Limits of HDPE

[sifu]

For anyone who has experience with the HDPE spacer tops

 

1- Is there a limit to how thick I can make HDPE top spacers? I'm considering between 2-3 inches.

 

2- I want to verify that outback sport and outback legacy front top hats will match. Here is a link to the templates I hope to use-

 

http://www.subaruoutback.org/forums/99-do-yourself-illustrated-guides/31520-diy-strut-spacer-lift-templates.html

 

 

Thanks a ton for the help on this one.

 

Chris

Edited December 16, 2011 by sifu

[monstaru]

I just literaly started cutting some out the other day. I am going 2".

I decided I wanted to try some plastic, and it seems like it will work.

 

The HDPE is torsionally resistant to about 45000psi.UHMW is like 57000.I may have those numbers backwards.

The folks at Laird Plastics that I talked to Locally were not even close to worried about the plastic being the problem.

With the loads being mostly from the downward force it should not be an issue at all.The thing to worry about is the longer bolt.(Since it will be taking almost all of the load from sideways moevement.

Properly torqued and inspected regularly , it should be fine though.Imean we are talking about grade 10 hardware(which is what I will use)

 

I will post some pics up later, as I will be finished fabricating them later today.

 

Go to your local junkyard, and undo a front strut top from any legacy(preferably while standing on the other side of the car so you do not get hit with strut pieces and such)then do the same for the rear.(once again not standing in front of it,I just do it from the inside of the car.)

 

Then you have your own templates.Obviously get your rear templates from the same knid of car you have acquired struts from, as these are the ones that changed over the years.I used a bandsaw with wood blade,and a spade bit in my drill press.

 

I had previously made some metal strut blocks, but the rears weere not lined up right due to hurrying at school.SoI will def. be using the plastic for the rear, but MAY use them for the front too...

 

I am not an engineer, but I have rednecked the hell out of some thingds, and am not worried in the least that this plastic will break.I used UHMW as it is used in alot of skidplate applications for rock racing rigs.I have seen BIG rigs come down hard on 1/2" skidplates and do no damage.So I doubt very highly that using them as spacer blocks will end up with disaster(provided the fab is done properly.straight up and down holes.etc)

cheers

 

You do realize that ifn you do strut spacers this big, you will almost surely need to add subframe blocks frot he front and rear subframes too , right?

Edited December 16, 2011 by monstaru

[Dylan]

I just literaly started cutting some out the other day.

 

LOL, I started cutting some out today. My friend helped me cut one out on a CNC router....way too much time and effort ended up with a fairly messed up spacer the way we mounted it to the table. The second spacer will get cut by hand with a jigsaw and a drill press.

 

I am making 1.25" spacers for the rear of my Legacy SUT. I will use the best 5/16 bolts Home Depot carries-most likely grade 8. I'm going to lift the front with junkyard 1st gen Forester struts for a 2-3" lift.

 

The plastic was either Delrin or UMHW. I can't remember what the guy said it was. A 12"X6"X1.25" chunk cost me $9.

 

I personally wouldn't go more than 1.5" I would assume the camber would get a little hard to fix with a 3" block?

 

I have a DXF file of the rear spacer if anyone is interested.

[Idasho]

Ive had some first hand BAD experience with Delrin HDPE.

 

Subframe bushing for my SHO Taurus.

 

While it may be a great material for some things, I will never use it for anything related to any vehicle suspension again.

 

It compresses over time... requiring a re-torque... again... and again.... resulting in a potentially dangerous situation.

 

 

I run solid subframe bushings aluminum now. Toque it once, and forget it.

[monstaru]

Delrin is different than HDPE.

Delrin is Acetal Homopolymer.

and

HDPE=High Density PolyEthelyne

 

There is a good explanation on this site.

http://www.spiratex.com/materials.php

cheers

 

 

Ive had some first hand BAD experience with Delrin HDPE.

 

Subframe bushing for my SHO Taurus.

 

While it may be a great material for some things, I will never use it for anything related to any vehicle suspension again.

 

It compresses over time... requiring a re-torque... again... and again.... resulting in a potentially dangerous situation.

 

 

I run solid subframe bushings aluminum now. Toque it once, and forget it.

[Dylan]

I run solid subframe bushings aluminum now. Toque it once, and forget it.

 

Aluminum was 4 times as much money for the same size of plastic.

 

I highly doubt I will run into problems with delrin strut spacers. The body lift on my Montero is 2" thick UHMW and I haven't had any problems.

[sifu]

Thanks for replies. Good stuff.

 

 

I've decided to mold some scrap pieces of HDPE and will build the blocks from there. If it goes well, I might make an effort to sell HDPE for strut spacers, considering that even thicker boards of HDPE aren't cheap.

 

Speaking of

You do realize that ifn you do strut spacers this big, you will almost surely need to add subframe blocks frot he front and rear subframes too , right?

 

Yup, unfortunately. I'm looking for some help on the subframe blocks, but outside of that, be prepared to be dethroned of the most badass obs title. Mine can make a nice run at it when its finished.