Turbo S/M3 suspension...
02-15-2002, 02:29 AM
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Turbo S/M3 suspension...
I know that suspension is an often posted topic, but I don't believe it's quite been addressed in this manner...
I have a stock Turbo S w/153K miles. I HATE the way it feels- it rolls like a Cadillac and is EXTREMELY rough- it will jolt your fillings out over bumps. For instance: when entering a corner w/an expansion joint- it's a VERY rough jolt and then a floaty, disconnected feeling- a lot like an old Lincoln Town Car, before it settles out...
I've driven several E36 M3's- they feel INCREDIBLE- the best of both worlds! Flat w/little body movement on smooth surfaces but smooth and gentle (yet WELL connected) over ruts and pavement irregularities- even over harsh bumps. I want my Turbo S to ride like an M3- I know this may be impossible, as the modern M3's are very sophisticated and technologically advanced, but what can I do to close the gap a little?
It is a street car that will see little track time. I was thinking about 250lb springs (linear)w/28mm hollow t-bars and Bilsteins. I don't really care for adjustability if the range is right. I also plan to change all suspnsion bushings that I can get to, but no one seems to know what all is involved- I get the standard sway, t-bar, control arm bushings mentioned, but I know there are more than just those(?). Any recommendations here and/or does anyone understand how I feel (have driven an M3 and understand)? I would love to be able to afford an M3, but they're a little out of my league- with all of the problems I've had w/this car, it would have been cheaper though, but there's no way now. Even still, I'm not convinced that an M3 would be what I want- I just like the way the suspension feels, and they handle so much better than any 951 I've been in so far- I'm sure that part of the prob is that the newest 951 I could drive would be 13years old and the OLDEST M3 would be 7, but there has to be a way to make the 951 compare, if not beat the pants off an M3 and still ride smoothly...
Also can the a-arm bushings be replaced or do I have to buy all new or rebuilt units?
any advice would be greatly appreciated on this matter, as I'm getting very frustrated- I see M3's at my mechanic's all the time and it drives me crazy that my car can't run w/one, and that it was ~$10K more new (MUCH more so when considering inflation)...
Thanks a lot,
Robby
I have a stock Turbo S w/153K miles. I HATE the way it feels- it rolls like a Cadillac and is EXTREMELY rough- it will jolt your fillings out over bumps. For instance: when entering a corner w/an expansion joint- it's a VERY rough jolt and then a floaty, disconnected feeling- a lot like an old Lincoln Town Car, before it settles out...
I've driven several E36 M3's- they feel INCREDIBLE- the best of both worlds! Flat w/little body movement on smooth surfaces but smooth and gentle (yet WELL connected) over ruts and pavement irregularities- even over harsh bumps. I want my Turbo S to ride like an M3- I know this may be impossible, as the modern M3's are very sophisticated and technologically advanced, but what can I do to close the gap a little?
It is a street car that will see little track time. I was thinking about 250lb springs (linear)w/28mm hollow t-bars and Bilsteins. I don't really care for adjustability if the range is right. I also plan to change all suspnsion bushings that I can get to, but no one seems to know what all is involved- I get the standard sway, t-bar, control arm bushings mentioned, but I know there are more than just those(?). Any recommendations here and/or does anyone understand how I feel (have driven an M3 and understand)? I would love to be able to afford an M3, but they're a little out of my league- with all of the problems I've had w/this car, it would have been cheaper though, but there's no way now. Even still, I'm not convinced that an M3 would be what I want- I just like the way the suspension feels, and they handle so much better than any 951 I've been in so far- I'm sure that part of the prob is that the newest 951 I could drive would be 13years old and the OLDEST M3 would be 7, but there has to be a way to make the 951 compare, if not beat the pants off an M3 and still ride smoothly...
Also can the a-arm bushings be replaced or do I have to buy all new or rebuilt units?
any advice would be greatly appreciated on this matter, as I'm getting very frustrated- I see M3's at my mechanic's all the time and it drives me crazy that my car can't run w/one, and that it was ~$10K more new (MUCH more so when considering inflation)...
Thanks a lot,
Robby
02-15-2002, 03:17 AM
#2
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I think Andrew can vouch for the ride-quality of my car...
[quote]For instance: when entering a corner w/an expansion joint- it's a VERY rough jolt and then a floaty, disconnected feeling- a lot like an old Lincoln Town Car, before it settles out... <hr></blockquote>There's two possibilities for this:<ol type="1">[*]stiction in the suspension pivots will typically cause harshness over little bumps, but large movements typically overcome the stiction, allowing the shock's damping to come into play. If your shocks are worn, then they will cause this "floaty" movement after the "jolt" breaks the suspension free from the stiction.[*]stuck pop-off valve in the shock causes too much high-velocity damping (velocity of shock, not car). The pop-off valve gives the shock a secondary compression damping (softer) to deal with sudden movements like bridge expansion joints or quick bumps like rocks. Meanwhile, your low-velocity damping that deals with road irregularities and the car's body movements is worn, giving you the boat-like wallowing.[/list=a]I suspect it's probably a combination of both these factors. Every couple of months, I'll take my suspension completely apart and grease each and every pivot and bushing. The smooth ride-quality afterwards is simply amazing!
It's not going to be possible to emulate the M3's suspension and ride-quality. First, the natural oscillation frequency of the M3 is much higher (the body structure is stiffer). Second, the M3 has a 5-link suspension that's even better than a double-wishbone layout (Ferraris, Corvette, 928, SupraTT, etc.).
However, your idea of Bilsteins and 250lb/in. springs will be an improvement from the worn shocks you have now. And the 28mm hollow rear T-bars should be about the right match for the front springs. Sounds like a good plan to me
Another idea is to keep your stock springs and torsion-bars and go for the M030 30/19mm sway-bar option. They should give you better roll-resistance than the 250lb/in spring & 28mm T-bar combo, and yet give you a better ride as well.
[quote]For instance: when entering a corner w/an expansion joint- it's a VERY rough jolt and then a floaty, disconnected feeling- a lot like an old Lincoln Town Car, before it settles out... <hr></blockquote>There's two possibilities for this:<ol type="1">[*]stiction in the suspension pivots will typically cause harshness over little bumps, but large movements typically overcome the stiction, allowing the shock's damping to come into play. If your shocks are worn, then they will cause this "floaty" movement after the "jolt" breaks the suspension free from the stiction.[*]stuck pop-off valve in the shock causes too much high-velocity damping (velocity of shock, not car). The pop-off valve gives the shock a secondary compression damping (softer) to deal with sudden movements like bridge expansion joints or quick bumps like rocks. Meanwhile, your low-velocity damping that deals with road irregularities and the car's body movements is worn, giving you the boat-like wallowing.[/list=a]I suspect it's probably a combination of both these factors. Every couple of months, I'll take my suspension completely apart and grease each and every pivot and bushing. The smooth ride-quality afterwards is simply amazing!
It's not going to be possible to emulate the M3's suspension and ride-quality. First, the natural oscillation frequency of the M3 is much higher (the body structure is stiffer). Second, the M3 has a 5-link suspension that's even better than a double-wishbone layout (Ferraris, Corvette, 928, SupraTT, etc.).
However, your idea of Bilsteins and 250lb/in. springs will be an improvement from the worn shocks you have now. And the 28mm hollow rear T-bars should be about the right match for the front springs. Sounds like a good plan to me
Another idea is to keep your stock springs and torsion-bars and go for the M030 30/19mm sway-bar option. They should give you better roll-resistance than the 250lb/in spring & 28mm T-bar combo, and yet give you a better ride as well.
02-15-2002, 10:35 PM
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Robby,
We spoke at length about this last night. From what you have written here I'd say your suspension is just plain tired. My son's '89 turbo does not exhibit any of these traits at 80K miles... although it's beginning to feel a bit loose to me, especially in comparison to my highly modified and very tight S2
The stock torsion bars lose some of their spring rate over time. I suspect if you replaced them with something a bit stiffer, increased the front spring rate to match, installed new rear Koni yellow shocks and had your M030 struts rebuilt you would see significant improvement. Your stock suspension sounds like it's bottoming out. As stiff as my car is I have none of the harshness you comment on.
Still... you have a lot of miles on your car and it's got some years under it too, so chances are some of the suspension bushings are a bit tired also. The quickest and cheapest first step would be to install new rear shocks and get your front units rebuilt (or buy the 968 M030 units at a hefty price). The possibilities really are endless.
We spoke at length about this last night. From what you have written here I'd say your suspension is just plain tired. My son's '89 turbo does not exhibit any of these traits at 80K miles... although it's beginning to feel a bit loose to me, especially in comparison to my highly modified and very tight S2
The stock torsion bars lose some of their spring rate over time. I suspect if you replaced them with something a bit stiffer, increased the front spring rate to match, installed new rear Koni yellow shocks and had your M030 struts rebuilt you would see significant improvement. Your stock suspension sounds like it's bottoming out. As stiff as my car is I have none of the harshness you comment on.
Still... you have a lot of miles on your car and it's got some years under it too, so chances are some of the suspension bushings are a bit tired also. The quickest and cheapest first step would be to install new rear shocks and get your front units rebuilt (or buy the 968 M030 units at a hefty price). The possibilities really are endless.
02-15-2002, 10:41 PM
#5
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[quote]Originally posted by Robby:
<strong>Flat w/little body movement on smooth surfaces but smooth and gentle (yet WELL connected) over ruts and pavement irregularities- even over harsh bumps. </strong><hr></blockquote>
Sounds exactly like my buddy's s2. He has a coil overs from <a href="http://www.morissdampers.com" target="_blank">www.morissdampers.com</a> . It is THE nicest riding car I've ever been in.
THe 400#'ers in the front were almost "too" soft though
<strong>Flat w/little body movement on smooth surfaces but smooth and gentle (yet WELL connected) over ruts and pavement irregularities- even over harsh bumps. </strong><hr></blockquote>
Sounds exactly like my buddy's s2. He has a coil overs from <a href="http://www.morissdampers.com" target="_blank">www.morissdampers.com</a> . It is THE nicest riding car I've ever been in.
THe 400#'ers in the front were almost "too" soft though
02-16-2002, 12:16 PM
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Welcome to the world of suspension!
Sounds like a tired suspension to me.
It's amazing the wallowing feeling that a car can have when all four dampers are operating at different rates!
I just had all my Konis rebuilt and put in all new solid mounts and bushings. Once you get it apart, you might as well refresh everything!
Ah, race car tight handling! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Sounds like a tired suspension to me.
It's amazing the wallowing feeling that a car can have when all four dampers are operating at different rates!
I just had all my Konis rebuilt and put in all new solid mounts and bushings. Once you get it apart, you might as well refresh everything!
Ah, race car tight handling! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
02-16-2002, 06:48 PM
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Robby,
I'll join the others. Sounds like wear has taken it's toll on your suspension. I've got 65K miles on my Turbo S and it doesn't exhibit what you have described. I suggest you find someone with a lower mileage example and go for a ride/drive. Good luck.
Mike
I'll join the others. Sounds like wear has taken it's toll on your suspension. I've got 65K miles on my Turbo S and it doesn't exhibit what you have described. I suggest you find someone with a lower mileage example and go for a ride/drive. Good luck.
Mike
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02-16-2002, 07:19 PM
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Hey Robby,
New, quality shocks like Koni Yellows will do a world of good. My '89 S2 with 107K miles was feeling a little Lincoln Town Car-y with the original dampers, and was really transformed by the change (also went w/ 275-lb. front springs and 28-mm solid T-bars). Stay far away from any sort of stiffer bushings in the suspension, as they will squeak if not continually re-greased. I went with Weltmeister poly-graphite bushings for the rear spring plates and they're starting to squawk after about 1500 miles (okay, as it's an auto-Xer that does weekends on the street).
Few will argue that the 944's rear suspension geometry is superior to an E36's. Remember that the same basic semi-trailing-arm design first surfaced in the 1976 924, which meant the design was probably locked in about 1974, so the BMW 5-link benefits from at least 15 years' development time (and CAD/CAM modeling that didn't exist in the Seventies). There's significant toe change in the 944's suspension through its travel. Minimize the travel (stiffer springs and shocks) and there's less toe change and more predictability. Reminds me of the old adage, "Any suspension will work if you don't let it." (Not entirely true, but it does have a nice ring to it.)
Anyways, I bet I could hang with a comparably driven M3 with my setup...it's firm but by no means punishing. Good luck!
--Doug
New, quality shocks like Koni Yellows will do a world of good. My '89 S2 with 107K miles was feeling a little Lincoln Town Car-y with the original dampers, and was really transformed by the change (also went w/ 275-lb. front springs and 28-mm solid T-bars). Stay far away from any sort of stiffer bushings in the suspension, as they will squeak if not continually re-greased. I went with Weltmeister poly-graphite bushings for the rear spring plates and they're starting to squawk after about 1500 miles (okay, as it's an auto-Xer that does weekends on the street).
Few will argue that the 944's rear suspension geometry is superior to an E36's. Remember that the same basic semi-trailing-arm design first surfaced in the 1976 924, which meant the design was probably locked in about 1974, so the BMW 5-link benefits from at least 15 years' development time (and CAD/CAM modeling that didn't exist in the Seventies). There's significant toe change in the 944's suspension through its travel. Minimize the travel (stiffer springs and shocks) and there's less toe change and more predictability. Reminds me of the old adage, "Any suspension will work if you don't let it." (Not entirely true, but it does have a nice ring to it.)
Anyways, I bet I could hang with a comparably driven M3 with my setup...it's firm but by no means punishing. Good luck!
--Doug
02-16-2002, 09:56 PM
#9
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Anyways, I bet I could hang with a comparably driven M3 with my setup...it's firm but by no means punishing.
Come on out and join me in the OTC! Looks like the only competition that's got me worried is an M3 (and Mike's SupraTT if his brakes last)!
<a href="http://www.opentrackchallenge.com" target="_blank">http://www.opentrackchallenge.com</a>
<a href="http://www.opentrackchallenge.com/field.new.htm" target="_blank">http://www.opentrackchallenge.com/field.new.htm</a>
<a href="http://www.opentrackchallenge.com/profiles/team951.htm" target="_blank">http://www.opentrackchallenge.com/profiles/team951.htm</a>
Come on out and join me in the OTC! Looks like the only competition that's got me worried is an M3 (and Mike's SupraTT if his brakes last)!
<a href="http://www.opentrackchallenge.com" target="_blank">http://www.opentrackchallenge.com</a>
<a href="http://www.opentrackchallenge.com/field.new.htm" target="_blank">http://www.opentrackchallenge.com/field.new.htm</a>
<a href="http://www.opentrackchallenge.com/profiles/team951.htm" target="_blank">http://www.opentrackchallenge.com/profiles/team951.htm</a>
02-17-2002, 02:22 AM
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Thanks for the input guys- I was afraid that i wouldn't get many responses since I mentioned that the M3 is a better handling car- I was only stating the obvious- it looks like you guy's took my thread the way it was intended- not a slam like "the M3 is the best ever and our porsches suck," but more like "my 951 isn't handling like it should- I assume that it should ALMOST be able to hang w/an M3 new vs new, but I want it to be even better than new- what should I do?"
I think I'm going to go w/250lb springs and Bilsteins- I just want the right shock valving for the springs- I see WAY too many places advertise that their shocks (wether Bilstein or Koni) are good for rates b/t 200 and 600 or so- this can't be right, and is probably the reason why BMW's are much better handlers than 951's- they have really gotten everything to work together almost perfectly and they have incredible range. Oh well, I'll do the bushings, shocks, and springs and keep my Koni's for possible future endeavors and mess w/the sways a little later. Any advice on where I should order the stuff from? I was planning to use Technodyne, but if there are much cheaper places(?)...
Thanks again,
Robby
I think I'm going to go w/250lb springs and Bilsteins- I just want the right shock valving for the springs- I see WAY too many places advertise that their shocks (wether Bilstein or Koni) are good for rates b/t 200 and 600 or so- this can't be right, and is probably the reason why BMW's are much better handlers than 951's- they have really gotten everything to work together almost perfectly and they have incredible range. Oh well, I'll do the bushings, shocks, and springs and keep my Koni's for possible future endeavors and mess w/the sways a little later. Any advice on where I should order the stuff from? I was planning to use Technodyne, but if there are much cheaper places(?)...
Thanks again,
Robby
02-18-2002, 05:04 AM
#11
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Try these folks for Bilsteins:
<a href="http://www.eshocks.com/bil_vehR.asp?Model=Porsche_944_Turbo&Model_Long=Porsche+944+Turbo" target="_blank">http://www.eshocks.com/bil_vehR.asp?Model=Porsche_944_Turbo&Model_Long=Porsche+944+Turbo</a>
<a href="http://www.alleuro.com/steinpor.htm" target="_blank">http://www.alleuro.com/steinpor.htm</a>
<a href="http://www.alleuro.com/raceshks.htm" target="_blank">http://www.alleuro.com/raceshks.htm</a>
<a href="http://www.performanceplusauto.com" target="_blank">http://www.performanceplusauto.com</a>
<a href="http://www.eshocks.com/bil_vehR.asp?Model=Porsche_944_Turbo&Model_Long=Porsche+944+Turbo" target="_blank">http://www.eshocks.com/bil_vehR.asp?Model=Porsche_944_Turbo&Model_Long=Porsche+944+Turbo</a>
<a href="http://www.alleuro.com/steinpor.htm" target="_blank">http://www.alleuro.com/steinpor.htm</a>
<a href="http://www.alleuro.com/raceshks.htm" target="_blank">http://www.alleuro.com/raceshks.htm</a>
<a href="http://www.performanceplusauto.com" target="_blank">http://www.performanceplusauto.com</a>
02-18-2002, 09:41 AM
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Robby,
I hope I don't repeat someones meaning, it's not easy for me to understand the full sense of the topics.
But I can tell you that I had the same trouble on my S2.
The rolling of the car in curves was really crazy.And thanks god, I had only one accident (after 30 years of driving)caused by that poor suspension.
I'd figured out that especially right hand drive was very "dangerous".
I replaced both rear shocks => no improvement.
I replaced the rubbers at the front torsion bar => no improvement.
I measured the settings of the suspension and found that toe(?) was out of spec,but no improvement after readjusting.
Then we measured the shocks.3 were at 79% one at 72%.
The one with 72% was front left.
So I replaced it and this was the break-through.
"Rolling" is much better now.I still have to replace the opposite front shock.(230 $ ;-((( )
Root cause for the problems is that the "piston-axis" of the (front) shock have free play, although damping is still fine.
You can listen to that free play of your shocks by pushing your car through at the front.
You hear noise like "clack".
Or if you have lifted your frontwheel , you can tilt your front suspension by a few millimeters.
THIS disappears completely when the front shock is new.
And it solves/improves your problem a lot.
I hope I don't repeat someones meaning, it's not easy for me to understand the full sense of the topics.
But I can tell you that I had the same trouble on my S2.
The rolling of the car in curves was really crazy.And thanks god, I had only one accident (after 30 years of driving)caused by that poor suspension.
I'd figured out that especially right hand drive was very "dangerous".
I replaced both rear shocks => no improvement.
I replaced the rubbers at the front torsion bar => no improvement.
I measured the settings of the suspension and found that toe(?) was out of spec,but no improvement after readjusting.
Then we measured the shocks.3 were at 79% one at 72%.
The one with 72% was front left.
So I replaced it and this was the break-through.
"Rolling" is much better now.I still have to replace the opposite front shock.(230 $ ;-((( )
Root cause for the problems is that the "piston-axis" of the (front) shock have free play, although damping is still fine.
You can listen to that free play of your shocks by pushing your car through at the front.
You hear noise like "clack".
Or if you have lifted your frontwheel , you can tilt your front suspension by a few millimeters.
THIS disappears completely when the front shock is new.
And it solves/improves your problem a lot.
02-18-2002, 03:12 PM
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Hey, Danno, those Open Trac events are a blast! I did one with my 2.0-liter 914 at Buttonwillow. A bit intimidating as I was in the top group (with Supras, Vipers, Corvettes), so I could hang in the corners, but I got inhaled on every short chute and straight. I probably won't track the 944, as I'm competing in a street stock autocross class in the PCA. Potenza S-03's are good, but they're not R-compounds like most are running at the track days. I hope you smoke 'em out there!
Robby, the Bilsteins are a great choice for street use/enhanced handling. I had them on the 914 and was really pleased at how comfortable they were with the really rapid, quick inputs (like when you hit a Botts dot, pavement seam or tar strip on the road). Yet they sharpen up nicely when you turn in. They make the car feel really solid and composed. Good luck!
--Doug
1989 Baltic Blue S2
Robby, the Bilsteins are a great choice for street use/enhanced handling. I had them on the 914 and was really pleased at how comfortable they were with the really rapid, quick inputs (like when you hit a Botts dot, pavement seam or tar strip on the road). Yet they sharpen up nicely when you turn in. They make the car feel really solid and composed. Good luck!
--Doug
1989 Baltic Blue S2
02-19-2002, 03:32 PM
#15
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Hey, Danno, those Open Trac events are a blast! I did one with my 2.0-liter 914 at Buttonwillow. A bit intimidating as I was in the top group (with Supras, Vipers, Corvettes), so I could hang in the corners, but I got inhaled on every short chute and straight.
Yeah, aren't they quite the adrenaline rush? I think almost as intense as skydiving, but lasts a whole lot longer.
Supposedly Mike's SupraTT is the guy to beat in TouringTwo, and I've been watching him. He's had nothing but problems at every event I've seen him attend. Maybe he's just leading me on and sandbagging? Who knows. I haven't been able to find the guy with the '01 M3 anywhere. I think he's from northern California. I still have -300lbs and +100hp to go before the OTC begins, so hopefully there won't be any surprises, heh, heh...
Yeah, aren't they quite the adrenaline rush? I think almost as intense as skydiving, but lasts a whole lot longer.
Supposedly Mike's SupraTT is the guy to beat in TouringTwo, and I've been watching him. He's had nothing but problems at every event I've seen him attend. Maybe he's just leading me on and sandbagging? Who knows. I haven't been able to find the guy with the '01 M3 anywhere. I think he's from northern California. I still have -300lbs and +100hp to go before the OTC begins, so hopefully there won't be any surprises, heh, heh...