S54 Vanos Exhaust Hub / Vac Motorsports??

[WhatTheFetch]

I'm having my Vanos refreshed this month with the Beisan upgraded parts including the re-drilled pump disk.

I'm hoping that my exhaust hub tabs are in good shape but want to be prepared in the event they are damaged. In my numerous searches I see that there are several options and I have read up on them. One that I don't find much info on is the Vac Motorsports hub. Does anyone have any experience with it? From what I see it appears to be a well made part. I do see that there are quite a lot of M3 guys that don't care for the company. I just want know if this is solid option or not.

If the hub does need to be replaced what would you recommend?

Thanks!

[StickMon]

Sure looks pretty, and cheaper than the TurboToy C300 hub that I have.
I would say go for it.

[pcube]

I came across the vac hub recently as well, and will be going with it when the time comes to refresh my vanos system. You will not need the re-drilled pump disk if you're taking this route.

[coh661]

Wow, didn't even know about this. Seems like a better solution than the Beisan re-drilled holes. This way you get the tighter clearance to the pump disc and a beefy tab. Price seems more appealing than the turbo toy. I might go this route. Curious to hear from those who have installed this.

[WhatTheFetch]

I'm considering just going with it and returning the Beisan pump disk. Seems to me it would be better to replace the oem hub that is known to fail. I just can't find where anyone has actually installed it or really any info other than their website. It really does look well made..

[jdoublehcubed]

looks like the same concept as the turbotoy hub, except that it looks like its made from one piece.

my biggest concern is that if they're manufacturing it themselves, they may not get the splines exactly right, especially the heat treatment of that area of the part. those splines are, by an order of magnitude, the hardest part to manufacture. i like that the C300 hub reuses the BMW machined splines. i used a C300 hub when mine needed replacement.

on the other hand, i think VAC are pretty competent people, i've been to their shop in person and came away impressed. they have a real focus there on the S54 and other BMW engines of that generation, so they probably know them better than most other BMW shops.

[XMetal]

Originally Posted by jdoublehcubed

looks like the same concept as the turbotoy hub, except that it looks like its made from one piece.

my biggest concern is that if they're manufacturing it themselves, they may not get the splines exactly right, especially the heat treatment of that area of the part. those splines are, by an order of magnitude, the hardest part to manufacture. i like that the C300 hub reuses the BMW machined splines. i used a C300 hub when mine needed replacement.

on the other hand, i think VAC are pretty competent people, i've been to their shop in person and came away impressed. they have a real focus there on the S54 and other BMW engines of that generation, so they probably know them better than most other BMW shops.

Agreed. But there are 100x more people using the Beisan redrilled disc without reported issues, why would you want to be the 5th or 10th person to try this out? The OE hub tabs aren't weak, it's the hammering process that breaks them.

[pcube]

Good points raised about the splines and track record of the beisan discs... now i don't know what to do lol

[jdoublehcubed]

Originally Posted by pcube

Good points raised about the splines and track record of the beisan discs... now i don't know what to do lol

if it isn't broken yet then just have a shop redrill the pump disc and you're good to go. There's no reason to pay for the beisan disc, its just an oem disc with 2 more holes drilled.

if the tabs are already broken then get the C300 hub. there are hundreds (low hundreds) of people using those without issues.

[WhatTheFetch]

Originally Posted by XMetal

Agreed. But there are 100x more people using the Beisan redrilled disc without reported issues, why would you want to be the 5th or 10th person to try this out? The OE hub tabs aren't weak, it's the hammering process that breaks them.

Great point, I don't see any reports of failures after having the redrilled disks installed and I know that there a lot of them on the road.

[SaltyNC]

Originally Posted by jdoublehcubed

if it isn't broken yet then just have a shop redrill the pump disc and you're good to go. There's no reason to pay for the beisan disc, its just an oem disc with 2 more holes drilled.

How much would you expect a shop to charge to drill the holes? I would just be concerned with precision. If it isn't exactly 180 degrees from the existing holes, it would be out of balance. They would also need to match the depth and chamfer the edges of the holes if they match OEM and what Beisan does. If they goof, that's an expensive part to replace outright. Not disagreeing that it could probably be done cheaper, but there would be some additional risk.

[GuidoK]

Originally Posted by jdoublehcubed

if the tabs are already broken then get the C300 hub. there are hundreds (low hundreds) of people using those without issues.

For sure the c300 hub is made from a far more exotic type of steel, which alone justifies the higher price.
C300 maraging steel is an extremely hard and tough type of steel, mainly used in aircraft so that the part can be made as light as possible, whereas the vac hub is made of 4340, which is a more common/ordinary type of steel, but also heat treatable.
I wonder what the main reason is why that exhaust hub breaks. Is the stock steel used too soft (weak)? Is it too brittle? or is it more a fatigue thing (s/n curve)?
So should the main reason for using a type of steel be the hardness/tensile strenght or for example results from an impact notch test?
Any hardcore steel experts here that really know what theyre talking about ?

In the end how controlled the hardening process is carried out is also a factor that determines the end result.

The turbotoy hub for sure is the most tested one. I think they also went from a more common steel to the maranging steel (its in its 3rd version of development/material choice)

[jdoublehcubed]

Originally Posted by SaltyNC

How much would you expect a shop to charge to drill the holes? I would just be concerned with precision. If it isn't exactly 180 degrees from the existing holes, it would be out of balance. They would also need to match the depth and chamfer the edges of the holes if they match OEM and what Beisan does. If they goof, that's an expensive part to replace outright. Not disagreeing that it could probably be done cheaper, but there would be some additional risk.

i'd expect close to $1000. the cost of the job full hub replacement is about $1200 in labor and $800 for the part. if you pull the pump disc you're still disassembling that whole area of the engine and throwing the timing off, so you're doing the bulk of the labor. saving $800 on the hub is nothing to sneeze at though.

[WhatTheFetch]

Fortunately my hub was intact so I ended up going with the Beisan Pump Disk and it is definitely a lot quieter than the oem disk. Mine really had a rattle at 2500 to 3500rpms.

I had the work done with Kevin or "Kaiv" over on the M3 forum. He really does know is way around the S54. He rebuilt the Vanos with all the Beisan goodies including their upper chain guide, also did a valve job and some other fluid maintenance items and I couldn't be happier. He kept me informed during the process. Afterward he provided pictures of all the work, included a write up with the parts list and also pointed out a couple items that will need attention down the road. If anyone has an S54 that needs a little TLC in the San Diego area I would surely recommend him.

[chronopete]

I wonder what people think about this - if the existing exhaust hub is intact, is it sufficient to just upgrade to the Beisan pump disk and leave the stock exhaust hub, or is it necessary to upgrade both the pump disk and the exhaust hub in order to help prevent the tabs from breaking in the future? Would that be an over-kill? I'm trying to decide if it's worth saving the money.

[XMetal]

Originally Posted by chronopete

I wonder what people think about this - if the existing exhaust hub is intact, is it sufficient to just upgrade to the Beisan pump disk and leave the stock exhaust hub, or is it necessary to upgrade both the pump disk and the exhaust hub in order to help prevent the tabs from breaking in the future? Would that be an over-kill? I'm trying to decide if it's worth saving the money.

It's one or the other, but not both. The Beisan pump disk have smaller redrilled holes to perfectly match the OE hub tabs, which prevents any excess "play" while the "upgraded" aftermarket exhaust hub have larger tabs to fit the holes on OE pump disk.

[chronopete]

Originally Posted by XMetal

It's one or the other, but not both. The Beisan pump disk have smaller redrilled holes to perfectly match the OE hub tabs, which prevents any excess "play" while the "upgraded" aftermarket exhaust hub have larger tabs to fit the holes on OE pump disk.

Thanks, that is helpful to know!

[AK72]

Pump disc now fixed