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I would rather be driving
 
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Tyson, if the compression adjustment is inside the strut tube then it is only blocked from external adjustment. Once set it should not be an issue unless you wanted to change between street and track settings.

Sherwood, I had the same idea. It would be great to remove the spindle, thread with 2" coarse on the inside and then spin them down a set of double adjustable circle track shocks. The a-arm would need to be modified so that you could run aan aftermarket ball joint. Shouldn't be too hard to weld a late model end to a steel a-arm. These types of dampers are found really cheap. That is what I would do with the extra Boge struts laying around...

Erik, it could be done but would take a while. The issue becomes how close to the edge you can remove material. A die-grinder stone will wear with a rounded profile and a drill obviously has a point. both of these prevent a clean edge for the part line between the strut tube and spindle. You don't want to puncture the tube as then you can't fill it with cooling fluid.

Now if you have a good drill press you could do plunge cuts with a mill bit jigged in the Jacob's chuck. This would work just as well and is effectively the same as what I did on the mill.
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Old 06-25-2009, 01:49 PM
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JP.. you've shared the trade secret.. we do the Bilstiens the same way ! Curses.. no more black art!

Nice work..
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Last edited by onboost; 06-25-2009 at 05:35 PM..
Old 06-25-2009, 02:16 PM
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I don't think it was that big of a secret. Yep, Bilsteins are done the exact same way.
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Old 06-25-2009, 02:38 PM
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I know of someone that has a set of Bilstein spindles lowered to "RSR " height, if anyone is interested PM me for contact info. He offered them to me but i'm using OEM struts on my RSR build, won't be dropping it that much.
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Old 06-25-2009, 02:56 PM
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FYI,

Check out the Koni front strut double adjustable conversion by TrueChoice on page 10 of 32. It has adjustment screws at the bottom of the strut.

http://www.truechoicekoniracingservices.com/TKRS_2005_Web_Catalog.pdf
Old 06-25-2009, 03:01 PM
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I knew it could and I see it can be done! Thanks for the link.

Now to figure out what insert they use for that application.
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Old 06-25-2009, 03:09 PM
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I belive they note using a Koni Boge or Bilstien as all being convertable to Koni external dual adjustable.
Old 06-25-2009, 03:31 PM
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I'm reading the 8611 as dual adjustment, with one being on the side of the insert near the bottom.

The 8610 (halfway down this page) appears to use the same removable white knob on the top for rebound only.

http://www.koniracing.com/8611.cfm

https://935motorsports.com/catalog/product_info.php?products_id=1171

the stock Boge is 14.5" internally bottom to lip.

there is one insert that is about 11.5" body length (8610-1436 Race), which would allow me to remove 3 inches of the stock Boge strut tube. However, it only has 5.5" of travel. Would that be enough on a street car? Probably not...

the 8610-1437 has a 13" body, which would allow me to remove 1.5". I currently have about 2 inches compression travel from static. At 3.5" (2+1.5), this would put me about in the middle of the 5.5" travel and be similar to the amount you guys are doing with the spindle mod...

the OD is correct at 1.7ish inches.
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Old 06-25-2009, 06:11 PM
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JP,
If I could ask a favor, and get you to measure your Boge strut tube bottom Dia. The reason I ask is I found some sticks of 50mm and 55mm tubing. If the Boge strut spindle is either Dia. I could convert Boges to use Bilstein or Koni inserts or just lower the spindles with new tubes. Plus, saves me some money before I go out and purchase a set of Boges.
Thanks
Tim
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Old 06-27-2009, 10:57 AM
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Since you're in the fabricating mode, how about high strength al tubing instead of steel? Machining would be easier + lose a few lbs of unsprung weight too. Top and bottom details might be a little more difficult to replicate however.

Just thought I'd contribute a brain fart.

Sherwood
Old 06-27-2009, 11:26 AM
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Tim, I do not have a set of Boge. I pulled the picture from the archives. The diameter of the lower section of my struts is 50mm.

Sherwood, Al would be great. I don't know how you would attach the steel spindle assembly. Of course, why not make a spindle assembly that mounts to an eared strut housing like most modern cars? That would be seemingly simple to do. I wonder if there is enough meat to weld some vertical adapters. But then how would you attach the ball joint?

Anyway, the project is not dead. Its only taken me 3 weeks to move the spindle back into the correct position. I just have had very limited garage time lately. I managed to move the spindles down to the correct position of 17mm. This was done by heating the spindle with a rosebud tip in the oxy acetylene torch and then shock cooling the strut tube on the inside with cold water. You all must realize that on 100+F temperatures in TX right now, heating is easier than cooling. The thermal difference was enough to allow me to move the spindle approximately 2mm per heat cycle when motivated using the deadblow hammer.

Tonight I was sick of working late and decided to fire up the welder. So the garage thermometer still reads 102F and I slather on the sunscreen and get to work. you must protect against UV burn and it was too hot for sleeves.

The spindles are now welded up. I ran a bead around the top and bottom of the spindle where it meets the strut tube. I also filled the milled section with a rosette weld. This was the first time welding up such a big hole. It turned out OK. Given that there is a weld bead on top of a spindle that took 10 tons to move I am not concerned about longevity.



Next step is to weld on the gussets. I have the stock but it was too late to cut metal with the disc wheel. maybe tomorrow.
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Old 07-15-2009, 07:27 PM
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I am amazed at the effort required to move the spindle on the strut tube.
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Old 07-16-2009, 05:27 AM
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I think Clint at Rebel Racing dose it for about $250.

It is another $200 or so to have them decambered at the same time.
Old 07-16-2009, 06:18 AM
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Quote:
Originally Posted by CBRacerX View Post
I am amazed at the effort required to move the spindle on the strut tube.
Me too, I cant imagine why the original designers.manufacturers would insist on an interference fit that tight. Seems like the welding would more than provide enough strength....maybe not.
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Old 07-16-2009, 06:29 AM
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JP
Thanks for the info. Don't forget to raise your brake line mount up also, otherwise you will have to bend the hard line the distance you raised the spindle.
Tim
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Old 07-16-2009, 08:31 AM
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Jamie - you raise a good question above. Do Koni's really require a cooling fluid in the strut ??
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Old 07-16-2009, 09:14 AM
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Tim, Thanks for the reminder on the brake hose boss.

Bob, Koni sealed inserts do not require cooling fluid. Although, Its not a bad idea for any sealed insert. Internal fluid can help transfer heat out for hard working suspension. The friction created by squirting hydraulic fluid through a small orifice can create a bit of heat. Overheating would only occur where the damper was under constant, high travel conditions. Think off-road, rally.

However, some Koni inserts had exposed internals where the strut-tube held the fluid for the damper to work. This was the style of the original inserts in this car. I will post a picture when I get home.
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Old 07-16-2009, 09:53 AM
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Nice job Jamie

The service by Truechoice is great for damping adjustments, but isn't the goal here raised spindles? I don't gather from Truechoice's description that they raise and/or decamber the spindles for us. I think for that kind of money, i'd instead choose a solution like Rebel Racing's Bilstein service. Rebel can also provide adjustable Bilsteins for a cost and I suspect you'd still end up ahead cost-wise with the decambering and raise spindles.

I do like how the Koni insert fits into a Boge strut better than the Bilstein-Bilstein strut-shock assembly which is unnecessarily complicated with the roll pin, strut tube radial seal, greased inner strut tube, strut bushing. The Koni and Boge are much simpler with their gland nut securing the strut insert.

One other upside besides damping adjustability is their coilover conversion. But then that begs the question what diameter spring do they use?
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Old 07-16-2009, 02:34 PM
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This is a most interesting discussion. I didn't know the Koni strut had the mysterious bulge a useful distance up from the spindle. I've never understood why Boge does this either.

Eric - yes you can cut the spindle loose with a die grinder and drill press. I did. Not pretty, but the tubes were bent so I didn't care about cutting through the tube (though I didn't). And you could weld up the hole if it mattered, or weld a piece over it so you didn't intrude on the innards. Note the krinkle marks where the tube was bent.




JPN - the picture of your press got the wheels turning. I don't have bench room for the usual kind, but I can mostly make one like this, I think. Pressing is a lot better than beating with a sledge. Picture shown.



I've thought of just using new tubing. If a guy had the tools he could thread the top. Or just cut off a stock top for its threads and weld. The bottom would be trickier. I suppose a large lathe could be used to cut off the ball joint receiver piece and turn it so it would slip into the new tube, ready for welding. Or one could get more creative with US roudny round parts for this function.

Aluminum (especially threaded) sounds intriuging. Is it strong enough for the application? Will it fatigue? Recall that the stock struts will bend (kink) at the spindle collar (hence reinforcing, though I think that just full circle welding on the bottom especially may cure this). And big wheel spacers/wider track will increase the stress here.

While it may make sense to reposition the brake line attachment, that is the least of one's worries. You can kludge this any number of ways. My roller track car came with a bracket which bolts on as if a washer under the top brake caliper bolt.

I have never liked the leverage looks of the long bolt styel bump steer pieces. Maybe they are no trouble at all, but is is so easy just to weld on a bracket with a hole in its end to reach out from the strut and capture/reinforce the bottom of that assembly. That's something I saw in Dave Banazek's (Dart Auto) own car, and I'll do if ever I need to.

Bill A: With your early suspension you can regain full shock travel and reset your bump steer pretty easily. Have a spacer machined to match what was sectioned out on top of the strut tube, and using longer bolts insert it between the steering/ball joint holder arm, and the strut.



This is a slick deal, and I like it so much I have put off converting to newer struts. However, if one runs these 40-45 year old parts on the track, it is a good idea to reinforce the forged cantilevered spindle assembly. I used the piece I sectioned off to build a perch for the coilover threaded tube.




With these early struts you can have an aluminum piece machined to hold 3.5" brake calipers (or any other size/location you might wish) to replace the steel stock fitting. In addition, since the strut tube proper on these early cars is symetrical, you can carry just one spare. This comes in handy if you haven't gotten around to reinforcing things, and watch a wheel, with brakes attached, roll off ahead of you. The forging can break right off where it sockets into the tube.



The Koni shocks of my acquaintance all have a steel peg on the bottom. This has no function other than as a spacer. So you can cut it off, and section out an equal length of strut tube below the threaded part, and come out the same. In my case, the section is a bit shorter than the resized shock, so I have to drop a washer or two down in the tube to shim the shock up so the collar will hold it tightly.

Sectioning strut tubing is not difficult. A chop saw with an abrasive cutoff wheel will make a nice 90 degree cut. I bevel the edges before welding, to be sure of penetration with my el cheapo MIG, and to allow me to grind off the excess while still leaving a fair amount of weld. If a guy isn't using coilovers (and the need to slip a threaded collar over the strut), grinding probably would not be needed. To be sure the tubes are perfectly lined up for welding I use an exhaust pipe expander (which never was strong enough to expand anything for me) inside the tube and tightened up for the first tack welds.

Given my welder and lack of skills, it was with some trepidation that I did this welding, but I have many years now on these welds with no issues.

Walt Fricke
Old 07-22-2009, 11:41 AM
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Walt, Excellent information. I like the spacer idea for the early struts.

I just thought I would wrap up the modification.

I moved the brake line bracket. simply scribe the location on the strut. Grind the three welds. Smooth the strut tube (important for the topmost weld). Reposition the bracket by the height of the spindle movement and re-weld. Took about 20 minutes.

next, I bent the ackerman arms down. First the goal was to restore the original tierod end position. then I figured I could correct some more bump steer. Let's just say I dropped them about 30 mm. I raised the spindles 17mm. This is a net reposition of 13mm.

The process was easy. Get out the rose-bud tip. Put lots of acetylene through it. clamp the strut tube in a vice. heat the ackerman arm just in front of the forward brake shield mounting hole until cherry red and start bending the arm downward. Let it cool slowly. Then repeat the process with heating just inside the tie-rod end hole. I wish I had saved the dead tierod ends to prevent distortion. I don't think I did any dimensional changes but it would have been a nice safety factor.

I measured from the top of the strut to the edge of the ackerman arm to ensure that both sides were dropped an equal amount.

When its all said and done it was time for a coat of primer, some new color and then a pair of new adjustable inserts.

The finished product.




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Old 07-31-2009, 07:25 PM
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