CBC is TRASH! Need recommendations

[MagicF8x]

Originally Posted by x_

It seems like the bolts that were installed were A2-70 from what I can see in the picture, which has a shear strength of 700N/mm² vs 12.9 grade which is supposed to have 1200N/mm².

This is in fact true , I can’t mention what company’s hub was used or the the shop that’s done the work per our agreement , they did take the car back in and replaced all necessary parts free of charge.

[aa2033]

I've only had my cbc installed for about 500 miles and maybe 4 months. My car spends most of it's time in the garage. I've driven it in the rain twice. I assume the surface rust of the bolts are not a issue. I also used blue loctite when I torqued the bolts. I've seen people use no loctite, blue, and even red. I chose the middle ground at blue.

[dezzracer]

After reading this thread pleased I left my CS totally stock. In fact, this is the only performance car I have ever had that I haven’t modified. And I’m 65. Even on cup twos this car can get Squirrley up to 50 mph. Why anyone would try to push more power through it is beyond me but to each their own. Not judging.. just happy with this car as is.

[FrankMstein]

Originally Posted by aa2033

I've only had my cbc installed for about 500 miles and maybe 4 months. My car spends most of it's time in the garage. I've driven it in the rain twice. I assume the surface rust of the bolts are not a issue. I also used blue loctite when I torqued the bolts. I've seen people use no loctite, blue, and even red. I chose the middle ground at blue.

It is not an issue.

[b_w.]

Just took off my Vargas CBC and here is what it looks like after 12 track days this summer. Only pulling it because I am now doing the crank hub. I purchased this on Black Friday last year so maybe the newer ones are coming with better hardware. ..

[hC1001]

Originally Posted by b_w.

Just took off my Vargas CBC and here is what it looks like after 12 track days this summer. Only pulling it because I am now doing the crank hub. I purchased this on Black Friday last year so maybe the newer ones are coming with better hardware. ..

Looks good.

[Wanted_M]

Originally Posted by b_w.

Just took off my Vargas CBC and here is what it looks like after 12 track days this summer. Only pulling it because I am now doing the crank hub. I purchased this on Black Friday last year so maybe the newer ones are coming with better hardware. ..

Interesting, you can see two holes where the bolts might have been over the TQ spec. The SS washer dug into the soft aluminum material, almost like they need to revisit their chemistry and up the hardness a bit so it's not that soft. Depending on how deep the washer dug into the face (hard to tell from picture), you may want to opt for a new CBC.

[RobEvans]

This also happened to me, my bolts rattled loose over 12 months. I could feel the car shaking on idle so I had a look, harmonic balancer was wobbling all over and the belt tensioner was shaking like mad.

Elongated bolt holes on the balancer so a new one of those along with a new 4 pin crank hub.

Iv seen this happen a few times now unfortunately.

[2sporty]

The pinned crank hubs are also a joke. People I have met at the track complain about how they twist out of position and break the pins off.

[imperfectluck]

Originally Posted by 2sporty

The pinned crank hubs are also a joke. People I have met at the track complain about how they twist out of position and break the pins off.

Do you have actual proof of this? Others in this thread have posted pictures to credit their claims

[MR RIZK]

Originally Posted by imperfectluck

Do you have actual proof of this? Others in this thread have posted pictures to credit their claims

https://f80.bimmerpost.com/forums/sh....php?t=1754512

Obviously this one said install failure but there has been others reported.

[Aeko]

The design of the BMW crank hub really sucks primarily because it puts ANYTHING (keys, pins, splines, or friction material) at disadvantage to the leverage and conservation of angular momentum of the much wider and heavier crank hub, pulley, and drive accessories. That is why CBC will not do anything long term because leverage and forces it has to deal with when the crank is changing speeds at high RPMs is greater than what the aftermarket can make provisions for. I think that's why the "best" solutions are going to see SCH in maybe 5-10 years+ (or never if it's stock car and it's not beaten on) instead of 2 years or less with some of the less ideal ones.

A solid crank hub with splines is probably the best solution for in situ upgrade due to the fact it's distributing the force across a much larger area rather than a key or pins. 4 pin solid crank hub is probably a close second. The *ideal* solution from a design perspective is to just replace the entire crank with a 1 piece (or weld the crank hub) but that's obviously insanely cost prohibitive.

[imperfectluck]

Originally Posted by 2sporty

No, I don't have proof. Maybe I can go to that guy's house and yell at him until he pops open the hood and shows me. Besides, I'm sure that guy just made it up because he has an incentive to have people not buying crank hub bandages for thousands of dollars. He probably makes a commission doing that.

My guy, you verbally came to a thread seven pages deep where people posted pictures and you reply with some verbal nonsense.

I suppose we should just take your word for it though.

[2sporty]

Originally Posted by imperfectluck

My guy, you verbally came to a thread seven pages deep where people posted pictures and you reply with some verbal nonsense.

I suppose we should just take your word for it though.

I get it bruh, you spent thousands on a "fix" and don't want to hear that it can still fail. It's okay to be insecure about it.

[lookitsapples]

Originally Posted by imperfectluck

My guy, you verbally came to a thread seven pages deep where people posted pictures and you reply with some verbal nonsense.

I suppose we should just take your word for it though.

Lmfao for reals, from now on anytime a crank hub post pops on here or Facebook group. I’m literally going to say “well a dude named 2sporty said they are useless. Trust”

[FrankMstein]

Originally Posted by lookitsapples

Lmfao for reals, from now on anytime a crank hub post pops on here or Facebook group. I’m literally going to say “well a dude named 2sporty said they are useless. Trust”

You could place the quote in your sig.

[GuyLedouche]

Just checked mine. Been installed for 2 years and 20ish track days. SSR 4 pin hub.

[GuyLedouche]

Further datapoint. I just removed my cbc and it appears the shop torqued all bolts appropriately and used red lock tite.

[Chris@VargasTurboTech]

Originally Posted by GuyLedouche

Further datapoint. I just removed my cbc and it appears the shop torqued all bolts appropriately and used red lock tite.

Yes, one of the MOST important aspects of installing a CBC is proper TQ. If not Torqued to spec, they can and do come loose, and once you get 1-2 loose you will start seeing things like snapped bolts, etc. As for the bolts. We ONLY offer 12.9 bolts sourced in the USA with these (we used to get them locally in Hayward, but now we get them from a vendor in So Cal). We have never offered anything other than US-sourced bolts. Previously we used 12.9 Black Oxide, which WILL surface rust, but as you can see from this post, that is all it is, surface rust, and it does not affect anything. Now we ship with US-sourced 12.9 Zinc plated bolts. This offers the strength of 12.9 bolts and surface rust protection. We sell close 1000 CBCs a year, and the ONLY issues we ever hear of are broken bolts, always caused by improper TQ.

[FrankMstein]

Originally Posted by Chris@VargasTurboTech

Yes, one of the MOST important aspects of installing a CBC is proper TQ. If not Torqued to spec, they can and do come loose, and once you get 1-2 loose you will start seeing things like snapped bolts, etc. As for the bolts. We ONLY offer 12.9 bolts sourced in the USA with these (we used to get them locally in Hayward, but now we get them from a vendor in So Cal). We have never offered anything other than US-sourced bolts. Previously we used 12.9 Black Oxide, which WILL surface rust, but as you can see from this post, that is all it is, surface rust, and it does not affect anything. Now we ship with US-sourced 12.9 Zinc plated bolts. This offers the strength of 12.9 bolts and surface rust protection. We sell close 1000 CBCs a year, and the ONLY issues we ever hear of are broken bolts, always caused by improper TQ.

I am glad someone spoke up from over there. I agree with everything you said including the black phos and the over/under tq. Despite where you "source" the fasteners, YFS (the manufacturer, China, and not from the US) is still not to be trusted IMO, it's your business. I would ask for certs from your supplier where they have done yield testing ($$) to the bolts and certify the lot. $3 of bolts should not be a placebo to a $3000+ repair of a S55. Everyone torque your parts correctly!

[b_w.]

I posted pics in my build thread but the kies cbc and vargas use the same bolts. Both are yes 12.9. Vargas are black, kies are stainless or plated.

[FrankMstein]

Originally Posted by b_w.

I posted pics in my build thread but the kies cbc and vargas use the same bolts. Both are yes 12.9. Vargas are black, kies are stainless or plated.

Those are zinc plated which is WAY better than black phos. Stainless will not come in 12.9 but 304 and 316 alloy and not achieve 12.9 strength. Zinc is good.