ARP Flywheel Bolts for the performance oriented 2nd generation Rxx series Mini Cooper S. Set of 6 bolts.
Fits the following Cooper S models:
2007-2013 R56 MINI Cooper S Hardtop
2008-2014 R55 MINI Cooper S Clubman
2009-2015 R57 MINI Cooper S Convertible
2012-2015 R58 MINI Cooper S Coupe
2012-2015 R59 MINI Cooper S Roadster
2011-2016 R60 MINI Cooper S Countryman
2013-2016 R61 MINI Cooper S Paceman
ARP kit # 101-2801
|Thread Size||M9 x 1.25|
It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants. Simply stated, there's not a better stud setup on the market today.
For openers, ARP uses a premium grade 8740 alloy that is rated far superior to 'aircraft' quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi. This procedure ensures complete heat penetration and the results are far superior to thos lesser quality studs from other manufactureres who just dump pieces in a basket and hopt for the best.
Following heat-treat, each stud is centerless ground to make it as close to perfetly concentric as possible. This procedure involves about ten very slight cuts and reuslts in an exceptionally strait part. It's important to note that lesser quality studs are not even centerless ground - the material is thread rolled in bar stock from (mostly before heat-treat, when tha material is easier to machine). Because ARP studs are manufacturered to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned - something that won't happen with inferior quality head studs.
ARP studs are thread rolled after heat-treat, which gives them about 1000% (that's ten times) better fatigue strength than those studs that are threaded prior to heat-treat (a very common industry practice). It costs a lot more to do it this way, because it's tough on tooling, but the results are well worth the extra effort.
You will also note that ARP offers specially undercut studs for several engines. This procedure (done only to shorter studs) more equalizes the 'stretch' of both studs, which makes for a amore consistend clamping force - one that compenstes for head gasket compression when the head is installed. This helps prevent blown head gaskets, and assures optimum sealing.
Clearly the best on the market today, and the favorite of leading professional engine builders in all forms of racing.