ZPOST
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   ZPOST > BMW Z4 Technical Talk > Engine, Exhaust, Drivetrain Modifications
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      08-26-2015, 04:12 PM   #1
Beedub
Major General
United Kingdom
423
Rep
5,327
Posts

Drives: 2007 Z4 M roadster vt2-500
Join Date: Sep 2007
Location: UK

iTrader: (0)

Ess supercharger bracket bolt TQ

Hey guys, looking to your ESS owners out their ..

I'm trying to keep the 2 s/c bracket bolts Tq'd nice and tight as i feel when these loosen off we see the dreaded cracked oil filter housing issues as the looser bolts allow flexing against this part.. This may b completely wrong but it definitely isn't going to hurt to keep things Tq'd up nicely, especially when you consider the weight of the bracket and s/c, imo it needed to be braced/secured further but thats another thread.

so the 2 long ass bolts holding the bracket to the alternator/ oil filter housing... How tight are you guys doing these things, i mean the bolts are huge so I'm sure they can take a decent amount but i don't want to over do it either.

Are you guys basically giving these all you've got or just a good firm solid sharp Tq load. Theirs no stated value set by ess so I'm just wondering what you guys did in this respect?? The sheer size and weight these things are carrying I'm guessing they need a decent tightening. These are subjected to alot of vibrations and heat so i think its something we should all get into the habit of checking regularly.
__________________
Z4MR VT2 - Clubsport build.
Multi award winning Detailing | Wrap | PPF specialists UK based - www.topwrapz.com

Last edited by Beedub; 08-26-2015 at 04:25 PM..
Appreciate 0
      08-27-2015, 09:12 AM   #2
Westersund
Captain
Westersund's Avatar
Sweden
478
Rep
859
Posts

Drives: BMW
Join Date: Nov 2011
Location: Hallstahammar

iTrader: (1)

I would tighten with moderation and use blue loctite.
Appreciate 0
      08-27-2015, 09:52 AM   #3
GuidoK
#buildnotbought
GuidoK's Avatar
10473
Rep
4,815
Posts

Drives: Z4 3.0i ESS TS2+
Join Date: Jul 2012
Location: Tinkering in the garage

iTrader: (0)

Doesn't TIS give a torque spec?
I mean you use an existing bolthole for the bracket don't you?
(where there used to be a factory fitted bolt)

Blue loctite can't hurt in this situation.

If you have the bolt size, bolt quality and thread pitch, there are generic values for bolt tightening torques.
__________________
Z4 3.0i | ESS TS2+ supercharger | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | Powerflex/strongflex PU bushings | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers/KW camber plates | Sachs race engineering clutch | tons of custom sh#t
Appreciate 0
      08-27-2015, 10:02 AM   #4
Beedub
Major General
United Kingdom
423
Rep
5,327
Posts

Drives: 2007 Z4 M roadster vt2-500
Join Date: Sep 2007
Location: UK

iTrader: (0)

Quote:
Originally Posted by GuidoK View Post
Doesn't TIS give a torque spec?
I mean you use an existing bolthole for the bracket don't you?
(where there used to be a factory fitted bolt)

Blue loctite can't hurt in this situation.
im not sure if the TIS Tq spec would be adequate in this situation, we now have a 20kg s/c and bracket arrangement hanging off a location that was not designed for the additional weight.

my key concern is not to over tighten or under tighten.... given additional weight of the blower and bracket, length and thickness of the bolts I'm guessing Tq would need to be significant. On checking they seems pretty tight so i gave them a small re-tq , they budged alittle but i didn't go crazy... i'll do the same yearly...
__________________
Z4MR VT2 - Clubsport build.
Multi award winning Detailing | Wrap | PPF specialists UK based - www.topwrapz.com

Last edited by Beedub; 08-27-2015 at 11:28 AM..
Appreciate 0
      08-27-2015, 11:37 AM   #5
Steeler
Colonel
Steeler's Avatar
2422
Rep
2,697
Posts

Drives: Built not Bought 04 Z4 VF
Join Date: Feb 2013
Location: Kitchener Ontario Canada

iTrader: (2)

Quote:
Originally Posted by GuidoK View Post
Doesn't TIS give a torque spec?
I mean you use an existing bolthole for the bracket don't you?
(where there used to be a factory fitted bolt)

Blue loctite can't hurt in this situation.

If you have the bolt size, bolt quality and thread pitch, there are generic values for bolt tightening torques.
Quote:
Originally Posted by Beedub View Post
im not sure if the TIS Tq spec would be adequate in this situation, we now have a 20kg s/c and bracket arrangement hanging off a location that was not designed for the additional weight.

my key concern is not to over tighten or under tighten.... given additional weight of the blower and bracket, length and thickness of the bolts I'm guessing Tq would need to be significant.
Guido is correct on this.
Any particular bolt diameter, grade of bolt and thread pitch has a max. torque value.
The fact that you are hanging more weight on a particular bolt has nothing to do with its torque capacity. More related to shear capacity of the bolt that hopefully ESS has taken into account by supplying a stronger tensile strength bolt, if they deemed necessary.

Add some Loctite, torque to TIS spec and enjoy the car.

As far as the brace idea goes, my VF blower plate has a brace added, likely for that reason. Might be worth looking into that.
__________________
W2A Intercooled Vortech V3Si, custom ducting, Alpha N, 60# Bosch,2.62 pulley, multi port WMI, Severn Tuning(pokeybritches), Tial, magnaflow,SS race muffler, 42 design,3.91LSD, H&R, Hotchkis,ST coils,Konis, Megan camber arms, AKG SS, Nylon mounts, Poly bushings, Carbon interior, CF Aero.APEX
Appreciate 0
      08-27-2015, 12:01 PM   #6
GuidoK
#buildnotbought
GuidoK's Avatar
10473
Rep
4,815
Posts

Drives: Z4 3.0i ESS TS2+
Join Date: Jul 2012
Location: Tinkering in the garage

iTrader: (0)

Or just ask ESS. They're mostly very quick with email aswers.
I don't know if they have a particular view on this.

It would be bad to crack your oil filter housing, it's an expensive part, not easy to change.
__________________
Z4 3.0i | ESS TS2+ supercharger | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | Powerflex/strongflex PU bushings | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers/KW camber plates | Sachs race engineering clutch | tons of custom sh#t
Appreciate 0
      08-27-2015, 02:07 PM   #7
Beedub
Major General
United Kingdom
423
Rep
5,327
Posts

Drives: 2007 Z4 M roadster vt2-500
Join Date: Sep 2007
Location: UK

iTrader: (0)

Quote:
Originally Posted by GuidoK View Post
Or just ask ESS. They're mostly very quick with email aswers.
I don't know if they have a particular view on this.

It would be bad to crack your oil filter housing, it's an expensive part, not easy to change.
i have done so, ill report back here for anyone else in the future.... :-)

thanks for comments :-)
__________________
Z4MR VT2 - Clubsport build.
Multi award winning Detailing | Wrap | PPF specialists UK based - www.topwrapz.com
Appreciate 0
      08-28-2015, 09:58 AM   #8
Westersund
Captain
Westersund's Avatar
Sweden
478
Rep
859
Posts

Drives: BMW
Join Date: Nov 2011
Location: Hallstahammar

iTrader: (1)

Reading this I'd say you'll be fine as the bolts holding the oil filter housing are (3x) M8 8.8 grade bolts: http://www.eng-tips.com/viewthread.cfm?qid=87318
Appreciate 0
      08-31-2015, 08:26 PM   #9
GuidoK
#buildnotbought
GuidoK's Avatar
10473
Rep
4,815
Posts

Drives: Z4 3.0i ESS TS2+
Join Date: Jul 2012
Location: Tinkering in the garage

iTrader: (0)

But it's not necessarily the bolt's strenght (grade 8.8, 12,9 etc).

Torquing a bolt down prevents the bolt from coming slightly loose. That might cause the bolt to wobble in the bolthole, and that can crack the bolt, or the mounting piece.

A bolt is only strong when it's firm&stationary.

I had that with my rear diff bolt, where I used a new type of polyurethane bushing.
Turned out that the core of the bushing was too weak, which ment it got crushed a bit and the bolt got minute play (so lack of torque, it lost it torqued down spec). Ample time later... the bolt cracked.
Lack of torque can cause the bolt to flex back&forth, giving metal fatique.

So too much torque and the aluminium housing (the threaded hole) can crack (or the bolt can break/strip), and too little torque can cause the bolt to come loose (come out) or flex and break.

So the correct amount of torque you need is somewhere inbetween
__________________
Z4 3.0i | ESS TS2+ supercharger | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | Powerflex/strongflex PU bushings | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers/KW camber plates | Sachs race engineering clutch | tons of custom sh#t
Appreciate 0
      09-04-2015, 03:53 PM   #10
Beedub
Major General
United Kingdom
423
Rep
5,327
Posts

Drives: 2007 Z4 M roadster vt2-500
Join Date: Sep 2007
Location: UK

iTrader: (0)

Quote:
Originally Posted by GuidoK View Post
But it's not necessarily the bolt's strenght (grade 8.8, 12,9 etc).

Torquing a bolt down prevents the bolt from coming slightly loose. That might cause the bolt to wobble in the bolthole, and that can crack the bolt, or the mounting piece.

A bolt is only strong when it's firm&stationary.

I had that with my rear diff bolt, where I used a new type of polyurethane bushing.
Turned out that the core of the bushing was too weak, which ment it got crushed a bit and the bolt got minute play (so lack of torque, it lost it torqued down spec). Ample time later... the bolt cracked.
Lack of torque can cause the bolt to flex back&forth, giving metal fatique.

So too much torque and the aluminium housing (the threaded hole) can crack (or the bolt can break/strip), and too little torque can cause the bolt to come loose (come out) or flex and break.

So the correct amount of torque you need is somewhere inbetween
pretty much what i tried to achieve! not that i'll ever know as ess don't give Tq spec ... its tight and ill just keep a check every 6 months... a firm sharp push with a fair amount of my weight behind it seems where I've settled...

interestly i when i spoke to hans ESS have decided to release a bracket to further brace the s/c and bracket from flex.... so it seems their may be something in these filer housings cracking. i respect ESS for continuing to improve the product, as its pretty damn solid as is imo.
__________________
Z4MR VT2 - Clubsport build.
Multi award winning Detailing | Wrap | PPF specialists UK based - www.topwrapz.com
Appreciate 0
      09-07-2015, 03:00 PM   #11
2skiddy
Private First Class
67
Rep
104
Posts

Drives: Z4M Coupe
Join Date: Jan 2014
Location: Notts UK

iTrader: (0)

I made a brace to stop the bracket from flexing. I was surprised it wasn't in the kit, as you can easily push the blower back and forth, no matter how tight the bolts are. Eventually this will cause damage, in my opinion, so I modified, prevention is better than cure!
Appreciate 0
      09-08-2015, 11:34 AM   #12
Beedub
Major General
United Kingdom
423
Rep
5,327
Posts

Drives: 2007 Z4 M roadster vt2-500
Join Date: Sep 2007
Location: UK

iTrader: (0)

Quote:
Originally Posted by 2skiddy View Post
I made a brace to stop the bracket from flexing. I was surprised it wasn't in the kit, as you can easily push the blower back and forth, no matter how tight the bolts are. Eventually this will cause damage, in my opinion, so I modified, prevention is better than cure!
i agree!! the bracket definitely flex's.... it NEEDS an additional brace hence my post on the bolt Tq.

any pics of what you did ?? so the turbo kit got the best of you i take it then??
__________________
Z4MR VT2 - Clubsport build.
Multi award winning Detailing | Wrap | PPF specialists UK based - www.topwrapz.com
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:26 PM.




zpost
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST