Urethane Bushings

[DSMTurboEclipse]

Can anyone explain Urethane Bushings to me? What are they? Are they worth it? Are they different for manual tranny's to auto tranny's?

 

[DarthBulk]

Urethane bushings are a synthetic replacement for the OEM rubber bushings on your car. The marketing hype is that urethane is stiffer than the rubber, so you should have a "tighter" feel to the car. Critics will say that urethane wears out faster, causes a rougher ride, and squeaks. I say those red urethane bushings look cool, and I needed replacements for all the bushings in the front end of my 91 Talon TSi, so I bought every urethane bushing kit I could get I don't know what the replacement OEM bushings would cost, but I spent maybe $250 on urethane bushings (including motor and transmission mounts). I installed them all, including the sub-frame mounts...but haven't driven the car yet because I am waiting for my motor to be returned from the shop!

And as far as the critics are concerned, if you use the included grease when you install urethane bushings, you shouldn't get the squeaky noise. And a tight car is a nice ride...if I wanted a soft ride I wouldn't buy a sports car

 

[jtmcinder]

Here's some technical notes about the benefits of stiffer bushings. And I'm going to do this in the context of cornering, since I autoX, not drag-race.

When you are cornering, there's a lot on inwards force on the lower edge of the outside front wheel. This causes the stock lower control-arm bushings to squish inwards. This force also pulls outwards on the upper bushings (i.e., the strut mount on a 1G and the inboard A-arm bushings on a 2G). The give in the bushings - mostly the lower one, since it is much bigger - means that you lose camber. To be precise, the outside wheel loses negative camber (or gains positive ... same thing). This almost always lowers grip, since it almost always means that the outside wheel goes into positive camber.

In other words, even if you dial in a ton of static negative camber (and swap in massive and properly matched sway-bars) in an attempt to increase lateral grip, if your bushings squish, you could well still have positive dynamic camber, which means less-than-maximum grip.

- Jtoby

 

[Turbo Shogun]

But how effective is it?

I've heard many a horror story about suspension bushing installs. I also heard they crack after a year - barring them from potential daily driver duties. Cusco supposedly makes harder rubber compound bushings in light of this, but I don't think they make them for DSM's. I've been considering polyurethane bushings for some time now, namely because they're cheap, but those stories have deterred me somewhat... Is there any truth to these myths?

 

[jtmcinder]

They are a pain to install. They need attention quite often. They make the street-ride much nastier. And you have to do it all over again on a semi-regular basis if the car sees pot-holes and such. For most people, the benefits are seriously overshadowed by the costs.

If we're talking about a dedicated road-racing or autoXing car, then you almost have to do it. You just can't throw away lateral gs. If we're talking about a daily-driver and/or occasional racer, then don't bother. Just get SP eccentric bushings for the front upper A-arm pivots and, maybe, flip the driver's-side compression-arm bushing (to equalize the caster) and call it a day.

To put it another way: for most of us, you can make the same gains (in terms of lap time) by focusing on driving, rather than a bunch of bushings. But if you are to the point where you are searching for those last few milliseconds and haven't done the bushings, it's time to do it.

- Jtoby

 

[Turbo Shogun]

Thanks for the slap back to reality. :laugh:

Just get SP eccentric bushings for the front upper A-arm pivots and, maybe, flip the driver's-side compression-arm bushing (to equalize the caster) and call it a day.

Okay, so do you think it would be practical to not install the *whole* set, but perhaps only the suspension pieces (The easiest ones to get to)?

Do you happen to know where they sell the SP eccentric bushings?

I'm planning to do struts/springs/SB/STB etc. etc., this x-mas.

 

[DarthBulk]

It is pretty easy to install the bushings on your front control arms, especially the larger bushings on the back pivot points. Just remove the 2 bolts and one nut from the U-shaped bracket over the bushing, and take the bolt out of the front pivot point, and you can get at both bushings on the control arms. My advice would be to not replace them unless your existing ones are deteriorated. But I see you have a 92 TSi, so if they are original they are probably dry and cracked. Also, when you take the big bushing off the rear of the control arm, check how bad the post is that the bushing slips over...they tend to rust pretty bad. If it is too far gone, your new bushings will be sloppy and it won't matter if they are urethane or not, the sloppiness will come from the interior diameter, not the exterior I think it would be worthwhile to just do some of the bushings, especially if you are doing a strut upgrade. Might as well get it done at the same time. But unless you want a major disassembly job, don't tackle the subframe bushings. I just took the whole subframe off to get at those, and put a new steering rack in while I was at it. That turned out to be a bigger job than I planned.

 

[Turbo Shogun]

That turned out to be a bigger job than I planned.

When does everything go according to plan?! :laugh:

But anyway, if I was gonna do bushings, I wouldn't even touch the subframe, from what you've told me. If anything, I think simply replacing bushings with OEM parts would suffice. I'd rather spend my money on camber plates or the like.

 

[thedsmsource]

I have a complete set, front a rear. They are very nice, but make an aweful amt of noise from time to time (i used tons of lubercant too). The fronts are very easy, the rear was a total pain in the ass. Some of the bolts wouldn't come out, i have to cut them, i spent hours in the shop pressing and cutting the old ones out. And the new ride sucks on a daily use, but they are great for racing and flying aroudn corners. It's the price we pay for high perf, well better performance.

 

[leet]

Bushings are worth the money. Have fun installing them though.

 

[theTuner]

I helped a friend install them on a sw20, it was actually fun burning the hell out of the bushings to get the old ones out.... and when they say Grease them monthy or they will squeak , THIS IS TRUE, they get kinda annoying too.

 

[Turbo Shogun]

Grease them monthy or they will squeak

Monthly? Even the subframe bushings? What happens if you *don't* grease them monthly? Will they dry out and rot or something?

 

[dave99gst]

the black ones are graphite imprenated... sposed' to make less noise.
one major advantage is for FWD'ers to help loose wheel hop. I installed the complete front set with out and major probs ( i got a 50 ton Arbor press that helped alot to ) . Just replacing the ones on the struts are suposed to help ALOT with wheel hop and those are prob the easyest to do.

 

[4pistons]

I've had a full set, front and rear, on my '91 GSX for 2 or 3 years now as a daily driver and I don't have any issues with them. No squeeks, no cracks, nothing harsh. The ride is tight and firm and the handling is very responsive.

Any replacement job will be a pain in the ass no matter what type of bushing you are replacing them with. Urethane is not any harder to do than stock ones.

Rick - '91 GSX

 

[RiceKiller_TSi]

My stock bushings are softer than Jello and I want to replace them with a "primo" bushing but I dont want to suffer great pains installing the complete front of the car. My question is, which bushings will stiffen up the ride for better cornering? I am currently on the pop under cornering bushing and strut system.

 

[DarthBulk]

You WILL suffer great pains if you replace all the bushings in the front of your car. The easiest ones to do (in my opinion) are the ones on the front control arms. I also think those will be the most effective in stiffening up your ride during cornering. I did a complete bushing replacement on my front end, but I did it with the engine and transmission out of the car.

 

[RiceKiller_TSi]

Originally posted by DarthBulk
You WILL suffer great pains if you replace all the bushings in the front of your car. The easiest ones to do (in my opinion) are the ones on the front control arms. I also think those will be the most effective in stiffening up your ride during cornering. I did a complete bushing replacement on my front end, but I did it with the engine and transmission out of the car.

In that case...control arms here I come! It'll have to get used to having the car on 4 wheels under cornering again. Thx

 

[Rodman]

4pistons, what brand of polys did you use?

 

[4pistons]

4pistons, what brand of polys did you use?

If I remember correctly (it's been a few years) they are Suspension Techniques. Any brand Polyurethane should be pretty equal unless you're talking about the Graphite impregnated (Poly-Graphite) or the Delrin/Aluminum (Del-Alum) ones. If you can find a brand that has the grease fittings on them pay the extra couple of bucks and get those.

Rick - '91 GSX

 

[NDgsx]

In regards to the squeking comment I've heard good things about PST bushings, http://www.p-s-t.com they do run a bit more than a ES kit from RRE though.
I haven't gotten around to doing anything about the rear subframe, but every other bushing on my car is polyurathane. The rear bushings on the front control arms and the upper control arm bushings out back are eccentric whiteline pieces, everything else is black energy suspension.

I don't have ANY problems with noise. The key is to first get everything very clean. Then liberally lubricate the bushings with a good quality lube, not some crappy lithium grease. The stuff that comes in the ES packets works great, I've also used redline CV2 grease (has molybendium in it) with good results. Remember to grease the flat faces of the bushings extremely well, that's where the noise is coming from.

After burning and cutting the front bushings I found it easier to have the bushings pressed out by my machine shop. Make sure you have a good employee though, a jackass could easily break your control arm.

I think that the bushings are very much worth the effort. I get much better feedback from the road and a good idea of what the car is actually doing. Much more direct connection to the road.
This does mean more NHV from bumps in the road, interior panels rattle a little more, etc.. I have a sparco rev seat, 5pt harness, 6pt cage, no balance shafts with prothane mounts, ATR 3", and an external, the extra NHV from the suspension bushings wasn't an issue at all.

 

[Turbo Shogun]

Very informative. Thanks.

Have you cracked any bushings yet? I heard that you'll have to redo some of the bushings if your car continually runs over rough pavement. It sounds like a good idea, but how much time did it take you to do all those bushings? I'll unfortunately have to leave my car behind in FL for awhile until I get settled in Chicago for college (Though I get to tool around in the winter in one of my uncle's spare cars ) and I'd wanna get them done before then, so as soon as my car comes off the transport, I'm ready to introduce myself to the Chicagoland Auto-X community! :laugh: I can't live a month without some Auto-X action.

 

[NDgsx]

I haven't had any problem with cracked bushings, but I've only been running this car since april. I definetly go over rough pavement and I'm not easy on the car at all.
I can't exactly say how long it will take, I was rebuilding the entire car from a bare shell when I put mine in.
I'd give it a full weekend at least though. If you have shop press out the old ones you'll save a lot of time, although it will cost you a bit more.

 

[4pistons]

I'm ready to introduce myself to the Chicagoland Auto-X community! I can't live a month without some Auto-X action.

Check out the Joliet Sports Car Club, although you'll have to wait til spring. www.jolietsportscarclub.com/pictures.html (The 2004 schedule isn't up yet.) It's a fun Run-What-Ya-Brung race. No classes so any mods are OK. It's a handicap/bracket type system. We get all kinds of cars showing up from stock Escorts to ZO6s, BMWs, Vipers and even full on, race prepped cars. It'd be nice to see more DSMs show up.

Rick - '91 GSX

 

[Turbo Shogun]

Originally Posted by 4pistons

Check out the Joliet Sports Car Club

Doesn't the Porsche Club of America hold events in/around there too? I remember checking out their schedule for 2003 a month ago.

Yeah, I'll be moving into Bolingbrook, so that's not too far away, I guess. You gotta wait 'till Spring? I was hoping they'd hold some Auto-Xs in the snow! It's all-year-'round here in FL (24 or so events if you count SCCA). It's less stress on your car, so I guess that's good.

 

[4pistons]

Yeah, I'll be moving into Bolingbrook, so that's not too far away, I guess

Welcome to Bolingbrook! It's about twenty minutes from the Joliet Junior College parking lot that we use.

Doesn't the Porsche Club of America hold events in/around there too?

They use Maywood Park Race track parking lot (it's a horse racing track) which is about an hour drive, but they do events at Rockford Speedway and Elkhart Lake.

You gotta wait 'till Spring? I was hoping they'd hold some Auto-Xs in the snow! It's all-year-'round here in FL

We'd be lucky to get May through October! If you checked out the website www.jolietsportscarclub.com/pictures.html you'd see we did one in a downpour but not in the snow. I don't think any of the clubs run events in the winter... Except maybe a 4x4 club.

Rick - '91 GSX