Can't remember/find any posts about my quest for a big brake kit..anyhoo.
Heres my progress...
Modding a car is not all about horses and torques, it’s extremely important to be able to control any power upgrades you strive for. Like anything else though it comes at a cost, and with the popularity of the Astra VXR, tuners offering upgrades are keen to make a buck and keep prices high. They’ll argue that they do all the R&D and they need to reclaim costs of bringing stuff to market to make it viable. They have a point, but compared to Astra GSI Turbo parts, it seems they’re keeping some prices artificially high.
Some big brake kits costing over a grand get very good reports, encouraging people to buy them … but often people dont think about the ongoing costs of using them. I’ve heard of replacement discs costing not far off a third of the price of the kit in the first place, which seems a swift kick in the wallet…
With this in mind, I was keen to keep costs down, so have been on the lookout for a cheaper better solution.
Looking at other high power cars on the market, they seem to mostly have at least 4-pot calipers, the Astra VXR only has 2-pot. So that was an area I was keen to improve on. By chance I spotted a bargain pair of Wilwood calipers that someone had bought in error, unable to return them I decided to buy them in the unknown hope that I could get them to fit the Astra. They are 6-pot lug mount superlites….maybe a bit overkill, but should certainly make an improvement !!
I also thought about the discs, the size of the Astra VXR discs at 321mm is fairly good, so I reckon I’ll get away with sticking to that just now, if I find it could be improved then the Vectra VXR discs at 345mm can be bolted straight on.
First stage of getting these fitted was to see if they will actually fit. This is the stage I’m at, by looking at the paperwork with the calipers, it seems alright. So onto todays progress, I started to mock things up to see what space was avaiable for getting brackets made up. As you can hopefully see it looks totally do-able so I’m very happy. Not quite having the confidence to make a bracket myself (although it looks easy, with being brakes I’d rather put my faith in someone more professional)…So i’ll be in touch with Ken Tattie Engineering for them, hopefully they’ll be able to help me out !!!
Spare suspension leg that I luckily had lying around
New Astra 321mm disc from EBC bolted on from EBC Direct.
Caliper placed on the disc centrally
Bracket must be this thick to fit between caliper mounts and original
caliper mount (yellow shaded area)
Lug mount and original caliper mount holes don’t clash, so thats good.
Update courtesay of Ken Tattie Engineering!
Some time ago COO mentioned that he had new calipers for his VXR and needed some brackets made, obviously I rose to the challenge. A few weeks ago he came round to drop of his new beauties, a pair of Willwood 6 pot Superlite calipers, along with a disc/hub/strut setup for me to use as a template.
The first job was to get the caliper mounted on the disc, I used some thin sheet metal and ground silver steel bar as shims to get it where I wanted,
This gave me the spacing I required from the mounting face of the hub to the caliper, from memory it was 8.5mm. Some more calculations followed using the Willwood data sheet, my trusty Mitutoyo calipers and other measuring equipment.
This was all taken to the PC and some sizes were created using the CADCAM system I use.
The next job was to find some suitable material and low and behold, we have some top quality brackets…..
Haha, fooled you!
The bit aluminium was used to check the sizes I had were right and that it’d all work. The plate was 8mm thick so didn’t give an accurate idea on the offset, though it all tied up with what I’d measured earlier. Here it’s all built up….
Now I was happy with that it was time for another mock up, this time is random plastic.
What I’ve done is erred on the side of caution. COO’s car is never going to become a 500kg F1 style warrior so I’ve beefed the thickness up to 25mm and made counterbores for the lugs to fit in, it’s a really nice fit IMO and it’s only going to increase the strength. It looks that wee bit more factory too .
Obviously the plastic wouldn’t last particularly long so it was off to the material racks to find something more suitable. A big lump of could rolled mild steel was hiding underneath everything and turned out to be ideal. What wasn’t ideal was the lack of decent cutters, that was easily sorted thanks to ebay though and within no time at all (actually a slight lie – there was a lot of metal removal!) we had the finished product;
PS- The eagle eyed may spot that the smaller holes aren’t tapped here. Well they are now .
I have every confidence that they’re way more than up to the job, none of this bit of steel with some holes drilled malarky here!
Anyway the next photo should be on the car, which brings us onto COO’s next problem, clearance with the wheel, though it should be easily sorted with some 5mm spacers he hopes!
Cheers to Ken, not sure when I’ll manage to get these on so watch out for an update