I need help from you experts out there, I installed a BBK system and when I brake at speeds over 60 miles a hour I get the wheel shake. So i returned the kit for inspection and they sent it back to with 2 thumbs up, no problem. I re installed and still have the same problem-- so what else could be wrong with the car? any input would be greatly appreciated!! thank you

 

I see you have H-Sport springs. How long have you been running them and have you been running them hard (be honest)
This is a very similar problem I had. After looking into every problem I found that my stock struts had failed being that I had lowered the car with H-sports. When replaced with new ones (PSS9) the vibration never happened again.

 

I presume your wheel shaking is noticed from the steering wheel (front wheels) and not the rear.

I have a BBK and when I change to new rotors or pads, I sometimes get a vibration when braking from >60MPH , but only until the pads "bed in".
Usually goes away after a couple of hard braking sessions at the track.

 

Onasled I have had them for about 2-3 months, but I think there was a chance they might have been damaged at a auto cross event when I went off the track, but at the time I didnt have the springs and the person that installed them might not have noticed or didnt tell me if he noticed a problem. So tell me how is it if a shock has a problem it is translated through the brakes?? after having the brakes inspected I am sure there is something wrong, and my brake guy told me he suspects its a strut as well. How will I know if I have a strut problem?

 

>> Hay Schooner2 is that you?


MINIMAX 1

 

MINIMAX its me JCWORKS LOL

 

Anyone else Have any input?? The more the better to help me to the bottom of this problem!!

 

>> How did you determine that the H-Sport Springs had caused the problem?

>> I have been running H-Sport Springs on my 03 Cooper S for 2 years + and have not had one single problem from them. In Fact I have had NO PROBLEMS with the car and it is very much modified. Please let us know.

>> MINIMAX 1

 

Many may "think" they have no problems but might be surprised to find that their struts are shot when used with lowering springs. It's not always apparent until a mod like a BBK is installed. I'd go so far as to bet that most who have driven with lowering spring 10K miles and more have damaged their struts.

The only way to really tell is to remove the struts and test them, or just replace with an aftermarket shock that is valved and set for the lower ride height.

 

I 'think' what onasled it talking about from our previous conversations is that when you drop the car down with struts that have full length shafts in them you run the possibility of damage to the shim pack and valve body at the bottom.

This comes from the valve body bottoming in the housing. Normally on a full strut the chances are very slim. Either the spring coil binds, the top of the strut hits, or most common; the part comes with 'bump rubbers'. Those are the hard rubber parts on the top of many shafts that get tossed in the "I don't need these any longer" pile. In reality you have a greater need for them. But they may contact sooner now as the stroke length of the shaft has changed.

When the brakes are fit the only reason I can place on the feel of this now is the greater radius of the caliper body and it's leverage on the rotor. Moving this out puts a greater load angle on the strut and perhaps more of a rocking motion. Often if the new parts are 'inserts' for a stock strut body the inserts can rattle in the can as well. This was common on some Koni applications years ago I worked with. Constant clunking with the insert moving in the housing.

Best thoughts I can muster from this end.

 

>> Thanks for your reply but I'm not convinced that what you have said is totally correct. I'm sure there have been some that have had problems with Struts but I can't believe that it is that big a problem. I have contacted several different Techs who are very qualified about this and they do not totally agree with your statment. It may just be differences in driving styles.

>> Thanks again for the reply,
>> MINIMAX 1

 

I thought it was just me! I've had my H-Sports for two years and likewise, when I brake from +60mph I get wheelshake. Despite all the braces, sway bars, etc. my suspension feels really loose. I was going to get an alignment done, but maybe that's not the problem. Veddy interesting grasshoppa.

Note: I have never tracked or raced my car.

 

oooppps

 

I hadn't either when this problem accrued with me.
Anyway, street driving is usually harder on the suspension then track (unless you leave the pavement)

Minimax, you might be surprised then on just how many people have had this problem.

 

I'd *love* to have Bilsteins' PSS9's for my car, but my old lady isn't going to let me drop $2k on coilovers. Can you let us know which aftermarket strut setups would be ideal for us H-Sporters? Thanks!

 

I'd *love* to have Bilsteins' PSS9's for my car, but my old lady isn't going to let me drop $2k on coilovers. Can you let us know which aftermarket strut setups would be ideal for us H-Sporters? Thanks!

 

I think you're mistaking Minimax1 for me, MinMax... but I still caught it (LOL).
Have a good one!

 

Well the car goes in tomarrow for new struts, so by tomarrow night I will know if the problem has been solved, thanks for all the input People! I do appreciate it!

 

While I can neither confirm or deny from personal experience that worn struts can cause wheel shake under braking, I can confirm that improper bedding of pads and pad transfer can cause this. I am quite familiar with this since I have done it more than once. If you are not familiar with this, there are several good write-ups on the StopTech web site.
Bottom line, it's possible to have transfer material on the rotor that gives the symptoms of a warped rotor (wheel shake is one). You may not be able to see this material but it is still there. There are methods to correct this, some work better than others.
I've experienced the same shake with new Koni struts but in the end, it was bad bedding of pads that caused it.

Schooner2, I hope you were getting new struts anyway, not just to fix the shake problem.

 

How did you correct your bad bedding and pad transfer problem? I bedded in the brakes as my sales man told me to. which means they were smoking after I was done doing it!

 

Getting the brakes hot is certainly part of bedding BUT cooling them off completely BEFORE coming to a complete stop is extremely important. Parking the car too soon is a cause of transfer. the last time I had the problem, I got stopped by a curious cop at a bad time, instant problems.

My personal method of curing the problem is to use Hawk blue pads as recommended by StopTech. It's like resurfacing your rotors as you drive. If you don't get the blues hot, they are very abrasive and a few stops will take care of the transfer material and you can then re-bed the original pads correctly. BE CAREFUL if you use Hawk blues. If not used at proper temps, they will consume your rotors in no time! When I use them, its in and out - same day.
I don't know what your problems really is, it could be your struts, I do believe that this is a viable issue. I just wanted to point out that bad bedding can aslo cause the same symptom.

 

I really appeciate you chimming in, I want to rule out all possiblilty. but there are other things that make me think its a strut problem, I have this funny harmonic feel and noise in the car at speed between 50-70, the timing is great because I need new strut mounts so that is under warranty, so I dont have to pay to have the new struts installed, and I found a new set of front struts for 100.00 for both so it cheap to replace, so I hope its the strut, I have been through all other possibliltys. can you describe what problems you had at what speed and what the steering wheel did when you had pad transfer and bad bedding?

 

Let's hope the struts fix the problem.

If not, try reading the white papers on the StopTech site. There's a lot of info there. Some more useful that others.

 

Thank You!

 

are you using aftermarket wheels with your BBK? my thoughts were making sure you have the correct centering ring. under heavy braking your wheels might be moving around your hub if you don't have a centering ring or the correct size centering ring.