best tortion bar setup for 73t (rs clone)?

ok. here it is.i have a set of 21 mm front tortion bars. what would be a good rear setup. i have bilstiens all around. i have a 87 carrera front suspension using the 73 control arms with s calipers.i plan on using stock sway bar( for now). car will have 7r 2.7 motor(when ever i finish paying race prep work at ollies)bought car with a rebuilt 2.4 s spec motor with e cams(fairly quick). fuchs 7,8x15. (tiresnot yet)? no interior other than 2 seats,cage, and some door panels.so it should be a fairly lite car. havent thought about or budgeted a cooler yet. i put all this info down because most people might ask these things before giving advise.

back to the original question:
what is the best matching tortion bar setup for the rear of my car. want to keep front 21mm because i already have them.

ps
will only be a weekend car and if i can hang with the big boys it might see willow once in a while.
thanks for the help!

[Tyson Schmidt]

I'd go with 28mm on that light of a car. Should be a good balance for the 21mm up front.

ment to say 73 struts not control arms.

2 people who own shops suggesred 31mm in rear but that seemed too much. i was told that a 10 spacing was normal for this type of setup. mind you that these guys have late model cars and are very success on the track. any thoughts.
joe

[Chuck Miller]

The standard old 'one-step-up' early car set up is 21/26 ... stock is 19/23...

I run 21/26 with 19/19 sway bars and stock S Konis ....
Corner balanced, and agressive alignment - about 2 degrees F/R

I run 7/8 x15's with S-03's for the street and Kuhmo DOT's for the track.

This set-up is great for the street and not to bad for the track...

Cheers,
Chuck

[Jack Olsen]

26 (Turbo) or 27 (Bruce Anderson's recommendation). I would only go stiffer than that in back if it was primarily a track car.

[Randy W]

As per Chuck and Jack, 21/26 with 2.4L motor or 21/27 with a 2.7RS motor is often recommended. Go with hollow bars if you can. These and stock Konis or stock Bilsteins will help keep the ride on the softer side.

as per another recomendation, i was going to get the bilsteins revalved at 200-150 for front and not sure for rear.very confusing.and yes i would like it to be a primarily track car. thanks for all the info guys.
joe

[Ira Ramin]

I'm running a similar car. 70 S (RS look) with 15x7 & 8 and 21/27 torsion bars. Used primarily for track and very well balanced.

Ira

[ted]

Some very qualified opinions on this thread.

What shop is guiding you with your choices?
They appear to like an aggressive suspension set up.
I have not heard before of the 10 spacing t bar rule?

Not every one enjoys the same set up so each opinion is correct for each owners driving style.

I think if you are new to racing a 911 a softer rear bar will be more forgiving, not as tail happy.

My 2 cents.

My 2200lb early 911 w/3.2 did have 21/26 t bars and Bilstien yellow sport shocks. They work fine and I think they are a good choice for the reduced traction found in parking lot AX events.

I believe softer and wider tires will allow firmer spring rates too.

That said mine has 17x8 and 10 rims with 255/40 and 275/40 Victor racers, sometimes Hoosiers with the 245/40 & 275/40 combo.
-3.2 front camber and -2.8 rear camber.

I have since installed 21 front and 30 rear t bars.
When I went to the stiffer rear bar I soon after changed to the re-valved Bilstien shocks and the car really started to work well.
The increased rebound control with the re-valved shocks really helps to control the stiffer t bars.

Future development will see a 3.6 installed and that too will offset the firm 30 rear t bar.

I’d plan to upgrade your rims too. New sets of 17 inch rims can be found for under $2k.

Do you have a pic of your car to share?

well, i called steve from johnson alignment who is very knoledgable and asked him if he had any used rear tortion bars and what size he suggested.he said i should look for 31mm. he sent my over to jeff from aase, who also knows his setups. these two guys said they use the 10 spacing rule. thats the info that i got. i have also heard people say that a while back someone came up with the theroy that 21\26 was the correct setup for this kind of project. so everyone ran with that. it seems that some people are going more agressive on suspensions these days. jeff from aase did say that i would have to get the shocks revalved.he told me he set up a car with 1000# springs in the rear and with a little revalving, the car was untouchable. again these are answers that people have given me. in case noboby knows this, bilstien in poway,cal. will revalve your bilstiens to any spec you want for 55.00 per shock. geting the correct valving is another thread. if anyone knows of a better deal, let me know. i think that 225.00 for used 31mm hollow bars is a good deal, but again i will have to get the shocks revalved
thanks
pics to follow

[Chuck Moreland]

I'll second the 21/27. Imho you will find a 21/31 will yield too much oversteer.

[RSupdate]

Great thread. thx all.

[rst73]

Here's my 2 cents,

I agree with Chuck, I to have a 73 RS replica and have updated Carrera and Turbo suspension with Bilsteins, 2.7MFI, 20mm front sway bar and 18mm rear sway bar, 21mm front torsion bars, 26mm rear torsion bars, and Carrera adjustable rear spring plates. This has worked very well for me both in daily driving and track time since 1984 and now just over 150,000 very fun miles.

All the best!

Roger Grago
R Gruppe #27
73 RS-T
70 2.4MFI VW Bus

[ted]

Originally posted by joseph herreros
well, i called steve from johnson alignment he sent my over to jeff from aase, who also knows his setups. bilstien in poway,cal. will revalve your bilstiens to any spec you want for 55.00 per shock.

Dude you got some heavy hitters there, I'd go with those suggestions.
It very nice of those guys to share their set ups too.
I'd say pick either Aase or Steve and go with their combo.
Your shock info is right on too.

Maybe some are going to more aggressive spring rates because they are running wider and softer tires now.
Wider tires effectively soften spring rates.
If you run little tires stay with light spring rates.

Good luck racing!

[ChrisBennet]

See this month (excellent!) Excellence article on shocks. Revalved shocks made a difference of 2-3 seconds on a ~1:50 sec lap.
Like joseph herreros said, getting the shocks revalved is only $55 but without knowing the correct settings to use it won't do you much good. You're going to have to send your shocks to someone who wil then send them on to Bilstein along with their hard earned (secret) valving settings.
-Chris

[Gordo]

I will Add my feeble .02 cents,

I have a 70T RS clone, 2.7, 22mm sway bars 6 and 7 x 16s and I am running the 21/27 setup, with koni adjustables. Although I loose regularly and impressively to Ted and the rest of the R-gruppe heavies in class, it is the nut behind the wheels fault, not the suspension. 21/27 is a firm but not insane street setting and feels pretty goood for autoX. I have noticed a little too much low speed understeer but that is more than likely a camber setting and swaybar issue. The main reason I went with the "Softer" setup on a track AutoX car is my lack of experience requiring a more forgiving setup. Eventually I will go bigger in the back but for my experience level I think the 21/27 is a very good setup. BTW I asked almost the same question you did and got the same advice I am giving you. listen to what they are saying these guys are fast! There are some VERY qualified opinions in this thread they know where of they speak.

Best, Jim

[RSupdate]

I'll have to second all of the above, some real sound and solid info here..... go with it. I wish I had something to add. But i don't

fwiw....I just upgraded to a 23/28 setup with revalved Bilstien sports & 25mm TRG s/bars. Although the front might be a bit stiff or the rear a click soft, it's leagues better than what I had originally. I'll probably go up to a 30 in the rear by the end of the year.....

again, great thread.

[Jeff Alton]

OK guys, I don't want to hijack this thread, but what should I run in my 84 3.2. Car has 22mm front and 21mm rear swaybars and Koni asjustables. I use it on the street, autox, and for DE. Car has been lightened to about 2575Lbs and is fairly well balanced right now but pushes a little to much on the slow corners at the autox.

Thanks, Jeff

[RSupdate]

CATCA, I had the same problem in my car....pushed like a snowplow!! My 73 had virtually all '84 Carrera suspension, with a 3.2 so I can kind of compare....

First off findout what your current setup is, stock I presume...Your torsion bars are...what I think 18.8/24 mm...if my memory is correct?? You will most likely want to stiffen up the rear end TB wise so as to induce some over steer into the equation....read the above posts...alot of informed info you can go by.

best of luck !!