Installed front strut tower bar, center power brace, rear sway bar - car rides rougher ...

It's probably the Cusco center power brace. I didn't notice the ride being rougher until I had my coil-overs installed. I did lower my tire pressure back to 35f and 32r. That helped soften the ride.

 

Anything that stiffens up the chassis will cause more NVH.

People install braces for improved handling, not for improved ride quality.

I have tons of bushings/braces on my Subaru and it's not for everyone.

 

I had the front strut tower brace installed first. Center brace and rear sway bars were next. I've since had the other two brace installed (all three installed has eliminated all rattles in the car). With the strut + center brace the chassis is stiffer so you will feel all the imperfection on the road especially here in SoCal.

 

I would take the center brace off first...then the rear sways. Have you lower the tire pressure to see if that helps?

 

Any lowering of suspension, any stiffening of the chassis, and larger wheels/lower profile tires will ALL give you a "rougher" ride to some degree. It's the trade off for greater handling performance. Cars like the prius are built for the general public who want to get from a to b in comfort, which is why these modifications don't come from the factory. If you are not familiar with the changes this makes to the vehicle, it's wise to do them one at a time.

 

I currently only have the rear sway bar on my car, and it has not created any additional harshness, just a flatter ride in the corners. Since I have grippier Michelin Primacy MXV4 tires on now, I notice an instability in the front track that I am going to fix with a front strut tower brace (Tanabe).

Having installed these two components on other cars, I can tell you they did not make the ride harsher. Lowering springs makes the suspension sharper, but with no additional harshness. I am thinking it is the underbody braces, myself, that are adding the harshness, since these act to get rid of the last bit of play in the chassis.

Chassis are always under-welded to add some compliance. You only re-weld for race applications. I have a feeling the braces give you the same affect. In any event, those are the easiest to remove and replace, if you wanted to test any one component. How is that going?

 

I would be very careful in choosing any stiffening or bracing element other than the cross brace and underbody stiffening components.

All these kits, however well intended, "have not" gone through the extensive static, dynamic and crash test that Toyota and the IIHS has done. That would cost too much.

I can see the efficacy of the two point cross body brace, since it has the same "loading points" as the OEM brace. While the center brace, like that of the discontinued BT Tech brace imparts some improvement ito the stiffness of the chasis, a much more effective design would be a "box beam." That would be much stronger and stiffer. A 1.5x3.0 inch box beem, with the height being 1.5 inch, will still have higher clearance than the bottom of the front suspension frame and the catalytic converter.

I see the four point stiffener imparting "some" additional stiffness, but, from my experience, I see very little due to the long length of its "lever arms."

 

I have the TRD RSB, Tanabe FSB & 2-point chassis brace. I noticed a little more stiffer ride after the install of the 2-point chassis brace but nothing that bothered my wife since it's her car. I run 40/38 for my tire pressure. I had heard from others that the power brace really stiffens up the ride & chassis so I went with just the 2-point brace which did help tighten things up.

 

I installed the 2-point Tanabe chassis brace. I di drive the car to test it out before the 2-point chassis brace. The car felt very much the same as far as ride before the chassis brace but the addition of it did stiffen up the car but not too much that my wife noticed. She doesn't even know I installed it. :lol:

 

How about having the wife removed on friday instead?

I kid! I kid!

 

I am totally going to agree with Scott1258...

I had my cusco under chassis power brace installed last month (the 4-point bolt-on one). The ride went from awesome & fun.......... to stiff and spine numbing. It made me not want to drive the car anymore. I took it off and the car feels beautiful to ride in again...not too stiff and not too soft. Too bad I learned the hard way and should have listened to all of you in the first place...

I will have a hard time selling it on craiglist unless I put it on for under 100$.

 

I also had the CUSCO power brace installed before, my wife and kids complain so much about the stiff ride so I removed it and luckily I bought the OEM brace from a 2012 Plug in, now the my car run a lot better and no more complaining, I have the CUSCO strut tower bar installed and TRD rear sway bar installed also, plus I had the Lexus CT 17" rim and tires, it's all good with the updated version of the OEM rear center brace, see photo...the bar on top is the updated from Toyota and the one below is the 2010-2011 version.

 

That's why I designed the "box beam" braces without the trailing arms of the CUSCO.

The right lateral side of the car is designed to allow twisting like a pair of scissors in comparison to the left side. If you examine both OEM braces, you'll see that the center section is like a torsion bar.

My "box" beams allow the same twisting motion, while they have the ultimate stiffness to end to end bending, even more than the upgraded OEM brace.

Instead of nearly three pounds of steel, five parts and ten welds, the "box beam" uses one piece of extruded and tempered aluminum. It is based on the "wing warping" concept patented by the Wright Brothers at the beginning of the Twentieth Century.