Lower Control Arm

[Spittybug]

Does anyone currently have theirs off the car? I'm looking for an accurate measurement between the pivot bolt (where it attaches to car) and the lower shock mounting bolt. I measured mine while on the car, but that only allows me to "eyeball" from bolt center to bolt center. With a good pair of calipers, near edge to near edge, along with the measurement of the hole diameters will give me as close as possible.

All the parts for my new LCA tubular brace have been sourced (steel tubes, grade 8 bolts and polyurethane bushings). I'm working out the best angle/pivot bolt length/brace length combination and think I've about got it using my close approximations of the above measurement. I use solvent welded PVC pipe for my mockups, but the real ones will of course be steel, probably painted with the truck-bed-liner-style paint that I've found works well on suspension parts.

I will make a welding jig from the prototype so that I can precisely repeat it. Nothing against the LCA braces already on the market; I just think I can make a better, cheaper mousetrap.

[Jeff K]

Does anyone currently have theirs off the car? I'm looking for an accurate measurement between the pivot bolt (where it attaches to car) and the lower shock mounting bolt. I measured mine while on the car, but that only allows me to "eyeball" from bolt center to bolt center. With a good pair of calipers, near edge to near edge, along with the measurement of the hole diameters will give me as close as possible.

All the parts for my new LCA tubular brace have been sourced (steel tubes, grade 8 bolts and polyurethane bushings). I'm working out the best angle/pivot bolt length/brace length combination and think I've about got it using my close approximations of the above measurement. I use solvent welded PVC pipe for my mockups, but the real ones will of course be steel, probably painted with the truck-bed-liner-style paint that I've found works well on suspension parts.

I will make a welding jig from the prototype so that I can precisely repeat it. Nothing against the LCA braces already on the market; I just think I can make a better, cheaper mousetrap.

Owen, mine are, I should be picking them up from the powdercoaters in a day or two. I can measure it for you. Although the powdercoater is notoriously always late on delivery for me..

[jmettee]

Mine are also, I can measure tonight.

[Spittybug]

Superb, thank you gentlemen.

[kenny]

All the parts for my new LCA tubular brace have been sourced (steel tubes, grade 8 bolts and polyurethane bushings). I'm working out the best angle/pivot bolt length/brace length combination and think I've about got it using my close approximations of the above measurement. I use solvent welded PVC pipe for my mockups, but the real ones will of course be steel, probably painted with the truck-bed-liner-style paint that I've found works well on suspension parts.

I will make a welding jig from the prototype so that I can precisely repeat it. Nothing against the LCA braces already on the market; I just think I can make a better, cheaper mousetrap.

Sounds interesting, looking forward to seeing the alternative to what the vendors are selling.

[jmettee]

My dial caliper is only a 6" & the holes are a bit farther apart. So this is not as accurate as you wanted, but I'll post the measurement anyway. Hopefully someone else will post with additional measurements.

I measured both sides of 1 LCA with NEW bushings installed. Holes were measured with a dial caliper. Distance between holes measured with a metal scale to the nearest 1/64"

Side 1: Hole 1: .502, Hole 2: .501, separation inside-inside 6.625". Result: 7.127 center to center

Side 2: Hole 1: .501, Hole 2: .502, separation inside-inside 6.641". Result: 7.142 center to center

Again, hoping Jeff K or someone else can give better numbers measured how you requested them to be measured.

[Spittybug]

Thanks Justin. From your measurements (including your caveats), it would infer that there is a left and a right LCA. DMCH shows only 1 on their parts page, but then again, they don't have any so maybe that's why.
Given the abuse these things can/do take, I wonder if that small amount of variance could be due to slight warping?

It will indeed be interesting to see what other dimensions we can get for comparison.

Thanks.

[jmettee]

Thanks Justin. From your measurements (including your caveats), it would infer that there is a left and a right LCA. DMCH shows only 1 on their parts page, but then again, they don't have any so maybe that's why.
Given the abuse these things can/do take, I wonder if that small amount of variance could be due to slight warping?

It will indeed be interesting to see what other dimensions we can get for comparison.

Thanks.

1 more caveat, I did need to do some minor repairs on both because there were slightly bent at the lower flange (incorrect towing & an accident are my guesses). The bulk of the control arm is clean/un-damaged in the area of the holes.

I would imagine there is some variability in the bushing too, which is obviously part of this measurement. Also, my side 1 & side 2 were the 2 sides of the same LCA. I didn't measure the second one. My measurements are within 1/64" of each other, which is about the best you can do with a straight edge. If I had easy access to a larger dial caliper, I'd get you better numbers.

[Bitsyncmaster]

My SS LCRs. Gap = 6.08", bolt hole 0.50" bushing hole 1.58"

Measurement done with steel ruler. I left my 6" calipers at work but I'm in the same boat without 12" calipers. These measurement should be about 0.01" accurate.

So C to C is 7.12"

[Bitsyncmaster]

My 6 inch dial caliper will work.

Gap = 6.089"
bolt hole = 0.503"
bushing hole = 1.554"

Not sure if the stock LCRs are the same as my SS LCRs but if your bushing is not installed, you can do it with a 6 " caliper.

[Spittybug]

Prototypes built, welded, painted and installed. Tomorrow I will drop it off the lift and test drive. I don't know what is involved with installing the Euro 317.93 ($416.46) kit from DeLorean Europe, but I know that I got mine done today in about 2 hours.



Raise car. I have a lift, but jacks would work. Ramps will not. I took off my wheel for the first one, but didn't even bother for the second.
Remove top nut from shock. Remove lower shock mounting bolt. Drop shock out of spring and through LCA.
Insert an internal-style spring compressor (free rental from O'Reilly). The easiest way is to slide the claws in through the springs (spread a little with bar) and then thread the rod up from below. Put the lower plate under the LCA and tighten.
Once sufficient compression of the spring has been achieved you can drive out the pivot bolt with the longer one without the LCA coming unattached.
Remove compressor, reinsert shock, drive home the longer bolt, install top nut to shock.
Put spacer on pivot bolt, fender washer, brace, fender washer and bolt.
Shock bolt also gets fender washer, brace, fender washer and bolt (no spacer).
Drink cold beer.


The braces are drawn-over-mandrel tubing with polyurethane bushings. The diagonal rod is schedule 40 pipe. Walls are all .12". They are saddle cut and professionally (ie, not me!) welded and dressed. The bolts are grade 8 (better than stock). Washers are stainless. Paint is tough truck bed liner.

I will report back on the test drive ASAP. Engineering wise, giving a greater "wishbone" effect than the other available units would certainly appear to be more in line with other LCA designs. No clearance issues and going with both front and back units was just overkill in my opinion. The hardest part in all sincerity was getting the compressor in and out of the spring! A couple of my pictures show the unit attached to the springs. ***WARNING*** Like anything else, the procedure above is use-at-your-own-risk. I did it without any problem whatsoever, but anytime you are dealing with springs you must be very careful. The safest way to do this work is to completely remove the assembly by following the shop manual instructions.

Here are the pics of my install today. Assuming test drive is as expected, I intend to make these available for sale. The price of the EU units is ridiculous in my mind; I'm leaning towards $275 delivered for all parts listed. They take a couple of days to make after ordering the necessary parts.

Feedback welcome.
PS. I'm always amazed at how much worse things look with flash photography! The shadows or glare makes things look uneven or not as good as they really are. The welds on these guys are nice!

[jawn101]

Wow, those look great. Hope the drive goes well!

[justlooking]

Consult an attorney before offering them for sale.

[Jeff K]

Nice work Owen!

I agree - flash photography makes things look so much worse.. I can't explain why. The harsh light reflecting maybe.

I did a suspension resto recently. I use a jack under the LCA's (with a block of wood and rag so not to scratch). I used the new bolt to drive the old one out like you did.

Jeff

[Nicholas R]

***content removed***
I don't know what is involved with installing the Euro 317.93 ($416.46) kit from DeLorean Europe, but I know that I got mine done today in about 2 hours.

The price of the EU units is ridiculous in my mind; I'm leaning towards $275 delivered for all parts listed. They take a couple of days to make after ordering the necessary parts.


Just FYI, you have to remember that the DMC Europe price INCLUDES the (very high) sales tax (or as they call it the value added tax.) Unlike in the United States, when they list a price in Europe, the price already includes the tax (unlike here where we add it after). Any time I buy from Ed Uding, he always sends me a revised invoice without the tax since I'm buying from the US. Currently the value added tax in the Netherlands is 19%. If you remove that, the actual price of the kit from DMC EU is only ~$340 (depending on the exchange rate).

Believe me this makes a pretty significant difference. I bought Ed Uding's radiator over the summer and I couldn't believe how much lower the price was after the price revision. It was less to purchase and ship Ed's radiator to me than it would have to purchase and ship DMCH's radiator to me, and Ed's is a pretty significant improvement. He also gives you options for shipping depending on how fast you want it. I used the slowest, least expensive shipping and ordered it on the Wednesday before DCS 2012. It arrived the next Friday (9 days later).

If you've ever looked at DMC Europe and thought about buying some of his parts, keep that in mind. They're more affordable than you think.

Anyway I didn't mean to hijack this thread. Carry on...

[Spittybug]

I have a call scheduled with the attorney this morning..... It's been rainy here so I haven't taken the car out for a drive yet. Maybe later today.

[Mark D]

Nice work, they look pretty damn good to me.

[Jeff K]

Great job Owen!

I have the EU ones on mine. I do notice a difference, for the better.

The car tracks nicer and is much more controlled under braking.

Best of luck with these. If this was available when I bought mine I would have choose yours for sure.

[DMC5180]

You don't need a spring compressor for that job. Just support the wheel with a floor jack.

[Spittybug]

You don't need a spring compressor for that job. Just support the wheel with a floor jack.
That would scare me and I would never advise it.... Yes, it would support the wheel end, but there would still be a lot of downward force on the pivot bolt that would be very dangerous when you tried to drive it out. Obviously to each their own, but I would never want to see anyone take unnecessary risk.

[DMC5180]

When you drive the old bolt out with the new bolt, nothing moves or becomes misaligned as long as you don't separate the lower ball joint and leave the shock in place while you change the pivot bolt first. All of the DMCEU kits are installed this way.

As you say too each his own.

[Spittybug]

Installation procedure aside.....

I test drove some more yesterday and so far so good! My car already had boxed LCAs and was stiffer than most to begin with. I'm going to try and see if I can get a remote camera down there and watch them in action. I have a rear view camera on a long cable that I should be able to mount in the wheel well. I just have to figure out the computer connection and software part......

What's the general view on these? Not looking for any commitments, but is there any interest out there other than those that have already PM'd me? I don't need to have a minimum number to justify building them, but since getting the DOM tubing is cheaper in longer lengths and combining shipping on bushings saves money, I'm just trying to keep costs down.

If I figure out how to get a video, I will. There is already video out there of non-braced motion of the arms. Can someone find it and repost here?

[ramblinmike]

http://youtu.be/CMHO4Aydk04

[DrJeff]

Is the purpose of the LCA braces to limit the forward/aft movement of the LCA? From the video posted you can see a good degree of forward/aft movement. I'm assuming this is not wanted as it puts too much stress on the joints at the frame.

[Spittybug]

Note to Mods.... I accidentally hit the "report post" button while replying to this... sorry! :spank:

Jeff, yes, to prevent or minimize the for and aft movement so visible in the video. I got my camera mounted behind the radiator and intend to shoot video from pretty much the same vantage point to see the difference. Modern LCAs are typically wishboned to prevent this undesirable motion. Lotus seems to have gone "cheap and cheerful" with this design for our cars. Hope to get video up later today.

[Spittybug]

As promised, here is the YouTube video I just posted. I've reexamined my initial price of $275 and decided that I can do $250 instead. That includes:



New grade 8 bolts (4)
New lock nuts (4)
Stainless washers ( 8 )
Polyurethane bushings, fully sleeved ( 8 )
Braces (2)
Shipping to US address (PM me if you are international)

I will offer these through my company, Neal Ventures LLC. As such, I am set up to to take credit cards via Paypal, but it also mean that I need to charge Texas sales tax if I ship to a Texas address. I'm not setting up a website or anything, so if you wish to order a pair (one per car side), please PM me as some of you already have. My company lawyer did advice me that I should get a waiver from each purchaser before shipping since this I don't have an "official" sales invoice with terms and conditions or limits of merchantability. See the photos in earlier post for finished braces on and off car.


http://www.youtube.com/watch?v=pfDMHgEVnrc

[Spittybug]

For the mathematically inclined, I offer the following givens or assumptions:

Car gross weight = 3180 lbs or 1443 Kg
Assume 60 mph or 96.6 km/h
Approximate stopping distance 164 ft or 50 m
Pi = 3.1416
F=ma
a=((final velocity)^2 -(initial velocity)^2)/(2*stopping distance)
area of circle = pi*r^2
Grade 8 bolt shear strength = 91,000 lbs/in^2
1 Newton = .2248 lbs of force


From these equations and facts we calculate the following:

96.6 kmh * 1000 m/km * 1 h/3600 sec = 26.83 m/s speed
using the above acceleration equation, a= -7.2 m/s^2 (neg because of deceleration)
This results in F = 1443 kg * 7.2 m/s^2 = 10,390 Newtons = 2,336 pounds of force exerted as the car stops

Since our force is on a 1/2" diameter bolt, (.25" radius), the shear strength of a grade 8 bolt is ~91,000 lbs/in^2 * pi * (.25)^2 = 17,924 pounds

Now lets look at the real situation;

There are 4 of these bolts with the brace set, not just 1
All of the force is not shear, only a % (uncalculated) of it is because the angle to the bolt is less than 90 degrees. Tensile strength of grade 8 bolts (stretch) is ~150,000 psi.
All of this force is currently being absorbed by the existing system through a combination of force on the stock bolts (<grade 8 ) and deflection of the sway bar.
It is true that by bracing the rear of the arm and preventing the sway bar from absorbing some of the energy, that energy is transferred through the brace through the bolt, to the strut tower portion of the car frame, thus keeping the road wheel from traveling aft (as it normally would) as the sway bar bends and returns.


I am not an engineer and hence my willingness to share these calculations for individuals to follow along and use this information in their decision making process.

There may be a risk that the shock tower can't absorb the extra force.
There may be a risk that the bolt bends but doesn't shear.
Different stress may wear bushings in a different manner than stock.


I do not have first hand experience with any of the above, nor have I seen any documentation on such. Any modification to a car suspension must be considered carefully by the owner. I am personally in favor of reducing the known twisting of the LCAs by reinforcing them through boxing, and minimizing the fore/aft motion of a rolling road wheel. If anyone has the least bit of concern that such solutions could be damaging to their car, they should not undertake them. The same holds true for electronic upgrades, aftermarket wheels, changing shocks or springs, different ride heights, fuel delivery systems, and so on......

I deliberately put this post in the originalLCA thread rather than in my For Sale thread so that those with differing opinions are free to intelligently debate the topic.

[Spittybug]

Update. A few hundred Houston miles later (75+ mph) and a check of the bolts shows no bending or other distortion. Bushing look fine as do all other components.
See for sale section for more info.

PM me if interested in ordering from the next production run.