Discussion
I KNOW there have been several threads on the Ford discs used on TVRs but others may be helped by my trials & tribulations today!?!?
Research on this and other sites led me to believe my '95 Chimaera 500 would have RS or Cosworth discs.
Indeed, the rear discs are the same as the ones listed in my local motor factors "bible" as on the Sierra Cosworth 4x4. (Diameter 273mm, depth 44mm)GREAT SUPER
Now for the front
The depth of the front discs of Cosworth / RS / normal Sierras was 58mm whereas the discs I took off were 53mm (?)
Either 'cos its an early '95 the discs aren't quite the same as the Griff 500 or mines a one-off (there is a washer between the hub carrier and the caliper - maybe taking up space?). I even trying fitting them but the extra 5mm inset brings the disc too close to the trackrod end for my liking!!
Anyway, scouring of the parts list and 3 trips to the local factors revealed that my front discs are the same as the Sierra XR4i 4x4. The 4x4 is important because the 2wd version front discs are different.
Here's to a dry day tomorrow so I can fit them all - good job I've holiday to use up!! Once they're done
I HOPE!!!
PS Hats off to Loverock Motor Spares up the road from me (Brierley Hill)-they spent ages helping me & know all about Chimaera brakes now! 4 new discs and set of rear pads- £121!
Research on this and other sites led me to believe my '95 Chimaera 500 would have RS or Cosworth discs.
Indeed, the rear discs are the same as the ones listed in my local motor factors "bible" as on the Sierra Cosworth 4x4. (Diameter 273mm, depth 44mm)GREAT SUPER
Now for the front
The depth of the front discs of Cosworth / RS / normal Sierras was 58mm whereas the discs I took off were 53mm (?) Either 'cos its an early '95 the discs aren't quite the same as the Griff 500 or mines a one-off (there is a washer between the hub carrier and the caliper - maybe taking up space?). I even trying fitting them but the extra 5mm inset brings the disc too close to the trackrod end for my liking!!
Anyway, scouring of the parts list and 3 trips to the local factors revealed that my front discs are the same as the Sierra XR4i 4x4. The 4x4 is important because the 2wd version front discs are different.
Here's to a dry day tomorrow so I can fit them all - good job I've holiday to use up!! Once they're done
I HOPE!!! PS Hats off to Loverock Motor Spares up the road from me (Brierley Hill)-they spent ages helping me & know all about Chimaera brakes now! 4 new discs and set of rear pads- £121!
I hate to say this but it is not as simple as this... 
The 500's have been fitted with a bewildering range of discs (including redrilled 5 stud Granada ones, Escort RS turbo mk 2) and I have seen nearly every single disc quoted including some that clearly can't fit. In essence you can't and should not assume anything. There are also different versions of discs for the same car depending on whthere a Trevis or Girling calliper has been fitted and whether it is a RS500 or a plain Cosworth...
The best bit of advice is to measure the disc to ensure that the replacement is the same.
Steve
www.tvrbooks.co.uk
The 500's have been fitted with a bewildering range of discs (including redrilled 5 stud Granada ones, Escort RS turbo mk 2) and I have seen nearly every single disc quoted including some that clearly can't fit. In essence you can't and should not assume anything. There are also different versions of discs for the same car depending on whthere a Trevis or Girling calliper has been fitted and whether it is a RS500 or a plain Cosworth...
The best bit of advice is to measure the disc to ensure that the replacement is the same.
Steve
www.tvrbooks.co.uk
quote:
£121 for disks and pads!! Wish i'd known that before I paid over £400 last weekPresuming they are the same on a Chimeara as a Grffith!
Fitted the fronts ok, but can't budge the calipers on the back! I'll have another go this weekend!
Some pads cost more, you can easily pay thirty or fourty quid a corner for pads, and the same again for drilled or grooved discs. Much more if you're going for something fancy. Make sure you don't try to use standard road pads, just because they're the right size and shape doesn't mean they're up to the job. You need fast road pads.
Remember you will need to wind the rear calipers back in too - this means you can't use the front wheel short-cut of undoing one of the sliders and pivoting the caliper round the other one (i.e. leaving the fixed part of the caliper bolted to the upright).
Whilst we are on the subject of discs. I'm looking to change my fronts, to a new set of Discs within the couple couple of months. I tend to do about 3 trackdays a year (after 6 laps of donnington in December last year, I couldn't lock the fronts, so I think I need some), and like fast road, so I fancy a set of either drilled or grooved discs or both...??
This is my question, what is the difference between drilled or grooved... or ones with both...? Would lI be able to tell much difference...
The majority of race cars you see with BIG brakes are drilled... So are these the best..?
jj
This is my question, what is the difference between drilled or grooved... or ones with both...? Would lI be able to tell much difference...
The majority of race cars you see with BIG brakes are drilled... So are these the best..?
jj
quote:
This is my question, what is the difference between drilled or grooved... or ones with both...? Would lI be able to tell much difference...
The majority of race cars you see with BIG brakes are drilled... So are these the best..?
Both types stop the pads glazing (so you can run harder pads) and de-gas the pads to improve high-temperature performance. The price is significantly increased pad wear (up to double the normal wear rate).
The big difference is drilled discs wear the pads quicker, and are prone to cracking if you get them really hot. Grooved discs don't suffer from this.
quote:
This is my question, what is the difference between drilled or grooved... or ones with both...? Would lI be able to tell much difference...
The majority of race cars you see with BIG brakes are drilled... So are these the best..?
I agree with Peter, grooved not drilled. We fit Brembo WRC brakes (tarmac and gravel spec) to customers cars and they are grooved not drilled because of the cracking problem.
quote:
Some pads cost more, you can easily pay thirty or fourty quid a corner for pads, and the same again for drilled or grooved discs. Much more if you're going for something fancy. Make sure you don't try to use standard road pads, just because they're the right size and shape doesn't mean they're up to the job. You need fast road pads.
The pads for the 520 retail at 120 pounds a set and that is just the front. Buy them in bulk now!
The pad issue is very interesting. I have seen about 10 different EBC numbers quoted for Griffi/Chimi/V8Si and while the have the same basic pad shape, there is tremendous variation in the amount of material on the pad. Definitely worth checking that the new pads are the same as the old ones.
Steve
back on the subject of drilled or groved discs...
My 500 came with groved discs on the front so I can't quote on the difference from "normal" disks.
However, when I have done track days I have noticed that the brakes have faded towards the end of the day. This turned out to be (I believe) because the groves were filling up with brake dust. I guess that the fluid deteriorating could have been a factor though. Anyway, when the front pads need changing next I intend to swap to Green Stuff pads or similar as they claim to create less dust.
I know Peter has views on these wearing the discs quicker than standard pads though.
My 500 came with groved discs on the front so I can't quote on the difference from "normal" disks.
However, when I have done track days I have noticed that the brakes have faded towards the end of the day. This turned out to be (I believe) because the groves were filling up with brake dust. I guess that the fluid deteriorating could have been a factor though. Anyway, when the front pads need changing next I intend to swap to Green Stuff pads or similar as they claim to create less dust.
I know Peter has views on these wearing the discs quicker than standard pads though.
If drilled discs are at risk from cracking, then why are they fitted as standard too:
All Porka 911s
All AMG Mercs
All Fwawis
All Lambos
All Maseratis
etc etc etc
Surely these manufacturers wouldn't fit them if they cracked al the time?
Edited to say that I am no expert and it is a genuine question.
>> Edited by hughjayteens on Friday 22 March 15:19
All Porka 911s
All AMG Mercs
All Fwawis
All Lambos
All Maseratis
etc etc etc
Surely these manufacturers wouldn't fit them if they cracked al the time?
Edited to say that I am no expert and it is a genuine question.
>> Edited by hughjayteens on Friday 22 March 15:19
quote:
If drilled discs are at risk from cracking, then why are they fitted as standard too:
All Porka 911s
All AMG Mercs
All Fwawis
All Lambos
All Maseratis
Because their owners are rich enough to afford the replacement costs when they crack and at several hundreds of pounds a disc, it is a nice little owner
Drilled discs are better than plain for de-gassing and drianing out the water that collects in the vents but they are more prone to cracking through heat stress. Manage this and drilled discs can last as long as groved. I had drilled discs on the 520 for years and then suddenly started crcaking them big time like 4 inch cracks just after switching to EBC Green stuff.
I've switched to grooved only on the 520 now and Ferodo 3466 race pads. The EBCs will be junked. They are alright but have no real bite.
Steve
www.tvrbooks.co.uk
quote:
However, when I have done track days I have noticed that the brakes have faded towards the end of the day. This turned out to be (I believe) because the groves were filling up with brake dust. I guess that the fluid deteriorating could have been a factor though. Anyway, when the front pads need changing next I intend to swap to Green Stuff pads or similar as they claim to create less dust.
I know Peter has views on these wearing the discs quicker than standard pads though.
The fade could be due to other factors.
I have yet to hear a competitive driver that has anything good to say about EBC except that they are cheap and easy to get hold off. I also find they eat discs. I also find that they have no real feel and once glazed are almost useless. For average road use they are OK but are really nothing special in my experience.
Steve
www.tvrbooks.co.uk
quote:
quote:
If drilled discs are at risk from cracking, then why are they fitted as standard too:
All Porka 911s
All AMG Mercs
All Fwawis
All Lambos
All Maseratis
Because their owners are rich enough to afford the replacement costs when they crack and at several hundreds of pounds a disc, it is a nice little owner
Drilled discs are better than plain for de-gassing and drianing out the water that collects in the vents but they are more prone to cracking through heat stress. Manage this and drilled discs can last as long as groved. I had drilled discs on the 520 for years and then suddenly started crcaking them big time like 4 inch cracks just after switching to EBC Green stuff.
I've switched to grooved only on the 520 now and Ferodo 3466 race pads. The EBCs will be junked. They are alright but have no real bite.
Steve
www.tvrbooks.co.uk
I thought that if the disc was forged with the holes it would be stronger, as opposed to having holes drilled after the metal has cooled ...
quote:
I thought that if the disc was forged with the holes it would be stronger, as opposed to having holes drilled after the metal has cooled ...
Don't know, does anyone do this? I think it is normal to stress-relieve the discs after drilling which presumably would give similar benefits? Anyway, all I know is people I asked warned me they were prone to cracking, then they cracked and everyone said 'told you so' so I've learned my lesson. No more drilled discs for me.
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