Jretal

So yesterday was the day that I was going to dyno the 4000 to a) see what kinda power she was putting down and b) get a good solid tune to bring my EGTs down since they were way too high at VIR back in April.

It all started off all innocent. Yesterday morning I pulled the valve cover off and retorqued all my APR head studs, checked my plugs, made sure everything in the motor was a-ok.

My buddy Keith showed up around 1230 and we drove the long miles down the street to Dyno Inc, the local 4wd dyno.

In not too short of a time, they were backing the 'ol girl into place:

<img src="http://lh4.ggpht.com/jretal/SKTkoD4f3_I/AAAAAAAAANo/O7oKZTD2XdY/s800/IMG_3200.JPG">

<img src="http://lh6.ggpht.com/jretal/SKTkoisnvmI/AAAAAAAAANw/0_LvT26iFY4/s800/IMG_3202.JPG">

At this point I was getting anxious to get this party started!

Once everything was strapped down, I got the laptop all hooked up and got the dyno calibrated and it was time for the first pull.... and it is here where things got ugly

Got the car in 3rd gear at around 2k rpms... got the go ahead and dropped the hammer. 3k hit quick, you heard the turbo start spooling, the RPMs started really climbing and the 'ol girl was screaming! Sounded really good! Then out of no where I heard screaming rubber, the car was jumping/bouncing everywhere like a damn wild stallion trying to break free of it's teathers and my buddy went running from the side of the car. I immediately let off the gas once the car started to violently bounce back and forth, but obviously couldn't hit the brakes as that would have made things worse on teh dyno... so it slowly spooled down.

This all went down at around 4-5k rpms and say 75 mph? Yeah, scary scary $hit!

When I got out of the car and walked around the side, I was welcomed by this:

<img src="http://lh3.ggpht.com/jretal/SKTkpHruFxI/AAAAAAAAAN4/EEldMYLa9wk/s800/IMG_3203.JPG">

Notice something wrong? Steering wheel is straight BTW... so is the driver's side wheel......... but not the passenger's side!!!!!!

What happened you ask?

<img src="http://lh4.ggpht.com/jretal/SKTkpWeCyDI/AAAAAAAAAOA/hgb25vHnvy8/s800/IMG_3204.JPG">

Yeah, the passenger side steering arm basically folded down on itself! I was in shock... basically, by folding the way it did, it cause the wheel to go to full lock as if I was turning left. It turned so sharp that the tire hit the inner wheel well as well as folded teh tire under the wheel so badly the lip of my front wheel got ground down a little bit (look later on for pics).

At this point, the guys came over from the other side of the shop because there were noises going down that should not be happening on a dyno. They all look at it in shock as well... yup, this was a first for them for sure! Best line though was the operator who goes "so how are we suppose to get it off the dyno now?" lol.

After about 30 min, I was able to get the steering arm off the upright so that we could turn the wheel straight and drive it off the dyno... and then I awaited patiently for AAA to show...

I was hoping not to have to do this again:

<img src="http://lh4.ggpht.com/jretal/SKTkp9vUEOI/AAAAAAAAAOI/o1rfabQNlCQ/s800/IMG_3206.JPG">

I rode home a little disgusted and a little embarassed. The guys were nice enough not to charge me for the dyno use, but I also have a feeling that they were nervous that I was going to try to pin this on them as well. I will get into reasons for potential failure a little later as well.

So I got the 'ol girl home and tore into it immediately after game planning w/ my buddy.

First off the wheel:

<img src="http://lh5.ggpht.com/jretal/SKTlXtdS31I/AAAAAAAAAOU/cUhJQHVcgrg/s800/IMG_3209.JPG">

and the contact on the inner fender:

<img src="http://lh3.ggpht.com/jretal/SKTlYhxkOZI/AAAAAAAAAOk/hc4-jryeWw8/s800/IMG_3212.JPG">

And finally the steering arm (mind you, this is <i>SUPPOSE</i> to be straight):

<img src="http://lh5.ggpht.com/jretal/SKTlYL7InyI/AAAAAAAAAOc/6LdPNqXeGR4/s800/IMG_3210.JPG">

After looking at the steering arm, it came apparent that my modifications that I made to shorten it came back to bite me in the ***. If you notice, it kinked right after my braces that I welded in there where I butted everything together... I can only guess that the heat from the welding weakened the steel enough to make it fail under the pressure. Regardless though, this <i>should NOT</i> have happened.

Other than the weak point in the arm, something else was screwy. I'm not sure if either these guys didn't tie the car down enough so it moved (car did lift up a little bit when it started really rolling, but being that it was the first time I've ever been on a dyno, I don't know if that's normal or not), or that my alignment was screwy enough (it was off a little bit, but I didn't think it was enough to cause THIS!) that it put undue pressure on the steering arm, causing it to fold under the force. Since no real damage was done to the car, I'm not going to make a big deal of it. All I lost now was time and a little $$ since I need to replace the TRE since we ripped the boot trying to steer it around the parkinglot to get it out of the dyno garage and onto the flatbed.

At this point, the car is sitting in the driveway w/o any steering arms. I took the driver's side one out and immediately cut it in half where I had butted it together (I shortened that one too) and inserted an 8" long 1/2" steel rod inside it to reinforce it so this didn't happen to that side (fool me once shame on you, fool me twice shame on me kinda deal). My buddy has an extra pass side arm that he is going to bend up for me and I'm picking that up this afternoon. I'm then going to shorten it and again insert an 8" rod into that one too and hopefully prevent this from happening again!

In the end, no one was hurt as the teathers did their job and kept the car where it belonged! I am eternally grateful for that part. Car can be replaced obviously... but thankfully, nothing was seriously damaged.

I'm at a cross roads though as to what I am going to do w/ the car. I was planning on using it at Watkins Glen on the 25th and 26th. I can't take it there w/o retuning it unfortunately as it was running way too hot and way too rich. Obviously this is a HUGE wrench in the gears when it comes to timing. What I'm planning on doing is to fix the steering tonight. If I can get that all buttoned up, I am going to get the car to the shop on Sunday to get it all aligned (PROPERLY THIS TIME) and tech inspected. If I can get dyno time for tuesday, then I will take the car... if I can't get it dynoed, the 4000 is going to have to sit this one out and the A4 will resume track duty again. We'll see how it works out I guess.

But that's it for this installment... and I hope to never ever repeat this again! lol

Katman

In retrospect, do you think it's better that it *did* fail on the dyno, rather than at the track? Failing on the track could have been 'interesting', to say the least...

Perhaps it all worked out for the best, in a bizzare sort of way? :-)

Glad that no one got hurt. That's probably the most important thing!

Pre95

Sorry to hear, hope you get some dyno time!

AudiSport4000

Somebody could have been hurt, but the outcome isnt too bad considering everybody is alright.
Perhaps buying a pre bent tie rod coming up Justin? Sorry to see this, but it could have been alot worse.

Jretal

I think the force of the wheel fighting against the rollers was arguably more pressure than propelling the 2900lb car in any condition.

Regardless, it pointed out a weak spot that I will address so it doesn't happen again. I was questioning my work there from the get go, but what have you. I'll get it right and get her back on the road

Jretal

they open at 11 and work util 8pm... lol. They rarely answer the phone, and when I missed my appointment on Wed (buddy couldn't help then), they didn't even remember I was suppose to be there.

So hopefully I can arrange some time. GOtta talk to my buddy to see if he can help me out on Tues, and if so I'll swing by the dyno place again and reschedule for tuesday sometime.

Jretal

thing was, it wasn't because it was bent as it didn't "break" near the bends, it "broke" near my welds. I'm going to have to shorten whatever rod I get, so what have you.

The price you pay for modifying these cars I guess :-P

fusilier

Get the whole thing Yellow white hot and then Dip it in cold water. That makes it hard but brittle. Then you temper it to give it some ductility (if you want). That is slightly red hot. I'm sure racing Tie Rods are probabaly all Martensite (hard but brittle)

If you just weld on it and let it air cool, you get a ductiles soft metal which is fine for absorbing energy like in an earthquake or something, but **** for something that needs to keep it shape under stress.

The material adjacent to your weld was tempered and lost all its hardness by relaxing and losing the crystalline structure.

hals86cgt

I cant tell from the pic... did the material in the rod crack..? Or did the thing simply buckle..? But, as you said, the solution either way is to insert and weld a smaller rod within the original.

Still a bummer....

Hal

ddg=shinebox racing

I love that show!!!
Anyways big fellah, in addition to what big Jim said about tempering, you also caused a stress point in the arm, the middle of the arm was solid and very stiff, focusing the flex point to one area, normally it would be spread out over the whole bar...
If I were you, buy a pair of pre made arms w/heim joints from 034 motorsport, you can cut the ends down slightly for more toe in.....