[dzenno]

Proof that a 6 puck ClutchMasters ceramic clutch indeed does put all that power to the GROUND

My driver's side halfshaft snapped inside the CV rubber boot right at the spline...460wtq to the ground to 0wtq to the ground in 0 seconds

On the bright side this launch would've been a 1.3sec 60' easy I launched at around 4200rpm didn't drop the clutch but quickly let it out and took off, got a tiny bit of wheel hop a few feet down the track when it SNAPPPPED LOUD!

The left one (driver's side) snapped, right one's CV is binding and doesn't have smoothest movement and is very possibly the reason for my recent vibration issue in case you followed up on that thread (thought it was the lightweight flywheel or the diff)...given that vibration was mostly felt from the rear it may be that this was already on its way out and it just gave out...It was a 60 mile tow back home free of charge courtesy of roadside assistance

Enjoy the pics! Talked to Lee@Driveshaftshop, they'll be bringing these back to life only MUCH stronger Chromoly shafts FTMFW!

[DefactoM6]

Sorry to hear...but that's the spirit! Bigger, Better, Stronger, Faster!

[ultimateendz]

yup...time for former boosteds halfshafts ...im not doing another hard launch until they are on my car...ive broken enough

[dzenno]

Originally Posted by DefactoM6

Sorry to hear...but that's the spirit! Bigger, Better, Stronger, Faster!

I just counted, 7 smileys in the original post...wow! not that happy about it really haha

[dzenno]

Originally Posted by ultimateendz

yup...time for former boosteds halfshafts ...im not doing another hard launch until they are on my car...ive broken enough

Yah, if you really launch this as you "should", especially in a 6MT, they'll break, period...on a 6AT, wheelhop will take'em...really weak...what's funny is if you look closely you'll see how precise the cut is where they broke right at the spline...you don't need to be at the track with DRs for them to break...enough to get some uneven road surface on launch and a mighty grabbing clutch and its kaput..

wonder what's next to break with upgraded halfshafts? wheel bearings? diff?

[ultimateendz]

Originally Posted by dzenno

Yah, if you really launch this as you "should", especially in a 6MT, they'll break, period...on a 6AT, wheelhop will take'em...really weak...what's funny is if you look closely you'll see how precise the cut is where they broke right at the spline...you don't need to be at the track with DRs for them to break...enough to get some uneven road surface on launch and a mighty grabbing clutch and its kaput..

wonder what's next to break with upgraded halfshafts? wheel bearings? diff?

id say the diff but i would think we would need a little bit more power for that to go...but who knows

[dzenno]

Originally Posted by ultimateendz

id say the diff but i would think we would need a little bit more power for that to go...but who knows

we should know pretty soon I guess the way things are going

[ultimateendz]

Originally Posted by dzenno

we should know pretty soon I guess the way things are going

yup...and the way my luck has been going ill be the first to find out...lol

[dzenno]

not much luckier here either, especially in the past 3 months lol...we should get a fund going for those low on karma these days

[ultimateendz]

Originally Posted by dzenno

not much luckier here either, especially in the past 3 months lol...we should get a fund going for those low on karma these days

i hear ya...almost like we got our "mojo" sucked out of us like austin powers...lol...everything just breaks we touch

[Irishace]

Damn, sorry to hear about this bro, glad you are getting the upgrades and I am hopefull this cures your vibration issue once and for all.

Your rear end will be readier than ever for those beautiful RB turbos!

[DefactoM6]

Originally Posted by dzenno

Yah, if you really launch this as you "should", especially in a 6MT, they'll break, period...on a 6AT, wheelhop will take'em...really weak...what's funny is if you look closely you'll see how precise the cut is where they broke right at the spline...you don't need to be at the track with DRs for them to break...enough to get some uneven road surface on launch and a mighty grabbing clutch and its kaput..

wonder what's next to break with upgraded halfshafts? wheel bearings? diff?

If prior BMWs (3 series specifically) are any indicator, it'll be something relating to the rear subframe.

[dzenno]

how do we address/eliminate wheelhop? I've already got the rear wishbone links and rear subframe mounts on their way from tischer from when I thought those might cure vibrations...some people are of the opinion that these along with some tuning of the coilover springs should eliminate it completely?

[lacartus]

Originally Posted by dzenno

how do we address/eliminate wheelhop?

If you are talking to the driveshaft shop, perhaps you could talk to them about changing the torsional windup (or deflection in engineer-speak) in each shaft. One of the causes of wheel hop on independent RWD cars is the windup of each half-shaft (imagine a rollbar or torsion bar under load). Like a pencil wound up in the middle of two rubber bands, the pencil (or rear differential) will transfer that deflection back and forth and make the pencil hop (try it) or the suspension and wheels in the case of the car. I'm sure someone has patented this...yup, here it is:
http://www.freepatentsonline.com/y2009/0159359.html
and here is an application of it...I see the patent holder is a GM engineer, so I suspect this is used on their RWD IRS cars.
http://shop.gforce1320.com/product.sc?productId=31

See if The Driveshaft Shop can alter the torsional rigidity by more that 1.4:1 like in the patent to address the issue. They could do this by using different diameters or materials.

[DefactoM6]

http://www.hpashop.com/product.sc?pr...categoryId=176

This, the bushings, and any other adjustable bits are probably a good place to start. Being able to dial toe in is pretty big in this area.

Oh, and what lacartus said. That too.

[marconi118]

doe the E92 M3 suffer wheelhop? if not then swap for the whole rear M3 subframe + LSD + Shafts...

[dzenno]

Of course it does..not meant for racing from a dig..

[Ilma]

Originally Posted by Irishace

Your rear end will be readier than ever for those beautiful RB turbos!

mmmmmm..... somehow that just doesn't sound right.

[Mr. 5]

Craziness.
I've launched pretty hard myself but haven't broken any yet.
The last time I went to the track I was launching at 4500 RPM and sticking really well.

I really think the wheel hop was the contributor here.

[dzenno]

Originally Posted by Mr. 5

Craziness.
I've launched pretty hard myself but haven't broken any yet.
The last time I went to the track I was launching at 4500 RPM and sticking really well.

I really think the wheel hop was the contributor here.

Probably not with your ACT clutch right? On OEM? OEM would slip a tiny bit on each wheel hop when worn in so it'd cushion the blow...with a grabby clutch wheelhop really becomes an issue...i think..

[only1]

with a z06 vette wheel hop is a big problem. shocks change it dramatically.

[Mr. 5]

Originally Posted by dzenno

Probably not with your ACT clutch right? On OEM? OEM would slip a tiny bit on each wheel hop when worn in so it'd cushion the blow...with a grabby clutch wheelhop really becomes an issue...i think..

No, it was with the ACT but it was with a street performace disc and not the puck style.