the BEST DIY rear cross member?

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rnorrish
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Post by rnorrish » 12 Dec 2006 23:22

i was reading that discussion ... i started Kelvin's "Crazy Canuck" think years ago. Shasta 2001.
250# coilovers, aluminum race seat, 1800 with 44 Mikunis, 4.62 diff.
12 hour drive to Shasta.

he couldn't believe it when i met up with them after crashing at the Vandercouving's place the night before. what a convoy - so much fun. the only person was with worse gas milage, oddly, was Lum with his EFI V6!

even then he was saying he'd love to try it someday. then he tried to sell me a set of bump steer spacers ;)

yes duke, you're a rare bird down there. maybe we can call you an honourary Canadian! :)
hence the PM's earlier this week - shhh.
richard norrish
'68 'goon resto / '71 ice racer / '72 'goon project / '70 4-door rust pile / '67 520 project
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Baz
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Post by Baz » 13 Dec 2006 03:34

duke wrote:Baz, do you guys machine those in-house?
No we do the design then sublet them.
The guy that does our work, has 9 axis machine & makes 4 barrel carbs
with variable jetting.
He will be doing our QTBs for our L4 injection kit.

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Baz
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Post by Baz » 13 Dec 2006 03:46

Two points here i guess.
for a race/rally car its rose/heim joints everywhere.
Noise is not the issue. Nor is the ride as long as its doing what you want.

For a porche,WRX,V8. R32/33 street killer driven on most days.
Quiet drive trains & muffled interiors are nice.
Also help keep the cops away.
With a well set up transient suspension you will out handle most cars on the street
AND your ladies wont have to wear sports bras.

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Post by marks510 » 13 Dec 2006 17:26

so how much for the DIY datsport adjustable rear subframe? basically all the hardware plus what i need to do to mine? I think round trip freight on a cross member to you guys would cost more then the modification!

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defdes
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Post by defdes » 13 Dec 2006 17:47

I think its about $480 US w/o shipping.

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duke
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Post by duke » 14 Dec 2006 00:05

Thanks Rich, I'm honored...just as long as I don't have to associate with those French Canadian weirdo's...I have spent my fair share of time in rural Quebec and I have to say, very strange. My one visit to B.C. was awesome, one of the few places out of California that I would love to move to in the future...mmmm, Whistler (I have a snowboarding problem).
Duke Schimmer

'72 2-Door 510
"Simplify and add lightness."

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Post by bertvorgon » 14 Dec 2006 07:34

Baz is spot on...on all fronts. A well set-up suspension, WILL out handle just about everything out there.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

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1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
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1971 Vintage 13' BOLER trailer

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defdes
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Post by defdes » 31 Dec 2006 16:36

So I am ready to have at it...
I think I am going to try Byrons method, I was going to do the DATSPORT one, but the slotted thru bolt seems like alot of work.
Anyway, I will replace the slottted outboard attachment points with single 5/8" holes, then redo the inboard mounts with the slotted plates. One bit is still unclear, I am going to use spherical bearings centered in the trailing arms, with a machined aluminum bushing on either side to act as the old poly one. My questtion is, the hole thru these bushings should be oversized, correct? in order to allow the spherical bushing to do its thing?
Here is the D.P. set:
http://www.designproductsracing.com/Por ... CF0015.jpg

I dont fully understand what all of those bits are for, tho it looks like the annodized/plated (yellow bits) are shouldered to fit into the sperical bearing.
Attachments
crossmember2.JPG

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thisismatt
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Post by thisismatt » 31 Dec 2006 17:27

defdes: My theory* is that the taller cylinders go on the "insides" of each side of the arms, then slide in the spherical bearing, then slide in the shorter cylinder to hold the bearing in place. Then the yellowish cylinders go on either side of the bearing and the washers after that.

*I've never seen them installed ;)
I'm your huckleberry.

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duke
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Post by duke » 01 Jan 2007 12:47

Defdes, the set that you linked to is for using the STOCK bolt for attaching the rear control arms. The zinc plated pieces are to locate the spherical bushing in the middle of the control arm mount and adapt the ID of the spherical bearing to the size of the stock bolt. What I would recomend doing is using a 5/8" shoulder bolt (or some kind of other bolt with VERY high machining tolerences***not from hardware bin***). By using this you would only need two 5/8" ID sleves to locate the spherical bearing in the center of the trailing arm mount. I'm not sure how clear that was, I could draw a picture, or maybe Byron has some pictures of his setup.
Duke Schimmer

'72 2-Door 510
"Simplify and add lightness."

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defdes
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Post by defdes » 01 Jan 2007 13:13

duke wrote: I could draw a picture, or maybe Byron has some pictures of his setup.
Would you? I think I get it, but I don't want to re-invent the wheel...or bushing, as it were. I like that D.P. set up, but it's too spendy, and I have a lathe and access to a press, so I should be good to go with the proper info. :wink:

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Byron510
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Post by Byron510 » 01 Jan 2007 14:15

On the Bronze, I have a 5/8 Gr.12 (aircraft) bolt that goes through the spherical (ball) bush, with a sleeve on either side to locate the control arm. A sleeve is also made and tack welded into the control arm to locate the outer diameter of the bush in the control arm.
Unfortunately, I don't have a photo, I'll see if I can do a quick sketch.
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Post by Byron510 » 01 Jan 2007 15:00

No apologies for the quality of the drawing or lack of dimensions I only spent 5 minutes on it. But you'll get a pretty good idea of what I do on my cars.
I make the inner sleeves out of 304 SS, so that the bolt can not corrode to the sleeves, and make dis-assembly imposable. A good amount of Never seize or Copper Slip during assembly on any steel parts would probably be fine – up to you, if you have any SS around I'd use it.
I've also shown the locations of the tack welds on the outer sleeves, that are made from mild steel. A .001" press fit on the outer sleeves into the control arm is what I shoot for; but honing or reaming of the bore in the control arm will first be necessary to fit the com10 bush - the 30mm dia, would mean a .0064" press fit which is excessive - if you even got it together! .001-.002" would be sufficient for that diameter.
Byron
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RLCA Mount003 (Medium).jpg

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duke
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Post by duke » 01 Jan 2007 20:33

Awesome, thanks Byron, thats exactly what I was going to do!
Duke Schimmer

'72 2-Door 510
"Simplify and add lightness."

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defdes
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Post by defdes » 14 Jan 2007 11:25

I am about ready to start welding all of the parts together, but I had a question regarding placement of the new unit. I wanted to retain as much meat as I could on the outer "ears" that handle the toe in adustment. As I have it now, in order for the head of the larger 5/8" bolt to clear the ears, I need to pull the "slotted yoke" 1/4" AWAY from the cross member. In other words, in the stock location, the bolt is 1 1/4" on center away from the cross member, the way I have it here, it is 1 1/2". This position will just put the whole rear swing arm closer to the 3/16"-1/4" toe in that I am looking for, correct? Or will it cause any interfernce I am not thinking of?
Attachments
diy3.JPG
diy2.JPG
diy1.JPG

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