Posted: May-10-2008 03:04PM

If it breaks, Improve it !

Posted: May-10-2008 01:02AM

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My Higher Authority is the German Purity Law of 1516 . 

Posted: May-09-2008 05:26PM

Thanks, Don.  I've always thought a rear bar was a mistake on coned Minis, but it wasn't until I spoke with winning Mini drivers who weren't running them that I really knew I was right.  You can tune your car without bars because you took the time, money and trouble to get your setup just right for your requirements.  Most of the Mini owners owning or wanting coilovers are not able to apply your expertise.  They often pick from what is offered and run the shocks valved as-is with whatever spring rates the vendor thought were a good guess.   Properly valved shocks, especially,  combined with proper spring rates can do a pretty good job of reducing and slowing roll.  You probably already know that the Haney and Braun book, "Inside Racing Technology" does a nice job of explaining the role of shock tuning and valving, including the effects of shocks on roll.

Did you mean a 2.3:1  rebound to bump ratio (meaning more rebound damping than bump)?  In my conversations with Avo, the discussions always involved using more rebound damping than bump.  Of course, this was always in the context of coned suspension.  Avo makes some nice looking coilovers and can easily valve them for Minis, coned, coilover or coil spring, because they do so much work with front-running coned Minis in England.  I run a coned car with Avos which are adjustable on the car and have rod ends at both ends on the front and a rod end on the bottom on the rears.

On another subject, the coil spring folks often end up with shocks that are poorly set up for the spring rates they use and then have too much roll to deal with.  Rather than slapping on sway bars, they'd be better off with properly valved shocks or a well-designed coilover setup like yours.  The critical difference is that you weren't satisfied with an off-the-shelf package, and that you rolled your own.

Maybe your story on this thread will raise the bar for those who are contemplating a coilover conversion.  Thanks for that. 

PS - you mentioned that you chose the Quantums for their light weight.  Were you simply trying to reduce the unsprung weight? 

Posted: May-08-2008 09:54PM

yan6,    take a look at what Don had to say above.  Especially the part about  "I had them set up on a shock dyno and tailored to my mini".

I'm not trying to speak for Don, but I suspect that he went to the trouble and expense of getting his shocks set up and dynoed so the shocks would be well-coordinated with the springs, motion ratio, travel and corner weights on his own Mini(not just any Mini).  This illustrates the need to very carefully and precisely plan and execute a coilover conversion if you really want it to meet your expectations.  

This is no knock on Huddersfield, but it's an unfortunate fact that some coilover "mini made" kits are sometimes, if not most times, not properly engineered and tailored to a Mini's unique requirements.  If such a kit comes with springs, how will you know before you drive it whether or not the springs are the correct stiffness for your own tastes?  How will you know before you drive the car if the springs and damping rates of the shocks are compatible?  How will you know if the travel of the coilovers is correct for your car?

I know that it probably sounds like I'm trying to make rocket science out of a coilover conversion, but if one is to end up with a really enjoyable setup, some research and precision is required. 

Posted: May-08-2008 05:00AM

If it breaks, Improve it !

Posted: May-07-2008 06:00PM

i run 175 lb coilovers on the front and 95 ib coilovers on the rear with and without a swaybar

the are 1 7/8 in diameter AFCO with about 40 diferent rates

Posted: May-07-2008 05:16PM

Thanks, Don, for the reply.  Two inch ID springs are mighty skinny.  No wonder there's not a wide variety.  Do they get those springs out of ballpoint pens?  I was asking about progressive springs for the reason I mentioned in my previous post.  I thought they might be useful as a two rate spring.  One for "normal" use and one for crises to avoid pounding the bumpstops too hard.  Other than that, I agree that there would probably be no benefit, for the average driver, in using truly progressive, constantly-changing rate progressives.

What was it about Quantum that caused you to buy theirs?  I know less than nothing about them.  Did you need to get any special valving to address the Mini front suspension's short wheel travel and even shorter shock travel?  Were you able to find a shock length and travel you are happy with?  Thanks !

I'm really happy to see someone knowledgeable take on the Mini coil spring issue and execute it correctly.  I hope others learn from your experience.  Just my opinion, but I believe that too many people are just blindly throwing on the huge coil springs, not coilovers.  Some of these folks then have serious issues with them, including breakage, unseating on droop and untailored shocks.  They also often find out that they need sway bars(anti-roll bars) to keep from scraping the door handles on the pavement.

Posted: May-07-2008 03:35PM

Rear coilovers can be made to work pretty well if done right.  Quality springs should need no settling and will remain consistent for much longer(forever) than cones.  As Don mentioned, you can easily raise or lower the coil spring seats to adjust ride height. Just make sure you choose units that accommodate commonly available spring inner diameters.  Good springs aren't free, so check with someone, like Don, about a good starting spring rate and spring length.  You really should have a very good idea what ride height(and thereby resting spring length) you plan to run.  Make sure to check for coil bind before full bump and make sure that the springs do not come completely free of their seats when the wheel is at full droop(rebound).  Depending upon your car's weight and the weight of any passengers or cargo you carry, you may have to select your spring rates based upon your own requirements rather than what would normally be "the way to go".  Better to be a little too soft than a little too stiff because you can stiffen the shocks to help slightly soft springs, but you can't compensate for shocks that are too stiff.  So, you have a bit of homework that must be completed before you order springs.  In case it isn't already understood, cutting the ends off of springs is really not a satisfactory method of getting the spring lengths or rates "just right".  Springs that don't seat squarely can cause you problems you'll hate.

I'm not trying to make this any more complicated than necessary, but you may be forced to choose between linear or progressive springs if both are available.  Ask Don.  I'm not sure just how useful progressive springs are on a Mini's rear, but at least consider using progressive rates.  Progressive springs are one way to run relatively soft spring rates under normal circumstances, but still resist bottoming out under unnatural times(curb bouncing, potholes) This naturally adds at least another step to the process of assessing a spring's fitness for the intended purpose. 

Posted: May-07-2008 03:06PM

I haven't driven on them yet though so I can't give you any helpful feedback!

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