825 miles for a National Test n Tune

Sitting in the passenger seat on the drive home from solo nats is a time of contemplation and reflection.  On this case of where things went wrong.

We took the Zoomboni up to the Peru tour last month and it was pretty good.  Not great but serviceable.  Then two weeks ago a local at NCM where it was excellent.

Then we towed it out to Lincoln and ran Emod.  Day one my co-driver went out to warm the tires and spun.  He came back and said it felt loose but should come in when the tires warmed up.  My first run and I got almost sideways in the long slalom and whenever I'd get deep in the go pedal it blew the tires off and went everywhere but where I wanted it to.  Subsequent runs were barely better and we ended the day feeling truly confused about why the car was so out of shape.  
 

Day 2, same story.  It was even worse, I spun, slid, washed out, and generally hated the experience.  I'm not a terrible driver and have been flogging this thing for a few years now so I should know how to herd it around the cones but I swear she was an undrivable pig.   Just before my final run I realized what had happened.  There had been a mystery oil leak from somewhere that I couldn't find somewhere in the back of the car.  I'd figured it was a output shaft seal from the trans....berkeleying shock absorber juice.  As soon as we realized what had happened it explained everything.  Completely undamped right rear 🤦‍♂️.   As recently as Peru we'd logged as high as 2.1 G lateral acceleration.  At nats we got a whopping 1.3 and completely unmanageable transient behavior.

Now for the good news!  It had been handed over to me with the description of the coilovers as being "eBay motorcycle shocks".  As soon as we realized that we needed some new stuff and I got to looking online at eBay shocks I realized they are swing arm units from a 2002ish Yamaha YZF R6 on the front and R1 on the rear.   Well that changes things, these are actually serious business shocks and had actually been doing some really good work until they blew up.

An aside: the giant wing is a bit heavy (16 lbs) being made out of Big Ass Fan blades and my "custom fabricated" uprights allowed more wiggle than I like so diagonal cross bracing will be forthcoming.

Bad timing for the part failure, sorry to hear. Love the car, I wish I could have driven it when it was last at the Challenge.

Would you be willing to post pics of how the motorcycle shocks are mounted?

In reply to MrJoshua :

https://grassrootsmotorsports.com/articles/2007-a-zamboni-odyssey/
 

You can see how the upright (where the normal Miata coilover goes), comes up to the rocker and pushes the forces sideways to the R1 unit.   Turns out the rocker is part of the Yamaha assembly as well.  According to the build sheet in the article they were pretty inexpensive back in 2007.

Ugh on the shocks and I’ve run on blown-out dampers, too. Like you said, just a mess everywhere. Glad you found the cause.

Very happy to see the Zamboni at Nats, though. 

The original article on the car is still online: The epic tale of an ice resurfacer turned autocrosser.

Good stuff. 

Photographic evidence of the waywardness.  This was a full spin with NASCAR style smoke show (I may have been a bit frustrated and over it at this point).