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Upgrade T-bars or not? Opinions wanted.

I'm planning to refresh my front and rear suspension (bushings, shocks, ball joints, tie rods) and I am on the fence about whether or not I should upgrade the T-bars. I don't plan to track this car, but I may try an autocross or 2 in order to get a better idea of the handling characteristics. Also, I don't want my teeth rattled out every time I go over a bump while I'm out for a ride. I just want the car to handle well and feel nice and taught when I throw it into a curve. So what would you do?

Old 01-04-2004, 09:58 AM
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I was in a simlar dilemma last Winter. Have a '83 Cab and wanted to maximize handling while not making it too uncomfortable. I do a couple Auto-x's per year - nothing too serious. I was replacing the shocks all the way around and decided to upgrade the t-bars front and back. Went with 21mm F and 28mm R along with the HD struts. No regrets. It has a great street feel without being too harsh.
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Old 01-04-2004, 10:53 AM
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I went with 21's and 27's on my '73 911 when I redid the suspension. After installing the T-bars, the ride was firm but not bone jarring. The ride was very good and the handling improved a lot. I'd always do the Neatrix bushings while you are in there - they bring everything back to stock alignment and operation.

After I installed 22mm sway bars all around, it became a different animal - now it isn't bone jarring but it isn't as compliant as it was when it had the stock 16mm sway bars on it.

I'd upgrade the torsion bars and see how you like it, then see if you need larger sway bars.

Jim
Old 01-04-2004, 11:32 AM
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Anybody else have any opinions on this topic?
Old 01-05-2004, 08:26 AM
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I'm pondering the same thing at the moment. I got a steal of a deal on 21 & 26mm torsion bars & I just know my bushings are shot. Does anyone run 21 & 16mm on an SC? Would 21 & 27mm be better?
Old 01-05-2004, 08:32 AM
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Do a search and you find many threads that discuss the same.
Try this one.
Torsions for a DE SC 3.2

My 2 cents.
Don't change anything untill you AX the car a couple times. You can meet other 911 owners that have made mods that can lead you in the correct direction.

After you AX you will know if you want to compromise your ride for lower lap times. If you decide not to AX anymore then there would be no reason to go to an aggesive track suspension set up.

Here is another thread that mentions shock revalving for heavy spring rates.
DE Torsion bars sizing - SC 3.2

For a mostly street car IMO 21/26 bars would be perfect with Bilstein sport shocks.
Good for a low traction parking lot AX and good enough for a big track DE.
Old 01-05-2004, 08:39 AM
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I have fairly new HDs right now. I want to try these with the 21/26 bars- hopefully they will not be under damped?
Old 01-05-2004, 09:06 AM
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I'm where Ted is. People have the curious idea that stiffer is better and stiffer bars are an "upgrade". They're not. There is nothing inherently wrong with the stock T-bars unless you are bottoming them out or rolling so far that you're falling off the camber curve. At the moment it doesn't sound like your doing either.

I'd keep the stock T-bars and do a couple of auto-X's and see what you think. Use the money saved to do a few more events, you'll get a lot more bang for your buck. In fact the softer bars will make the car more controllable, easier to handle as a novice and maximise the traction in low grip situations. Once you're running consistant times, you can step back ask yourself where you are losing time -- and then tune the car to address that specific issue.
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Old 01-05-2004, 09:38 AM
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Do torsion bars 'age' significantly? Part of the reason I'm looking at stiffer bars is because after 23 years & 200 000 miles I'm thinking the stock bars deserve retirement? If I'm going to spend up for new bars I felt I may as well get something stiffer, plus though I can't really beat a full set for $100.
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Quote:
Originally posted by ubiquity0
Do torsion bars 'age' significantly?
They will take a "set" after awhile which may end up lowering your ride height, but unless they suffer from corrosion, cracking, or spline wear, they will still work. It's the bushings that take a beating over the years.
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Old 01-06-2004, 07:05 AM
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If you had a 2250# early car you don’t need as stiff torsion bars as a 3300# later 911 Targa with A/C, electric windows, etc. to achieve the same effect. Your limiting factor is a Targa chassis is not as stiff as a coupe with a roll cage. I think 22 mm fronts and 28 mm rear torsion bars are about the limit before the spring rate is determined by the chassis flex.

Competition shock settings will jar your teeth out. MinuteMan posted ‘”Harshness” is typically caused by shocks, not springs.’ He is right on. Good stock Boges work just fine with stiffer spring rates, say 22-28mm torsion bars. Gas shocks will feel a little softer for the same shock rate.

Plastic suspension bushings transmit much more road shock and noise than the stock rubber ones. I would usually opt for new rubber bushings for street use. My ’68 always has always had rubber bushings (2nd OA at a Seattle Parade with a 2.5 and race tires.)

When you have the torsion bars out, remember to coat them with grease (even if they are epoxy coated) and apply rust preventative inside the torsion bar tube. Your ’76 should have the reinforcement between the rear tube and the chassis at the tunnel. Get the splines in the car and suspension parts perfectly clean and oiled. Test fit all the splines prior to assembly.

When you have things apart, carefully inspect the bores of the front struts that accepts the ball joint and wedge pin. The wedge pin and steel loc-nut are critical parts.

You will be confronted with a decision as to ride height upon reassembly. Too low is worse than too high. You do not want to be riding on the rubber shock bumpers, the ride is bad and the handling is worse.

Keep track of your alignment actual settings. Use corner scales to set the final torsion bar adjustments. Re-check the alignment settings after some driving. Remember to set the alignment with one side of the sway bars disconnected and there should be no pre-load on attached sway bars.

Tom is right about the “set.” The other side of that is cars that just sit will raise the ride height.

2c

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Old 01-06-2004, 08:41 AM
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