what upper tubbular control arm do you like to use?

I got 3 different types over the years, Firm Feel would #1, QA1 is a close 2nd. SPC are most flexible in settings

I put the SPC's on my challenger this summer. Should have done it years ago.

Could you expand on this?

I've got SPC's for my Dart. I'm a little anxious about how easily they will be to set up. Lots of adjustment in them but the bolt-together end I'm not 100% sold on. Any tips/tricks to make it easier? Did you use the supplied cam bolts(with no eccentric washers) or did you use the factory bolts with eccentric washers? I thought maybe using the factory washers would make the final fine tuning easier?

The ability to dial in +4.5-+5.0 deg caster and being able to maintain 0 to neg .5 camber makes the car drive so nice.

Eliminating the eccentrics is icing on the cake. Adjustments can be made without lifting the front of the car to take the weight off the eccentrics or worrying about flattening the "ears" on the eccentric cups.

I have fairly new Hunter Hawkeye machine in my shop, and the combination of the SPC arms and that machine....I can align or adjust that car in 20-30mins with less error due to not disturbing the process through raising and lower the car.

Very cool! Thanks for explaining in detail.

I favor any design that offers adjustable caster and camber. The FF is, unfortunately, pre-set in their design... I'm aware of some cars getting up to almost 5 pos caster and about neg 2 camber.... that is great but.. not guaranteed with all cars.

The SPC design has had past breakage issues... at least reported in some other older posts... I've never actually seen a broken SPC UCA. Regardless, I still like their overall design.. and may someday try them.

Then... there's the Hotchkis UCAs... a good design, but requires relocating one of the attachment points... supposedly, improving bump-steer.

I'd say... you pay for what you get.

Personally, I have modified factory UCAs that give me, at my current settings, 5.5 pos caster, 1.5 neg camber... have run them for past 40 years... works great.

Also,, consider installing the Moog offset UCA bushings,,, installed opposite of their directions... will give you more positive caster and neg camber.

I have Hotchkiss on order for three months now, supposed to ship in Feb. I just want to improve the caster and get rid of the negative camber at full extension of the front suspension ( drag race)
My stock arms/suspension so far is pretty good to me, but maybe im used to it? LOL have been as fast as 160mph

I liked my Firmfeel UCA's. I set the rear bolts all-in and the fronts all-out and with one tweak things looked good (5.0 pos caster, 1.8 neg caster, 1/16" toe in, -.5 camber). My other car is getting a set along with greasable LCA pins.

What is the big deal about 4-5 degrees of positive caster? Making a big change in caster will lower the outer tie rod. This will change the toe pattern. Could be better. Could be worse. From my own experience my drag car has 2 1/2 degrees positive caster. It drives right down the track straight as a arrow. It has had bump steer corrected.
Doug

Years ago a Ford guy told me that they had always cut 1/4" or so out of the trailing arm of their upper control arms. So I tried it and have done that with my stock arms for decades. That, along with the Moog offset bushings gets me all the adjustment I have ever needed with no problems.

I am kind of in line with Doug , stock arms with around 2 1/2 deg caster , 0 deg camber , 1/16 toe . Manual steer is quite light .
Would I like new arms , maybe but really probably just need eurothane bushes .
Like a lot of people I get a bit monkey see/ monkey do .
Don't forget front ride height will also affect what alignment numbers you can get


Tex

In my opinion additional positive caster, within reason, makes the car drive better during cornering. The best way i can describe the driving experience is that the car steers better with less "push" in the corners giving you that "on rails" feeling while cornering. I actually think too much positive caster in a drag car can be a bad thing. We are tring to keep the car going in one direction and having the front end "want" to steer is not a good thing. For instance a Mustang II or strut spindle mount seems really happy at around 2-2.5 deg positive caster in a lightweight, big tire drag car. Same goes for steering box ratio - more is not nessecarily better in straight line racing.

I'm just a greasemonkey/hobbyist but that is my take based on personal experience.

Expanding on this-

Do we agree that the best way to set up the front end as follows:

1. Set ride height +1"

2. Set toe

3. Set camber

4. Set caster sweep

5. Verify bumpsteer/toe setting

6. Drive car, verify all settings.

Caster and camber cant be set individually. One effects the other. There us way more to suspension geometry than what has been discussed here. Scrub radius , camber gain, anti-dive, oll center, Ackerman, are just a few. All effect steering and handling. There are some real good reads out there.
Doug

I have the Hotchkis geometry correction upper arms on my Charger, my car drives very nice.

If your numbering them in order then that's the wrong order. Toe is the last adjustment you do.

I have the RMS uppers with hiem joints. I have been very happy with them.

My understanding is the positive caster makes the car want to go straight, increasing steering effort is a down side to that. My car has around 4 or 5 positive and it drives very well. It does take some steering effort and the steering returns to center very quickly.

This is one of those subjects that gets beat to death. I’m no expert, but all of the theories and preferences usually service a specific style of racing. What we used to use circle track racing on dirt would slow down my drag car, and my drag car settings would have put my circle track car in the grandstands. Have an understanding of front end basics, then go talk to the people that are going fast in the type of racing that your doing. Someone on this board commented a while back about how a fellows drag car moved once when a light breeze came up, , I like my car as freed up as possible with just enough positive caster to make it stable at 150 to 180 mph. Suspension travel, along with correct steering arm placement, inner and outer tie rod placement, will allow me to pop the brake pedal at speed and not have to worry where car will go. I was fortunate enough in the dirt days to work with a guy that understood how every movement of the steering wheel affected every other corner of the car, and knew how to change it. Learned lots from him. Jim.

Back to OP’s question, I like the adjustability of the SPC arm. I prefer to be able to have ability to adjust, where as sometimes stock or modified stock arms, you don’t have that option. Am building my 64 Coronet for my son and will probly use those. Jim.