Poly Bushings

[inheritthefire]

Re: Poly Bushings

http://www.gvperformance.com/store/i...&productId=302



k member

When it says that "Works with stock a-arms or any aftermarket a-arms (minor modifacations required)" what modifications does it mean?

(Also, misspelled modifications is a turn off to me for credibility... but then again, that's just a pet peeve of mine.)

[ssms5411]

Re: Poly Bushings

PA Racing makes them, ^ probably best place to get it is what VR4GASM posted. I got mine, brand new from a member for $240 shipped. Price shopping does wonders. Got my progessive methanol kit for $300 normally $550. My turbo normally goes for $1600-$1700 and I paid $1300.

[inheritthefire]

Re: Poly Bushings

Price shopping does wonders.

I went through my list (I've got an excel sheet with the parts, numbers, specs, price, and places available) and compared prices... Summitracing.com had the best price on everything so far, except for the K member.. The original K member I was looking at was a BMR one, and this one is a bit over $100 cheaper.

[inheritthefire]

Re: Poly Bushings

I think I have spent at least $5000 in suspension with rims/tires, drag radials, skinnies and suspension parts the Tub K ,A arms ETC. So it adds up over the years.

Yeah, I added up
BMR Tubular Upper Control Arms
BMR Tubular Lower Control Arms
BMR Tubular K-member
BMR Tubular Non-Adjustable Panhard Bar
BMR 32mm Hollow Front and 21mm Solid Rear Sway Bars
BMR Torque Arm
BMR Tubular Lower Control Arms
Bilstein Suspension Kit

all of that and it came to about $2600 shipped from Summit Racing.

If I added on the rim/tire combo I want I'd be up around 4 grand, no doubt.

[ssms5411]

Re: Poly Bushings

Yeah it def. adds up , my LCA's and Panhard rod are adj. chromoly and the QA-1's added alot along with the rims/tires for street and strip.

[inheritthefire]

Re: Poly Bushings

Yeah it def. adds up , my LCA's and Panhard rod are adj. chromoly and the QA-1's added alot along with the rims/tires for street and strip.

Hmm... Is it worthwhile to go adjustable? One of my friends put adjustable tension rods on his 240sx, and they've just caused him a headache because he can't get them set right...

I was wanting just a get in and go, no muss no fuss kind of set up. It's *technically* a DD, but that's getting to be different as time goes on, as I won't be driving it in the winter months anymore.

[ssms5411]

Re: Poly Bushings

Mine were set about 9 years ago, ha them 10 years now and I haven't touched them , since they centered everything. The tires side to side and in the wheel wells so everything is even. I think when they messed with them when they installed the new rearend. So it would be up to you, I like adjustability thats just me though, just like I wanted the chromoly LCAS and Panhardrod.

[inheritthefire]

Re: Poly Bushings

Mine were set about 9 years ago, ha them 10 years now and I haven't touched them , since they centered everything. The tires side to side and in the wheel wells so everything is even. I think when they messed with them when they installed the new rearend. So it would be up to you, I like adjustability thats just me though, just like I wanted the chromoly LCAS and Panhardrod.

Is the chromoly worth it? Cost vs Weight wise, at least?

[ssms5411]

Re: Poly Bushings

I don't really know I just bought them when they had a sell on them from RK Sport 10 years ago. If your not worried about weight just get the regular, there not too much difference I don't think.

[inheritthefire]

Re: Poly Bushings

I don't really know I just bought them when they had a sell on them from RK Sport 10 years ago. If your not worried about weight just get the regular, there not too much difference I don't think.

Okay, good deal... It saves me a few hundred dollars going with regular steel over the chromoly stuff.

And if I did my research right, I think the chromoly only comes out to be 1 lb/ft^3 better... which is better, no doubt... but even so... 1 lb?

Sources: http://hypertextbook.com/facts/2004/...therland.shtml
Mild Steel Density - 490 lb/ft^3
http://www.suppliersonline.com/propertypages/4130.asp
4130 Chromoly Steel Density - .283 lb/in^3
http://google.com
For conversion, .283 lb/in^3 = 498.024 lb/ft^3

[ssms5411]

Re: Poly Bushings

I was alot younger 10 years ago and didn't reesearch it as much, just saw them having a sell 20% off something like that and just bought them. I'm glad you did your research you'll save alot looking around on craigs list, ebay and the forum also.

[inheritthefire]

Re: Poly Bushings

I was a lot younger 10 years ago and didn't research it as much, just saw them having a sell 20% off something like that and just bought them. I'm glad you did your research you'll save a lot looking around on craigs list, eBay and the forum also.

Yeah, I think the price difference on some of the parts was pretty ridiculous.

And, taking LCAs as an example:

The price difference is $30, from Summit Racing.

The LCA uses roughly 4.854 in^3 of metal in the standard steel assembly, and roughly 3.397 in^3 in the chromoly, given that the standard steel tubing is 1.625" OD with a thickness of .12", and length roughly 16.45". The chromoly is 1.625" OD with a thickness of .083", and the same length.

Next, given that the density of standard steel is .2836 lb/in^3 and the density of chromoly steel is .283 lb/in^3, the weight of the standard steel LCA is approximately 1.377 lbs, while the chromoly LCA is approximately 1.374 lbs.

That's a difference of .003 lbs, or 1.36g. That is roughly the equivalent of HALF OF A PENNY, meaning buying both LCAs in chromoly would only save you a penny's worth of weight.

You could save more weight by emptying your coin holder, or by vacuuming the carpets.

Correct me if I'm wrong, but that doesn't seem like a good bargain at all. However, if the price was 20+% off, that would make it reasonable to go with chromoly, as the price gap would only be $4. Also, the weight savings would depend on how much chromoly you used. I would imagine on a part such as the K member it would make a much more significant impact, and (if you're of the mindset) you could always argue that every little bit matters.

P.S. - I'm really bored and needed something to do, hence the lengthy calculations and whatnot.

[ssms5411]

Re: Poly Bushings

I didn't understand any of the math,LOL but if I remember right it was 20% off and free shipping. The K member and lower arms were and big difference in weight, the upper tubular A arms were just a little lighter, not much but I needed new bushings in the joints and what not so I figured I would buy them and they were on sale also so between the K member and A arms it was about $900 since I got the K member for $240 shipped and got the K member and lower A Arms installed for $100 and I did the upper A Arms myself.

[inheritthefire]

Re: Poly Bushings

I didn't understand any of the math,LOL but if I remember right it was 20% off and free shipping. The K member and lower arms were and big difference in weight, the upper tubular A arms were just a little lighter, not much but I needed new bushings in the joints and what not so I figured I would buy them and they were on sale also so between the K member and A arms it was about $900 since I got the K member for $240 shipped and got the K member and lower A Arms installed for $100 and I did the upper A Arms myself.

The math looks more complicated than it is... I took the volume of the entire shaft, if it were whole, and subtracted out the hollow part.

Basically, (pi)(Diameter/2-wall thickness)^2 gives the cross-sectional area, and then you multiply by the length of the pipe to get the volume. then multiply by the density of the material.

The k-member for 240 is a steal, and why did you get the lower A arms installed? Are they hard to do? I know the k-member is a pain...

[ssms5411]

Re: Poly Bushings

^ lol o.k.