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Best torsion bar for 250lbs spring ?

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Old 01-19-2006, 02:49 PM
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dede944
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Default Best torsion bar for 250lbs spring ?

Hi !

I'm in the process of updating my suspension on
my 944NA 85.5. Right now I've got turbo sway bar
25.5 and 18mm on the car, 250lbs weltmeister springs
and 4 Bilstein waiting for this summer.

The car will be use as street/track.

So what would be the good size of torsion bars ?
I want a car that is as neutral as possible...

Looking here : http://dspace.dial.pipex.com/prod/di...suspension.htm

I've found that 27mm bars with 250spring would keep
the same ratio as original as I did with sway bars 20-14 to
25.5 and 18. The rear torsion bars being exactly 10% softer
than front.

But torsion bar 26mm + are only aftermarket and are expensive...(300US).

I maybe could get used turbo bars near home, so would
turbo bars would do a good job too ??

Thanks
Old 01-19-2006, 03:15 PM
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tifosiman
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Hi dede,

951 torsion bars really won't be enough with 250lb springs. You will still have understeer issues. If you can go with 27mm or 28mm torsion bars, that would be the best for that spring rate.

T.
Old 01-19-2006, 03:20 PM
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Oddjob
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Turbo t-bars are 23.5mm, the same as what you have in your n/a.

Turbo S/M030 t-bars are 25.5mm, but are probably a little light to match with a 250 lb front spring.

I think you probably want a 27mm bar, but as you note, they are somewhat expensive, especially if you go with drilled/hollow bars.

May want to wait and shop for a used set, sometimes you will see ugraded t-bars for sale when guys go to coilovers.

EDIT: Tifo beat me to it.
Old 01-19-2006, 04:04 PM
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Owain
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I have 28mm t-bars with 250 lb/in springs and find the car to be pretty well balanced. That combo gives an even rate front-to-rear (250f, 254r) so it's not the same ratio as from the factory, but most street cars are set up from the factory to have understeer for safety. Dialing some of that out is probably good for a track car. 50-50 weight distribution; 50-50 spring rate. It's a theory, and it feels pretty good to me at both autoX and the track, for whatever that's worth. I don't know what the optimal ratio should be, but I guess it depends a lot on your driving style.

Tifo: what ratio do your spring rates work out to?
Old 01-19-2006, 04:16 PM
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tifosiman
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I'm running 400lbs on the front, and 400lbs on the rear plus 23.5mm tbars (re-indexed).
Old 01-19-2006, 04:42 PM
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josephsc
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I have a pair of uninstalled (but bit rusty) 27mm hollow t-bars I'd consider selling -- I'm thinking that going to rear coil overs w/ t-bar delete might be a fun time bomb to play with (versus the headache of t-bar install....)
Old 01-19-2006, 10:07 PM
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dede944
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Thanks for all the answers guys !

27-28 looks like th way to go for me...
considiring I hate understeer

Joseph, may consider your 27 hollow (equal to 26 solid,
would be not bad...). How much are you thinking fo them ?

Old 01-19-2006, 10:46 PM
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Actually, these are 27mm effective -- I can't remember the exact outer dimension, but it's stamped "1227" on the ends. I'd let them go for $240 (2/3 of new price -- and a hair less than the price of new solid t-bars) plus shipping. PM me if you're interested.
Old 01-20-2006, 10:51 AM
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M758
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I would recomment 28mm bars for the 250's, but you probaly can do fine with 27's too. Alot depends on street vs track vs autocross and what kind of balace you want.
Old 01-20-2006, 08:38 PM
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Bri Bro
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I run 28mm with 250's. Has been working well for me.
Old 01-21-2006, 02:13 AM
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TRP951
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what about for a 86 951? what springs and torsion bars would you run with konis and what settings should the koni be on?

P.S. sorry for the hijack
Old 01-21-2006, 10:20 AM
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brad-cam
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Is there any possible way to add coil-over rear shocks to the 951 to allow the use of the stock torsion bars and not require a re-indexing ? It seems maybe with the QA1's or something, we could add any spring rate we wanted to the shock coil over and with the right length springs, ride height could be kept neutral and not require a re-index... is this possible with any available coil-over shocks or is this my personal pipe-dream ?

You can see I'm avoiding doing the re-index job, but I am running M030 sways and 250lb coil-overs on the front and haven't touched my rear spring/shock setup yet...
Old 01-22-2006, 08:04 AM
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tifosiman
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Originally Posted by brad-cam
Is there any possible way to add coil-over rear shocks to the 951 to allow the use of the stock torsion bars and not require a re-indexing ? It seems maybe with the QA1's or something, we could add any spring rate we wanted to the shock coil over and with the right length springs, ride height could be kept neutral and not require a re-index... is this possible with any available coil-over shocks or is this my personal pipe-dream ?

You can see I'm avoiding doing the re-index job, but I am running M030 sways and 250lb coil-overs on the front and haven't touched my rear spring/shock setup yet...
You're going to need to re-index.
Old 01-22-2006, 08:39 PM
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Frank944
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What do you think of the suspension package described here:

http://members.rennlist.com/944sandmore/stick.htm

-Koni's all around
-Weltmeister 250 lb/in. springs
-Weltmeister 26mm Rear Torsion Bars
-Weltmeister 28mm front sway bar
-Weltmeister 22 mm Rear sway bar
-225/50/15 tires on four corners

According to you the rear torsion bars would be too soft and the car would have a tendancy to understeer, am I right? 28 mm would be better, and by the way, what do you think of weltmeister sway bars?

Last edited by Frank944; 01-23-2006 at 10:29 AM.
Old 01-23-2006, 10:30 AM
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Frank944
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ttt


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