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PoBoyR6

E46 M3 Subframe Reinforcement

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ken o
Per the TT Rules - bolding added.

 

 

1) Every vehicle must retain its OEM frame rails (or unibody), strut towers, floorpan, and subframe. Tube-frame chassis conversion (partial or complete) is not permitted without a waiver from the National TT Director. Floorpan modifications to include items such as subframe connectors, roll cage bracing, and fuel cell placement may be approved on a case-by-case basis by the National TT Director. Such modifications

will be subject to approval and possible modification factor assessments.

 

Thanks, but how does adding non-connecting plates to prevent tearing add a performance advantage? I am new to this so I am trying to understand.

Does it make the car handle better? No.

Does it make more power? No.

I think this makes the car safer as in the case of the Lotus. The Lotus had an identified weak point and is allowed to strengthen it for safety.

 

I understand each car has it warts. But replacing the floor pan every year (not sure if you could do it that many times) at a cost of $6K does not make sense at our level when a kit exist to repair and/or prevent future failure without add an performance advantage.

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dew-e

It is not guaranteed that it is going to fail and rip. BMW sold thousands and thousands of E46s. In my local circle of BMW friends/club, I know of two E46 M3s that have had this problem. And both of them had pretty stiff suspensions on them and were beat on pretty hard on the street by young drivers. I don't think the rules should take into consideration what it costs if your car has a problem. If the potential problem and fix is out of your budget, run a cheaper car. BMW didn't pay to fix either one of those cars because their cars were not stock. Check out the exclusions for the settlement, which I think pretty clearly makes that settlement a mute point for any racing group.

 

If you run a really stiff suspension, stiff bushings, and super grippy tires, the chassis on these cars could potentially have problems. All BMWs have this problem. You can find plenty of examples of BMWs of multiple generations ripping subframe mounts, ripping out sway bar mounts, or cracking subframes. Seems like it would be hard to only allow this for E46 cars when E36, etc.. also have similar issues and there are similar kits available for those cars that by your definition "don't have a performance increase." Look at the Spec3 rules, their rules recommend installing front/rear chassis reinforcements. I know those cars take the points for the subframe reinforcement parts.

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ken o

Like the allowance made for the Lotus based on safety this should be considered along the same line. I had a Lotus Elise and never had the tie rod problem. Tracked and never had the problem. Have several friends who still track them and have not made this upgrade. But it is safer to upgrade. Just like it is safer to add the plates to the M3.

 

I also know of several M3s that had suspension mods and BMW did fix them at no cost to the owner. I think it was purely a dealer decision and if they thought they could get it approved they did it.

 

It is not so much a cost but how many times can you weld in a new subframe?

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ken o

I am trying to understand how this would be worth +3. If Hoosier R6 are +10 and Hoosier A6 are +13 that is a +3 difference. Do I gain the equivalent of R6 to A6 by adding a couple of plates? I don't think it does. So, how would I make this a true +3 mod?

Thanks

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TurboShortBus

General statement: Somewhere out there, a car benefits so much from the modifications in F4 that it is worth the +3. This may or may not be true for your specific car. Not worth the points for your car? Then don't install them.

 

Per an E46: This is apparently being researched, and it could wind up in your favor, so don't go pissing on anybody just yet.

 

Note that the argument of "Oh, it's a modification for safety" has been shot down more than once if a performance gain results.

 

Mark

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ken o
General statement: Somewhere out there, a car benefits so much from the modifications in F4 that it is worth the +3. This may or may not be true for your specific car. Not worth the points for your car? Then don't install them.

 

Per an E46: This is apparently being researched, and it could wind up in your favor, so don't go pissing on anybody just yet.

 

Note that the argument of "Oh, it's a modification for safety" has been shot down more than once if a performance gain results.

 

Mark

 

 

Thanks. Just asking and trying to understand.

Edited by Guest

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TurboShortBus

Don't worry, you'll get your chance...lol

 

Mark

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dew-e

And the only opinion that really matters at the end is the official ruling. Everything else is bored, not at the track, banter.

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abad46

Reading through this thread and actually having an e46 m3 in ttb, I haven't seen anyone give a reason why this adds any performance gain? I planned on having this done for preventative maintenance, but I am glad I haven't yet...

 

I can see if the "fix" required solid subframe bushings or something like that, but it's just plates in the factory locations?

 

All we can do is hope for a fair review!

 

FWIW, I had an 02 m3 before the one i have now and before I even did a hpde we noticed cracks in the subframe mounts, bmw did fix it with a replacement piece as pictured before, but the bill (bmwna paid for it) was over $3k! The turner kit installed at my local shop is $1,100. The 2 grand I'd be saving could go toward nasa events.... just sayin'

 

Food for thought, in lieu of the turner kit, all roll cages for the e46 tie in to the subframe mounts, essentially strengthening it... If the turner kit is 3 points, can't we just do a rear "cage/rollbar" for 0?

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Varkwso

Frame and floorpan mods are not limited to this car. Improving the floorpan, for safety, in a C5 or C6 Vette is a .4 mod factor.

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bobzdar

A non-oem solution could allow you to run a stiffer, more agressive suspension setup and tires than the oem solution without damage, providing a performance benefit over the oem solution. In that case, someone with the oem solution would potentially have to do a points modification to get their car to the same stiffness level that would allow the suspension/tire mods. It doesn't appear that cost plays into any decisions of this type. If it did, modifications for my car would be 1/10 the point value in the rules because the parts cost 10x as much. But, that's the price you pay for having a BMW (or Ferrari in my case).

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abad46
A non-oem solution could allow you to run a stiffer, more agressive suspension setup and tires than the oem solution without damage, providing a performance benefit over the oem solution. In that case, someone with the oem solution would potentially have to do a points modification to get their car to the same stiffness level that would allow the suspension/tire mods. It doesn't appear that cost plays into any decisions of this type. If it did, modifications for my car would be 1/10 the point value in the rules because the parts cost 10x as much. But, that's the price you pay for having a BMW (or Ferrari in my case).

 

I see your point, if this was in fact relevant to running a stiffer suspension system. There is no rhyme or reason for the sub frame failures as it is for ALL E46 chassis'. Half of the failures were never raced a day in their lives.

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kbrew8991

And if you give them a TSB similar to the Lotus stuff you can elimiate alot of the potential for performance gain and leave it just enough to increase the reliability of the tub. Writing the rules such that you're forced to risk rendering the tub as scrap isn't good buisness. But there could be something I'm missing here...

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bobzdar
A non-oem solution could allow you to run a stiffer, more agressive suspension setup and tires than the oem solution without damage, providing a performance benefit over the oem solution. In that case, someone with the oem solution would potentially have to do a points modification to get their car to the same stiffness level that would allow the suspension/tire mods. It doesn't appear that cost plays into any decisions of this type. If it did, modifications for my car would be 1/10 the point value in the rules because the parts cost 10x as much. But, that's the price you pay for having a BMW (or Ferrari in my case).

 

I see your point, if this was in fact relevant to running a stiffer suspension system. There is no rhyme or reason for the sub frame failures as it is for ALL E46 chassis'. Half of the failures were never raced a day in their lives.

 

Oh, I understand that. I was just providing an example of how allowing a blanket 'repair' of the problem vs. using only allowing the OEM solution could provide a performance increase. I don't think cost should factor into it if it's not identical to OEM. I have a reliability issue with my car where the factory headers crack after around 30k miles. OEM replacements with minor updates to address the issue (but not elliminate it) are $4k. Per side. Aftermarket 304 stainless headers that will last the life of the car are less than half the price and provide no performance increase (in fact, some reduce mid range performance as they are a 4-1 instead of the factory 4-2-1). I'd still have to take the points for an aftermarket header. If the factory headers go and aren't caught right away, the exhaust valves will burn up and melt down the engine causing a bit of a safety issue, not to mention a $20k plus repair bill. That's one of the (many) warts of my car.

 

This sounds a lot like the s2000 guys that didn't want to shell out the cash for the oem hard top because the aftermarket one was half the price (but didn't exactly follow the contour). I think the solution was if it's identical to OEM, ok, if not then you have to take points. I don't see why this would be different? Just to be clear, I personally wouldn't begrudge you the non-oem solutions. But, at the same time, I fully understand the reason for not allowing a non-oem repair because somebody could find a way to take advantage of it. Good luck.

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dew-e
A non-oem solution could allow you to run a stiffer, more agressive suspension setup and tires than the oem solution without damage, providing a performance benefit over the oem solution. In that case, someone with the oem solution would potentially have to do a points modification to get their car to the same stiffness level that would allow the suspension/tire mods. It doesn't appear that cost plays into any decisions of this type. If it did, modifications for my car would be 1/10 the point value in the rules because the parts cost 10x as much. But, that's the price you pay for having a BMW (or Ferrari in my case).

 

I see your point, if this was in fact relevant to running a stiffer suspension system. There is no rhyme or reason for the sub frame failures as it is for ALL E46 chassis'. Half of the failures were never raced a day in their lives.

 

Given that the settlement presented specifically excludes cars that have been modified for any reason, I think the stiffer suspension argument applies. The settlement is pretty much saying that if you alter the suspension in any way this could happen, and that BMW is not liable for that, and the settlement group agreed to that term. There is no federal TSB for this as far as I'm aware. I'll go back to my original statement that almost every BMW that is tracked heavily has subframe re-inforcement plates similar to the ones that Turner sells because they all have issues with cracking subframes, motor mount points, and sway bar mounts with stiff suspensions. If the plates resolve a known weak point in the car and now allow you to run 1300# springs, as opposed to a competitor that can only run 500# springs, I would say you've gained an advantage. You would both be taking spring points, but the max stiffness of the spring you can run is really dependent on what the car can handle. Maybe having a super stiff spring isn't the best setup for you and your car, but there are some drivers that can make a really stiff car perform wonderfully where it would be frightening for others.

 

I think another important point that I hope Greg is looking into further, is, has there ever been a catastrophic crash/failure from this happening? My thought is no, I've never heard of an accident happening because of this. It usually starts to tear and a really bad clunking noise develops and maybe you see some wear tire wear from your alignment shifting. It isn't like you are going to be coming down the front straight at 140 and bam there goes your rear subframe and everything else like somebody had it hooked up to a chain, hollywood style... It isn't like the lotus problem where a link breaking renders the steering wheel completely useless and you are just along for the ride until you can get the car to stop. If your car is developing this problem, proper maintenance and inspection should prevent any accident from occurring as a result.

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PoBoyR6
A non-oem solution could allow you to run a stiffer, more agressive suspension setup and tires than the oem solution without damage, providing a performance benefit over the oem solution. In that case, someone with the oem solution would potentially have to do a points modification to get their car to the same stiffness level that would allow the suspension/tire mods. It doesn't appear that cost plays into any decisions of this type. If it did, modifications for my car would be 1/10 the point value in the rules because the parts cost 10x as much. But, that's the price you pay for having a BMW (or Ferrari in my case).

 

I see your point, if this was in fact relevant to running a stiffer suspension system. There is no rhyme or reason for the sub frame failures as it is for ALL E46 chassis'. Half of the failures were never raced a day in their lives.

 

Given that the settlement presented specifically excludes cars that have been modified for any reason, I think the stiffer suspension argument applies. The settlement is pretty much saying that if you alter the suspension in any way this could happen, and that BMW is not liable for that, and the settlement group agreed to that term. There is no federal TSB for this as far as I'm aware. I'll go back to my original statement that almost every BMW that is tracked heavily has subframe re-inforcement plates similar to the ones that Turner sells because they all have issues with cracking subframes, motor mount points, and sway bar mounts with stiff suspensions. If the plates resolve a known weak point in the car and now allow you to run 1300# springs, as opposed to a competitor that can only run 500# springs, I would say you've gained an advantage. You would both be taking spring points, but the max stiffness of the spring you can run is really dependent on what the car can handle. Maybe having a super stiff spring isn't the best setup for you and your car, but there are some drivers that can make a really stiff car perform wonderfully where it would be frightening for others.

 

I think another important point that I hope Greg is looking into further, is, has there ever been a catastrophic crash/failure from this happening? My thought is no, I've never heard of an accident happening because of this. It usually starts to tear and a really bad clunking noise develops and maybe you see some wear tire wear from your alignment shifting. It isn't like you are going to be coming down the front straight at 140 and bam there goes your rear subframe and everything else like somebody had it hooked up to a chain, hollywood style... It isn't like the lotus problem where a link breaking renders the steering wheel completely useless and you are just along for the ride until you can get the car to stop. If your car is developing this problem, proper maintenance and inspection should prevent any accident from occurring as a result.

 

Dew-e, you seem to be arguing against this being a free mod (not sure what your stake in this is) but the points you raise don't seem to be helping your argument. You state that this is a known issue, and is worse on cars with modified springs/suspension and sticky tires...which is basically anyone who tracks their car. That is exactly why I'm raising the issue! Regardless, the problem occured on cars that were never modified and never saw the track. The concern about spring rates is puzzling to me. If there was a massive performance gain to be had from running 1300# springs, the rules would have been written that way. But they aren't. Every chassis has its limits with how stiff you can set it up, it just so happens that on E46s they were severly limited when they rolled off the assembly line.

 

To keep things simple. I want my car to last and don't want to spend thousands of dollars to make it last when there is a known issue surrounding the subframe and a cheap and relatively easy solution to make it last exists. There is no performance advantage with this modification. There is no unintended performance advantage. There is also the safety issue which I have raised. If the subframe lets go the car will not spontaneously combust but if you're driving on the limit in a corner it could be enough to take you off the track into a wall...even if there is no documented incidents its about being proactive, not reactive.

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dew-e

I'm just a Guy that likes the track and BMW's. No real stake in this unless something was also allowed for e36 cars. I'm just having a discussion around the points raised and how people interpret the rules. I really don't think the people making the rules are coming here to get there information, and I have no official say in the matter.

 

I would expect that there is a certain criteria used for this kind of decision and I'm not privy to how a performance impact is assessed. So what I'm saying or thinking doesn't really matter. Same as for most everybody responding unless you have some great new piece of the puzzle, which I don't.

 

Nothing personal. I'm sure we could share the track or a beer and have a good time.

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PoBoyR6
I'm just a Guy that likes the track and BMW's. No real stake in this unless something was also allowed for e36 cars. I'm just having a discussion around the points raised and how people interpret the rules. I really don't think the people making the rules are coming here to get there information, and I have no official say in the matter.

 

I would expect that there is a certain criteria used for this kind of decision and I'm not privy to how a performance impact is assessed. So what I'm saying or thinking doesn't really matter. Same as for most everybody responding unless you have some great new piece of the puzzle, which I don't.

 

Nothing personal. I'm sure we could share the track or a beer and have a good time.

 

No probs and thanks for the clarification.

 

I just wanted to make sure that my overall viewpoint was put on the table, which is basically that we should all be trying to keep grassroots motorsports as cheap and as safe as possible. I mentioned the similar problem with E36s in my original post because of this and you have also mentioned it goes back to E30s also. Of course I'm not campaigning for those cars because I don't own one but I would have no problem with someone requesting the same concession for those cars because in the end this is just a hobby, all we want to do is rip around on the weekend and bring the car (and driver) back in one piece. Then we go back to our day jobs wishing we could do it for a living. Just because people drive a certain brand of car they should not be penalized with excessive maintenance costs if there isn't a need for it. If the Ferrari guy can make a case for using the cheaper aftermarket headers that last forever but don't provide a performance advantage and it makes it into the rules, I say good for him. Just because you drive a Ferrari doesn't mean you should have to pay 10x more than everyone else if there isn't a need for it. Although having said there are plenty of Spec Miata teams with big wallets.

 

This hobby is already expensive enough...just ask my wife...but she doesn't complian too much because she made me stop bike racing once the kids arrived and getting into cars was the compromise. A rather expensive one but now there is a much better chance of me being around to play with the grandkids!

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PoBoyR6

For anyone subscribed to this thread Greg has just posted a subframe reinforcement TB at the top of the TT board which allows the Turner kit (or similar) to be installed on all E46s with no modification penalty.

 

Thanks Greg.

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BlkGt3
For anyone subscribed to this thread Greg has just posted a subframe reinforcement TB at the top of the TT board which allows the Turner kit (or similar) to be installed on all E46s with no modification penalty.

 

Thanks Greg.

 

+1

 

Peter

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