more bushings - V8 RX-7 Forum

gobeer net · #1 (**permalink**) 03-21-2006, 10:55 PM

So, anyone use these bushings?? They are on the club forum by Wanklin. SuperPro polyurethane bushings.

Any experience. I need some of them, so i'm thinkin about just buying the set.

http://www.rx7club.com/showthread.ph...39#post5436639

I read up on more than a few bushing threads, but didn't see any detailing these bushings. I'm not too worried about the harshness, mainy worried about lasting.

Sabre002 · #2 (**permalink**) 03-21-2006, 11:05 PM

The BG Delrin set is 500 shipped!!!!

gobeer net · #3 (**permalink**) 03-22-2006, 07:59 PM

yup yup, but i'm impatient. Only downfall i can see in these is "too soft"? Think there is such thing as too soft? I'm not overly worried about ride quality.

Sabre002 · #4 (**permalink**) 03-22-2006, 09:25 PM

Yes there is to soft I'm with you could care less about how the car rides. what bushings are you in need of, like are there only a few that are bad in yer car? You getting bad wheel hop or something?

wanklin · #5 (**permalink**) 01-14-2007, 11:50 AM

The bushings in question are rated at 80 & 90 Shore A depending on the position of the arm per application. Softness is not an issue as these bushings, though neither is NVH (noise vibration and harshness) as these retain near-stock NVH levels. Just to provide another point of reference; Delrin is roughly 83 Shore D which is significantly stiffer than a hard hat (75D).

Just to provide a point of reference, the Mazdaspeed bushings are 70 A shore. Assuming a 10-20S difference, the SuperPros are actually quite a bit stiffer then the MS bushings.

Durometer Scale Tutorial

There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the A and D scales. The A scale is for softer plastics, while the D scale is for harder ones. However, the ASTM D2240-00 testing standard calls for a total of 12 scales, depending on the intended use; types A, B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R. Each scale results in a value between 0 and 100, with higher values indicating a harder material.[2]

Method of measurement

Durometer, like many other hardness tests, measures the depth of an indentation in the material created by a given force on a standardized presser foot. This depth is dependent on the hardness of the material, its viscoelastic properties, the shape of the presser foot, and the duration of the test. Short durometer allows for a measurement of the initial indentation, or the indentation after a given period of time. The basic test requires applying the force in a consistent manner, without shock, for 15 seconds, and measuring the depth of the indentation. If instantaneous depth is desired, force is applied for only 1 second. The material under test should be approximately 6.4 mm (.25 inch) thick.[3]

Testing equipment - Shore Durometer Type A and D[3] Durometer Indenting foot Applied force (g) Type A Hardened steel rod 1.1 mm - 1.4 mm dia, with a truncated 35? cone, 0.79 mm dia. 822 grams Type D Hardened steel rod 1.1 mm - 1.4 mm dia, with a 30? conical point, 0.1 mm radius tip 4550 grams The final value of the hardness depends on the depth of the indenter's penetration. If the indenter penetrates 2.5mm or more into the material, the durometer is 0 for that scale. If it does not penetrate at all, then the durometer is 100 for that scale. It is for this reason that multiple scales exist. Durometer is a dimensionless quantity, and there is no simple relationship between a material's durometer in one scale, and its durometer in any other scale, or by any other hardness test.[1]

Durometer of various common materials

An automotive tire tread, one of the many rubber or polymer objects categorized by its durometer hardness. Tires typically range from 50A to 70A, depending on their application.

Examples:

Material Durometer Scale
Hard Hat 75 D
Non-spark hammer 60 D
Hard skateboard wheel 100 A
Solid truck tires 50 D
Soft skateboard wheel 70 A
Automotive tire tread 70 A
Door seal 55 A
Rubber band 25 A
Sorbothane 40 OO
Sorbothane 0 A
Chewing Gum 20 OO

TireSmokin7 · #6 (**permalink**) 01-14-2007, 02:24 PM

Bla bla bla...

Testimonies From Delrin Lube Groove Bushing Users

Quote:

Originally Posted by hotrodrx7

I have them on my car. They are really well made and the ride is not harsh at all.

http://www.rx7club.com/showthread.ph...53#post6075053

Quote:

Originally Posted by unnerv

As far as handling is concerned there is a noticeable difference in the curves. The car feels SOLID. I just had a base alignment done for now so the car wasn't so twitchy. I plan to get it corner weighted in the next month or so. Turned out the caster on one of the front corners was off by 5 degrees which shows how shot my old bushings were. Everything is so tight now. No longer hit my head on the roof over the expansion joints, no clunking, incredible in the corners.

After driving for a couple of days I noticed the car is a bit noisier, esp at low speed you can hear the diff. So if you are sensitive to noise you may want to skip the diff busings and stick with rubber. Once up to speed it is drowned out by tire noise and such tho.

http://www.rx7club.com/showthread.ph...47#post5723447

Quote:

Originally Posted by unnerv

The ride is not bad. If you check back a couple of pages I left some comments. It is a little noisier overall, but nothing to complain about. Unfortunately I have never ridden in a stock FD so I can't compare. I bought mine with tien coilovers. Since I had 130K on the stock bushing/pillowballs the ride actually is less harsh after the bushings.

http://www.rx7club.com/showthread.ph...65#post5769265

Quote:

Originally Posted by fd3s7007

excellent product. i swapped them in together with all other pillowball and lets just say its smooth and responsive. i'm on stock bilsteins and its not as noisy as anticipated. my exhauset is too loud to actually notice reported drivetrain noises so its all good.
tiresmokin7- is an excellent seller. shipped items out to Malaysia at no extra cost and they arrived much earlier than expected. Thanks matey!!

http://www.rx7club.com/showthread.ph...84#post6097884

Quote:

Originally Posted by byrden

I'm surprised these bushings aren't on more running cars, maybe people are too busy having fun.

I just finished installing all bushings, but at the same time I replaced the stock springs with an Eibach Pro kit. Also replaced the 6 pillow ball joints. The car has about 99k miles.

I was able to get by with a 12 ton harbor freight shop press, and various sockets (including some 4X4 hub sockets) that I had sitting around the garage. It was tricky getting some of the suspension peices in the right configuration with the sockets, but I was able to press out/in every peice.

The car goes on the rack tomorrow, but I did take the car for a drive. Wow, even with the car out of alignment, the car is so much tighter. Before the car was downright dangerous (in a bad way). Passing cars on a two way road (where the road is high in the middle) the car felt barely in control, and the rear end was out of control around turns at seemingly low speeds with light throttle. After installing the delrin bushings and new pillow ball joints, the car feels like a go cart. The steering wheel doesn't pull all over the place when driving through ruts at traffic lights. The rear end is much more composed around turns.

At normal cruising I barely notice much difference at all. Under medium to heavy throttle and higher rpms seems to transmit more noise into the cabin, but its not objectionalble (to my taste at least). It almost seems as if the exhaust is a little louder. I hear a slight bit more gear noise in first and reverse gears but once in third gear I couldnt notice any more noise.

As for ride quality, it did not seem any rougher than before the bushings. Maybe it was my imagination but it seemed like the suspension moves more freely. Much to my surprise, the effect on ride quality (in my opinion) was minimal to not even noticable.

Overall, I'm impressed. Almost no effect on harshness or ride quality, a little more sound from the exhaust and rear diff (which I don't mind), and the car is much tighter and easier to control.

Now I can't wait to really work this car once I get the alignment tomorrow.

Thanks again Steven for this excellent group buy.

http://www.rx7club.com/showthread.ph...87#post5928387

Quote:

Originally Posted by Unknown_ssk

the turns feel really good but with only the fronts installed the car feels squirly in back compared to the front. i'm installing the rears in december, as i am in college and have no access to tools or anywhere to do the work. i can let everyone know if they want to wait that long...

http://www.rx7club.com/showthread.ph...93#post5944293

Same person 100 miles later posted this on TC?

Quote:

Originally Posted by BlackR1

I installed the front ones already and have driven on the front ones for approx. 100 miles. the car ride isn't to harsh at all. i have all original equipment suspension wise. the car did have 140k miles on it. the driving difference in the front is incredible. the front of the car handles corners no problems. now all i have to do is take care of the back ones...

http://www.torquecentral.com/showthr...829#post345829

Quote:

Originally Posted by Julian

The nylon, delrin, rigid polureathane bushing question and the JimLab nylon delrin debate.

First yes, Delrin (r) is a DuPont tradename product and still only source for momopolymer Acetal just as MS is still sole source for "Windows (r)". A simlilar product ,"Celcon (r)", copolymer Acetal is available from Celanese, copolymers are easier to produce but have reduced mechanical properties.

This does not make Delrin better or worst than polyamides or nylon as it is known, only newer. "Nylon" was also a DuPont invention and tradename that was not protected as well. Delrin was later developed by duPont as a simliar application plastic that had outstanding abrasion and fatigue properties.

The attributes of these materials for the required application is what is important, not the source, name or price. In no particular order:

1 machinability - can you make the bushing as desired (Delrin best) (Polyureathane molded no machined)
2 abrasion restistance - will the bushing wear out with dirt and road grime (Delrin best)
3 stiffness - is it stiff enough for function, rigid without harshness (otherwise use metal on metal)nylon delrin similar, Poly softer
4 fatigue resistance - with it break down after prolonged use and get sloppy (Delrin best)
5 impact strength - toughest to weakest: Delrin 1.4, Celron 1.3, Nylon 1.0, Poly ~ .7
5 dimensional stability, dry wet, oiled, tared etc. - will it swell up and bind or srink and get loose
6 low friction, for linear stiffness - will it bind, does it need lubricating - Delrin more self lubricating than nylon which in itself is good.

You pick!

http://www.rx7club.com/showpost.php?...2&postcount=40

andrewb70 · #7 (**permalink**) 01-14-2007, 02:42 PM

So glad I don't have a hard on for FDs....

Andrew

TireSmokin7 · #8 (**permalink**) 01-14-2007, 02:47 PM

How much is a bushing kit for the FC, $115?

highwayinthesky · #9 (**permalink**) 01-14-2007, 02:55 PM

i would like to know about the fc bushings aswel, i need new ones so why not go with the best ones i can find?

TireSmokin7 · #10 (**permalink**) 01-14-2007, 03:14 PM

I was close!

$109 for Urethane bushings.

http://www.amazon.com/Energy-Susp-Su...8&s=automotive

In comparison Delrin bushings will be about 5x more at $538. :yup:

http://www.mazdatrix.com/rmounts.htm

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