Urethane Upgrades

[Jean]

Good thread. You should add the solid aluminum "bushings" to this list as well (unless I missed it) :)

[Aptyp]

I would, but that would be in subframe mounts. We haven't gotten to a single component yet, where solid aluminum parts would be acceptable.

[Aptyp]

Rear Subframe Mount
ADDED 3.24.09

So here's the question, how committed are you? I don't mean to your car, I mean mentally. If you feel like you should have been institutionalized the day you got your e-dirty and you have all special tools, friends, patience, and press then follow along.

Contrary to popular vendor myth, stock subframe mounts are long lasting, and you'll find that out when you'll try to remove them. As a matter of fact, you must be laying quite a bit of power and going airborn to destroy stock mounts.

There are plenty contenders here, and this is the first component that can be 100% solid: PowerFlex 80A/95A, Ireland Engineering Street/Race, Aluminum, Group N, AKG 70A/75D.

*Note: Stock e30 subframe mounts aren't solid for a reason... You must understand the way subframe mounts, and that subframe itself isn't solid. When you stomp the pedal and car jerks with all it's "mighty e30" power, subframe bows. It is designed to do so, and rubber mounts assist subframe in doing so. When subframe suddenly become solid, it starts putting all that extra stress on differential mount and driveshaft. Stock e30 differential mount is no weak-link either, so they'll handle all the abuse as long as you're not going solid. Another plus, is that rubber doesn't transfer as much road noise into the cabin, that all performance upgrades will.

Rating here will be based on quality, purpose, and price.
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1. PowerFlex: world class. There's very little to say that hasn't been said already about this brand. They make two different sets, and both are very streetable, as neither set is 100% solid. Purple ones are softer, and black ones are harder. There are a lot of members that run these, and you'll never hear a bad review of them. I've been in a few e30's with these installed, but never had an opportunity to have them installed in any of my cars.
Purpose: :):):):)
Quality: :):):):):)
Price: :):):):)

$104.99 Purple 70A and $119.99 Black 95A :D:D:D:D-
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2. Ireland Engineering: decent quality, and still for decent money. I have had both sets in my cars. I started with green/street, and ran them until my car was totaled. For my new car, I thought I'd get red/race mounts. I've been very happy with each set. I've daily driven both cars, and this mounts have been nothing but great. There are some complaints about IE, like forgetting to put top washers into boxes (some aren't capable of removing their original ones because of age). I haven't run into that problem, though.
Purpose: :):):):)
Quality: :):):):)
Price: :):):):):)

$90 Green/street and $110 Red/race :D:D:D:D-
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3. Group N: unless you're fooling someone, this is a true waste of money. They cost way too much compared everything else. Before we go any further, they cost well over $300 and are rubber.
Purpose: :?::?::?::?::?:
Quality: :?::?::?::?::?:
Price: :down:

$378 and I'd question my sanity, if I ever spent this kind of money and ranked it.
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4. AKG: I must say, they're 70A ones are perfect for street driving, and 75D are the most inexpensive solid mounts out there... but I took AKGs out. When I saw what happened to my TABs, I wasn't in a mood to keep any AKG products on my vehicle. Either way, this is another time that AKG has a good price, but inner race is made of extremely light aluminum that easily deforms. Alert: if getting 75D, get a solid diff mount.
Purpose: :):):):)
Quality: :):):)
Price: :):):):)

$90.00 either 70A or 75D :D:D:D+
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5. Aluminum: this can be had from practically every tuner, and should only be considered to be put on race cars. Solid aluminum transfers all of the road noise into the cabin, and with all the road noise comes all the road stress onto the chassis. Without proper reinforcements, you should avoid this options. There are a lot of them on the market and how different can two chunks of aluminum be?
Purpose: :):):):):)
Quality: by brand, but all are high
Price: by brand
Check out: Turner Motorsports, BimmerWorld, VAC, and practically every serious tuner that races.
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Again, please add do it, as I can only write-up what I have experience with.

[guibo09]

the stock bushings are made of extremely soft aluminium also, so why is that a problem if aftermarket bushings use them?

[nando]

are you going to go through diff bushings as well?

I had a really shitty poly diff bushing for a long time (I don't remember the brand). It let the diff move enough that I could hear the bushing "pop" under load. Replaced it with an AKG 75d bushing and needless to say it's a little too much for a DD. Love the feel though..

[guibo09]

are you going to go through diff bushings as well?

I had a really shitty poly diff bushing for a long time (I don't remember the brand). It let the diff move enough that I could hear the bushing "pop" under load. Replaced it with an AKG 75d bushing and needless to say it's a little too much for a DD. Love the feel though..

dam am i in for a dissapointment? i plan on DD'ing a full AKG 75D setup (motor/tranny/dif/subframe/RTABS)

[Gooch]

This is the first time I've heard negative opinions about the AKG bushings. Has anyone else had similar experiences?

[nando]

dam am i in for a dissapointment? i plan on DD'ing a full AKG 75D setup (motor/tranny/dif/subframe/RTABS)

Lets just say I avoid driving at 70mph now. :p

[gearheadE30]

I dd full AKG, although the subframe mounts are 70A and the diff bushing is whatever their softer durometer is with no problems. Its actually quite livable, at least for me.

[guibo09]

I dd full AKG, although the subframe mounts are 70A and the diff bushing is whatever their softer durometer is with no problems. Its actually quite livable, at least for me.

they only seem to have the 75D durometer on their website for the diff mount.

do you also run the engine and trans 75D mounts? im quite tolerant to NVH.

[Aptyp]

Solid/Near Solid components are a bad idea for DD cars. Bumps, pot holes, debris, and etc. has to be absorbed by something. Once you replace all rubber, chassis absorbs all those stresses, instead of suspension rubber.

Honestly, if all you ever do is DD your car, then perhaps, you should get softest urethane possible, if any. Without stiffening chassis (roll cage) you shouldn't allow chassis be your suspensions, no matter how tolerant you are, metal tends to break when you bend it enough times.


PS: I can't really do diff. bushings, I've always driven on stock without any issues, and I've never had any extremely solid subframe bushings in my car.

[guibo09]

Solid/Near Solid components are a bad idea for DD cars. Bumps, pot holes, debris, and etc. has to be absorbed by something. Once you replace all rubber, chassis absorbs all those stresses, instead of suspension rubber.

Honestly, if all you ever do is DD your car, then perhaps, you should get softest urethane possible, if any. Without stiffening chassis (roll cage) you shouldn't allow chassis be your suspensions, no matter how tolerant you are, metal tends to break when you bend it enough times.


PS: I can't really do diff. bushings, I've always driven on stock without any issues, and I've never had any extremely solid subframe bushings in my car.

the car is for summer only (about 6 months where i live) and will be used for Auto-x. that was the motivation for harder mounts.

indeed, pot holes can be devistating on a 20 year old chassis, but at least i will be reinforcing it in key failure locations. im also very good at avoiding them, and i will be running 50 profile tires.

[LaserAWD]

Update: It seems the fancy grease didn't help my squeaking AKG CABs any at all. I'll probably be ordering up some PowerFlex CABs in the near future to replace these. From what's been discussed here the PowerFlex will probably end up in my rear subframe (street) and trailing arms.

[Aptyp]

I don't know about roads in Canada, but if they're any close to Chicago, I suggest to no doing this.

[Jean]

I would say obviously springs/shocks/type and size of tire will also play a role here in your selection. I bet if you replace the subframe bushing with solid on a 100% stock car you probably won't even notice the difference. Now replace the rest of the components and go up a size or two in tires etc and it will all start to make a difference..