funnyclub

iTrader: (4)

Hey Guys I seen this thread on the MLR from a UK Evo6 owner he was running tein flex coilovers.
Abit worrying then again it could be just one faulty unit.

If you've got Tein Flex Struts (or ones with a similar bottom bracket) check them very carefully, this happened to one of mine on Sunday













The cracks appear to have been growing for a while, until the bracket failed at the rearmost weld, which then caused the mount to bend round shearing the bracket at the front weld (also with signs of pre existing cracks).

The struts were less than 2 years old and fitted in the UK and I've had no side impacts or 'kerbing'

Luckily it happened at comparatively low speed and I didn't total the car or die, which was nice.

The other side mount looks like it may have some cracks on close examination.

You'll have to look carefully and probably clean the paint off the weld to see the cracks.

Actual thread: http://www.lancerregister.com/showth...5&pagenumber=1

Noob4life

that seems like an incredibly thin wall to use on a lower mount for a strut.

funnyclub

iTrader: (4)

Very thin indeed.
Must be why they chnaged the design on the Tein mono

JOOTZ

wow,that dont look so appealing for Tein products

ZzyzxM

iTrader: (1)

I've never liked the Tein Flex design - the flanges are very thin and don't have much support. Though this total failure is indeed spectacular, I can only venture to guess that the lower flanges are flexing (no pun intended...) all the time under braking, which clearly isn't ideal for your front end suspension geometry.

I prefer this design, though I may be biased:

kekek

iTrader: (22)

Wow.

That is one big reason I tend to do at least a quick visual inspection every time I change wheels (like almost every weekend).

Glad to hear you weren't hurt.

Mad_SB

iTrader: (8)

Dammmmmm,

Glad you are alright man. I'd be calling tein about that, or actually sending them the pics.......

EVO8LTW

iTrader: (41)

That is scary. Reminds you of where not to be too cheap on your car, particularly if you are tracking it. I know that that chase cam video on nasioc.com of a wheel coming off an STi in the middle of an autocross run when a weld failed on the JIC coilovers really made an impression on me (don't have the link, sorry). And then there were the bent mounting flanges on the KWs on another STi (I saved that picture -- attached). Better to pinch pennies on power parts than on parts that support the weight of the car!

ZzyzxM

iTrader: (1)

That was an Impreza 2.5 RS, running in DSP. The strut broke on Day #1, and we took the coilovers off the rear of my XP RS and quickly slapped them on the car overnight. Worked like a charm on day two but unfortunately the driver in question never got a run for Day #1, so he didn't end up good in the standings, though his 2nd day times were pretty impressive.

The pic you attached I'm pretty certain is from a customer of mine. He decided to switch to my coilovers after his KWs got all bent out of shape, so to speak.

DaWorstPlaya

iTrader: (31)

+1 agreed ... that's some scary stuff ... suspension is definately not an area where one should be skimping.

EVO8LTW:I remember that video of the JIC FLTA-2 breaking off on the Subie during the middle of an auto-x. It has forever tranished my opinion on JICs and basically any of the cheaper brands. That is why I always try to steer people away from the cheaper brand products.

ZzyzxM: Beautiful and solid construction on those Zzyzx Motorsport Coilovers

kekek

iTrader: (22)

Deformation (KW's) is still better than total failure. Those flanges look pretty beefy in comparison to the Tein's at the top.

DaWorstPlaya

iTrader: (31)

That is correct. All higher end shocks, from what I know, are designed to bend and deform during heavy impact inorder to protect other suspension parts from breaking. DMS are also known to do that, it is supposed to deform vs break/shatter.

chmodlf

iTrader: (19)

This is not a unique situation. I was autoxing last year and an STI with Flexes let go in the middle of the run. It failed in the same spot as this incident. Bent the crap out of the fender when the tire went into it...

kekek

iTrader: (22)

Lemme guess...the old Bristol Lot? That place is not known for being easy on cars.

ZzyzxM

iTrader: (1)

Let's delve into some metalurgy and why I don't recommend KWs (or Teins, obviously...).

The KWs are made of essentially a 3-series stainless steel they call "Inox". This steel in not heat treatable, unlike a 4-series stainless. The best clue to the nature of the steel on the KWs is to take a magnet to it - it's non-magnetic (suprised?); a clear characteristic of 3-series stainless. Also, keep in mind that the ears on the KWs are welded onto the strut body and only a few stainless steel alloys weld well at all, 3-series being one of them.

Back to the Teins - the failure that you see is metal fatigue. This is not a total failure in tensile strength. It's a failure due to repeated stress on an under-engineered part along the welds.

On the KWs you will likely never see this sort of failure. Why? Well, because stainless steel has the unique property that it's yield strength is about half it's tensile strength. Yield strength is the force required to bend the material, tensile strength is the force required to essentially rip it in two.

That's to say, it's takes only half the force to bend it as it does to rip it apart. In point of fact, the yield strength of 3-series stainless steel is less than 6061-T6 aluminum. That's probably an eye-opener to most people.

This is why, for instance, KWs have been known to bend on STU cars (the pic above). No impacts, and not even the brake torque of a competition car on big R compound tires. I hate to think just how much they flex on such cars running them right now.

Regarding stainless steel if you want to get the word from "the man", pick up Carroll Smiths "Engineer To Win". He basically states that "stainless has no place on a race car".

I for one see no reason to disagree with him.