Blair

I have a roush stage 2 suspension on my 2010 gt and the ride quality was excellent. The suspension includes roush springs and struts/shocks. I recently installed a stoptech big brake kit. Now the car handles bumps and irregularities in the road terribly. The suspension crashes the body heaves more. I assume this is due to the increase in unsprung weight. Other than upgrading to adjustable shocks is there anything else I can do for this?

Thanks,
Blair

157dB

What was on there for brakes and what is the difference in weight between the Roush Stage 2 OEMs and the StopTechs?

I have never known that little of a difference in unsprung weight on the front
to cause the problems you describe.

Heaves?
Do you mean it rolls or sways in the turns?
Crashes? Do you mean it bottoms out easier?
Handling bumps and irregualarities bad?
Do you mean it follows ruts and bump steers?
Come on Trickle, I cant fix what I cant understand.. LOL

Blair

I didn't measure the weights of the stock brakes vs. the stop techs, but I imagine the stop tech caliper & rotor weighs 3-5 lbs more per corner. This would all be in the rotor as the stop tech calipers were surprisingly light.

In terms of ride quality change it feels like the car reacts more to impacts in the road. It feels more underdamped in the front. Like the struts are having more of a problem controlling the body movement and it takes the car longer to settle down after a bump. That's the best I can describe it. For example, there is a set of railroad tracks I drive over everyday. Before the big brakes the car would stay very composed over the tracks and the body motion would be minimal. It would feel like going over highway dots... a few small thumps and a little noise. Now when I go over the tracks at the same speeds it seems to take a little longer for the body motions to stop and the car to settle down. The thumps are louder and the body pitches a little. Seems like a lot in my opinion for just adding a little more suspension weight.

Blair

157dB

Then the struts need to be upgraded for ones that dampen the load more.
http://www.tokicousa.com/
Fully agjustable for those added unsprung weights.
One mod needs/deserves another.
Might as well get the rear tokico shocks as well...

Argonaut

With the dramatic difference you are describing I can't believe the BBK is the culprit. Many, many guys have installed BBKs on stangs and lots of other cars and I've never heard this before. I've swapped tons of wheels around - light wheels vs heavy wheels, like 10-15 pounds diff of unsprung weight and I've never had a change like you describe. Who did the install? Are you 100% sure everything is correct?

Blair

I did the install and am 100% sure it is right. The Stoptech instructions are excellent and I have been working on cars for many years. I rechecked the torque on everything and bedded the pads in last night. Everything brake wise is working great. After 10 stops from 60-5 mph to bed in the pads per the instructions, the brakes were still pulling the car down hard, although they smoked a lot for several minutes. I'm doing an HPDE in a few weeks and can't wait to see how they perform.

I am very surprised about the ride change was well. I expected that it might be a little more sluggish off the line, but not that the front would suddenly feel underdamped and bouncy. Especially considering I only have 2k miles on the Roush struts.

Blair

retfr8flyr

This is very strange when I did my Wilwood brakes I didn't notice any change in ride quality. Is the Stoptech rotor a 2 piece or the heavier one piece?

Earl

Sleeper_08

I find it strange too as I'm running 18 x 9.5 rims with 285/40/18 tires and the GT500 front brake kit so my front end unsprung weight is way up over stock and I don't feel any of the probelms described by the OP.

I'm running Tokiko front struts set to 5 on the street and Steeda Competition springs.

acarzt

Sounds like some blown dampers. :-)

Your brakes should have no effect in how the damping feels. Gravity pulls down, not up. The dampers are really only slowing the transfer of the weight of the body towards the ground and then rebound away from the ground. The wheels and brakes can pretty much be considered stationary.

Blair

I'm running the one piece rotors and the things weigh a ton. I'd estimate probably 25-28 lbs each. As for shocks they are non-adjustable Roush blue shocks that come with the stage 2 kit. So far I am very happy with the performance of the new brakes, it just seems like the front end gets more unsettled by bumps and takes a bit longer to get back to neutral. I might call Roush this week and ask them about this as some of there models come with BBKs as an option.