Pss9 and floaty front end....
03-14-2004, 05:27 PM
#17
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Sorry I guess I missed that. Sometimes when going down the road, expecially bumpy or undulating ones, it kind or darts one way than the other it seems. It could be tramlining from what everyone says. It has also done this on the highway but we do have pretty badly crowned roads here in South Carolina. I do not feel like there is any pogoing going on with the front or rear of the car. If I hit a bump it will absorb it and not oscillate up and down or anything. Is there any way to see if any internal seals have been damaged from the spinning of shock shaft?
03-14-2004, 05:53 PM
#18
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TrackJunke,
Other than the rake, the toe in and out, the camber, the tire pressures, the corner balance, the drop links being set, etc ... you should not be feeling this way if they are set correctly. although you said that the cars rake might have changed due to settling. That is important to follow up on.
That said, I have talked with quite a few people who feel that their 993's dart around a bit and also feel as though, say on the freeway here in California, that the car bounces a little more. Usually when the PSS9's are set to 1 with the freeways being laid in sections. The grooving for rain drainage also contributes to darty feelings. Since you are not use to more camber and you mentioned you have many crowned roads this will also contribute greatly. I cannot drive my car anywhere on the street without two hands on the wheel given my settings ( 4F/3.75R). You should be able to set your PSS9's to 9 and any darty feelings should be minimized but will still be there on crowned or ruts on the road. I know you said that this was not the case so I am concerned that you may have something wrong or you may be need more time with the suspension to get use to how it feels. These are very difficult to diagnose without actually driving the car.
Does the car pull one way or the other under power or when you get off the power when you are on a flat road? If not, then I doubt there is much wrong. Try and eliminate some of the variables like crowned roads and see how that feels. Make sure your tire pressures are exact rear to rear and front to front. Let us know what the flat road test I mentioned above yields.
Other than the rake, the toe in and out, the camber, the tire pressures, the corner balance, the drop links being set, etc ... you should not be feeling this way if they are set correctly. although you said that the cars rake might have changed due to settling. That is important to follow up on.
That said, I have talked with quite a few people who feel that their 993's dart around a bit and also feel as though, say on the freeway here in California, that the car bounces a little more. Usually when the PSS9's are set to 1 with the freeways being laid in sections. The grooving for rain drainage also contributes to darty feelings. Since you are not use to more camber and you mentioned you have many crowned roads this will also contribute greatly. I cannot drive my car anywhere on the street without two hands on the wheel given my settings ( 4F/3.75R). You should be able to set your PSS9's to 9 and any darty feelings should be minimized but will still be there on crowned or ruts on the road. I know you said that this was not the case so I am concerned that you may have something wrong or you may be need more time with the suspension to get use to how it feels. These are very difficult to diagnose without actually driving the car.
Does the car pull one way or the other under power or when you get off the power when you are on a flat road? If not, then I doubt there is much wrong. Try and eliminate some of the variables like crowned roads and see how that feels. Make sure your tire pressures are exact rear to rear and front to front. Let us know what the flat road test I mentioned above yields.
03-14-2004, 05:58 PM
#19
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The car really is not pulling under power or off of power on a straight road. I think I am just getting used to driving a car with this much camber. I had a boxster with stock alignment before this and I guess I am comparing apples to oranges. Perhaps the I mis described the floaty feeling, I probably should have called it light. The front end seems light to me. But I guess that would make sense considering the engine is in the back.
03-14-2004, 06:03 PM
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There is a significant difference in 993 steering feeling in the front when the gas tank is empty compared to when it if full. Try a full tank of gas.
Last edited by kary993; 03-14-2004 at 07:13 PM.
03-14-2004, 07:15 PM
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I have not driven a Boxster in more than a year so it would be difficult for me to comment on that question. Sorry! Anyone else have some experience with a Boxster and 993?
03-14-2004, 08:49 PM
#24
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So here's a question from somebody who actually HAS a floaty setup. With my settings at 7 or 8 I could SEE the front end oscillating up and down at 70mph. A friend could also see the rear end doing this. That seems odd to me. So I set everything at 6 and it seems to have pretty much disappeared. (as a side note, my car tramlines terribly so I need to get the alignment settings checked, I think...)
03-14-2004, 09:53 PM
#25
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Eric,
My first ride with the PSS9s were on setting 9, and I noticed in the first 10 minutes that the whole car felt oversprung/underdamped. The car felt bouncy and harsh over freeway expansion joints; I believe this is what you are describing. I then set the shocks to 7 front/6rear and it improved dramatically. I'm betting it is due to the PSS9's spring rates being a bit much for the mild damping when set at 9. I am now at 6F/5R and I think I'm keeping it there as it seems to still provide a good street ride (I don't know that I want to go any stiffer for my commute) while still offering good control on the track.
As a side note to all the "trammeling" comments, the lower profile of 18" tires certainly exacerbates the problem, as do higher tire pressures. Moreover, while each brand of tire will obviously feel different, as a tire ages and tread goes away, its road characteristics tend to go south, as well. Also, I've always read that more neg camber results in a car that follows road imperfections more readily. I found this out first hand when I got my alignment; a little dartiness is not really a "bad" thing, just something that requires a bit more attention when driving. My point is that when a few or more of these conditions are combined such as worn tires, high-ish tire pressures, lots of neg camber, ruts in road, and throw in whatever else you like, you will get some odd handling traits. TrackJunke, perhaps it is best for you to take a careful look at all your variables. Before making any drastic changes, assess what possible shortcomings you may have so as not to "fix" one thing when it's really something else that's "broken."
Edward
My first ride with the PSS9s were on setting 9, and I noticed in the first 10 minutes that the whole car felt oversprung/underdamped. The car felt bouncy and harsh over freeway expansion joints; I believe this is what you are describing. I then set the shocks to 7 front/6rear and it improved dramatically. I'm betting it is due to the PSS9's spring rates being a bit much for the mild damping when set at 9. I am now at 6F/5R and I think I'm keeping it there as it seems to still provide a good street ride (I don't know that I want to go any stiffer for my commute) while still offering good control on the track.
As a side note to all the "trammeling" comments, the lower profile of 18" tires certainly exacerbates the problem, as do higher tire pressures. Moreover, while each brand of tire will obviously feel different, as a tire ages and tread goes away, its road characteristics tend to go south, as well. Also, I've always read that more neg camber results in a car that follows road imperfections more readily. I found this out first hand when I got my alignment; a little dartiness is not really a "bad" thing, just something that requires a bit more attention when driving. My point is that when a few or more of these conditions are combined such as worn tires, high-ish tire pressures, lots of neg camber, ruts in road, and throw in whatever else you like, you will get some odd handling traits. TrackJunke, perhaps it is best for you to take a careful look at all your variables. Before making any drastic changes, assess what possible shortcomings you may have so as not to "fix" one thing when it's really something else that's "broken."
Edward
03-14-2004, 10:01 PM
#26
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Assuming the alignment is right and the tire pressures and tires are OK, you might want to look at the ball joints in the a-arms. Depending on age and wear (mileage) they could be worn and make the car difficult to track in a straight line. Also check the tie rods for wear.
