A Body Spindle Options

[matthimself456]

As time allows I'm going to take a run at resurrecting our mothballed 1966 LeMans project this summer. Step 1 is to get it rolling so I can move it the 3 miles from my folks house to my shop.

The goal for the car is to be a nice, competent driver. Not a high-dollar build and any kind of autocross or HPDE is not really the target but who knows. I'd like it to go/handle/stop on an equivalent level of a modern sport sedan (like 540i, not M5). Given those goals I won't be doing anything too involved or expensive like frame reinforcements or full coilovers. But proper geometry is important to me and I have to buy spindles and control arms anyway so I might as well optimize that. The stock drum spindles, hubs, and steering arms were unfortunately scrapped many years ago in anticipation of the B-body tall spindles that were the hot setup at the time. Right now I'm starting with bare frame rails from the firewall forward. I have not settled on which control arms I will use yet but that decision will be based on similar criteria of best bang-for-the-buck without using something with an unsafe level of quality.

As I understand it geometry-wise these are 3 main improvements to be made:
1. Increase caster by moving upper ball joint back and/or lower ball joint forward
2. Improve camber curve by increasing the distance between the effective centers of the upper and lower ball joints
3. Reduce or eliminate bump steer by moving the pivot point of the outer tie rod end up (and maybe outboard too?)



In addition to these I'd also like to lower ride height. I am a fan of the idea of having modern unit bearings for their maintenance, strength, and wheel fitment advantages but I don't consider this a must. I'm not too concerned about brake compatibility as I have a plan that will require custom hardware no matter what.

The options I'm aware of are:

1. Stock spindles or stock-height drop spindles. I can use +0.9" upper ball joints to increase effective spindle height and +0.5" lower ball joints for even more height as well as supposedly decreasing bump steer. Global West also has very affordable steering arms to fix bump steer and quicken steering (a very attractive benefit). But if I combine the Global West steering arms with the +0.5" lower ball joint does it move the tie rod up too much and ruin the bump steer benefit? If so maybe one of the rod-end style bump steer kits could bring it back to optimal?

2. Speedtech AFX spindles. Benefits of light weight and unit bearings. Fixes all geometry but pretty tough on the budget when compared to other options - especially with the aluminum steering arms too.

3. CPP "C5" iron spindles. From the limited information available these are tall but maybe not tall enough to be optimal? Steering arm bolt holes seems to be in "stock" locations so could combine with +0.5" lower ball joint or Global West steering arms for bump steer correction?

4. Church Boys Billet Spindles. I just found out these exist and almost no information on their site. It probably doesn't matter because they are really expensive.


What else is out there? And what opinions or data do the experts here have on the above options?

[csouth]

Speedway has their G Comp AFX spindle, which is a tall spindle with a 2" drop. It would provide the drop and eliminate the tall ball joint which would mean you could always find a replacement in a pinch. They provide the Camber improvements you're looking for. Since they use stock steering arms you might need to utilize a bumpsteer kit if looking for help in that area. ridetech includes them in their kits now as they were with the one I have for my Nova and I'm pretty sure this is the spindle UMI now sells.


https://www.speedwaymotors.com/G-Com...ars,80737.html

[FORDvsCHEVY]

ridetech:

https://www.ridetech.com/product/rid...spindles-pair/

[Hotwire]

(this is more info than you asked for, but I've done the research and have a very good understanding of this a-body setup. I can answer questions, verify fitting/specs, and am not just spitting out links with no knowledge of the outcome of those parts)

0.5" lower balljoints will lower the front 0.5", keep that in mind when putting things together.

Riding the line between safety, reliability, function, and budget are tough. I've had to put my car together with a very limited budget due to a pissed off 4' 10" irish woman that sleeps beside me. My daughter rides shotgun 90% of the time so I had to make the car as safe as possible too. I'm pretty happy with my setup, yes it could be a lot better, but my dollar spent per smiles ratio is pretty good too. It is an extremely nice ride, it's factoryish as far as cruising, but go into a corner and the sway bars kick in and keep the car flat. The lack of bushings don't even come into play until you hit an abrupt hole or bridge abutment, then you can tell the suspension isn't stock. I do plan on ~400inlb springs up front, 200 in rear, better shocks, and stickier tires, possibly going w/ nitto 555 g2.

Front
used CPP 2" dropped spindle spindle, factory steering arm
SPC fully adjustable uppers (used to dial in caster, with below a-arms it pushed front tires to the rear of the wheel well when added caster)
Ebay tubular lowers (they do NOT add caster and the installed balljoints are trash)
Proforged 0.9" taller upper ball joints
Proforged 0.5" taller lower ball joints
Proforged center link, inner and outer tie rods, idler
cut Moog stock springs (6200, 290lbs/in, they're soft, factory ride, but bottom out when big boys ride with me)
KYB Gas-A-Just shocks
Hellwig solid 1 5/8" sway bar
S10 ZQ8 steering box (quick ratio), bolted right up to LS steering pump/hydroboost lines

Rear
Used BMR solid lower control arms w/ spherical bearings (don't really need adjustable lowers)
Used BMR sway bar
Speedway adjustable uppers (dialed in pinion angle with LS swap)
cut Moog stock springs (6197, 138lbs/in, again, soft factory ride but bottom out when multiple people ride)
KYB Gas-A-Just shocks

Brakes
2000 Camaro disc (came off V6, same as Z28)
1980 Corvette master cylinder
Hurst roll control used as distribution for front brakes
2005 Tahoe Hydroboost (came from pull a part, ~$40)
Wilwood proportioning valve on rear brakes, NO distribution block, lines go straight from master to calipers)
CPP Billet hubs (got off craigslist)

Frame braces
SC&C front frame brace, triangulates frame bumper area w/ crossmember, very effective
UMI rear shock tower brace, didn't notice a lot with it
UMI rear control arm tie brace, noticed a big difference when launching, much stiffer

https://www.youtube.com/watch?v=ZQk2RT3G-uQ

[/url]

Yes, it's a 4 door (cheap and is stiffer than a coupe), it's got a 60 footer resell red paint job on it, but I'm getting more smiles per mile than I deserve out of it.

[jetmech442]

(this is more info than you asked for, but I've done the research and have a very good understanding of this a-body setup. I can answer questions, verify fitting/specs, and am not just spitting out links with no knowledge of the outcome of those parts)

Most excellent post Hotwire! These kinds of posts are why I keep coming back to this forum year after year. My approach has been very similar to yours as well as my experience. The ebay lowers(I got mine from speedway), had very sketch welds and the ball joints we're nearly frozen. I tried to install my Howe BJ into it and it ruined it(tolerance on the arm was a 20 thou press!)....I ended up putting teeth to concrete and bought the SPC lowers. The SPC are great, no doubt, excellent welds, came with a tall BJ, put my wheel back to center of the wheel well(it was visibly to the rear after I added the caster)...but man are they pricey. probly the most pricey part on the car in terms of perceived performance. I do HPDE events so it was a little easier to convince myself that these were a good investment.

Two things that I"ll add on to Hotwire's list... shocks and watts link. I ran VarishocksSS in the beginning and they are great, very controlled touring shock that seems to mimic the feel of a 5 series(not harsh, not soft..just controlled). Just before the pandemic I leveled up to the VarishockDA(Dual adjustable) because I wanted the ability to totally ruin my setup when I'm at the track lol. Large body, divergent valved shocks make a big difference and in my opinion are worth the money. I’ve heard good things about the ridetech shocks as well.

As far as the Watts link.
A watts link stops lateral tire movement, so you can fit the largest tire without it shifting over and cutting into the wheel well.
Since the lateral movement is completely stopped, as you dive into an off ramp or trying to throttle out of oversteer, the rear end does not shuffle side to side several times, it just plants and responds the way your shocks and springs intended.
Additionally, you can now change the rear roll center with a single bolt (2 minutes), which will change your car from oversteer(less rear grip) to understeer(more rear grip) and any balance in between those. Want to Hoon on the street and do easy, predictable slides?..or go to the track and add more grip to the rear?-just move the bolt. 😊
This isn't needed for everyone, but after I installed it on my stockish 10 bolt I fell in love with what the car turned into. That sloppy feeling you get with a triangulated 4 link(yes even with aftermarket uppers and lowers) as you dive into an offramp, you know that feeling where the rear end takes a moment to settle over, and then bounces side to side slightly until it damps out…a watts(or panhard bar) eliminates it. The whole car feels connected and predictable.
there is plenty of arguing over theory of having two roll centers and I ran the FAYS2Watts for about a year or two and the only time I found the rollcenter bind issue was when I was testing the extremes of the rollcenter height(which I never run in those areas anyways).
As far as brakes, the stock D52’s offer a ton of piston area and good clamping numbers for street cars, no real improvement on stopping power when you go to big Z06 brakes…just added thermal capacity for track use.

Hope this helps man, post pics and let us know which direction your headed!

[matthimself456]

Thank you for all these replies! You all reminded me / made me aware of some options that I had left out.

Hotwire and jetmech442, you are both big inspirations and encouragements to this project as both of you have some truly excellent information that you have posted. Hotwire, I've read your build thread a couple times and the accomplishment per dollar is such a great contrast to all of the $100K pro touring builds. Jetmech442, I really appreciate the impression of your watts link. I'm trying to formulate a plan for the rear as well and a couple of the options I'm considering include some more robust form of lateral location. I've experienced exactly what you described on even factory triangulated 4-link car I've driven - and usually not even driving them hard. The fact that Ford invested the money to convert the ancient Panther platform to parallel 4 link and watts very late in life sort of underlines the deficiencies. But for now the stock rear suspension at least exists so priority 1 is assembling the front so it can roll.

I feel like I have a good understanding of the general concepts at-play and how improvements are practically made (except for bumpsteer, this still seems like it is way under-documented). I bought a copy of Mark Savitske's book and have next week off to read and digest it at the lake on vacation. I sure wish his business didn't end the way it did so I could just call him up for advice but at least he left us that book.

I have begun compiling specs of the various spindle options and will share that here. I'll probably do the same for A-arms and maybe eventually for the rear suspension as well.

[CapSS92]

Hi, for my 65 Chevelle I used the CPP C5 spindles stock height with SKF Corvette hubs, 13.5 C6 brakes, Eibach 1" lowering springs, and Global West steering arms. For the control arms, I used uppers from McGaughy's Suspension and eBay lowers with new Moog ball joints. I found that a 2" drop was too much for me, especially with speed bumps. The steering arms from GW made a big difference in the handling. I would have loved the AFX spindles and probably would have gotten them if I was single but...Overall I am happy with the setup. Here's a link to some info from one of the guys involved in designing them. Hope this helps.

https://www.pro-touring.com/threads/...Packages/page2

Alex

[Hotwire]

Thank you for the kind words and glad to hear the build thread may have helped.

I sat through Mark's 45 min "laying it out" phone call, he talked so long I didn't have a chance to put in an order, which I'm somewhat thankful of. He did have great info and wish he was a better business man than engineer. The way he was robbing Peter to pay Paul and the over the top lying soured me.

Back on subject, this chevelle is getting better and better. I've tried to do upgrades one at a time so I could understand what each part does. I'm to the point where the tires are the limiting factor and can't wait to get a stickier compound.

As stated above, even with solid heim joint lower control arms in the rear I've felt the rear shuffle and unload at speed, its puckering at times.

Wish you the best and hope to see you thrashing on the car, when it starts working as hard as you it makes everything worth it.