Front Torsion Bar Upgrade: 20mm or 21mm ??

Hi Everyone:

I have a 1971 911T that recently had its suspension refreshed with: Elephant Racing rubber bushings; Bilstein HDs; Turbo Tie Rods; and a 15mm Front TTB Sway.

Initially, I left the torsion bars alone thinking comfortable would work. After I refreshed my engine, the squatting under acceleration and body roll became too much to bear while enjoying Angeles Crest. So, increasing the torsion bars became the "next" item.

Pertinent Details: The car and I live in LA (crappy roads). The car runs 70series CN36s (I know, the sidewall isn't helping me). I don't track but prefer a firm ride (the T's stable mate is a 997.2 GT3). I increased the rear torsion bars to 26mm and, while the car is in the shop, I would like to address the fronts as well.

Questions: (1) Should I go with 20mm or 21mm front bars; and (2) why?

Thanks in advance!

This is on my 71T. I like it. I run same cn36 tires. Balance is good. But this isn’t a gt3. They lean and move around and that’s part of the fun. Learn to embrace the movement let it slide.

Suspension: 21F/26R Torsion bars, 18F/18R factory mounted sway bars, turbo tie rods, bump steer spacers, elephant racing spring plates. New strut insert VonShock/bilstein digressive valved, New rear shock Von Shock digressive valved. Custom valved for 21/26 torsions + 2300 lb weight from Elephant Racing. New rubber top bushing elephant racing.

I also have a 997 gt3rs.

Attachment 550559
Attachment 550560

Quote:

---

Originally Posted by Spyerx

This is on my 71T. I like it. I run same cn36 tires. Balance is good. But this isn’t a gt3. They lean and move around and that’s part of the fun. Learn to embrace the movement let it slide.

Suspension: 21F/26R Torsion bars, 18F/18R factory mounted sway bars, turbo tie rods, bump steer spacers, elephant racing spring plates. New strut insert VonShock/bilstein digressive valved, New rear shock Von Shock digressive valved. Custom valved for 21/26 torsions + 2300 lb weight from Elephant Racing. New rubber top bushing elephant racing.

I also have a 997 gt3rs.

---

Thanks, Spyerx! How is the ride up front with the 21s? Comfortable? Jarring? Overly firm? Does the front bobble (porpoise) on our horrid freeways??

Based on the 3RS, I’ll trust your judgment. :) (Off Topic: Which color/variant do you have?)

21s are still very soft. I run 23s on my 73 T and that makes for firm tight handling. But OK on streets with the softer older style tires. Shocks are Bilstein sports

Similar suspension setup to spyerx: Bilstein Sports front/rear; fronts are inserts in Boge housings. Factory 15mm sways front/rear. 21/27mm torsions front/rear (hollow Sander, Elephant plugged/plated). Turbo tie rods/bump steer kit. All suspension rubber replaced with Elephant rubber. Tires are 195/65 P6000s on 7X15 Fuchs.

Could be stiffer but I think a fair compromise since I drive on some fairly potholey roads in PA/NJ/DE.

Attachment 550570

Attachment 550571

Quote:

---

Originally Posted by Frankr

21s are still very soft. I run 23s on my 73 T and that makes for firm tight handling. But OK on streets with the softer older style tires. Shocks are Bilstein sports

---

Quote:

---

Originally Posted by teenchy

Could be stiffer but I think a fair compromise since I drive on some fairly potholey roads in PA/NJ/DE.

---

Ok, I think you guys have me convinced to go with 21s instead of 20s. What I don't want is a front suspension that "slams" into bumps, road imperfections and/or concrete transitions. Any other input ride quality on would be greatly appreciated.

(The cars posted in this thread look great, by the way!)

I run stock SC torsion bars on my 69 and find that a nice set up.

Quote:

---

Originally Posted by GreenTea

Thanks, Spyerx! How is the ride up front with the 21s? Comfortable? Jarring? Overly firm? Does the front bobble (porpoise) on our horrid freeways??
Based on the 3RS, I’ll trust your judgment. :) (Off Topic: Which color/variant do you have?)

---

The ride is fine, not jarring, but it is quite a bit firmer than stock. When I first got the car it had no sway bars, a higher ride height, and stock torsions and it was FLOPPY. Now it feels controlled, supple enough, and proper sports car, without going so far it feels like a later car (ie, I don' want it to drive like a G or a 964 etc). The suspensions on these aren't super sophisticated so there are limits. If you mean the 405 expansion joints through the west side... I dont notice it porpoising there.

Suspension feel and setup is pretty personal, I went with this setup after doing quite a bit of research and was happy enough I haven't changed it.

Nice cars all.

So after sitting at the body shop for a while, my front shocks gave out (left and right) followed by the torsion bar bushings shortly after getting it out and driving around.

Also live in the LA area.
Car isnÂ’t tracked
Just enjoyed on grocery runs, coffee, PCH, the 405.
The chassis is a 1968 911L
The suspension I believe is from a 1976S, (front and back) with an RS tribute.
I donÂ’t need it aggressive.

What would you do? Just change the inserts and Swamy bar bushing call it a day? Or?

Here’s a couple of pics of my tangerine