Bumpstop Issues With PSS9's
#1
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Last question b4 i buy them.
under what circumstances will i hit the bumpstops. Bearing in mind that i'm not going for the "lowridah" look, just a bit of lowering, maybe to factory X73 spec plus minus/depending on road condition.
under what circumstances will i hit the bumpstops. Bearing in mind that i'm not going for the "lowridah" look, just a bit of lowering, maybe to factory X73 spec plus minus/depending on road condition.
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Originally Posted by DeAd-EyE
Last question b4 i buy them.
under what circumstances will i hit the bumpstops. Bearing in mind that i'm not going for the "lowridah" look, just a bit of lowering, maybe to factory X73 spec plus minus/depending on road condition.
under what circumstances will i hit the bumpstops. Bearing in mind that i'm not going for the "lowridah" look, just a bit of lowering, maybe to factory X73 spec plus minus/depending on road condition.
i've heard of the problems on 996TT that have been lowered to gt2 specs. the problems arose during extreme cornering and the strut was compressed to the bumpstops resulting in zero suspension travel thereby destabilizing the car.
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Originally Posted by C4S Surgeon
I would stick with factory stuff, m030, x73/74, can't go wrong.
can't do x74 on pre '02 cars.
pss9s are great cause you can fine tune the shock settings for the street and the track.
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Actually, except for steady-state cruising, you are usually on the bumpstops in the stock configuration. With the RoW 030, I think you are on the front bumpstops all the time. Technically, they are not bumpstops but foam rubber "additional springs" as Porsche calls them. They are a part of modern OE suspension design. The factory springs are about 200lbs/in, so you cannot obviously have 3" of suspension travel when you slam on the brakes. I don't recall the exact numbers, but PSS9s are in the 400 to 500 range. I really don't know what happens to the bumpstops on PSS9s. It would depend on the height of the shock housing vs. the ride height--a fairly complex and interactive arrangement to make generalizations about.
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I run my C4 about 10mm below GT3 ride height... can't say I've ever had any strange handling problems. This includes the odd trackday and many autox.
My biggest problem is transversing driveways!
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My biggest problem is transversing driveways!
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Originally Posted by SPR
1. You are not on the bumpstops all the time 2. Pss9's have internal bumpstops. Ride height does limit your overall travel range of course.
2. What "internal bumpstops" are you referring to? Do you mean internal to the shock? I think not.
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Originally Posted by karlooz
ROW m030 not much bang for the buck IMHO.. too much like stock. US m030 is kinda a waste of money.
can't do x74 on pre '02 cars.
pss9s are great cause you can fine tune the shock settings for the street and the track.
can't do x74 on pre '02 cars.
pss9s are great cause you can fine tune the shock settings for the street and the track.
Chris
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The PSS9 has internal bump-stops. The PSS9 isn't a full race suspension, its a middle-of-the-road solution that gives you pretty good track performance and a great street ride (better than OEM IMO). In my setup, with my car lowered 1" or so front and rear, I have never hit the bump stops on the track or on the street that I could notice. If you are lowering the car more than that, either you are being too aggressive than necessary for DE or you really should be buying an all-out race setup.
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Yes, normally at cruise you are riding on the helper spring, which is considerably less stiff than the main spring. This is why the PSS9 rides so nice. At the track, that helper quickly bottoms out and then the main spring takes over. You can't even barely feel the transition, but in a full race setup you wouldn't have the helper.
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If you look at the helper springs they are actually completely compressed at static ride- They really perform no progressive function other than maybe rebounding and holding the main spring on the collar- I was surprised when I saw but by reading the material it denotes just that function
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You can't infer static ride from the car standing still. Even so, my car doesn't completely compress the helper springs while standing still. If the purpose was solely to keep the springs on their perches, then the strut shaft would be shorter, or the main spring would be longer. If the helper is fully compressed, then it does nothing, and there would be no reason for Bilstein to put a spring there -- they could make the main spring longer. Helper springs are characteristic of hybrid/compromise struts.
An informed friend taught me "if the factory put it there, then it serves a purpose". They are certainly not in the business of making extra parts.
An informed friend taught me "if the factory put it there, then it serves a purpose". They are certainly not in the business of making extra parts.