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Join Date: Jan 2004
Location: Spain
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Question Bump steer kit

The euro-high 911 carrera needs bump steer kit?
What is the relation between size bump steer kit and car-high?

I hope making a lot of friends in this forum.

Thanks to everyone.

My daughter,Andrea,help me with English.

Old 02-01-2004, 12:30 PM
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I do not think a car at euro ride hieght will need a bump steer kit. I you lower it much in the front, put one in. Ideally you would like to be able to raise the steering rack the same amount that you lower the car- not always possible.

Welcome to the board, Jeff
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Old 02-01-2004, 01:09 PM
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I don't think you need a bump steer kit if you're at Euro ride height.

Most people use them when the car is lowered even further.

Your English is fine..and you have a nice daughter if she helps her father this way !

---Wil Ferch
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Old 02-01-2004, 01:09 PM
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Diana, here are a couple of corrections to help you with English:

DOES the euro-highT 911 carrera need[] a bump steer kit?
What is the relation between THE size OF THE bump steer kit and car-highT?

I hope TO MAKE [making] a lot of friends in this forum.

Thanks to everyone.

My daughter, Andrea, helpED me with MY English.

- It's a very complex and difficult language but you are doing great. Best wishes.
Old 02-01-2004, 01:14 PM
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My car is at euro height w/ bump steer kit. I think it is actually contributing to bump steer?
Old 02-01-2004, 01:20 PM
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Ubiquity:
Not sure...but if the "sweet spot" has the steering gear fairly level at Euro ride height...then it is possible that the bump steer kit adds bump steer tendency.
Think of a clock. If 3 0'clock is perfect and bump steer kit brings you from 4 to 3 o'clock at BELOW Euro height....then it can bring you FROM 3 TO 2 0'clock by using a kit *AT* Euro ride height. It such a case, you actually "dialed-in" the bump steer you're trying to avoid.

....conceivably .....

--Wil Ferch
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Old 02-01-2004, 01:56 PM
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Thats what I was thinking Wil, but when I try & picture what the bump steer kit actually does vis a vis lowering the car I have trouble.... actually now I don't. I was thinking that the spacers lower the rack, but really they raise it above the aluminum cross member. Now I see it. I'm assuming that my tie rods angle down to the wheels & ideally they need to be level. I'll remove when I do the A-arm bushings.
Old 02-01-2004, 02:06 PM
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Yes..you want the tie rods to be as level as posible at "your" ride height. If you think about it, this gives the least amount of "sideways" unwanted movement of the steering ...as the tire goes up ( or down) a small amount... from a bump. At any tie rod angle that is not "flat"...the same bump deflection ( up or down) will cause somewhat more sideways motion of the steering. Best to draw a picture of a circle and look at the radius...and plot this out yourself. I'm also a "visual" kind of guy and this helped me too in the early days.
----Wil Ferch
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Old 02-01-2004, 02:53 PM
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The term, "bump steer" has usually meant the excessive toe-in or toe-out resulting from lowering (or raising the suspension). The tie-rods should remain level at rest. If not, as the suspension goes into "jounce" (suspension compression) the resultant misalignment of the tires (tires point some other direction) causes instabillity. In other words, the car becomes harder to control any time the suspension compresses/decompresses (during braking and turning maneuvers).

The "bump steer" kit tries to maintain the factory geometry by raising the steering rack as high as possible to compensate for the amount the car is lowered. In a 911, there is limited space to raise the steering gear when the car is lowered excessively.

Sherwood
Old 02-01-2004, 03:24 PM
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Following on Sherwodd's example...typical bump steer spacers are only 12-13mm thick..that's how much room you have to raise the rack. If you lower your car only 12-13 mm ( about 1/2") then you should be able to regain your original geometry.

Unfortunately, most guys who lower..do so beyond 1/2" lower than Euro..and the bump steer kit only "partially" compensates.

For a better fix, and one that can be fine-tuned for lowering amounts greater than 1/2"...the ERP kit is expensive but does work. It essentially cantilevers another joint at the end of the tie rod ...so the tie rods remain flat...and the shock tubes's steering arm is flat too...now connected by a vertical drop piece. Look elsewhere here on this board for more info and pics.

---Wil Ferch
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Old 02-01-2004, 04:56 PM
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Hi,
I think I've read it in another thread I just can't find it so please let me ask this:
If I add a bump steer kit do I have to align the suspension?

In my case the kick-back on the steering is not bad I just wouldn't let both hands off the wheel when changing lanes for example or during uneven pavement.

101 projects suggest that it may need an alignment, but I'd like to hear from other owners if this is was required for him/her.

I'm concerned that the car may loose the alignment and I wouldn't be able to tell, I mean if the car pulls to one side or the other it's pretty obvious but if the toe-in/toe-out is affected how can I tell?
I'm still a newbie so this may be a stupid question

Thanks
-J
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Old 02-01-2004, 08:13 PM
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If you're lowered now adding a bump steer kit will probably marginally increase toe in. Getting the tie rods more 'level' will effectively lengthen them. I think it would only be by a tiny amount though, so you're probably ok. If anything you could probably just get the front toe checked & readjusted, rather than shelling out for a full 4-wheel alignment.
Old 02-01-2004, 08:20 PM
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Probably mostly affects toe-in ...which can also be done at home. See the many threads on "home alignment". I have some suggestions on toe procedures for home too..
---Wil Ferch
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Old 02-02-2004, 06:11 AM
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Look under the car and see if the rods are horizontal -- if not, you need to adjust bump steer. IF so, leave alone.

Old 02-02-2004, 11:44 AM
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