm spacers showing hub-centric location.
"Cast type" 5mm spacers showing lack of hub-centric location!
Here's how the PDF templates work...
I just took a couple of pics of the 260mm OEM disc-fit (one-off prototype) kit for reference...
There are quite a few options, each "kit" includes calipers/brackets+inserts/discs/bolts - pads and line are extra (to see if a kit will fit your wheels open it's PDF, print it out, check the scale....and offer it up to your wheel!).
When comparing WMS and other 4-pot kits it's well worth noting that EBC pads for the WMS calipers are about half the cost for the same size and material as to fit our main competitor's calipers, and that the WMS/Earls lines are a proper "E30 specific fit", where as the lines supplied with one competitor's kits in the UK are "not great" (do a search here on the zone)! Also the WMS-style of CNC brackets with stainless insterts are not found on competing E30 kits and neither are the WMS/E30 1.25" piston sizes.
Here are the WMS E30 kits (each includes calipers/brackets+inserts/bolts etc/discs):
4P025 - 280x22 size kit with best wheel clearance (printable clearance test profile: 280x22 kit PDF ) = (£439.75+vat RRP - 5% E30Zone member discount) = £417.76+vat, PRICE HELD AT 2013 RATE
4P028 - 298.5x24 size kit, normally for 16"+ wheels (printable clearance test profile: 298.5x24 kit PDF ) = (£490.32+vat RRP - 5% E30Zone member discount) = £465.80+vat
Wheel clearance:
4P025 (280x22, starts at "-2mm" due to thinner flange):
- 15" BBS (FPS and BBS versions)= no spacer needed (but adding 2mm will get the wheels EXACTLY back in the std position)
- 15" BBS (Alu version) = 2mm spacer, only back to std wheel position again though/
- 15" 4x4 (325ix) BBS = Doesn't fit due to different offset
- 16" Alpina replicas (rare!) = Needed a thin spacer
- 16" Alpinas (real) = No spacer I'm told
- 16x7.5j ET25 AC Schnitzer = No spacer I'm told
4P028 (298.5x24):
- 15" BBS (all versions probably, tested on FPS) = DOES FIT...but you will need a 20mm (maybe 22mm) wheel spacer!!
- 16" Hartge = 2mm spacer needed (maybe 3-4mm)
- 16" Hartge split-rim = 1mm spacer needed (so 2mm)
- 16" Alpinas (real) = 6mm spacer needed, but still "VERY tight"
- 16" Lenso's = No spacer I'm told
- 16" Keskin KT-4 = No spacer I'm told
- 16x7.5j ET25 AC Schnitzer = No spacer I'm told, but "tight"
- 16x9J ET15 Borbet B = "doesn't fit"
- 17" Alpina replicas = Fits, no spacers needed.
OPTIONS:
- Grooved discs are offered as a service, and add £40.00+vat/pr. (price lowered)
- EBC Red pads (fast road / "200bhp+") are £38.08+vat/pr
- EBC Yellow pads (fast road / track) are £44.01+vat/pr
- EBC Blue pads (race only) are £45.20+vat/pr
- EBC Orange pads (fast road / track) are £53.24+vat/pr
- Ferodo DS2500 (fast road) = £61.20+vat/set
- Ferodo DS3000 (race) = £62.22+vat/set
- Front Earls WMS-fit braided brake lines = £35.39+vat/pr
- WMS hub-centric 2.0mm G60 (280x22) disc offset-fix spacers = £19.20+vat/pr (these work on Wilwood 280mm kits as well)
- WMS hub-centric 4.0mm G60 (280x22) disc offset PLUS 2MM spacers = £25.82+vat/pr
- Rear discs = £33.15+vat/pr
- Rear EBC Reds = £46.21+vat/set
- Rear Ferodo DS2500s = £81.91+vat/set
- UK shipping = £FREE (if settled by bank transfer, £10+vat if by PayPal, applies to brake kits only)
SPARES:
- Replacement 280x22mm discs are £60.00+vat/pr
- Replacement 298.5x24mm discs are £87.14+vat/pr
We also do these "OEM Fit" bits if it helps:
E30 325i etc (vented front discs, rear discs not drums):
EBC Red front = £POA+vat
EBC Red rear = £POA+vat
EBC Yellow front = £POA+vat
EBC Yellow rear = £POA+vat
EBC Blue front = £POA+vat
EBC Blue rear = £POA+vat
Standard handbrake shoes = £POA+vat
260x22 front discs = £POA+vat/pr
258x10 rear disc/drum combo = £33.15+vat/pr
Earls braided hose kit (4 lines) = £POA+vat
E30 M3:
EBC Red front = £POA+vat
EBC Red rear = £POA+vat
EBC Yellow front = £POA+vat
EBC Yellow rear = £POA+vat
EBC Blue front = not available for some reason
EBC Blue rear = £POA+vat
Earls braided hose kit (6 lines) = £POA+vat
I've been working on bias a bit recently, ONLY as a simplified "brake setup vs brake setup" comparison, not an overall car study - so this ignores everything other than the caliper/pad/disc.
Here are four examples, interesting results I thought!
Standard E30 saloon (not Touring!)
...fitted with 280mm disc / 1.25" piston WMS kit:
...fitted with 298.5mm disc / 1.25" piston WMS kit:
...fitted with 280mm disc / 1.38" piston WMS kit, this is the earlier spec and is still available for people wanting more front bias inside the 15" BBS (due to running semi-slicks for instance):
---- photos ----
Here's the 280x22 4P025 fitting inside the 15" BBS (made for BMW by BBS) and the FPS-BBS (made for BMW by FPS), but the Alu-BBS (made for BMW by Alu) does NEED the 2.0mm spacer as it's tighter behind the spokes:
290mm vented 2-pot retaining the handbrake, one is already in Beta testing:
"Why do WMS use threaded inserts?"
They are about getting the best of both worlds. Aluminium brackets are easily strong enough to take the loads created during braking, but have a few issues:
- Aluminium is a bit soft to have threads in it if the bolt is taken in and out a lot.
- They are also at risk from people fitting extra washers and/or shorter bolts etc resulting in less engagement, or over-torquing, basic human error etc.
Steel/Stainless brackets on the other hand are fine for the threads, but also have issues:
- They are heavy.
- They are also very expensive to machine.
By fitting heavy duty stainless inserts into aluminium you get the lighter bracket, but with the stronger threads! In effect the aluminium "sees" a much larger bolt/thread so it has an easier life. Other things worth noting:
1 - The inserts are 431 or 303 Stainless Steel. 431 is a VERY high grade of steel, in fact its properties and tensile strength are similar to a Grade 12.9 bolt (think ARP rod bolts etc).
2 - The inserts are fixed into the bracket with a grade of Locktite retainer that can withstand high temperatures (the softening/"disassembly temperature" is 250 degrees C) and is fully resistant to motor oil, unleaded petrol, brake fluid and ethanol.
3 - In destruction-testing we tried to pull an M10 bolt/insert out of a bracket by over torquing it. It made it to 80FtLb (twice the 40FtLb suggested for use one the car) before the Grade 12.9 BOLT stretched.
4 - Lastly this is not an untested concept: Wilwood's own USA-market brackets are aluminium with threaded inserts as well.
Brackets before inserts are fitted:
"What's the lowdown on the G60-disc-correction spacers?"
- 2.0mm thick, use to get the offset exactly back to standard when using G60-based 280mm kits.
- 6082 Aluminium, water cut to avoid heat distortion/lumpy edges. Obviously far more accurate than stamped or cast versions...
- Very accurate thickness due to being cut from sheet.
- Hub-centric on the E30 when using the 5mm-flange 280mm disc (Wilwood and WMS).
- Full-contact to spread wheel loads properly (no wasted holes), also allows maximum heat passage from the disc to the wheel for cooling.
* Probably NOT hub-centric on cars with the 260mm disc as they have full-thickness 7.0mm flanges, thereby "covering" the centre of the hub.
If you want custom versions of these (thicker 280mm type, 260mm type, thicker 260mm type etc) please let me know and I'll be happy to quote. There's a price drop at 5pr, but I can do one-off pairs if badly needed for some reason!
Photos showing the advantage over normal wheel spacers:
WMS 2.0mm spacers showing hub-centric location.
"Cast type" 5mm spacers showing lack of hub-centric location!
Here's how the PDF templates work...
I just took a couple of pics of the 260mm OEM disc-fit (one-off prototype) kit for reference...
thanks!
