Master Bushing Kits Worth It?

[indy95talontsi]

I am considering installing a urethane master bushing kit on my 95 Talon Tsi FWD this winter while I am installing new springs/struts. I know it is a considerable investment in time.

Mainly using the car for street and weekly drag. Will be increasing power substantially with upgrade from T28 to GT35R.

Is the bushing mod worth it? Looking for a little advice or should I spend time/money elsewhere?

Thanks in advance for your inputs.

Mike

 

[wret]

I was kind of hoping someone would field this one and give you a good answer because it's a good question. I'm sure there are a few in the DSM crowd that have actually compared handling results of urethane bushings to stock, but I have not.

I have only recently installed Energy Suspension bushings but I have done a little research. The primary difference between stock bushings and urethane replacement bushings is bind. By design, stock bushings bind or resist motion of the suspension. The metal core of the bushing is held firmly to the suspension arm and bonded to the rubber center. The outside shell is pressed firmly into a frame or support bracket. So the only movement allowed is through the flex of the rubber center.

This presents a couple of problems. The resistance of the bushings will be added to (or subtracted from) the spring resistance and will obviously be progressive in nature. Not what you want if you are trying to identify the optimum, linear spring rates for your vehicle. The second problem is that the resistance of several of these bushings is added together for each corner but not in any consistent way. The bushings may be locked into place at installation but it would be difficult to assure that each of them is any consistent or optimum orientation when bolted in. Even then, some may slip somewhat at the bolt and some may not.

The design of urethane replacement bushings allows free movement of the metal core within the bushing and the bushing within the mounting point eliminating nearly all bind. Another improvement provided by urethane bushings is that the material typically has less flex than the stock rubber making handling and steering more precise and responsive. This is somewhat at the expense of ride quality. I don’t detect a significant difference after installing Energy Suspension bushings but there is no practical way to test for it. Prothane bushings are harder than ES providing another step up in handling precision with another step down in comfort.

The kits themselves are not that expensive. At just over $100 for the ES, it is one of the cheapest mods as far as parts cost. The real expense is labor. This would not be something you would pay a shop to do as the labor costs would be prohibitive. I gave some installation tips in a thread in this forum a few weeks back.

Is it worth it? For a street driver only, no. For an autocrosser, probably. For a race only car, definitely.

Hope this helps.

 

[jtmcinder]

There's a bit more to this issue of binding.

The lower arms in the front of a 2G not only swing up and down. The lateral arm also rotates back during bump, because it is not parallel to the compression arm. So, while uerthane bushings greatly reduce or eliminate the binding causes by bonded-rubber bushings, they are much more resistance to movements off-axis. For this reason, you will only see all of the benefits of urethane if you have also greatly increased your springrates to reduce travel.

- Jtoby

 

[indy95talontsi]

Wow.

Thanks for the great responses.

I am running my talon in weekly drags at Indianapolis Raceway Park and several other events throughout the year.

Does it make since for me to do a complete bushing set or just focus in on specific bushings such as the control arms?

Thanks

indy95talontsi