I wanted to post my experience with Fat Cat Motorsports and their bump stops. http://www.fatcatmotorsports.com/FCM_Products_Mini.htm

I have an '07 MCS w/ LSD and sport suspension. I am in my 3rd year of D-stock/street tire autocross and have always been at the back of the pack of regulars. I experienced strong understeer if went too fast into a corner and very quick onset oversteer if I throttle lifted in a turn. The understeer is my adrenalin pumping too hard and am learning to go in slow into a corner to come out fast. The oversteer scared the sh** out of me. When at the limits around a corner, there would be times I would need to ease off the throttle and SNAP... I'd be sitting backwards on the course. My solution to this was to not get near that threshold which added a 10th here, a 10th there, a 10th everywhere.

After talking to Shake at Fat Cat Motorsports I decided to try his bump stops on my OEM struts. The stops along with an alignment and a few tools, made a vast improvement in the handling and predictability of my MINI for under $250. I could go faster into a corner before understeer would arrive and I have not experienced any snap oversteer. The suspension feels smoother in transition through the slaloms. I finished mid-pack in the first autocross of the season! (IF, in my dreams... I could have counted my 5th run against the other's competition runs, I would have placed 2nd.)

I am NOT an expert by any means, but learned alot about suspensions from Shake and his website. There was also the satisfaction of learning to tear down my suspension and putting it back together. (Thanks Bentley Publications)

I'll try to update this thread as I go through this autocross season and learn more about the handling characteristics of my MINI. I should have more insights as I trust my car more and push it, and myself harder. Whoo Hoo

 

I was just looking at their bumpstops to get a little more travel out of my JCW suspension- Thanks for the great write-up!

How did they affect ride quality for daily driving?

 

No change at all for my daily driving. Not sure about yours.

 

Thanks for the additional feedback.

 

My 2nd and 3rd autocrosses were this past weekend. Finished 4th/13 and 2nd/12. 2nd!!!! Never done that before! So, here are my second impressions/experiences with my MINI w/FatCat bumpstops.

Going into a corner: In hard braking, the car felt like it dropped down forward, but didn't slam into the limit. The bumpstop helped the car behave like I precisely lifted the brake slightly as I reached the limit of compression. I did not feel any unsettling rebound.

Going around: I screwed up my courage and pushed it a bit and was rewarded with what seemed like controllable rotation. With adequate speed, I was able to ease off throttle and the back end would begin to come around. The speed of the rotation felt like it could be controlled with how far I eased off the throttle (need to test this more). Once I rotated the car far enough, application of the throttle ended/slowed the rotation.

Never had so much fun! I've never played with my MINI at it's limits, before I would often spin. I might, with lots of experience, have been able to get and use rotation with the stock set up, but I've been able to leap forward because of the confidence I have in the car. Before, I knew oversteer would come on throttle lift, but now I can predict when and am beginning to control it.

I may just be describing the obvious to those with experience, but I'm soooo stoked with the change I've made. It is, by far, the best $90 I've ever spent.

 

Defiantly look like a good investment. I was wondering by any chance if you know the difference between the fat cat and the ones that way sells for half the price?

 

Installing these this weekend with Koni Yellows, JCW sport suspension springs (12mm lower), upper rear control arms to match the lowers from RennSport Racing Australia, 20mm Whiteline RSB (having second thoughts about this) and custom front camber plates, again from Elie at RennSport and his invention. The plates, expected to give about -1.2 degrees to go with the -.7 I already have, for an easy $150. These plates to be the prototypes and fitted to an R56 in Australia.
It's been a long wait for these suspension mods. Hopefully they will be all I desire. If that is possible.

 

Well, the autocross season is over.
My opinion of the Fat Cat bumpstops remains... the best low $$$ mod you can make. Paired with OE sport shocks/springs and a 19mm swaybar, I won my regional SCCA SOLO Street Tire division - Dstock. (7th in 2011).

I became a better driver this year for sure, and a huge portion of that was due to the predictability my car displayed. Transitions "ramped up" rather than arriving suddenly. I believe this is due to the material and design of the bumpstops. The resistance to travel of the bumpstop was progressive and allowed me to feel and predict when changes in grip would occur.

It is amazing the fun I had with my MINI this year. Rather than trying to keep it below some threshold to maintain control, I was able to play AT that threshold to get the most out of the car.

Next year I am going to change out my 19mm rear swaybar for a 22mm. I want to get similar rotation without having to jack up my rear tire pressure 45lbs.

Don't know if the $$$ are available yet but am looking into changing out shocks. The car seems to dive quite a bit under hard braking and takes some time to settle. I think I could be quicker if the car were at a steady state going into an element. OK, OK... braking earlier could be a solution too.

 

My installer is having trouble installing the boots on the smaller diameter bumpstops. Did you use the original boots or not use any boots at all?

Thanks in advance.

 

^ im confused, if the diameter is smaller wouldn't it be easier to put the boots on?

 

That's true, but he felt that the bumps tops were so much smaller that the boots would slip off even with zip ties.

 

Well the shocks are in with no boots on the front. No call back from Fat Cat or Koni. I hope the shocks last. The installer didn't see an issue.

 

Sorry I didn't see your post earlier. I was told that running without boots would be OK too, but went on a search for replacement boots anyway. Nothing seemed to fit the bill. I ended up stacking two OEM boot together to get the height I needed to cover the shaft. I also had to cut the top edge so the boot wouldn't compress and stick on the strut hat rendering it useless.

 

i guess i'm still confused. what dampers/boots are you referring to?

here are a few shots of my suspension, dust boot covering:

 

Thanks Mini2NA. I'm glad to hear that running without a boot is okay. Kyoo - I'm referring to the blue boot in your picture. The original boot is black rubber. Apparently the front boot is too big and stiff to fit around the new smaller diameter Fat Cat bumpstops tightly, even with zip ties. Perhaps if my installer was more than a 2 man shop who did a lot of aftermarket work, he would have had a boot with a smaller diameter to fit the smaller bumpstop.

 

MINI2NA,

Did you trim the rear FC bump stops or leave them at 58mm?

 

I trimmed them, but unless you are running SCCA SOLO you'd be fine with them as is.

 

What setup are you running? Are those Koni sport or Bilstein?

 

bilsteins baby

 

Sweet.
Hd or sport?
Are they jcw springs?
If so can you post pics of the car and ride height?

 

sports & jcw springs - lot of pics in my thread and blog

 

what are you running? red & white? i think i'm gonna swap white to blue in the rear... car's just not as loose as i want it to be in the hotter months (june-aug)

 

I'm running whites all the way around. In the warm months I bump the rear tire pressure up a bit. I'm getting plenty of rotation for me with my ZII's.

 

i'll pm you in a bit here