Rear coil-over shock......
03-05-2003, 09:42 AM
#1
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Rear coil-over shock......
Hey all....
We're thinking of making a rear-coil over kit for the 944. We think we can do it at a reasonable cost. Some concerns, though...
A rear coil over setup, with the torsion bars removed, would mean all the rear weight of the car is on the lower shock mounting point on the banana arms. I'm not sure this mount was designed to handle that weight. As a helper spring setup, ala 968 Turbo RS, obviously it would be fine as the factory did it. Not sure if they beefed up that mounting point, though.
Anyone have any comments? Know anything about this I don't??
We're thinking of making a rear-coil over kit for the 944. We think we can do it at a reasonable cost. Some concerns, though...
A rear coil over setup, with the torsion bars removed, would mean all the rear weight of the car is on the lower shock mounting point on the banana arms. I'm not sure this mount was designed to handle that weight. As a helper spring setup, ala 968 Turbo RS, obviously it would be fine as the factory did it. Not sure if they beefed up that mounting point, though.
Anyone have any comments? Know anything about this I don't??
03-05-2003, 09:54 AM
#3
Racer
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Hi Scott,
Every coil-over manufacturer uses the stock banana arm mount with no issues. I don't think there is any problem with this setup, as pretty much EVERY 944 racecar is using coil-over in the rear (with or without Tbars, mostly without).
Racer's edge sell a 'hardend adapter' which converts the lower Porsche 14mm bolt to a more industry standard 1/2" (to fit most coilover bearings), but this is not necessary unless you go for sperical bearings (in place of bushings).
What's your target price range? Adjustable shock (single/double)? 2.25"?
Tell us more, I'm in the market for a rear-coil over right now (debating between turbo cup vs. leda oil).
Every coil-over manufacturer uses the stock banana arm mount with no issues. I don't think there is any problem with this setup, as pretty much EVERY 944 racecar is using coil-over in the rear (with or without Tbars, mostly without).
Racer's edge sell a 'hardend adapter' which converts the lower Porsche 14mm bolt to a more industry standard 1/2" (to fit most coilover bearings), but this is not necessary unless you go for sperical bearings (in place of bushings).
What's your target price range? Adjustable shock (single/double)? 2.25"?
Tell us more, I'm in the market for a rear-coil over right now (debating between turbo cup vs. leda oil).
03-05-2003, 11:43 AM
#4
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Thread Starter
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Russ Murphy:
<strong>Dunno,
What don't you know? <img border="0" title="" alt="[Wink]" src="wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">If I knew what I didn't know, I'd think I'd know that.
<strong>Dunno,
What don't you know? <img border="0" title="" alt="[Wink]" src="wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">If I knew what I didn't know, I'd think I'd know that.
03-05-2003, 11:48 AM
#5
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by RPG951S:
<strong>Hi Scott,
Every coil-over manufacturer uses the stock banana arm mount with no issues. I don't think there is any problem with this setup, as pretty much EVERY 944 racecar is using coil-over in the rear (with or without Tbars, mostly without).
Racer's edge sell a 'hardend adapter' which converts the lower Porsche 14mm bolt to a more industry standard 1/2" (to fit most coilover bearings), but this is not necessary unless you go for sperical bearings (in place of bushings).
What's your target price range? Adjustable shock (single/double)? 2.25"?
Tell us more, I'm in the market for a rear-coil over right now (debating between turbo cup vs. leda oil).</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Externally adjustable shock. 2.25" ID spring. Shooting for a price around $500/pr, not sure at this point if that's gonna be accurate or not. I've seen the Racer's Edge adapter. Nice piece and we'll have something similar. I'm not really concerned with the adapter strength as the strength of the banana arm mount point itself.
<strong>Hi Scott,
Every coil-over manufacturer uses the stock banana arm mount with no issues. I don't think there is any problem with this setup, as pretty much EVERY 944 racecar is using coil-over in the rear (with or without Tbars, mostly without).
Racer's edge sell a 'hardend adapter' which converts the lower Porsche 14mm bolt to a more industry standard 1/2" (to fit most coilover bearings), but this is not necessary unless you go for sperical bearings (in place of bushings).
What's your target price range? Adjustable shock (single/double)? 2.25"?
Tell us more, I'm in the market for a rear-coil over right now (debating between turbo cup vs. leda oil).</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Externally adjustable shock. 2.25" ID spring. Shooting for a price around $500/pr, not sure at this point if that's gonna be accurate or not. I've seen the Racer's Edge adapter. Nice piece and we'll have something similar. I'm not really concerned with the adapter strength as the strength of the banana arm mount point itself.
03-05-2003, 01:09 PM
#6
Drifting
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> If I knew what I didn't know, I'd think I'd know that. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Sorry, couldn't resist. 
I just wanted you to expound on what you do know, that way we could give you meaningful feedback. You're right, it's kind of hard for you or me to know what you don't know.
Five hundred a pair is pretty darn reasonable based on the rather thorough search for coilovers I just went through. I know this number isn't set in stone, but are you including the ride height bits and any adapters in this price?
I just wanted you to expound on what you do know, that way we could give you meaningful feedback. You're right, it's kind of hard for you or me to know what you don't know.Five hundred a pair is pretty darn reasonable based on the rather thorough search for coilovers I just went through. I know this number isn't set in stone, but are you including the ride height bits and any adapters in this price?
03-05-2003, 01:28 PM
#7
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Russ Murphy:
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> If I knew what I didn't know, I'd think I'd know that. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Sorry, couldn't resist. I just wanted you to expound on what you do know, that way we could give you meaningful feedback. You're right, it's kind of hard for you or me to know what you don't know.
Five hundred a pair is pretty darn reasonable based on the rather thorough search for coilovers I just went through. I know this number isn't set in stone, but are you including the ride height bits and any adapters in this price?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">It would be ride height adjustable. Complete, all bits included to bolt it up to the car. But, we're really early into this. Still in the talking/neog phase with some possible vendors.
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> If I knew what I didn't know, I'd think I'd know that. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Sorry, couldn't resist.
I just wanted you to expound on what you do know, that way we could give you meaningful feedback. You're right, it's kind of hard for you or me to know what you don't know.Five hundred a pair is pretty darn reasonable based on the rather thorough search for coilovers I just went through. I know this number isn't set in stone, but are you including the ride height bits and any adapters in this price?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">It would be ride height adjustable. Complete, all bits included to bolt it up to the car. But, we're really early into this. Still in the talking/neog phase with some possible vendors.
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03-05-2003, 01:32 PM
#9
Three Wheelin'
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by PorscheG96:
<strong>It would be a huge plus [though I'm not sure if it's possible] to have a rear coilover setup that doesn't require reindexing the torsion bars. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Just do some voodoo magic or something.
<strong>It would be a huge plus [though I'm not sure if it's possible] to have a rear coilover setup that doesn't require reindexing the torsion bars.
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Just do some voodoo magic or something.
03-05-2003, 01:56 PM
#10
Drifting
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Couldn't that be accomplished with simply a short enough spring in the coil-over?
(when suggesting dumb ideas, it helps to be dumb <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> )
(when suggesting dumb ideas, it helps to be dumb <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />
)
03-05-2003, 02:08 PM
#12
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Re-indexing torsion bars necessary? I guess this is one of those things that I don't know. Why can't you add the adjustable coil-over and use it's adj height feature to adjust height??
03-05-2003, 02:29 PM
#13
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I'm just about to install some rear coil overs. My torsion bars and rear dampers are worn out, and the rear ride height is too low. I'm going to try installing the coil overs and using 200 - 300 lb springs along with tender springs without re-indexing. I'll adjust the ride height to raise the car slightly from its static height. Wish me luck.
...I'm sure I'll be reindexing soon.
...I'm sure I'll be reindexing soon.
03-05-2003, 02:50 PM
#14
Race Car
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Steve Lavigne:
<strong>I'm just about to install some rear coil overs. My torsion bars and rear dampers are worn out, and the rear ride height is too low. I'm going to try installing the coil overs and using 200 - 300 lb springs along with tender springs without re-indexing. I'll adjust the ride height to raise the car slightly from its static height. Wish me luck.
...I'm sure I'll be reindexing soon.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Cool! Good luck.
<strong>I'm just about to install some rear coil overs. My torsion bars and rear dampers are worn out, and the rear ride height is too low. I'm going to try installing the coil overs and using 200 - 300 lb springs along with tender springs without re-indexing. I'll adjust the ride height to raise the car slightly from its static height. Wish me luck.
...I'm sure I'll be reindexing soon.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Cool! Good luck.
03-05-2003, 03:05 PM
#15
Race Director
Ok,
I have done torsion bars twice on my race car so I know the job and rear suspension.
Once to install 28mm bars and then to install 30mm bars.
I have developed an excel spreadsheet the calculates the proper ride heights given a torsion bar swap. It is long job, but does not need to be done more than once with this tool.
Here is link to it <a href="http://az.pca.org/tech/tech.htm" target="_blank">Az PCA Tech page </a>
Anyway any change to rear spring rates will require an adjustment of the torsion bars or their removal.
If you have a "helper spring" arrangement you need to re-index the bars to get the right height since the spring rate is now different. If you leave the helper "loose" and get the ride height to right level then you have a two spring system and will see a dramatic change in spring rate when driving. Not a good thing!
Thus you need to adjust the bars.
If you are JUST using coilovers then you still need to get in there and remove the bars anyway so you still have about 85% of the work for a normal t-bar adjustment. Only benefit is that you don't need to worry about the "right" setting and doing the job over again.
Bottomline is that anychange to rear spring rate requires touching the t-bars to mantain ride height. No way around doing it at least once!
I have done torsion bars twice on my race car so I know the job and rear suspension.
Once to install 28mm bars and then to install 30mm bars.
I have developed an excel spreadsheet the calculates the proper ride heights given a torsion bar swap. It is long job, but does not need to be done more than once with this tool.
Here is link to it <a href="http://az.pca.org/tech/tech.htm" target="_blank">Az PCA Tech page </a>
Anyway any change to rear spring rates will require an adjustment of the torsion bars or their removal.
If you have a "helper spring" arrangement you need to re-index the bars to get the right height since the spring rate is now different. If you leave the helper "loose" and get the ride height to right level then you have a two spring system and will see a dramatic change in spring rate when driving. Not a good thing!
Thus you need to adjust the bars.
If you are JUST using coilovers then you still need to get in there and remove the bars anyway so you still have about 85% of the work for a normal t-bar adjustment. Only benefit is that you don't need to worry about the "right" setting and doing the job over again.
Bottomline is that anychange to rear spring rate requires touching the t-bars to mantain ride height. No way around doing it at least once!