BMW M3 Forum (E90 E92)

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


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Track / Autocross / Dragstrip / Driving Techniques
 
Post Reply
 
Thread Tools Search this Thread
      09-28-2019, 12:58 PM   #1
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Converting to track car

Ok - so I have searched and read up quite a bit and can't find a definitive answer on two questions I'm contemplating as I am beginning to turn my e92 into a track toy.

The quick back story - I've been track driving for a number of years and previously had a pretty well built e36 M3 (see below) I have recently sold it because I wanted to upgrade my platform and have paid off my e92, so I figured I'd step up into this as my new platform.

So my two questions are:

- First question: I am planning on a "True" rear coilovers. I know in the e36 chassis this required major reinforcement. Do we need any reinforcement to run true rear coilover on our cars or can we run them on OEM mounts without additional bracing?

- Second question: What are the general thoughts on the safety of a bolt in "roll bar" VS just a bolt in Harness Bar (Such as the BK version) - I plan to do a weld in, custom cage down the road but want to get the other areas sorted out first (ie: wheels, tires, coilovers, brakes, Cooling, etc....) but also want to ensure I am safe while on track. I just helped a buddy install a Mumbray Motorsports GTS cage and it was REALLY great quality and mounted to, what I thought, are good factory mounting points. So the question, would this cage provide any sort of extra safety in the event of a wreck or since bolt in it's probably more dangerous and I should just got with BK Harness Bar until I spring for the real deal welded in cage? Pics of the Mumbray cage below (Again, can't say enough good about this thing - amazing quality)

My E36 I sold Mumbray Cage - note the mounting points and my e92 that I'll be building


Thanks in advance guys - looking forward to getting back out on track with some more powah!
Attached Images
        
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      09-29-2019, 09:06 AM   #2
dogbone
Colonel
dogbone's Avatar
5303
Rep
2,799
Posts

Drives: '09 E90 M3 - IB
Join Date: Feb 2012
Location: 93 million miles from the Sun

iTrader: (1)

Garage List
2009 BMW E92 M3  [0.00]
2009 BMW E90 M3  [0.00]
Question #1: After many years of asking people about this topic, there are no 100% clear answers. You'll get different answers depending on which race shops and suspensions brands you ask. The best I can tell you for the E9x M3 platform is: in the short term, you don't need to reinforce. But in the long term, when you go through the effort of building a full cage into the car, I would reinforce.

Question #2: Having a properly installed roll bar is better than having a harness bar. If you have a harness, you should have a neck restraint. If you have a neck restraint, you should have some extra roof-crushing protection since you can't really move your head out of the way. Since you plan on building the car more fully later, I am assuming you are not worried about "ruining" the interior of the car. Why not look at the option of welding a roll bar into the car? If your main worry is about a bolt in roll bar coming loose during a rollover, perhaps you could start with a pre-made bolt-in rollbar and find a builder that will weld it in too. Then, when the time comes to build the cage, the welded roll bar can still be removed.
Appreciate 1
MinionM3492.00
      09-30-2019, 12:05 PM   #3
SYT_Shadow
///M Powered for Life
SYT_Shadow's Avatar
11421
Rep
10,296
Posts

Drives: E90M/E92M/M4GTS/M4GT4/X5M
Join Date: Sep 2010
Location: Greenwich, CT

iTrader: (2)

Schroth (or however you write their name) published a white paper where it was very clear the harness bar and 6 points were better than not having it, but a properly built half cage will be better soon.

That said, as I don't plan to weld anything into either of my track cars I am using the BK bar. It's excellent.
Appreciate 0
      09-30-2019, 05:24 PM   #4
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Converting to track car

Quote:
Originally Posted by SYT_Shadow View Post
Schroth (or however you write their name) published a white paper where it was very clear the harness bar and 6 points were better than not having it, but a properly built half cage will be better soon.

That said, as I don't plan to weld anything into either of my track cars I am using the BK bar. It's excellent.
So that's my dilemma - I could go for a nice bolt in "half cage" while I build out the rest of the car and then remove when its time for the full cage build - or just do a Harness Bar until the full cage build. I'd guess the car will probably see 10-12 events before it goes down for a weld-in cage. I'm far less worried about the money side, I just don't know if I believe a bolt in cage is actually safe and sturdy...

So - does that white paper say bolt in = safe or is a bolt in basically as good as a Harness Bar? My concerns of course are the fact that it's just bolted in, and what if the bolts shear at one of the mounting points, then you've got a boat load of metal possibly moving around and causing more harm than good - or maybe in just overthinking it and a bolt in is fine and better than nothing at all?

__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      09-30-2019, 05:26 PM   #5
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Had a nice little shopping spree this weekend
Attached Images
 
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 1
///Mobbin1474.50
      09-30-2019, 05:45 PM   #6
SYT_Shadow
///M Powered for Life
SYT_Shadow's Avatar
11421
Rep
10,296
Posts

Drives: E90M/E92M/M4GTS/M4GT4/X5M
Join Date: Sep 2010
Location: Greenwich, CT

iTrader: (2)

Quote:
Originally Posted by MM135 View Post
So that's my dilemma - I could go for a nice bolt in "half cage" while I build out the rest of the car and then remove when its time for the full cage build - or just do a Harness Bar until the full cage build. I'd guess the car will probably see 10-12 events before it goes down for a weld-in cage. I'm far less worried about the money side, I just don't know if I believe a bolt in cage is actually safe and sturdy...

So - does that white paper say bolt in = safe or is a bolt in basically as good as a Harness Bar? My concerns of course are the fact that it's just bolted in, and what if the bolts shear at one of the mounting points, then you've got a boat load of metal possibly moving around and causing more harm than good - or maybe in just overthinking it and a bolt in is fine and better than nothing at all?

In my sig there's a link to the BK install, i believe i linked to the white paper there

The paper discusses stock belts vs harness bar specifically relating to the 'in a rollover you can't move out of the way of the roof and the roof with be crushed if you use a harness bar' topic which is so popular

I would definitely run the bk bar until you have a full cage.
Appreciate 0
      09-30-2019, 06:28 PM   #7
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Quote:
Originally Posted by SYT_Shadow View Post
Quote:
Originally Posted by MM135 View Post
So that's my dilemma - I could go for a nice bolt in "half cage" while I build out the rest of the car and then remove when its time for the full cage build - or just do a Harness Bar until the full cage build. I'd guess the car will probably see 10-12 events before it goes down for a weld-in cage. I'm far less worried about the money side, I just don't know if I believe a bolt in cage is actually safe and sturdy...

So - does that white paper say bolt in = safe or is a bolt in basically as good as a Harness Bar? My concerns of course are the fact that it's just bolted in, and what if the bolts shear at one of the mounting points, then you've got a boat load of metal possibly moving around and causing more harm than good - or maybe in just overthinking it and a bolt in is fine and better than nothing at all?

In my sig there's a link to the BK install, i believe i linked to the white paper there

The paper discusses stock belts vs harness bar specifically relating to the 'in a rollover you can't move out of the way of the roof and the roof with be crushed if you use a harness bar' topic which is so popular

I would definitely run the bk bar until you have a full cage.
But would you run the BK bar over the below half cage?
Attached Images
    
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      09-30-2019, 06:46 PM   #8
dparm
Stop the hate, get a V8
dparm's Avatar
United_States
3848
Rep
8,625
Posts

Drives: C7 Corvette GS, AMG C63 S
Join Date: Jun 2013
Location: Frisco, TX

iTrader: (1)

If you're going to do a half-cage, why not just do a full-cage? I'm asking out of my own ignorance, but it seems like if you go through the trouble for the half...
__________________
Now: 2017 Corvette Grand Sport, 2021 AMG C63 S sedan
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      09-30-2019, 06:49 PM   #9
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Quote:
Originally Posted by dparm View Post
If you're going to do a half-cage, why not just do a full-cage? I'm asking out of my own ignorance, but it seems like if you go through the trouble for the half...
Up-front cost I suppose and impatience to get the car to a point I'd feel comfortable taking it out.

I'd estimate a nicely done rear cage customs built and welded in will ballpark $4-5k where as that bolt in cage can be had for $2k so it gets the car to the track faster 🤷🏻*♂️

But I do see your point as I type that out - why do it twice if the plan is to do welded in anyway and I don't want to track without harnesses and proper seats.
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      09-30-2019, 06:51 PM   #10
dparm
Stop the hate, get a V8
dparm's Avatar
United_States
3848
Rep
8,625
Posts

Drives: C7 Corvette GS, AMG C63 S
Join Date: Jun 2013
Location: Frisco, TX

iTrader: (1)

I get it, but last I checked no one here has unlimited money so compromises have to be made. If you can later convert the half to a full, that seems like the smart choice.

Are you planning to compete? Or is this purely for HPDE?
__________________
Now: 2017 Corvette Grand Sport, 2021 AMG C63 S sedan
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      09-30-2019, 06:54 PM   #11
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Quote:
Originally Posted by dparm View Post
I get it, but last I checked no one here has unlimited money so compromises have to be made. If you can later convert the half to a full, that seems like the smart choice.

Are you planning to compete? Or is this purely for HPDE?
Purely HPDE - it won't be a NASA or SCCA car - at least that's not the initial intent. I "compete" in Bimmer Challenge, but that's just timed laps during HPDE sessions 😂😜

The only concern I have is safety with a bolt in - I have always felt bolt in cages are a fashion statement and nothing more - but is the general consensus that they actually provide the driver with any added safety?
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      10-01-2019, 11:48 PM   #12
tsk94
Lieutenant Colonel
tsk94's Avatar
Canada
1516
Rep
1,588
Posts

Drives: E92 M3, E82 128i, F82 M4, E36
Join Date: May 2017
Location: Calgary

iTrader: (2)

I would recommend reinforcing while running the rear coilover. I did on my race car, but it was also while doing a full custom cage..

How stiff of a rear spring are you running? I'm running a fairly stiff spring (in a rear coilover) so I wanted the reinforcement for piece of mind. These chassis are not as prone to failure as the E36 or E46. Almost all professionally built E92 race cars I've seen have had it done, including the factory built GT4 - which ran rear coilovers.
Appreciate 0
      10-03-2019, 09:39 AM   #13
Montaver
Lieutenant Colonel
Montaver's Avatar
No_Country
2068
Rep
1,630
Posts

Drives: 718 GT4 & M340i LCI
Join Date: Jul 2017
Location: NY

iTrader: (0)

Seems like a lot of effort just for HPDE... why not build it to the specs of a proper race/TT class so you can move into that? If your able to build a completely not street-able car it would seem the logical move. Plus easier if you ever went to sell it.
Appreciate 1
dparm3848.00
      10-03-2019, 10:28 AM   #14
OG Shark
BimmerPost Supporting Vendor
OG Shark's Avatar
4658
Rep
2,518
Posts


Drives: Angry
Join Date: Oct 2014
Location: Spring Branch, TX

iTrader: (5)

Quote:
Originally Posted by MM135 View Post
Purely HPDE - it won't be a NASA or SCCA car - at least that's not the initial intent. I "compete" in Bimmer Challenge, but that's just timed laps during HPDE sessions 😂😜

The only concern I have is safety with a bolt in - I have always felt bolt in cages are a fashion statement and nothing more - but is the general consensus that they actually provide the driver with any added safety?
On my E92 build the first thing I did was go with a 1/2 cage/harness bar. I one I used is an excellent product & really liked the design and how it bolted in.

Right now the car is in the process of having a full cage installed to be up to spec for wheel to wheel. I will say that watching this has changed my mind a bit on half cages. When you see the front of the cage being constructed - the roof, side pillars, etc - it is kind of eye opening on how exposed that whole area is with just a half cage. We run fixed back seats, harnesses, all that good stuff that is all also used as part of a system with a full cage. You start to really see the potential faults of a half cage with the one main hoop - will that hold in a rollover? Will that keep the front roof area from collapsing? With a fixed back seat does that possibly expose you even more? Maybe, maybe not - but definitely gave me a feeling that I was more vulnerable than I believed at the time.

This has changed my viewpoint on half cages a bit - to the point where I would bypass them in favor of a full cage. I could be completely wrong - but I feel like the half cage can potentially still leave you pretty exposed - and in some cases maybe even worse that not having one at all. There is no data either way - so this is obviously just my opinion.

And when people say why all that for just an HPDE car - I say why not? It is your safety that you are talking about here - not theirs. If you have the means & want to minimize the risk to that extent then 100% go for it. Shit still happens in HPDE, do what you need to do to get to your comfort level. Also - you might be surprised how quick the jump to the more competitive formats can happen
Appreciate 1
dparm3848.00
      10-03-2019, 10:54 AM   #15
Ximian
.
Ximian's Avatar
United_States
1885
Rep
1,854
Posts

Drives: E92 M3
Join Date: Oct 2016
Location: MN

iTrader: (1)

Garage List
2011 BMW M3  [0.00]
2021 BMW M3  [0.00]
Quote:
Originally Posted by OG Shark View Post

And when people say why all that for just an HPDE car - I say why not? It is your safety that you are talking about here - not theirs. If you have the means & want to minimize the risk to that extent then 100% go for it. Shit still happens in HPDE, do what you need to do to get to your comfort level. Also - you might be surprised how quick the jump to the more competitive formats can happen
It totally makes sense to go to a full cage. However, at that point for most people, it becomes a track-only car as you definitely shouldn't drive around in a car with a full cage without a helmet.

A half cage is a fair compromise.
Appreciate 1
OG Shark4657.50
      10-03-2019, 11:49 AM   #16
OG Shark
BimmerPost Supporting Vendor
OG Shark's Avatar
4658
Rep
2,518
Posts


Drives: Angry
Join Date: Oct 2014
Location: Spring Branch, TX

iTrader: (5)

Quote:
Originally Posted by Ximian View Post
It totally makes sense to go to a full cage. However, at that point for most people, it becomes a track-only car as you definitely shouldn't drive around in a car with a full cage without a helmet.

A half cage is a fair compromise.
Yeah absolutely agree it would become a track only car at that point - I probably misinterpreted it but thought that was the direction the OP was going with his car.

And I'm definitely not knocking half cages or anyone that runs them if it came across that way. I personally am not comfortable with them on the street - but I know many people are. I certainly am not in a position to say which is right and which is wrong for anyone else - only just what I feel is right for me.
Appreciate 0
      10-03-2019, 12:08 PM   #17
SYT_Shadow
///M Powered for Life
SYT_Shadow's Avatar
11421
Rep
10,296
Posts

Drives: E90M/E92M/M4GTS/M4GT4/X5M
Join Date: Sep 2010
Location: Greenwich, CT

iTrader: (2)

Quote:
Originally Posted by tsk94 View Post
I would recommend reinforcing while running the rear coilover. I did on my race car, but it was also while doing a full custom cage..
I was pleasantly surprised that the F8X M3 uses a eye to eye rear shock perch with a massive area to distribute the force.

So now in the CS I'm running a true coilover

In the E9X the car is no longer made out of paper mache like the E46 and previous generations, but I would still want a reinforced rear area to run a true coilover
Appreciate 1
tsk941516.00
      10-03-2019, 12:10 PM   #18
SYT_Shadow
///M Powered for Life
SYT_Shadow's Avatar
11421
Rep
10,296
Posts

Drives: E90M/E92M/M4GTS/M4GT4/X5M
Join Date: Sep 2010
Location: Greenwich, CT

iTrader: (2)

Quote:
Originally Posted by MM135 View Post
But would you run the BK bar over the below half cage?
Yup, in fact I do on two cars. At least one of those could easily have a half cage but I still go with the BK one.

You seem to want a cage so get one, but until you do maybe it makes more sense to run the BK bar which you can easily sell.
Appreciate 0
      10-03-2019, 04:10 PM   #19
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Quote:
Originally Posted by OG Shark View Post
Quote:
Originally Posted by Ximian View Post
It totally makes sense to go to a full cage. However, at that point for most people, it becomes a track-only car as you definitely shouldn't drive around in a car with a full cage without a helmet.

A half cage is a fair compromise.
Yeah absolutely agree it would become a track only car at that point - I probably misinterpreted it but thought that was the direction the OP was going with his car.

And I'm definitely not knocking half cages or anyone that runs them if it came across that way. I personally am not comfortable with them on the street - but I know many people are. I certainly am not in a position to say which is right and which is wrong for anyone else - only just what I feel is right for me.
The idea is for the car to become a weekend/track car and not a daily - I don't know how people take on the risk of tracking their daily drivers...

My previous track car had full cage - door bars - etc.... and frankly not having the front windows and deleting the AC/radio/etc... made the drives to and from the track absolutely miserable - especially when you'd encounter rain or any remotely hot weather days.

So for this build I want it to be capable/safe but also not such a PITA driving it to and from the tracks. Don't have the luxury of being able to tow at the moment so I want this one to be somewhat comfortable driving to and from events.
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      10-03-2019, 04:12 PM   #20
MinionM3
Lieutenant
MinionM3's Avatar
United_States
492
Rep
577
Posts

Drives: 2012 E92 M3 // 2020 M2CS
Join Date: Apr 2012
Location: Torrance, CA

iTrader: (4)

Quote:
Originally Posted by SYT_Shadow View Post
Quote:
Originally Posted by MM135 View Post
But would you run the BK bar over the below half cage?
Yup, in fact I do on two cars. At least one of those could easily have a half cage but I still go with the BK one.

You seem to want a cage so get one, but until you do maybe it makes more sense to run the BK bar which you can easily sell.
Dead on accurate - the more I think about it I am pretty set on a welded in cage or "rollbar" to be more accurate - actually talking with a local race shop now about pricing and appointment availability
__________________
Instagram: @MinionM3

Current Garage:
2012 M3 ZCP, Mineral White, DCT: Track Build
2020 M2CS, Misano Blue, 6MT
Appreciate 0
      10-04-2019, 09:20 AM   #21
OG Shark
BimmerPost Supporting Vendor
OG Shark's Avatar
4658
Rep
2,518
Posts


Drives: Angry
Join Date: Oct 2014
Location: Spring Branch, TX

iTrader: (5)

Quote:
Originally Posted by MM135 View Post
The idea is for the car to become a weekend/track car and not a daily - I don't know how people take on the risk of tracking their daily drivers...

My previous track car had full cage - door bars - etc.... and frankly not having the front windows and deleting the AC/radio/etc... made the drives to and from the track absolutely miserable - especially when you'd encounter rain or any remotely hot weather days.

So for this build I want it to be capable/safe but also not such a PITA driving it to and from the tracks. Don't have the luxury of being able to tow at the moment so I want this one to be somewhat comfortable driving to and from events.
Yeah read into it that you were using this car only on the track - please disregard my comment
Appreciate 0
      10-04-2019, 09:39 AM   #22
SYT_Shadow
///M Powered for Life
SYT_Shadow's Avatar
11421
Rep
10,296
Posts

Drives: E90M/E92M/M4GTS/M4GT4/X5M
Join Date: Sep 2010
Location: Greenwich, CT

iTrader: (2)

Quote:
Originally Posted by MM135 View Post
So for this build I want it to be capable/safe but also not such a PITA driving it to and from the tracks. Don't have the luxury of being able to tow at the moment so I want this one to be somewhat comfortable driving to and from events.
Wait - you're thinking of adding a full cage to a car that is still driven on the street?
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 03:17 AM.




m3post
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