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DLF
03-27-2009, 12:58 AM
I'm starting to make spring perches for the Mark VIII LCA's.

The current aluminum version (that I recently put in my SC) has a few problems, in my opinion.

The height of the inner perch, at 1.6" is too short (shorter than the stock MN-12 LCA's), and renders the air bags I have installed useless.

They're heavy.

They raise the ride height.

My design will not have a tilt to the base, I don't see the need for it, and it raises the ride height unnecessarily.

They'll be made out of black UHMW (other colors may be available), with a drilled hole for air bags, and sell for $150 shipped (lower 48) per pair.

I've got one request so far, and the first 3 sets will be ready to ship in 1-2 weeks.

Any interest?

ricardoa1
03-27-2009, 09:45 AM
I thought we needed these to raise the ride height to match the height that the stockers provide. Is that not the case?

DLF
03-27-2009, 09:51 AM
I thought we needed these to raise the ride height to match the height that the stockers provide. Is that not the case?

They're needed to position the springs, and a 1/2" base is all that I believe is required to match the ride height. Additionally, the center of the perch is used as a base for air bags to push against.

DLF
03-27-2009, 11:07 AM
I just installed both the stock MN-12 and Mark VIII LCA's in one of my cars and took some measurements.

When both are at the same ride height, a couple of inches compressed, as measured at the lower knuckle pivot points......

The Mark VIII spring pockets are 10" from the frame rail, both inside and outside.

The Stock LCA's are 9" from the frame rail on the inside and 10" on the outside.

So there is a difference of about 1/2" (on average) between the spring pocket depths.

ricardoa1
03-27-2009, 11:16 AM
How can it be two different measurements on the inside and outside on the stock ones. Are they at a different angle then the stockers?

quick35th
03-27-2009, 11:31 AM
Not to hurt sales because thats not what I want to do, but do you really need these spring perches to run Mark8 LCA's on our birds? I know the perches are for locating the spring in the LCA but even without then the spring cant move around inside the arms when the car is siting on them. My '92 in my signature has the mark8 LCA with cut stock SC springs without perches and I autox'ed the tar out of it to the tune of a championship last season without any problems.

Shane
Glynn Motorsports

90blkbrd
03-27-2009, 12:34 PM
My SC has the Mark VIII LCA's and aluminum spring perches and my rear sits lower (just a little) than the front. I was told it was because of the LCA's and perches. :confused:

Ddubb
03-27-2009, 01:42 PM
How much lighter is the UMHW ?

- Dan

DLF
03-27-2009, 02:37 PM
How can it be two different measurements on the inside and outside on the stock ones. Are they at a different angle then the stockers?

The spring perch is, but the pivot point for the lower knuckle bolts was at the same height.

DLF
03-27-2009, 02:40 PM
Not to hurt sales because thats not what I want to do, but do you really need these spring perches to run Mark8 LCA's on our birds? I know the perches are for locating the spring in the LCA but even without then the spring cant move around inside the arms when the car is siting on them. My '92 in my signature has the mark8 LCA with cut stock SC springs without perches and I autox'ed the tar out of it to the tune of a championship last season without any problems.

Shane
Glynn Motorsports

I'm sure that you can get away with it, but the airbag pocket in the Mark VIII LCA's is quite a bit bigger than the springs, and there's no inner perch for the aftermarket airbags that I, and others, use for drag racing.

DLF
03-27-2009, 02:43 PM
How much lighter is the UMHW ?

- Dan

I haven't had a chance yet to weigh the completed UHMW perches, as well as the aluminum perches, but I will.

UHMW floats in water if that gives you any idea, it's specific gravity is less than 1.

DLF
03-27-2009, 02:48 PM
My SC has the Mark VIII LCA's and aluminum spring perches and my rear sits lower (just a little) than the front. I was told it was because of the LCA's and perches. :confused:

But does the rear sit higher or lower now than it did with the stock LCA's (not compared to the front, but before and after at the rear)?

XxSlowpokexX
03-27-2009, 03:34 PM
direct contact not good for steel and aluminu

Mercutio
03-27-2009, 04:01 PM
I'm interested in a set. FWIW the aluminum perches weigh 3.45 pounds each. I attacked my set with a drill press and shaved a pound of that. Also, depending on the exact alloy in question aluminum weighs about 2.8 times as much as high density UHMW, so judging by what Doug is saying of his design I would assume each new perch to weigh right around 1 pound each.

And black would be fine with me, but I really don't care so long as they're not pink or something.

XR7 Dave
03-27-2009, 04:18 PM
My SC has the Mark VIII LCA's and aluminum spring perches and my rear sits lower (just a little) than the front. I was told it was because of the LCA's and perches. :confused:

Are you sure your springs were not cut? I believe they were due to the car sitting way too high in the back.

Shane, your application hasn't seen 1000 miles since it was installed. That it "works" in your application has no real reflection on how it would hold up on the street, subjected to all sorts of impacts, etc. If the spring were ground flat on the bottom I'd feel a little bit differently about letting the spring sit on the aluminum, but with the spring cup in the control arm being comparatively thin and the spring putting extreme pressure on it at it's unground/formed end, leaves me very uncomfortable.

I never plan to run airbags so I'm not worried about that. I just want a properly formed and fitting spring perch, that's all. Using plastic between the aluminum and steel gives me warm fuzzies too. :D

DLF
03-27-2009, 04:24 PM
Here are three pics.

The first is a poly spring isolator centered in the pocket.

The other two show how much movement there could be without a perch. :eek:

Not on my car :)

ricardoa1
03-27-2009, 04:33 PM
I had mine with no insert for about 20-30k street miles. ;)

Damon were is the metal on metal contact you are talking about. There is a rubber isolator that separates the two. The spring once it is seated does not move around. The only reason for this upgrade that I can see is for correct ride height.

XxSlowpokexX
03-28-2009, 01:03 AM
Rico,

I wouldnt be to sure about the side to side movement. It can happen. And without the spring being located or centered and only relying on the force of the spring itself...I think that exces movement may lead to premature wear of the poly isolators. WHen my tax refund check comes in I may just get me a set of these for a rainy day. I have teh aluminum ones but they do weight a bit and my car is now a bit higher in the rear

DLF
04-04-2009, 09:16 PM
Because UHMW is so resistant to abrasion, it heats up the tool bits, and as a result, it's very difficult, and time consuming, to machine. Then there's the fact that soooo much material needs to be removed from a 6" diameter rod to make a perch.

I'm sorry, but no one, other than the one person who's already paid, is going to get these from me for $150.

Expect me to offer these for closer to $175.

If no one is interested, I'll certainly understand.

Pics of a piece on the lathe, and a couple of pics of a prototype (bare and with a poly isolator).

Regards,

XR7 Dave
04-05-2009, 12:00 AM
Doug, I think many people would be interested in these perches if you only made them so as to locate the spring. I know I would buy a 2nd set that was made only an inch or so high if that would save on materials and machining costs.

DLF
04-05-2009, 12:45 AM
Doug, I think many people would be interested in these perches if you only made them so as to locate the spring. I know I would buy a 2nd set that was made only an inch or so high if that would save on materials and machining costs.

I could probably do that for the $150 price....

I'll take a look tomorrow at the height of the poly isolators, and see what it is.

BTW, I don't have any of the stock rubber isolators, these are being machined to fit the Poly isolators..... I'm pretty sure that they'll also work with the stock isolators, but I have no way to be certain.

Mercutio
04-05-2009, 10:12 AM
I agree with Dave. I'm in for one either way, but if the perch is delivered as shown it will probably meet with my porta-band to remove the excess. I don't see the need for the perch to be higher than the isolator. And if I recall correctly the urethane isolator is, if anything, a tad smaller than the stock rubber one.

XR7 Dave
04-05-2009, 10:17 AM
The poly isolators cause the springs to sit a little higher than stock. I for one won't be using poly isolators.

90blkbrd
04-05-2009, 11:02 AM
Just thinking outside the box. Why have an isolator at all? Why not build it to have the spring mount directly to it?

DLF
04-05-2009, 11:54 AM
I agree with Dave. I'm in for one either way, but if the perch is delivered as shown it will probably meet with my porta-band to remove the excess. I don't see the need for the perch to be higher than the isolator. And if I recall correctly the urethane isolator is, if anything, a tad smaller than the stock rubber one.

The only reason to have the perch higher than the isolator, is to use AirLift air bags inside the springs. If you're not going to do that, than it could be shorter.

DLF
04-05-2009, 11:55 AM
Just thinking outside the box. Why have an isolator at all? Why not build it to have the spring mount directly to it?

Anything's possible, but that would add much more complexity to the machining process, way beyond anything I could do.

DLF
04-05-2009, 12:07 PM
If I make the center of the perch 1.6" tall it will be just a bit taller than the isolators (for use without AirLift bags).

To use with the AirLift bags, they need to be 2.1" tall (the height of the stock MN-12 LCA perch).

I can make the shorter pairs for $150 shipped, and the taller sets for $175 shipped.

I've got more material on the way, but it's mostly white instead of black, so if anyone really wants black, now's the time to step up. It's hard to find 6.25" round stock at a decent price.

I've already sold two sets, and have material in house to make another couple of the shorter pairs in black.

PM me for payment details. It'll take 3-4 days for them to ship after you've paid.

DLF
04-05-2009, 10:56 PM
Material left for one more set.

DLF
04-07-2009, 07:13 PM
Here are pics of both the tall and short production perches.

David, your sets are in the box and shipping tomorrow.

Will, your set will go out Thursday.

Regards,

DLF
04-08-2009, 05:36 PM
I finally got a scale.

The short versions of the UHMW Perch weigh just over 1 lb each.

A stock cast iron LCA (with my Delrin Bushings installed) weighs just over 23 lbs.

A Mark VIII LCA (also with my Delrin Bushings installed) weighs a little more than 16 lbs.

So, the Mark VIII LCA / UHMW Perch combo will save almost 6 lbs. of un-sprung weight per wheel.

Mercutio
04-08-2009, 08:41 PM
Just out of curiosity did you weigh the arms with or without the toe links? I've cut and filed a bit on my Lincoln LCAs and with your bushings in them (no toe compensators, obviously) they weigh 15 lb 1 oz each.

DLF
04-08-2009, 11:13 PM
Just out of curiosity did you weigh the arms with or without the toe links? I've cut and filed a bit on my Lincoln LCAs and with your bushings in them (no toe compensators, obviously) they weigh 15 lb 1 oz each.

Neither had the toe links (both sets of LCA's have Delrin Bushings installed), so it looks like you've shaved off over a pound.

DLF
04-09-2009, 11:59 PM
I've got plenty of material (mostly in white) in stock now.

PM me for payment details if you're interested. I'll make these to order, so they'll ship 2-3 days after I receive your payment.

Also, as I'm making these to order, there's an opportunity to adjust the thickness of the base (normally 1/2") if anyone wants to do something different with the rear ride height. I don't think it's a good idea to make the base any thinner, but it could be made thicker if you needed to raise the rear for any reason.

If anyone wants to order a Delrin Bushing kit(s) at the same time, I'll knock $10 off of the price, as I can ship them together.

http://www.sccoa.com/forums/showthread.php?t=105574

90blkbrd
04-11-2009, 03:38 PM
Are you sure your springs were not cut? I believe they were due to the car sitting way too high in the back.

You are right they were cut. :(:eek::(

Super XR7
04-19-2009, 07:37 PM
FWIW, I just installed Airlift airbags that are made for a 92-97 with the following configuration: alum perch, 1.5 drop Eibach springs and the plastic jounce bumper/metal support removed. With the car on jack stands and the rear suspension at full down travel the airbags lacked approx 3/8" from touching the upper support but with wheels on the ground there is interference; so I guess that appears to be correct, right? I put 15 psi on them and there is definitely a difference in downward travel in the suspension.
I would make two suggestions to the perch design; drill a 1" hole thru the center and mill a slot across the bottom for the airline. This will keep the line from coming out the bottom of the lower control arm. That's what I did and it worked great.

Mike

DLF
09-27-2009, 09:58 PM
UHMW Spring Perches may be ordered here (http://home.comcast.net/~dlfraleigh/Delrin/UHMW.html).

DLF
11-22-2009, 11:34 PM
1 of each size, boxed up and ready to go.....

DLF
01-08-2010, 12:45 PM
Only 1 set of tall perches in stock.....

DLF
02-04-2010, 09:56 PM
The last set is sold.

I'll be making these to order in the future, with a two day turn-around after payment.

housefull
02-19-2010, 01:04 PM
I had mine with no insert for about 20-30k street miles.

Damon were is the metal on metal contact you are talking about. There is a rubber isolator that separates the two. The spring once it is seated does not move around. The only reason for this upgrade that I can see is for correct ride height.

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DLF
02-22-2010, 08:48 PM
FWIW,

I'm just about out of the 6.25" UHMW round stock that I use to make these, and I haven't yet been able to find a reasonably priced place to get more, so these may go the way of the dodo soon. :(

DLF
02-10-2011, 11:33 AM
I found some reasonably priced stock, so these are available once again. Click the link under my signature to order.

DLF
04-22-2011, 07:18 PM
I have ONE pair of short UHMW perches still available.

After that, they're likely gone for good, as I'd have to purchase new raw material to make these, and it's not cheap.

DLF
04-23-2011, 01:10 PM
The last pair of perches that I had in stock have been sold, and I have no more raw material left.

So, if someone wants a set, you'll have to be patient, and the price will probably be a bit higher.

DLF
06-15-2011, 01:27 AM
I have found some reasonably priced stock, in black this time, so these are once again available. I make these to order, so there's a 3-4 day delay from payment to shipment.

Click the link under my signature to order.

DLF
06-24-2011, 09:50 AM
I have a fresh pair of tall perches ready to ship.

DLF
10-21-2011, 01:22 AM
I'm still getting negative comments on the price I charge for these, so here's a little reality check.

I don't have a $10,000+ CNC lathe, I use a $1,500 bench lathe in my garage, which means I have to setup and make each cut by hand. To whittle down a 6"+ piece of UHMW to 3.6", at .0150" per cut, takes 80+ cuts (for each perch!), and I have to stop every 4 cuts to score the work due to the nature of the UHMW. The ends and the radius' also have to be cut. It's a very difficult material to work with, but I chose it because it's very strong and light.

A 36" long piece of 6" diameter UHMW is over $213. I can make 6 sets of perches from that, which works out to $35.50 just in materials. It takes 6+ hours to make a pair, and ~$10 to ship them, so I make less than $20/hr. And that doesn't even take the cost of the lathe and special tooling into account.

Following this post is a step-by-step pictorial on how I make a perch. Note the time stamps on the pics.

DLF
10-21-2011, 01:29 AM
After cutting the raw UHMW to length, it's mounted on a 6.25" diameter flat plate.

1. The perch base is cut slightly greater than .25", leaving a 1.6" center. Note the time - 3:10pm

2. The center diameter is cut down to 1.52".

3. A .5" portion of the outside is cut down to 6".

4. A hole is drilled through the perch (for later mounting on the lathe and air bag lines).

5. The center length is cut down to .25"

This completes the bottom of the perch.

DLF
10-21-2011, 01:36 AM
1. The center hole is counter-sunk to accept a 7/16" socket head bolt. This also makes room for the nipple on Air Lift air bags.

2-3. The UHMW is mounted to the lathe with a thru rod and the 7/16" socket head bolt. This is necessary because the .25" center previously cut on the bottom does not provide enough strengh to hold the UHMW in position on the lathe for further machining.

4. It is necessary to score the UHMW due to it's properties, and I have to stop every 4 passes to score it again.

5. This shows how the UHMW comes off in strips.

DLF
10-21-2011, 01:44 AM
1. The UHMW is cut down to 4.2" in .0150" passes.

2. The base is cut to .375".

3. Back off .375" and cut down to 3.6" in .0150" passes.

4. Trim the end to length.

5. More strips of UHMW.

DLF
10-21-2011, 01:46 AM
1. An outside radius is cut at the top.

2. An inside radius is cut at the bottom.

3. The finished perch. 6:16pm, over three hours on one perch.

4. More trash.

Kurt K
10-21-2011, 10:22 AM
Doug,

Thanks for sharing the information. As a mechanical engineer, I understand these processes and the time required to machine things. The people that really want the parts will still buy them.

Kurt

JeepsterSC
10-21-2011, 08:43 PM
I don't think your prices are all that out of line. There are other pearches out there for a little less money, but, You're selling a much lighter pearch for $30 more shipped, seems reasonable to me. I'm just happy that things such as this even exist at all for our cars. These arn't Mustangs we're talking about here

DLF
10-21-2011, 11:01 PM
I don't think your prices are all that out of line. There are other pearches out there for a little less money, but, You're selling a much lighter pearch for $30 more shipped, seems reasonable to me. I'm just happy that things such as this even exist at all for our cars. These arn't Mustangs we're talking about here

Thanks!

Actually, my shorter perches are $160 shipped (lower 48).