SSR 4-pin crank hub vs. Insane Performance 4 pin crank hub

[RugbyBro]

Originally Posted by Chris@VargasTurboTech

Please re-read what I stated. I haven't seen any CBC only failures under 600 whp in the past year. That is a very different statement than "there are no failures under 600 whp". There have been CBC only failures, none posted on this forum but we've (VTT and affiliated shops that I'd have visibility into) have seen them. The complete solution is and always has been to address both means of crank hub deficiencies, which is vibe (CBC) and insufficient torque capability even with appropriate bolt torque (hub).

This gets twisted and posted, and re-posted by those looking to assuage their own concerns, and pretty soon it ends up with "you're promised to not have any issues as long as you are under 600 whp". Simply isn't true -just that I haven't seen any in the past year. Could be that most of the S55's being tuned and aggressively driven have already slipped and had the whole package replaced... could have been dealt with at other shops, lots of factors and possibilities. My observations were offered as a courtesy to be used with a grain of salt from my (limited) observation viewpoint, nothing more. Time does tend to weed out the frequency of occurrences, simply because the platform is aging.

Cheers,
Chris

Yup this was my interpretation from what you posted in the other thread, Chris!

I think us CBC guys have to be fair here in that a CBC isn’t a promise your hub won’t slip as it doesn’t change anything about the hub design. All it functions to do is lock the bolt down and prevent it from losing any more torque than it may have potential lost prior to install. The side effect is clearly that it keeps the pressure on the friction washer and at the very least significantly reduces the chance of SCH. Whether you think the friction washer (when proper pressure is applied) is enough is a different story. Personally, for my use (stock, maybe CS/GTS power one day) I don’t see a reason why it wouldn’t be enough. If I was building a 6, 7, or 8 bill monster, you bet I’m throwing in a spline lock amongst other things (rods, bearings, etc.).

[Kossos]

I'm no mechanical engineer but the single big key on the Precision Dynamics 1 piece seems like it would be unbalanced and cause vibrations vs a crank hub with 4 equal pins.

[TopJimmy]

Originally Posted by Kossos

I'm no mechanical engineer but the single big key on the Precision Dynamics 1 piece seems like it would be unbalanced and cause vibrations vs a crank hub with 4 equal pins.

I'm more concerned that a single keyway puts load in one spot. This is why the original Woodruff Key hub-fixes failed. I like how the 4-pin is balanced with load across a more even area.

[Big_Buck///]

Originally Posted by TopJimmy

I'm more concerned that a single keyway puts load in one spot. This is why the original Woodruff Key hub-fixes failed. I like how the 4-pin is balanced with load across a more even area.

I believe that Mike say's in the Precision video that it's made out of billet aluminum, and they state on their website that it has a higher sheer strength than the dowel pin designs. I don't know, but it seems that even though the load is higher in one spot, the strength of the hub would be more than enough to not fail. Add to the fact that it is a one-piece, there is no possibility of timing going off other than the key physically breaking, no? As far as vibration goes, can you explain how the unbalanced weight would produce that?

I say all the above with a curious mindset, by no means am I asserting that my answers are correct from an engineering standpoint. I am merely stating what initially came to mind in regards to the one-piece solution from Precision. All replies welcomed!

[TopJimmy]

Originally Posted by Big_Buck///

I believe that Mike say's in the Precision video that it's made out of billet aluminum, and they state on their website that it has a higher sheer strength than the dowel pin designs. I don't know, but it seems that even though the load is higher in one spot, the strength of the hub would be more than enough to not fail. Add to the fact that it is a one-piece, there is no possibility of timing going off other than the key physically breaking, no? As far as vibration goes, can you explain how the unbalanced weight would produce that?

I say all the above with a curious mindset, by no means am I asserting that my answers are correct from an engineering standpoint. I am merely stating what initially came to mind in regards to the one-piece solution from Precision. All replies welcomed!

It may have a higher shear strength but the flaw I see is the single keyway-like hump on the mating surface. They drill a single large hole in one side of the crankshaft instead of the four dimples. That one hole could unbalance the crank a tiny bit right where the front oil seal is.

I see the 4-pin solutions as best due to spreading load. They're balanced, and are several revisions engineered. The one piece is best if the engine is apart for a big build, and the two piece just as acceptable (I have the two piece). The only difference on a two piece is the oiling sprocket can still slip ONLY if the bolt backs out (so add the CBC) or you overpower the disc (nobody's reported it yet). Even if the disc and oiling sprocket slips it doesn't damage anything like the valve train sprocket can.

[Big_Buck///]

Ahh okay that makes sense. I was viewing from the hub viewpoint, but your point about the crank being unbalanced could be a concern, I wonder to what extent Precision took that into account. Side note: I have been looking for a m4 to my liking for about 2 months now, but have been a huge fan ever since their release, so I've been researching A TON of common issues and their fixes. When I saw the one piece solution come out from Precision, it took away the anxiety of having a shop here in GA (we don't have any really well known BMW shops here, at least to my knowledge) having to drill 4 holes in my crank lol.

[Ilvez]

Precision solution appears to be extremely solid design as the relatively large key on the hub is able actually to hold torque, compared to dovel pin ones. Also, it reduces potential installation errors and avoids the destruction of the hub by pressing in the splines.

Unbalancing is not an issue because:

1) Net effect of unbalancing is the difference in removed weight from shaft compared to the added weight of the key. When assembled they form single symmetrical rotational unit, so the effect is neglible.

2) Unbalancing effect is even more reduced as the potential weight difference of the added key vs removed section of the crankshaft from drilling is very close to the centre of the crankshaft where the centrifugal forces at play are not pronounced.

3) One needs to consider that a lot of rotational mass is attached to the hub e.g. harmonic balancer (3+ kilos vs max few grams net difference of the key/crank material), which evens out any effects in the differences of the weight of the key vs removed material from the hub.

[TopJimmy]

Originally Posted by Ilvez

Precision solution appears to be extremely solid design as the relatively large key on the hub is able actually to hold torque, compared to dovel pin ones. Also, it reduces potential installation errors and avoids the destruction of the hub by pressing in the splines.

Unbalancing is not an issue because:

1) Net effect of unbalancing is the difference in removed weight from shaft compared to the added weight of the key. When assembled they form single symmetrical rotational unit, so the effect is neglible.

2) Unbalancing effect is even more reduced as the potential weight difference of the added key vs removed section of the crankshaft from drilling is very close to the centre of the crankshaft where the centrifugal forces at play are not pronounced.

3) One needs to consider that a lot of rotational mass is attached to the hub e.g. harmonic balancer (3+ kilos vs max few grams net difference of the key/crank material), which evens out any effects in the differences of the weight of the key vs removed material from the hub.

If their hump instead was a circle the exact same size as the hole then I could see the crank is still being balanced. Until I actually had eyes on the fitment and saw better then my 4-pin I'm not sold.

Regardless of unique hub shape or stock...the hub is still held to the crank with 'crush' by the crank bolt. As long as a Crank Bolt Capture plate ($100) is installed over any aftermarket hub (if installed properly) then I see the actual "unique shape" pretty much irrelevant. As long as the hub bolt can't loosen and the valve train sprocket doesn't move everything is good.

[Big_Buck///]

I decided to reach out to Percision Dynamics and inquire about some of the points of possible concern in their one-piece design. They promptly responded and I think they did a great job of providing thorough answers. I'm going to post the email conversation below. Please excuse all the grammar errors, as I was driving and using the voice-to-text option haha. I thought their input would provide value in making a decision between different Crank Hub fix designs.

[Datgrey.m4]

Originally Posted by Singham14

Hey all,

Sorry if there is a post already out there regarding my question, but I couldn't find it. I am going in for my crank hub upgrade and just wanted to see what others have to say about SSR performance hub vs. Insane performance 4 pin crank hub. I am leaning towards the Insane performance 4 pin as it's a little cheaper and also one piece vs. two pieces and I also have the crank bolt capture.

Thanks

i've done a research on that, its my opinion, i don't know if its right or wrong, but lets stick to the basics first, there two ways that your crank hub might slip, one is the crank hub it self slips, the other is when the crank bolt back out which also causes the crank hub to slip, so if you're installing a crank hub, you're not 100% safe, because although the crank hub might not slip, but the bolt might backout (its hard, but happens) so to make a complete fix you need the CBC, and a crank hub upgrade, now for the SSR VS insane, and honestly they're both the same in reliability, but the insane crank hub requires more labor, but its also safer, why? because its a single piece with4 pins drilled, since its a. single piece, it would never slip unless there was an installation error, for the 4 pin SSR crank hub, its know of its quality, idk, i just don't like the keyed design(just my opinion), doesn't mean its not reliable ( it os proven to be), but its just my preference, but in the end, between these two, you could never go wrong, so choose the one thats cheaper in price, and that you prefer!

[Nisse Järnet]

I removed my Insane hub after first install to inspect, all the pins were fine

[Nisse Järnet]

[Dippydo]

Originally Posted by chetrickerman

Having installed a few 1 and 2 piece crank hubs myself, I can definitely install a 2 piece hub without dropping the oil pan.

Its possible SSR recommends it just incase any metal shavings find their way into the oil pan during drilling.

That’s the point really to drop it to make sure no shavings get in there. If a tech told me he could do the job without dropping it, I’d wonder what other risky shortcuts he was doing. Lol

[mike@x-ph.com]

Originally Posted by Nisse Järnet

I removed my Insane hub after first install to inspect, all the pins were fine

[chetrickerman]

Originally Posted by Dippydo

That’s the point really to drop it to make sure no shavings get in there. If a tech told me he could do the job without dropping it, I’d wonder what other risky shortcuts he was doing. Lol

Lol, if done properly, its not a risky shortcut at all. I drill slowly using lots of cutting oil, and use cardboard in a U shape covered in oil so that when shavings do get on it, they stay in place. Works very well, done it several times.

[f82_spooly]

So have we come to the conclusion that the Insane crank hub 4 pin design is a cheaper more cost effective solution compared to SSR?

[MR RIZK]

Originally Posted by Nisse Järnet

I removed my Insane hub after first install to inspect, all the pins were fine

It would be great if you can post images of the sprockets to show if there are any evidence of teeth wear. Also the mileage on the hub.

It is rare on this forum that anyone has removed the hub post install regardless of manufacturer.

All hubs are pretty much proven. Comes down to longevity and teeth profiles as a differentiator.

Or did I miss understand your post and you removed the hub immediately after install?

[Nisse Järnet]

Originally Posted by MR RIZK

It would be great if you can post images of the sprockets to show if there are any evidence of teeth wear. Also the mileage on the hub.

It is rare on this forum that anyone has removed the hub post install regardless of manufacturer.

All hubs are pretty much proven. Comes down to longevity and teeth profiles as a differentiator.

Or did I miss understand your post and you removed the hub immediately after install?

Sorry yes, i did the installation, then removed it to check that everything was ok before final assembly.
Haven't started the engine yet, i put forged pistons and rods in it now etc, but soon hopefully!

[N44RP]

Any further recommendations on the one piece? I’d like to reduce the risk during install and it sounds like drilling 4 holes perfectly isn’t ideal.

[sonicnofadz]

I'm not sure about on the f8x/s55 platform, but on the N54 platform there have a TON of documented failures with people running ONLY the CBC. I would not rely on this as a "bulletproof" fix for the s55 either. A lot of the n54 guys have seen the VTT unit in particular have the cheap chinesium hardware bolts shear off completely and have the entire harmonic balancer come off (lol). I'd stay away from using this, and probably just stick with new OEM hardware torqued to spec.

[SflBimmer8484]

Originally Posted by sonicnofadz

I'm not sure about on the f8x/s55 platform, but on the N54 platform there have a TON of documented failures with people running ONLY the CBC. I would not rely on this as a "bulletproof" fix for the s55 either. A lot of the n54 guys have seen the VTT unit in particular have the cheap chinesium hardware bolts shear off completely and have the entire harmonic balancer come off (lol). I'd stay away from using this, and probably just stick with new OEM hardware torqued to spec.

Insane now makes a 4 pin for the n54 as well. Cbc is band aid that can cause issues of its own as well.

Just go for a insane crank hub and call it a day they are the first and most widely used single piece hub out here and they have upgraded their hardware to be even stronger. . 2 pin or 4 pin it doesn't really matter.

[Track/S]

Originally Posted by SflBimmer8484

Insane now makes a 4 pin for the n54 as well. Cbc is band aid that can cause issues of its own as well.

Just go for a insane crank hub and call it a day they are the first and most widely used single piece hub out here and they have upgraded their hardware to be even stronger. . 2 pin or 4 pin it doesn't really matter.

2 pins is enough, 4 is a fight between manufacturers to sell more units.