All dressed up and no place to race...
04-25-2007, 06:20 AM
#1
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All dressed up and no place to race...
<center><img src="http://pictureposter.audiworld.com/711/05-27-06.jpg"></center><p>
My track day was cancelled yesterday due to rain/snow... and I mean LOTS of it!
For those trying to determine what a "sport 90 quattro" is, well when ya own one you won't be asking any more. You'll KNOW!;-)
So I spent the day designing adapters for the new front shocks I'm going to use interimly until the new motor goes in and I can valve the GT3 RSR Ohlins 3-way adjustables for the fronts. Just too much money to waste that quality on the car now and have to re-build the Ohlins again later. And I can get Bilsteins dirt-cheap locally. My original UrQ "sport" Bilsteins have become extinct/unavailable and the only shock available for the UrQ-sized front struts (from the CQ rear) is the heavy duty Bilstein. After a few days on those it leaves me not necessarily "wanting" more, but wondering how much better "more" can be. Since UrS4/6 struts were originally designed for a car that's 800lbs heavier than mine is today they ought to be a good fit for my needs. Certainly better than UrQ which is a lighter car tho I love it's dramatically larger pistons and valving over the B4 part numbers.
I got hold of my suspension engineer contact at Bilstein in San Diego from the Champagne Hill Climb car days and we started poring over the comparative dynamics and specifications for some alternative struts that will be a far more solid and race-oriented strut for the CQ rear struts used in my B4Q fronts. Looks like the UrS4/6 front sport struts will get the nod. Actually an even better upgrade from UrQ sports than the PSS-9 race suspension upgrades offered for newer platforms above their "sport" struts.
UrS4/6 are same external dimension tubes & hydraulic rod diameters as UrQ's but dramatically better damping/rebound/valving characteristics. Also significantly stronger internals on all parts from disc thickness, piston rod dia and piston urethane internal seals, larger cross-section urethane o-rings and bump-stops instead of 100% rubber used in the UrQ that are 12mm lower than the UrQ. So while the shock is the same length uncompressed it gives me 1/2" more downward shock/spring/suspension travel before encountering the internal bump-stop. With the spring rates I'm running up-front this promises be a really, REALLY good choice strut replacement. Had I know of it years ago I would've gone this route initially instead of UrQ sports. Even the strut cap is not just close but same part # between UrS-Cars and UrQ.
Bad news (if you can even call it that) is I have to machine some adapter sleeves to adapt to Pro-Mounts. UrS struts have a radically different threaded stud up top than all small-chassied Audis. But because I designed the Pro-Mounts with proprietary open-architecture they will also be plug-n-play for any mount system I've ever made or will make, ie; if they fit Pro-Mounts they also fit solid mounts and so on and so on. They will NOT fit standard, OEM or "any" other generic or aftermarket strut mount.
So Mother Nature you can keep me off the race track, but you can't keep the race track out of my garage!
My track day was cancelled yesterday due to rain/snow... and I mean LOTS of it!
For those trying to determine what a "sport 90 quattro" is, well when ya own one you won't be asking any more. You'll KNOW!;-)
So I spent the day designing adapters for the new front shocks I'm going to use interimly until the new motor goes in and I can valve the GT3 RSR Ohlins 3-way adjustables for the fronts. Just too much money to waste that quality on the car now and have to re-build the Ohlins again later. And I can get Bilsteins dirt-cheap locally. My original UrQ "sport" Bilsteins have become extinct/unavailable and the only shock available for the UrQ-sized front struts (from the CQ rear) is the heavy duty Bilstein. After a few days on those it leaves me not necessarily "wanting" more, but wondering how much better "more" can be. Since UrS4/6 struts were originally designed for a car that's 800lbs heavier than mine is today they ought to be a good fit for my needs. Certainly better than UrQ which is a lighter car tho I love it's dramatically larger pistons and valving over the B4 part numbers.
I got hold of my suspension engineer contact at Bilstein in San Diego from the Champagne Hill Climb car days and we started poring over the comparative dynamics and specifications for some alternative struts that will be a far more solid and race-oriented strut for the CQ rear struts used in my B4Q fronts. Looks like the UrS4/6 front sport struts will get the nod. Actually an even better upgrade from UrQ sports than the PSS-9 race suspension upgrades offered for newer platforms above their "sport" struts.
UrS4/6 are same external dimension tubes & hydraulic rod diameters as UrQ's but dramatically better damping/rebound/valving characteristics. Also significantly stronger internals on all parts from disc thickness, piston rod dia and piston urethane internal seals, larger cross-section urethane o-rings and bump-stops instead of 100% rubber used in the UrQ that are 12mm lower than the UrQ. So while the shock is the same length uncompressed it gives me 1/2" more downward shock/spring/suspension travel before encountering the internal bump-stop. With the spring rates I'm running up-front this promises be a really, REALLY good choice strut replacement. Had I know of it years ago I would've gone this route initially instead of UrQ sports. Even the strut cap is not just close but same part # between UrS-Cars and UrQ.
Bad news (if you can even call it that) is I have to machine some adapter sleeves to adapt to Pro-Mounts. UrS struts have a radically different threaded stud up top than all small-chassied Audis. But because I designed the Pro-Mounts with proprietary open-architecture they will also be plug-n-play for any mount system I've ever made or will make, ie; if they fit Pro-Mounts they also fit solid mounts and so on and so on. They will NOT fit standard, OEM or "any" other generic or aftermarket strut mount.
So Mother Nature you can keep me off the race track, but you can't keep the race track out of my garage!
04-25-2007, 06:37 AM
#6
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Interesting...
Without going to extent you did on designing steering arms, would it be possible to take CQ rears and simply weld on steering arms from front struts? I was thinking about this...
Also, I've been browsing around trying to find an adjustable shock tha would fit inside the McPherson housing, then drill a hole on the bottom for the hydraulic hose to be slid through and attashed to the shock - highly unlikely it would work but I was thinking about it. Oe thing that I'm not sure of is whether that shock would have to spin inside the strut housing - if so then forget this.
Another thought I had is....I was looking at a Moton setup on a 993. Shock itself has 2 tang/brackets on the bottom that our hub knuckle could possibly get attached to with some adapters. Unfortunately I couldn't measure its length. Also here the issue would be steering arm for the front, but at least it may be doable on the back...
<img src="http://www.gocpt.com/gallery/c2_motons/photos/DSC06902.jpg">
<img src="http://www.gocpt.com/gallery/c2_motons/photos/DSC06904.jpg">
Also, I've been browsing around trying to find an adjustable shock tha would fit inside the McPherson housing, then drill a hole on the bottom for the hydraulic hose to be slid through and attashed to the shock - highly unlikely it would work but I was thinking about it. Oe thing that I'm not sure of is whether that shock would have to spin inside the strut housing - if so then forget this.
Another thought I had is....I was looking at a Moton setup on a 993. Shock itself has 2 tang/brackets on the bottom that our hub knuckle could possibly get attached to with some adapters. Unfortunately I couldn't measure its length. Also here the issue would be steering arm for the front, but at least it may be doable on the back...
<img src="http://www.gocpt.com/gallery/c2_motons/photos/DSC06902.jpg">
<img src="http://www.gocpt.com/gallery/c2_motons/photos/DSC06904.jpg">
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04-25-2007, 06:45 AM
#8
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Not that loong but his point was having a B4 90 and modifying it to a certain level...
I guess Mike was one of the 1st "on this forum" who has done some upgrades....its a guess, I wouldn't know as I wasn't around since beginging.
04-25-2007, 06:57 AM
#9
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Thread Starter
Yes, we've done welded arms to get larger piston'd struts on several ralley cars...
The killer with welding is "clocking" the steering arms correctly before a single weld bead is applied. Do it wrong, even by 1/64" and you've got paperweights. Tho some measure of correctiveness is available if you go with spherical bearing tie rods and lose the stock ones.
I'm a huge fan of Moton and likely would've considered that way myself if I werent so well-connected with an Ohlins motorcycle custom builder. I'd still rather have a Moton steering damper than anything else on the planet but at $3,500-a-pop I'll likely attempt making my own with some Ohlins tubes, pistons, valving and opposing compression springs.
You can basically do anything you want on the fronts. Biggest obstacle to most is the intimidation factor. Bottom line is strut tubes are altogether easy to make even from scratch. Easier yet to modify to work. That 993 set-up would be altogether easy to adapt and even if every part made from scratch wouldn't eat up more than $500-$600 for both to have something ready to drop in them.
I'm a huge fan of Moton and likely would've considered that way myself if I werent so well-connected with an Ohlins motorcycle custom builder. I'd still rather have a Moton steering damper than anything else on the planet but at $3,500-a-pop I'll likely attempt making my own with some Ohlins tubes, pistons, valving and opposing compression springs.
You can basically do anything you want on the fronts. Biggest obstacle to most is the intimidation factor. Bottom line is strut tubes are altogether easy to make even from scratch. Easier yet to modify to work. That 993 set-up would be altogether easy to adapt and even if every part made from scratch wouldn't eat up more than $500-$600 for both to have something ready to drop in them.