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I would be interested in a street/track setup. would like to lower rear of the car more with more camber/toe adjustment.
Sadly what you are looking for will not be cured by spring rate/type. To get more range/ease of adjustment of the rear camber/toe of a 944 (especially when lowered), a 935-style spring plate is needed, with threaded rod adjustment for separate adjustment of toe without affecting camber. The Kokeln rear suspension setup had this, and besides roll center correction is the main reason I am on the hunt for a used one!
In short, don't lower the front or rear ride height beyond 968CS settings, otherwise you will run into all sorts of geometry/adjustability issues as documented elsewhere on this forum.
Sadly what you are looking for will not be cured by spring rate/type. To get more range/ease of adjustment of the rear camber/toe of a 944 (especially when lowered), a 935-style spring plate is needed, with threaded rod adjustment for separate adjustment of toe without affecting camber. The Kokeln rear suspension setup had this, and besides roll center correction is the main reason I am on the hunt for a used one!
In short, don't lower the front or rear ride height beyond 968CS settings, otherwise you will run into all sorts of geometry/adjustability issues as documented elsewhere on this forum.
Thanks Chris,
I read the title and immediately thought it was that setup.
So I got some education from Karl at Racer's Edge. Obviously a lot of people have been running torsion bar delete's in a variety of high stress environments and of course, his lower shock mount adapters are well known and proven solution.
Turns out the failure mode I've experienced was obvious to Karl. It's as simple as stud in single-shear vs bolt in single-shear. I may botch the information but TLDR: Bolt in single-shear torqued to 150 ft/lbs will have the entire bolt in tension and will be strong enough for single shear. A stud doesn't have the same characteristics in that usage and will fail.
He recommended I just use the factory bolt but I've since taken some measurements and will need to figure out an alternative. The intrax stud is 100mm (with a 14mm spacer to give the upside down shock clearance from the control arm). Factory bolt is 85mm. I'll need to source a M14X1.5X100 bolt of the appropriate grade strength and a 14mm spacer since mine went walkabout when the stud broke at 65mph on the freeway. Somewhere there's a squirrel who has found my nice spacer...
@v2rocket: thanks for the rec. I'll definitely look in their direction.
@droops83: Ground Control or Bilstein will have to be the solution if I can't get my existing setup working well. I like the lower mount setup on the ground control setup as well and given Karl's information, their choice of mount and bolt makes a lot more sense than Intrax's stud/spacer/nut setup. I'm going to see if there's a way to buy their lower mount and bolt alone. Current springs on the intrax coilvers are 560 lbin so they're more street than track, I'd say. Pairing them with 27mm torsion bars, if I can make the pre-load and helper spring work, will hopefully recreate what's happening in the front suspension. BTW, your guidance on 968CS ride height is helpful.
@shortyboy: Agree with @droops83. My experiment will do nothing for more toe and camber. My experiment might result in a decent street ride while being stiff enough to balance my front axle on track.
Worst case scenario here is that I'll be out $50 bucks in parts and have to swap out the rear setup for a Ground Control, KW, or Bilstein setup. Really worst case I can always just throw stock Koni's back on once the torsion bars are back in. Given that I like what I've got in the front, I'm hoping to make the intrax setup work.
In case anyone is interested in "before" pictures:
Snappity snapped stud.
Stud is torqued in at 150 ftlbs. Odd's I'll extract that successfully? Low
Passenger Side so you can see how it's "supposed" to be installed. Obviously, I'll replace this mounting setup with whatever I do on the driver side.
Surprise! Stud extracted without loss of skin, blood, or even excessive usage of curse words. Ok, there was some hammering and muttering involved...
So I got some education from Karl at Racer's Edge. Obviously a lot of people have been running torsion bar delete's in a variety of high stress environments and of course, his lower shock mount adapters are well known and proven solution.
Turns out the failure mode I've experienced was obvious to Karl. It's as simple as stud in single-shear vs bolt in single-shear
" 4) I don't think I insinuated that you made an install error. I was trying to say that you are using a part that obviously has design problems. The shoulder area that is torqued against the rear arm surface is much larger on the Racer's Edge piece. I have never seen one of those fail "
Wow, that looks like it was a sketchy setup! No wonder it broke.
If I were you I would get the Racer's Edge or Ground Control lower mounts and be done with it. Do stacked rear coil springs if you must, unless you have lots and lots of time on your hands to attempt to get T-bars and coils to play nice together . . . .
Wow, that looks like it was a sketchy setup! No wonder it broke.
If I were you I would get the Racer's Edge or Ground Control lower mounts and be done with it. Do stacked rear coil springs if you must, unless you have lots and lots of time on your hands to attempt to get T-bars and coils to play nice together . . . .
This guy will never listen to me if I told him, but while the bolt is shady, it's not his real problem.
T, does it have anything to do with the red spring?
The red spring is just a helper spring (likely with near-zero actual spring rate), keeps the main spring seated while the shock is extended during wheel droop. I have these on all 4 corners, helps prevent clunking while deriving over bumps.
The original poster took the idea a step further in the front and used stiffer helper springs to make the overall wheel rate progressive.
appears to me that the spacer between shock and arm is too long...the shock eye should be perpendicular (like stock) to the bolt, yours is cocked on its ball joint, may be applying forces to the bolt/stud at an angle the arm hole wasn't intended for.
" 4) I don't think I insinuated that you made an install error. I was trying to say that you are using a part that obviously has design problems. The shoulder area that is torqued against the rear arm surface is much larger on the Racer's Edge piece. I have never seen one of those fail "
So basically what I already told you.
T
Per Karl the shoulder area has nothing to do with it.
But you know what you’re taking about! I’ll let Karl know you’re here to educate him.
To be specific I’m not using helper springs in front, they are tenders and meant for stacked spring setups.
Stacked spring setups truly are dual rate, rather than progressive. Stacked spring rate is about half the rate of the dual springs. You design them so one spring (tender)will fully compress first. At that point you’re only on the main spring rate. Check out the original thread for rationale and mechanics of it. To be clear it’s not for everyone. I only see value in it for a dual use car.
In the rear rear those are helpers, and used just to locate the springs when the suspension is unloaded. They have no meaningful spring rate.
TLDR: Helpers are not the same as tenders.
And again, not doing stacked springs in the rear.
Guys, this isn’t rocket science. It’s just a variation on the same setup the factory uses on the 968CS, etc made possible because there are already helper springs on the Intrax coil overs.
Its literally “reinstall torsion bars, set ride height, dial out pre-load on the coil overs so that only the helper is compressing and therefore the main coil over spring isn’t in effect for the first 1/2” of wheel travel.” No that’s not a stacked spring setup.
If you’re interested in a stacked spring setup...look elsrwhere. This is only about replicating the effect of a dual spring setup.
Last edited by ninefiveone; 06-02-2018 at 04:58 PM.
Per Karl the shoulder area has nothing to do with it.
But you know what you’re taking about! I’ll let Karl know you’re here to educate him.
Keep up the great work, Inspiration!
LOLZ, Karl already knows who I am....., he sends his mechanic's son down to where we paddock to check on spares when they don't have it, and the kid is an aspiring racer that he sent down to look at our car as an example of an SP2 car to target....,
again,
Dude, listen, quit trying to be a harda$$. I can help you.
Uh huh. And yet you don’t know how Karl’s adapters work. But fine. Go nuts. Please tell me what to do to accomplish my goal.
Not your goal. My goal.
Go.
You had a bolt/stud in shear, with no support except the threads (piece that is a collar that bolt turns in serves no strengthening purpose).
The Racer's Edge part has a large support surface that torques flat against the aluminum receiver then the shock bolts to it separately.
Yeah, you got me though, I don't know how they work.
I have installed a dozen sets of these and race them all over the country on three different cars.
I think any reasonable person following this can see that you are being purposely obtuse.
Let me know when you decide when you want to learn what your real problem is.
06-01-2018, 02:19 PM
