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Discussion Starter · #1 ·
I just had my suspension lowered and had all the suspension performance goodies I could get. Koni Shocks, Tme Springs and Strut brace, new hardware, etc. Ok, so now I have been noticing that the car seems unstable at highspeeds. I would say after about 90 mph or so is when it gets noticable. Now incase there are any police, and because its the truth, I didnt do this on public road ways. I decided to take it to a few tracks to test my new stuff out, and I noticed it there. Im not sure if the instability is because the car is now lower and the groundeffects no longer work right-doesnt make much sense to me, or if it always did it and I just never really drove to those speeds that often. Thing about it is that I have driven over 90 on the track before, and I dont remember having such shakes and instability. The car handles like nobodies business, its plenty fast, now it needs some stability. I have heard numerous times that spoilers and groundeffects really serve no purpose on streetable cars, that you will hardly ever go fast enough for them to work, and that most are not effective anyway. For this reason Im afraid to drop 500+ dollars on such items and still have the problem. What sorts of things can I do to help with this issue, Bonrath Cup Wings, R model front end, aftermarket groundeffects, rear spoiler, etc. As of now, appearance wise, I basicly have a bone stock Volvo 855 turbo, other than tires and wheels, I have done nothing to change its appearance. Any help would be appreciated. Oh and by the way, not that I can explain why, but I ran my best times at the track after lowering it. I dont just mean time either, I ran faster than I ever have before, and at the drag strip I ran my best quarter-mile times and the highest speeds ever. It was a difference of a few mph, but still, I have never run that fast before, then boom, Im now running consitantly faster than before. Its really amazing. Actually my track times were way better, the car can take turns so much faster than before its rediculous. I took the shecane(not sure how its spelled), at 67 mph, previously I had never taken it faster than 45 without squealing and uneasyness on my part. Quite a difference, I would say thats the most dramatic increase, but none the less, I would say I was able to take every turn about 30-60% faster than before.
 

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Re: real working spoilers (pj's 850)

if its very unstable I'm thinking maybe you had your shocks adjusted too hard. Could be because your wheel is hopping. Try that (if you get a chance to) and see.

I think the 850 have a pretty heavy front, if it didn't feel unstable before the mods it shouldn't be a downforce problem.

However, the rear wing on a 855 will decrease drag from 0.32cd to 0.31cd (so I've heard) and it will make you go even faster, downforce... well I dunno, maybe a bit but its not really designed to create much.

a R front spoiler should help a little too. But the first thing I'll check is your shocks, adjust them a bit softer and see.
 

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Discussion Starter · #3 ·
Re: real working spoilers (xtremepsionic)

Thankyou for the response. It could be what you say, but I dont have the shocks set up very hard. Infact they are on there softest settings now, and were before. I havent really tried adjusting them much yet, though I do plan to as things break in. I am also still wating on my strut brace before really messing around with things. Though I understand that the drag coefficiant number lowers I have to say, at what speed, in what conditions. Spoilers need a certain amount of air across them inorder to be effective, and so I have to wonder, at what speeds do we see the increase in downforce. I remember reading about how revolutionary Ferraris new designs are for being able to create downforce as low as 70mph without any spoilers, and I believe it was saying no setup had done the same even with spoilers. For that reason I have to assume that the Volvo spoiler will not produce a lot of downforce until highspeeds, possibly too high to be useful. However, it doesnt really look bad, so I guess it cant hurt to try. Im really thinking that the R frontend with a Bonrath front spliter-which is adjustable as I understand it, would be good. However these Cupwing things from Bonrath, which I have seen on Volvo 850's, seem to be hard to get, because I cant find them anywhere. I found the US distributor, but they dont seem to sell as much as distribute, maybe they do and I should give them a call. I dont know.
 

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Re: real working spoilers (pj's 850)

Normally the normal T5 front spoiler can handle speeds up to 140 mph without unstable feeling.
I drove my 850 at 140 mph with standard suspension and 16" perfo's yesterday and it felt rock solid, much better compared to a standard S60T5 dynamic setup.
I had a V70T5 classic at ~175 mph on tacho a few years ago and at that point the nose felt very light.
I think the unstable feeling is because, i think I read in another post, you have new tires also which feel a little unstable in the first miles.
Maybe the alignment isn't 100% yet or the stabilizers are to hard making the car hunt for lower parts in the road surface.
It's all new and I think it has to sttle a little.
Front shocks should be set a little softer compared to the rear shocks.
I have the rear shocks on my S60 set to one turn, 360 degree, which is half way I think and already a little to the hard side.
 

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Discussion Starter · #6 ·
Re: real working spoilers (towerymt)

I dont know, Im not personaly very machanicly inclined, would be nice if I was, but I have shops do all the work. They did the alignment for me when they put the lowered suspension on the car, however I dont know the settings. If this makes any sense, I would assume they did everything as nuetral as possibly. I saw that they were using a calibration device on each wheel with digital readouts, and I believe they set it up on the lift, off the ground. I dont know if that would help in knowing how and in what manner they would have done it.
 
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