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Thread: Suspension Issues

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Posts: 1-10 of 13
2009-08-16 23:35:32
#1
Suspension Issues
I want to start off saying I have not tracked my car yet, but I'd like to get it sorted before I do. What I do drive is a local, mostly deserted, 10 mile long b-road that snakes around a reservoir. This road has a lot of mid corner bumps and rough patches of road.

My main issue is that I'm having to battle the steering wheel in the corners to the point that my arms feel like they're about to give in. Keep in mind my power steering is deleted. Originally I thought I had a bump-steer issue but research lead me to the conclusion that bump-steer is mainly a straight line problem. The car wants to steer you away from you straight line. The issue I'm having is I'll turn in and any bump mid corner has my steering wheel flying in the opposite direction or further into the corner. This problem (along with others) has me hating my Progress coilovers, although it may not be related. I was told that the Progress kit was the best lower cost option for B13s and the valving was great. I thought great valving (especially if its matched for a relatively low spring rate of 350/250) would give you a better ride than stock with more control. Instead, I have an almost nervous ride. This car is not my daily, but I did have to drive it to work for 4 months while my brother borrowed my daily NX. I discovered that the car doesn't seem to want to settle over small sharp bumps, it crashes over some of the bigger ones and the freeway ride is horrid, never a smooth moment.

Here is my suspension set-up:
Progress Coilovers
Ground Control camber plates
BIB bump steer kit (set with one small spacer to about parallel with the control arm)
Progress rear sway and control arm brace
Bushings all around
15x8 949 Racing 6ULs with 5mm spacer front 15mm in back
205-50R15 Kumho XS 35psi front 30psi rear (planning on running 225/45, hence the spacers)
Gutted to 2250lbs no driver full tank

Any wisdom and wild ass guesses are welcome.
2009-08-29 17:29:28
#2
You figure out you problem yet?
2009-08-29 17:44:04
#3
How's the alignment?

Also, I noticed this behavior seems to be related to a wider than stock track up front. The 8" wide wheels and 5mm spacer up front are likely (what is the offset of those wheels?) the cause of most of this behavior. Not only this, but the shape of the contact patch changing from a forward facing rectangle to a lateral facing rectangle allows road imperfections to have much greater leverage on the steering input.
I don't know if anything can be done about these two things.

I could be wrong though, it's just what I've experienced on my own car and wild conjecture. =]
2009-08-30 05:12:56
#4
I guess this won't help for track set-up, but to help settle it on the road, try loading some stuff into the car to get rid of some of the lack of resistance to the rebound of the coilovers, this will help with some of the bouncing over bumps in the road.

However, a track won't have these bumps. But it will still help you find out what might be wrong while you try to figure it out on public roads.
2009-08-31 08:22:43
#5
Wow replies! Thanks for the input guys. I am still battling these issues and I'm considering installing my Progress kit on my daily NX and see how it feels.

BenFenner, my alignment is 2.5 deg up front with 0 toe and 1 deg out back with 0 toe. When I was forced to daily this car I had it set to somewhat preserve tire life.

I was having this problem on my 15x7s, 35et wheels as well.
2009-08-31 13:57:20
#6
Originally Posted by Skullsroad
I want to start off saying I have not tracked my car yet, but I'd like to get it sorted before I do. What I do drive is a local, mostly deserted, 10 mile long b-road that snakes around a reservoir. This road has a lot of mid corner bumps and rough patches of road.

My main issue is that I'm having to battle the steering wheel in the corners to the point that my arms feel like they're about to give in. Keep in mind my power steering is deleted. Originally I thought I had a bump-steer issue but research lead me to the conclusion that bump-steer is mainly a straight line problem. The car wants to steer you away from you straight line. The issue I'm having is I'll turn in and any bump mid corner has my steering wheel flying in the opposite direction or further into the corner. This problem (along with others) has me hating my Progress coilovers, although it may not be related. I was told that the Progress kit was the best lower cost option for B13s and the valving was great. I thought great valving (especially if its matched for a relatively low spring rate of 350/250) would give you a better ride than stock with more control. Instead, I have an almost nervous ride. This car is not my daily, but I did have to drive it to work for 4 months while my brother borrowed my daily NX. I discovered that the car doesn't seem to want to settle over small sharp bumps, it crashes over some of the bigger ones and the freeway ride is horrid, never a smooth moment.

Here is my suspension set-up:
Progress Coilovers
Ground Control camber plates
BIB bump steer kit (set with one small spacer to about parallel with the control arm)
Progress rear sway and control arm brace
Bushings all around
15x8 949 Racing 6ULs with 5mm spacer front 15mm in back
205-50R15 Kumho XS 35psi front 30psi rear (planning on running 225/45, hence the spacers)
Gutted to 2250lbs no driver full tank

Any wisdom and wild ass guesses are welcome.


Skullsroad, the highlighted is what is throwing me off. If it's throwing you further INTO the corner. Then, are you on or off the gas or steady state throttle. Do you have a Nismo LSD? One other thing, show me a picture of how your bumpsteer kit is installed.

Andy R.
2009-09-01 07:54:28
#7
Well, it does either/or depending on the corner, bump, dip or whatever. My post states "opposite direction OR further into the corner". Sometimes it knocks my steering in and when I try to correct the angle it bumps out and I end up over correcting. The next run I film I'll point the cam at my hands.

I'll post up a picture of my tie rods tomorrow for you SERacer. I really could use some input on my setup. I know the way it is set up isn't ideal, but I think without modified control arms, ideal is unattainable.
2009-09-01 21:08:48
#8
So here are some pictures. Its really hard to get a good angle to portray the relationship between the tie rod and control arm. The car was sitting on my slanted driveway. Basically the rod is slightly higher than the control arm. The idea spot is somewhere in the middle of the spindle mounting point, but that isn't possible of course. Mounting the bearing under the spindle is way too low and putting any more of a spacer on top would be too high.




2009-09-02 11:16:47
#9
I am glad you took the time to take the photos. The copper washer should always be at the top of the knuckle. That is what centers the bolt. A few other people have complained about play in the steering after installing the kit.
In your last photo, is that a lower control arm stress bar? If not get one. Replace the sway bar end link bushing too.
So you solution, install the copper washer at the top of the knuckle like in my photo and reset the toe. Also try droping the tire press to 30fr 28 rear and see how it feels.
I hope this helps.

2009-09-02 11:24:28
#10
I just noticed something. Make sure the taper on the bolt faced down like the stock tie rod. The bolt only installs one way. with the copper washer to hold it in place.
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