Big Block Dart Forums banner
1 - 14 of 14 Posts

·
Registered
Joined
·
168 Posts
Discussion Starter · #1 ·
Hey Bill,
I have been reading your tech section on the swap to F body spindles from the existing A body 73' spindles. My purpose is to use A 2" drop spindle for these applications, which are now available. If I would install these spindles on a '73 A body would the actual ride height be lowered 2" or less than that ? Additionally, do your upper A arms add some caster adjustment? What comments do you have on this possible modification for the purpose of lowering the front ride height ?

Thanks for you comments and info...
 
G

·
I did massive testing on these spindles, along with a few others. It was very interesting how alignment and geometry changed just by swapping the various Mopar spindles.

Here's what I found on the dropped spindles...

First, you have to do a massive clearance grind in the back so it clears the lower balljoint - it was intended for the 73-up B-body steering arm, which doesn't have a balljoint in it. Not to big of a deal, just a lot of grinding. The dropped spindles are just a giant slab of 3/4" thick steel plate, and you have to grind a big relief in the back of it, similar to what stock mopar spindles look like on the back side.

Next, although it's "designed" after the 73-up B(and F) spindle, the king pin angle was greater, and the dropped spindles I had varied some, presumably from the welding. The steeper king pin angle REQUIRES at least offset control arm bushings to get a normal alignment. even at that, I didn't get passed 1 degree of caster until I put the adjustable uppers on. With the greater king pin angle, even with the stock adjusters all the way back, I still didn't have 0 camber - that's why I had to use the adjustable uppers.

Bumpsteer also increased with them - from the center of the available travel, 3" compressed or extended gave me about 1/4" toe change per wheel - I started with 0 toe in the middle or travel range, and 3" compressed gave me a total toe of 1/2" toe-out, while 3" extended gave me 1/2" total toe-in.

I did find they drop the car almost exactly 2", with all else being equal.

They may be ok in a drag car with the tube uppers - I think most of the geometry issues with them would have more affect on handling than anything else.

Oh...the tube arms I make can be set anywhere from 0 caster to maybe 12 degrees - pretty much anything you want. If you just throw it together and check it you'll be in the neighborhood of 5 degrees - the design was made for 5 degrees with the ends out 2 threads and the cams centered. Course, that varies somewhat just from differences in each car.
 

·
Registered
Joined
·
168 Posts
Discussion Starter · #3 ·
What about after market brake availability, I have an old JFZ which is very similar to the Wilwood kits but its for a 70-72 with drum brake spindles. Are there possibly hubs and caliper brackets available for these spindles ? There didnt use to be.... Also do you think the bumpsteer thing could be minimized somehow..... I would really like to drop the front end 2 inches if possible but not too crazy about the bumpsteer issue with this setup..... especially the toe out on the compression... What do you think ? Are there other options.
 
G

·
Not much for brakes - only kits that use the original caliper bracket holes - all the race kits use the dust-shield holes, and these spindles don't have any dust-shield holes. I'm not sure of the spindle position in relation to the plate, but it's possible you could drill your own mounting holes for a wilwood bracket... If the stock brakes work, I'd have to assume the face is the same position, so it should work.

If you switch over to a rod end for the outer tie rod end, and lower it 1/2" more than the stock pivot, it's brings the toe change down to 0.050 toe out in both directions - it would be better to have a toe-in condition, but 050 is pretty tiny. Keep in mind, you can account for it - If you do 1/8" toe-in per wheel static, the maximum toe-out condition will still leave you with more than 1/16" toe-in per side, so you'll never have any problems. It's amazing the tie rod has to go down 1/2" to fix that mess - that's a long way to make a correction.
 

·
Registered
Joined
·
168 Posts
Discussion Starter · #6 ·
Ive been ok, busy at work lately, havent been able to race. How about yourself ??? Appears youre keeping busy....

With the correction for that setup it doesnt sound too bad. 1/2" doesnt sound too excessive except that youre talking the pivot point so the spacer would be more than that,... correct ? Also, if I went to a rod end on the tie rod would it have enough range of motion for that much suspension travel ?

Do you carry these spindles ? What about Mustang II dropped spindles on your K-member ???
 

·
Registered
Joined
·
168 Posts
Discussion Starter · #7 ·
Bill, I posted this on your Alterkation web page but copied it here too so you wouldnt miss it...

Lowering with the Alterkation..

Me again, I'm thinking that Im looking at spending close to 2K in front end mods to accomplish two things, 1) correct front end geometry (ive been running a DARE kmember for about three years now and am tired of the compromises that Im forced to deal with) 2) lower the front end 2"
As you know its a drag only car but is now going very close to 150 and as I get older Im less willing to take risks, so as i get more concerned with handling Im going in this direction...
Im committed to fixing the geometry and if it going to cost that much I would rather do it correct so this leads me in your direction. Additionally, if Im spending that money, Ive always wanted the car a little lower so I would also like to accomplish that too.
Again drag only so I would want no motor mounts, manual steering and drag 4 piston caliper mini-GN style brakes, and need to adapt to a 3/4" steering tube only (I already have pinto style splined adapter,... same as Mustang II ?).
Is there a dropped spindle option ? I see quite a few dropped spindles for Mustang II around, are they quality pieces or junk ?

Whatever is available... how much could I expect to lower the front end ??
Additionally, is front end track width changed ?

Thanks for the time...
 
G

·
Yea, keeping busy, that's for sure. Suppliers are terribly frustrating, but I'm having fun, so I have no right to complain.

I'm surprised you made it 3 years with a dare unit - usually the word "dare" is immediately followed by "severe tire shake".

I think a rod end would have enough travel if you use a small od spacer on both sides to get the most out of it. Keep in mind though, that's a 1/2" lower at the pivot point - a stock tie rod end pivot is an inch or so below the steering arm, so the spacer would be pretty long - it'd have to be a long, welded spacer like I use on the alterk to keep it rigid.

I think the basic alterk would fit the bill. There's also a shorter shock I can use to get the height right down to the minimum. With the shorter shock bottomed out, a milodon low profile pan is 1/2" off the pavement, and ride height for that shock woud put that pan about 2.5" above ground. This is with a 26" diameter front tire. I won't go lower than that because I have to limit travel so it bottoms before the car does.

I use the shorter shock instead of dropped spindles - I don't mess with the dropped spindles because they require an 18" wheel to clear the tie rod - The normal spindle only needs a 17 to go really wide for the pro-touring look. And I hate the 18" bling looking wheels, so I don't even mess with that whole thing :) Since the geometry is fine that way, and I can substitute the shocks for no added cost, it makes more sense than adding cost for dropped units.

So it'd be a straight-forward basic system, we'd just have to choose the shock length based on how low you want to go. The steering hookup is included, so we'd just give you whatever was needed to hook up to whatever you have in there.
   Brakes are also no problem - anything you want can be had for the MII spindle, and we might be able to just convert what you have.... what do you have?

Track width does change, but it varies depending on brake kits. With the typical wilwood/strange/aerospace brakes, the a-body is 5/8" wider per side. On request, we can do 3/8" shorter a-arms, which puts you just 1/4" wider per side.

Going that fast, you might also want to consider double adjustable shocks - pricey, but it would be a good addition for a 9sec car. I can also sub AFCO shocks instead of the normal QA1/Varishock models, which would be better for a dedicated strip car.

...Lots of possibilites that aren't listed on the site, so it's usually a lengthy phone call to get one ordered, but it works better in the end.
 

·
Registered
Joined
·
168 Posts
Discussion Starter · #9 ·
Bill,
Thanks again for the info. I've been looking at your web page and pricing,... a little more than I was expecting. Sounds well worth it though, just means another decision that I have to contemplate. But I feel Ive already wasted enough so Id like to do it right an quit messing with it. So I'm trying to make up my mind, kinda knowing what I should do.

Anyway, my brakes are old JFZ mini-GN style with 3/8" solid rotors, 11" I think, or close to that, Im pretty sure that the mini-GN caliper is a direct bolt in replacement for the Wilwood small 4 piston calipers but I think that maybe noting else would fit the Wilwood parts, Sierra now makes most of the JFZ parts but not the specific front end kits, so for the brakes I think Id be better off selling what I have and just getting a complete Wilwood front kit with the 3/8" solid rotors, the Wilwood hubs may not set the tire out as far as the JFZs.

On the F body dropped spindle deal, and the outer tie rod spacer,... I guess its ok to weld on the steering arm ? Is that correct ? Wouldn't want to weaken or stress it with the heat

Oh, also I only measured about a 20lb difference between my stock Kmember and the Dare rack unit, how about your unit compared to a stock Kmember with all the motor mount stuff removed and clearanced for the milodon pump stuff and my style brakes and the motor mount stuff ground off is there a wght savings or about equal or what ? Equal would be fine much more would make me think more.....
 
G

·
Yea, the steering arms are forged steel - easily weldable, just remember to keep a wet rag around the balljoint - there's a nylon cup inside there, so you have to take a little care not to melt it. The end of the steering arm is pretty far away, so it's not a big deal.

The alterk frame itself is actually 35lbs - same as the stock bare frame. The weight savings is in all the rest of the parts. From a stock a-body suspension with manual steering, it saves 80-100lbs. I always tell people to expect 85lbs savings to be on the safe side. If you already did work to the stock stuff, I'd think 50-70lbs savings would be a closer estimate. If you have the stock parts laying around, you can compare - the alterk fully assembled on the floor, spindle to spindle, weighs 90lbs. The is the complete unit including the upper arms, coil-overs, and steering ujoints, without brakes.
 

·
Registered
Joined
·
168 Posts
Discussion Starter · #11 ·
Ok,
So with the short shocks and the short control arms, how much lower do you think... I believe my fronts are 27 I think, the loaded tire radius is 13 inches. I have a Charlies dragster pan with the kickout that Mancini sells, their best one and its over 6 inches off the ground static. Im looking for 2 inches lower. but close would be good too.
It sure looks like this is what i need to do......
 
G

·
For comparison, I have the shorter shocks on my dart right now, and at ride height with a 26" tire(12.5" loaded rad), the rockers are 8.5" off the ground at the front of the door. This gives me about 2.5" of travel in both directions. I could go 1" lower than this and still have decent travel in both directions, but that's pushing it with my current exhaust. With these shocks, there's 5" of total wheel travel top to bottom.
The normal shocks ride about an inch higher than this and provide 5.75" of total wheel travel.
 
1 - 14 of 14 Posts
Top