[rohrt]

Did anyone happen to see this yet?

https://ridetech.com/product/gm-afx-hub-spindles/


I went with both upper and lower SPC arms on my 68 FB and just upper SPC arms on my 64 Tempest. I can't really say I love them. They have their pros and cons.

The SPC lower BJ is 1 deg forward to allow more caster. I use to have some tire rub on one fender. Now I have no rub and 5 deg caster dialed in. MY 68 is a mis-match of parts but it handles pretty good now considering its on 235/60/15 tires.

When SC&C was still around Marcus always suggested going with the SPC upper arms and keep the stock lower arms. The upper arms have the tall BJ and the adjustability to increase caster, so this makes sense for a mostly street driven car.
The SPC lower arms have a lowered spring pocket. I had to use several shims to make them work with my 2" lower Ridetech springs.

[HWYSTR455]

Yes, I've seen the Ridetech ones, and the CPP ones. I have firsthand experience with the CPP ones, pretty sure I posted that info here, originally bought them for the 442, and they were near unusable. It would have been better if I kept the original suspension on that car. And to fix it, I went to the ATS/Speedtech AFX spindles and arm.

After looking at the SPC lowers, and the Ridetech ones, it appears the pocket is dropped lower than others (drops 1" off ride height). I guess they did that to better accommodate coilover conversions, but just guessing.

You start stacking 1" here, 1" there, and drop spindles, it adds up. Keep in mind that the optimum location for a lower control arm puts it parallel to the ground. That puts it in the starting position where it's in the range of motion that the suspension was designed around.

Ridetech spindles are too much drop (2"), like many of their' products, and much like the CPP ones (I think they drop 1"). You have to add the $150 for 'standard' brake caliper brackets, $450 for the wheel bearings (and that's just for the regular vette bearings not the upgraded ones), then you need to figure out which steering arm to use. So your very close to spend as much for the ATS/Speedtech stuff, or more.

SC&C/SPC took the F/B-body spindle swap and did it with the tall ball joint approach, using the original A body spindle. Since the uppers have adjustable rods, you avoid having to stack shims in some cases. But like I said, there's deflection in that.

I still don't think it's a supported config to run tall ball joints with ATS/Speedtech AFX spindles, and there's no need to. The more drop built into the spindle will tilt the wheel back more as caster increases, and adding a tall lower BJ will make it worse.

The ATS spindles have a 'street performance' alignment that is 4-4.5 caster, which is plenty. You can go 5+ but will depend on the uppers you use. I'm at 4.25 on both the GTO & 442 and it's great, plenty good for aggressive street and some autocross.

There's no caster 'improvements' in the arms like Speedtech & GW (just checked), and they are specifically designed around the ATS AFX spindle. All the 'magic' is in the design of the spindle and steering arm.

I still believe the Speedtech ATS/AFX spindle and either the Speedtech or GW arms are the best bang for the buck without going to a full (or partial) aftermarket frame.


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[chiphead]

So far, the biggest "gotcha" with the AFX spindle is the need to run large wheels. I looked on their website, and on the steering arm page, it says their steering arms will not fit with 17" or smaller wheels.

https://speedtechperformance.com/pro...mp-steer-kits/

As far as my driving skill, I'd guess I'm slightly above average (who doesn't?) but I've got no track time. I've got no frame of reference other than my '15 Charger RT, which I think is amazing other than the stock 20/45/245s are a little undersized for the power. I understand how a good suspension should handle, in theory. All my other vehicles have been trucks or stock classics. My first car was a '54 Bel Air, which makes a dump truck seem like a Porsche. Steering on one of those has got to be 7 turns lock to lock. I also had a '73 International Scout II, which rode like a stagecoach, minus the horse.

The current LeMans has a worn out front suspension, drag springs, CE drag shocks and 215/70 tires on 4" Prostars. 275DR out back. (PO setup). Anything over 70 feels like I could die at any moment. I'll still throw it into a curve at high speed and hacksaw it through, but I can tell it's not right. That's the whole reason I'm not setting this car up for drag racing, because street handling sucks so bad. I'd rather drive it on the street and enjoy than suffer 90% of the time for 10% drag use.

Any long-term reliability concerns with the SPC uppers or AFX spindles?

[HWYSTR455]

I purchased the ATS spindles when ATS was still holder of the patent, and actually talked Tyler into making a steering arm for the A bodies. Pretty sure that thread is here, but may be on Pro-Touring.com. Tyler's main interest was for his 67-69 F body. At that time, he worked directly with Doug at GW to design and make the tubular control arms, lots of R&D went into those, not just a copy of the OE arm in tubular form.

Originally, the ATS AFX spindles used F body ball joints, but when Speedtech picked the rights up, they modded them to accept A body ball joints.

Anyway, I can say that with the ATS spindles and GW arms, the suspension rivals C5/C6 vettes. It brings the car(s) into modern territory, and along with an OD trans, is better than a lot of later model performance cars.

Having to upgrade brakes is not a 'gotcha', it's a blessing. Many wanted big brakes before any suspension enhancements kicked off with what is now called 'pro-touring'. Once your car has more power and better handling, you pretty much NEED big brakes. Once you reach that realization, looking at big brake kits will make your head swim and your wallet sweat, especially if you have to go back and replace stuff you recently upgraded.

I can say hands-down, the AFX setup is the one 'best' upgrade I've ever done, even more than adding more power.

Aftermarket control arms are way more reliable than OE, no worry of stress fractures, ball joints getting loose in the hole, and no/little deflection. I daily drove my LeMans for many years (@ 1991-2014), and beat it in the worst conditions imaginable. I've tried many different parts, most documented here, and yes, the AFX setup is the 'best' upgrade I've ever done.


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