Torsion Bar Resizing with already revalved shocks

[Blander389]

Looking to soften up my very stiff torsion setup that has bilstein sports in front that were revalved to match the big front torsion bars. Do I really need to get them revalved again or will I get a good result just swapping t-bars?

Current Setup: 24mm front/33mm rear T-bars, 22mm front/rear tarett sway bars, poly bronze bushings all around, Bilstein sports 4 corners, QC spring plate, bump steer, etc... Only the fronts were revalved for the 24mm. Pretty sure rear bilsteins are stock sports. This actually doesnt drive as harsh as it sounds, probably bc the fronts revalved and running 15" wheels with 70 and 60 aspect ratio tires so some decent cushion. I also dont mind stiff. 15% track 85% spirited street, not really ever just out cruising. I do want to start running Toyo RA1s which are a 50 aspect ratio, so thinking it will just get too harsh on the street.

Thinking was to go to a 22/29 t-bar setup and see what happens. Do i really need to get the fronts revalved again? clearly i could just try the 22/29 combo and see what happens, but wanted to see if that was just wasting time and the already revalved fronts for 24mm is going to screw stuff up with a 22 swapped in. I figured the stock rear sports will be ok enough with the 29mm rear bar.

Thank you

[Zeke]

If you really want the car to ride well, the shocks and springs should be calibrated. I'm probably not allowed to name a vendor that I used that does this for you. I did the package and it went very well.

Believe it or not, this car rode better than ever with a mild increase in suspension rates, but well matched.

[Blander389]

Thanks for the response Zeke. You are probably right. Ill just sack it up and do it correct.

[PeteKz]

I recommend doing it in steps. The shocks cause more felt stiffness than the springs/torsion bars, so change those first. This is a reason I also like Koni Sport adjustables--you don't have to pull them out and disassemble them, just twist a knob. I have them in my fairly light 1973, set to full soft with Rebel Racing front A-arm bushings and 21mm bars, and I think they are just about right on the street. If I want to go to the track or AX, I can crank up the shocks a couple notches.

However you have some very stiff t-bars with 24/33. And sway bars. And polybronze bushings. In fact, at those diameters, the body of the T-bar is about the same diameter as the splines, which is not good engineering. Personally, I think that if you want to go stiffer than about 21 on the fronts, you should go to a coil-over shock setup like the KW's. Likewise on the rear, about 29 is as far as I would go without switching to coil-overs.

What year car? Heavy or light? Street or track? You said 85/15, but trying to do both involves a lot of compromises that makes it not very good at either use. IMO, if you aren't racing, you're better off to set it up for a reasonably comfortable street use, and enjoy "driving a slow car fast" on track days. If you go to 50 series trees, that WILL make the ride even stiffer.

How about this: 21mm fronts, 27mm rears, and revavle the fronts to be softer, sway bars set at least resistance, and run your 15" wheels and tires on the street, and buy a set of sticky 50-series tires and appropriate wheels for track use? Swapping wheels for the track is a whole lot easier than changing other stuff every time. If cost is no object, get the KW's for all four corners (and get the dropped front spindle at the same time), so you get easy adjustability.