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The guy who set up my car (street) used poly bushings.  After driving the car for a couple of years, I've decided I just dont like the way it rides.  Any bump feels like someone is taking a sledgehammer to the bottom of my car.   Louder than hell.  Jarring.   My question is; is that in my head?  Would rubber bushings do the same?  The car feels so g.damn stiff that its almost not fun to drive at times.  Wonder if its the springs?  Of course, it corners nicely.  But as a percentage compared to just driving, I'm not seeing a big pay off.

 

Seeing all these bushing questions, made me thing to ask.

 

Thanks for any input or insight.  

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Polyurethane comes in different stiffness or durometer. Sounds like you have high durometer bushings meant for racing.

 

The common consensus is that on a street car you should replace the old worn out rubber bushings with new rubber bushings except for the swaybar bushings.

 

I have Prothane poly front control arm bushings on my 2002 and haven't noticed anymore stiffness or noise from them. They seemed only a bit stiffer than regular rubber, and were a lot easier to install then the aftermarket rubber bushings that are to big and tend to rip during installation.

 

Do your research and ask peoples opinions about different brands and durometer and their experiences. I found this article that explains a lot about polyurethane bushings and durometer.

 

Some of the brands advertise the durometer of their bushings, others just say polyurethane or racing/track use.

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1 hour ago, bento said:

What springs and shocks?

^^^ Help us understand this first. 

 

I feel damper/spring combo will have a greater effect. 

 

There's a lot of opinions out there. Having done poly everything so far, the only thing I'd go back to is rubber engine mounts for a street car. Poly engine mounts transmit a lot of engine buzz, but are a great reminder that your ITB's aren't as perfectly in-sync as the could be when idling around town, no matter how hard you've tried. 

 

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Yeah, I, too, don't have much problem with poly bushings, except for the engine and trans- trans mounts are the worst offender I've found so far.

 

Shocks and springs (and ride height) need to be understood.  Maybe tire size as well, no?  But mostly shocks and springs.

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It can be a compounding problem. Poly bushings on a fairly stock car won’t be bad, but if you go to 15” rims the ride will get harsher. Add stiffer springs and performance shocks, even more. 
 

Maybe try just replacing the inner control arm bushing at the subframe with a rubber bushing. That is where most of the force is transferred when you hit a bump but keeps most of the stiffness with the other bushings staying poly. 

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For a street car, I tend to like Poly only in specific areas like front thrust arms, all swaybar bushings and end links, and rear suspension arms (where arm attaches to subframe). Any more and you will feel it. Vibration is real once you start replacing rubber for poly in areas like engine mounts, tranny mounts, subframe mounts. Better to leave those in rubber if you enjoy your spine and teeth fillings staying in tact. 

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1 hour ago, D Seattle said:

Thanks guys.  That great direction to start trying to figure it out.

D

So what are the shocks and springs? Folks probably have experience with whatever is fitted and can comment on their experience with same. For example, I found Bilstein Sports rear shocks intolerably stiff on my 02 and swapped to HD. Made a huge difference in 30 minutes or so. Much more of a difference than any of the Poly suspension bushings on my car.

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FWIW, I have all poly bushings, except for the rear subframe mounts where I chose not to insert the spacer/stiffeners.  I have the Ground Control kit with 350lb springs, and Koni single adjustable dampers.  I would everything the same again, except maybe 300lb springs instead.  The ride is firm and sporty, but nowhere near the harshness you describe.  

 

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I've got almost all the offenders for a 'harsh ride', and I like how my car rides :)

 

15' wheels.

50mm dropped Suspension/matched dampers

Poly All-the-things

 

And while you'll never find a road as bad as the NY Belt Parkway in Europe, it's only on the chunkiest of old city cobbles where going back to a 13 crosses my mind. Tighter cobbles it just hums right along. 
 

Who knows, maybe your dampers are worn, the car was lowered by cutting a few coils outa stockers, and you're hittin' the bump-stops. 

Which breaks another thought... how are your roads? Even with a dialed suspension, if the surfaces you frequent are not so great then I could see over time wanting to soften things up. 

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I have Powerflex all around and if I had to do it again I wouldn't put poly everywhere. Its not loud though, it just transmits too much. I have a healthy diff, but with the poly I hear it. It is however super tight, if any joint goes south you notice it immediately. 

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My premise has been, generally, driveline- no, everything else- yes.  For me, the poly trans mounts were the worst.  I've never tried the diff mounts because I heard they were loud like the trans mounts.  I currently have poly engine mounts because I need to control my engine because I didn't have enough room after the PO swap to keep the header off the chassis- I need to try stock rubber/fluid mounts and see if I do since doing some work.

 

Having said that, my car is low, stiff, well damped.  My expectations may be different from yours.

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