Torsion Bar Size with 200# Springs
11-27-2005, 09:46 PM
#1
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Torsion Bar Size with 200# Springs
What torsion bar do you recommend using with 200# front springs? 26mm or 27mm?
If this helps, I currently have the following suspension modifications on my
'87 951:
968 Front and rear Sway bars 30mm and 19mm respectively.
Koni "Yellow" Sport Front Struts w/ 200# Weltmeister springs.
Koni "Yellow" Sport Rear Shocks.
KLA Strut Tower Brace
If this helps, I currently have the following suspension modifications on my
'87 951:
968 Front and rear Sway bars 30mm and 19mm respectively.
Koni "Yellow" Sport Front Struts w/ 200# Weltmeister springs.
Koni "Yellow" Sport Rear Shocks.
KLA Strut Tower Brace
11-27-2005, 10:36 PM
#3
I would go with 27mm.
Torsion bar vs spring rate:
22m = 98.03 lb/in
23mm = 117.11
24mm = 138.84
25mm = 163.47
26mm = 191.24
27mm = 222.40
28mm = 257.22
29mm = 295.98
30mm = 338.97
31mm = 386.47
Torsion bar vs spring rate:
22m = 98.03 lb/in
23mm = 117.11
24mm = 138.84
25mm = 163.47
26mm = 191.24
27mm = 222.40
28mm = 257.22
29mm = 295.98
30mm = 338.97
31mm = 386.47
11-27-2005, 10:53 PM
#4
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Originally Posted by jturbo
What torsion bar do you recommend using with 200# front springs? 26mm or 27mm?
If this helps, I currently have the following suspension modifications on my
'87 951:
968 Front and rear Sway bars 30mm and 19mm respectively.
Koni "Yellow" Sport Front Struts w/ 200# Weltmeister springs.
Koni "Yellow" Sport Rear Shocks.
KLA Strut Tower Brace
If this helps, I currently have the following suspension modifications on my
'87 951:
968 Front and rear Sway bars 30mm and 19mm respectively.
Koni "Yellow" Sport Front Struts w/ 200# Weltmeister springs.
Koni "Yellow" Sport Rear Shocks.
KLA Strut Tower Brace
Thought I would wait till I increase the front springs to something stiffer before I tackle the fun job of T-bar change.
What problem are you having with the stock T-bar ?
11-27-2005, 11:11 PM
#5
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The car had significant understeer with the stock 160lb springs in the front and the 23.5mm torsion in the rear. I am currently installing the konis front and rear and weltmeister springs, so I have not gotten a chance to try out this set-up. But I imagine, with the increase in front spring rate, that the understeer problem will be magnified.
It seems as though all of the 968/951 "Sport" suspension cars that came from the factory have an even effective rate front to rear.
It seems as though all of the 968/951 "Sport" suspension cars that came from the factory have an even effective rate front to rear.
11-28-2005, 07:11 AM
#6
You have some choices here, actually. Factory M030 spec, although slightly outdated by today's track car standards and your own 200# upgrade, is a 25.5 mm torsion bar....so advice to go to 26 or 27 mm is probably pretty good advice.
Another option, however, which costs a little more money and may not save you any labor (sounds bad already, huh
is to go with coil overs in the rear. Good news is that you get a little room for adjustment on spring rate....bad news is that you will probably raise the rear ride height and end up reindexing the torsion bars anyway.
The right answer may depend on your intended primary use for the car. My 200# front coil Weltimeistered NA is a ***** cat on the street with 23.5 OE rear torsions and yellow Konis and can hang the tail out with the best of them on the track depending on front shock stiffness setting, rear sway bar setting and rear tire pressures. My 951S, in contrast, is a filling-flinger, hard as rocks street ride with upgraded rear 968 80# coil overs and 25.5 torsion bar....and STILL tends to plow on track days with 968 M030 spec front arms, 30 mm front bar and stock 951S adjustable perch front springs. This spring we're going to experiment with front ride height settings and more camber in the front.
Another option, however, which costs a little more money and may not save you any labor (sounds bad already, huh
is to go with coil overs in the rear. Good news is that you get a little room for adjustment on spring rate....bad news is that you will probably raise the rear ride height and end up reindexing the torsion bars anyway.The right answer may depend on your intended primary use for the car. My 200# front coil Weltimeistered NA is a ***** cat on the street with 23.5 OE rear torsions and yellow Konis and can hang the tail out with the best of them on the track depending on front shock stiffness setting, rear sway bar setting and rear tire pressures. My 951S, in contrast, is a filling-flinger, hard as rocks street ride with upgraded rear 968 80# coil overs and 25.5 torsion bar....and STILL tends to plow on track days with 968 M030 spec front arms, 30 mm front bar and stock 951S adjustable perch front springs. This spring we're going to experiment with front ride height settings and more camber in the front.
11-28-2005, 02:23 PM
#7
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I have the exact same setup and went with the 27mm. It seems to be a pretty good fit although I haven't pushed it too hard yet. The other problem I ran into is that Pelican Parts only had the 27mm vailable. Paragon only offered the 30mm.
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11-29-2005, 10:42 AM
#8
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From Clarks Garage:
"Example Suspension Setups:
Sport Suspension
A good sport suspension setup for a car that is primarily driven on the street might include 220 lb. front springs, 27 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. Personally, I like a car that has very neutral steering characteristics. If you prefer to maintain the understeering characteristics of the stock 944, you might prefer a 26 mm sway bar to the 27 mm. If you prefer a car that oversteers, you might choose a 28 mm torsion bar. Just realize that a car that oversteers is much more sensitive to steering corrections and can you into trouble during a panic maneuver. With regards to the sway bars, I really like the 968 M030 sway bars. The reason I like them is that the 19 mm rear bars are 3-way adjustable which give you another option when it comes to changing the steering characteristics.
High Performance Street/Track Suspension
A good high performance suspension for a car that it used on the street and track might include 260 lb. springs, a 28 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. Again, if you want more understeer, you might choose a 27 mm torsion bar. And, if you want some oversteer, you might choose a 29 mm torsion bar. As I've already cautioned you about oversteer we won't repeat that again.
Full Race Suspension
While I've seen this suspension setup used on the street, I don't recommend it. A good combination for the track might include 400 lb. front springs, 31 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. "
"Example Suspension Setups:
Sport Suspension
A good sport suspension setup for a car that is primarily driven on the street might include 220 lb. front springs, 27 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. Personally, I like a car that has very neutral steering characteristics. If you prefer to maintain the understeering characteristics of the stock 944, you might prefer a 26 mm sway bar to the 27 mm. If you prefer a car that oversteers, you might choose a 28 mm torsion bar. Just realize that a car that oversteers is much more sensitive to steering corrections and can you into trouble during a panic maneuver. With regards to the sway bars, I really like the 968 M030 sway bars. The reason I like them is that the 19 mm rear bars are 3-way adjustable which give you another option when it comes to changing the steering characteristics.
High Performance Street/Track Suspension
A good high performance suspension for a car that it used on the street and track might include 260 lb. springs, a 28 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. Again, if you want more understeer, you might choose a 27 mm torsion bar. And, if you want some oversteer, you might choose a 29 mm torsion bar. As I've already cautioned you about oversteer we won't repeat that again.
Full Race Suspension
While I've seen this suspension setup used on the street, I don't recommend it. A good combination for the track might include 400 lb. front springs, 31 mm torsion bar, 30 mm front sway bar, and 19 mm rear sway bar. "
