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Bump steer in rwd daytonas

Posted By: Rampage16v

Bump steer in rwd daytonas - 03/06/10 03:02 AM

Hi finding I have alot of toe in change when the front wheels move throughout their travel. The tie rod ends on the dakota rack are about 2 inches longer then the lower control arms. Anyone got any pics of what the did to correct this. I was thinking of getting another set of minivan knuckles and machining off the arm going to the tie rod and making a new one 1.5 to 2 inches closer to the middle of the car to try and make the tie rods the same length as the lower control arms. Maybe bolt it to the lower wheel bearing bolts.
Posted By: MR_P_BODY

Re: Bump steer in rwd daytonas - 03/06/10 03:56 AM

Quote:

Hi finding I have alot of toe in change when the front wheels move throughout their travel. The tie rod ends on the dakota rack are about 2 inches longer then the lower control arms. Anyone got any pics of what the did to correct this. I was thinking of getting another set of minivan knuckles and machining off the arm going to the tie rod and making a new one 1.5 to 2 inches closer to the middle of the car to try and make the tie rods the same length as the lower control arms. Maybe bolt it to the lower wheel bearing bolts.




Get a shorter rack
Posted By: 10sec440

Re: Bump steer in rwd daytonas - 03/06/10 04:59 AM

It spells it out pretty good in the Mopar chassis book. I don't have one handy but going from memory I think if it toes in when you raise the front the tie rod ends need to be lowered and vise versa.The arc of the tie rod end has to match the arc of the control arms.
Posted By: Rodney

Re: Bump steer in rwd daytonas - 03/06/10 03:11 PM

miss aligned, bent or not matching components causing SAI or king pin angle variances can also contribute to a bump steer condition.
click here
Posted By: roadhazard

Re: Bump steer in rwd daytonas - 03/06/10 03:46 PM

Keep in mind if you use the Mopar Chassis Book for reference all of the data and graphs in there is for a "Rear Steer".

If you have the rack out front you must convert the formula's for "Front Steer".

Someone correct me if I am wrong
Posted By: QWK_ENUF

Re: Bump steer in rwd daytonas - 03/07/10 02:39 PM

http://www.heidts.com/support_suspension_101.html


hope this helps

EXPLAINING BUMPSTEER
Since the tie rod ends attach to the spindle steering arm, the tie rod controls the steering angle of the front wheels. If your car goes over a "bump" the spindle goes up and down in its swing radius, determined by the upper and lower arms . If the tie rod swings in a different radius than the spindle during this suspension travel; it will push or pull on the steering arm of the spindle, changing the direction of the front wheel, "steering" the car. And that is how the term and the monster "BUMP-STEER" were created, where 95% of the problems with incorrect suspension design are found. It is from people not really understanding this most important relationship between the tie rod length (not the overall rack length) and the spindle swing radius.They feel that if they are able somehow with enough modifications to the parts, to "physically assemble all the parts" that it must be OK. Then they pull down the driveway, over that first curb and low and behold: BUMPSTEER. When you drive a car with BUMPSTEER, the car tends to wander or hop around as you drive down the road over bumps and dips. You have to constantly steer the car to keep it in the lane. Not what you would call an enjoyable ride.

Posted By: Rampage16v

Re: Bump steer in rwd daytonas - 03/07/10 08:36 PM

Quote:

It spells it out pretty good in the Mopar chassis book. I don't have one handy but going from memory I think if it toes in when you raise the front the tie rod ends need to be lowered and vise versa.The arc of the tie rod end has to match the arc of the control arms.



Well I have the mp k frame with a dakota rack and minivan spindles all like the kit that was sold over the counter. So does this mean the iroc cars had the same problems? I know some ppl made new steering arms off the spindles to the tie rod ends moving them in closer to the rack so the tie rod length was closer to the length of the lower control arms.
Posted By: draginmopars

Re: Bump steer in rwd daytonas - 03/08/10 05:13 AM

I used a pinto rack (narrowed) to the same width as the lower control arm pivot.
the inner tie rod makes the same arc as the lower control arm.

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Posted By: dirt

Re: Bump steer in rwd daytonas - 03/09/10 01:45 PM

the ideal thing would be to have a rack narrowed to move the inner pivot point of the tierods closer together. but with the dakota rack , if its mounted in the right place you should have only a small amount of bump steer and you wouldnt even notice it driving the car if its right.
i am guessing you need to either space the rack up higher or space the tierod ends down on the spindle. one question for you is ,did you mount the tierod to the top or bottom of the spindle arm? if its mounted to the top you will have really bad bump steer. if its mounted to the bottom it may need spaced down. are you using a factory tierod end or a aftermarked type rod end?
i normally use a 5/8 rod end and drill out the spindle for a 5/8 grade bolt and use spacers to set the bump steer. you should be able to get it to work well with out narrowing the rack.

are you using the parts on a daytona or rampage?


Posted By: dirt

Re: Bump steer in rwd daytonas - 03/09/10 01:58 PM

here is what the tie rod looks like on my daytona. i dont have a MP kit but it is similar. i am using the one that we make so the rack may be located a little different not sure .

looked at some of the pictures you posted of the daytona. that will be pretty wild witha 4 cyl. judging by the rampage i am sure it will fly.


Posted By: Rampage16v

Re: Bump steer in rwd daytonas - 02/25/11 11:10 PM

Quote:

here is what the tie rod looks like on my daytona. i dont have a MP kit but it is similar. i am using the one that we make so the rack may be located a little different not sure .

looked at some of the pictures you posted of the daytona. that will be pretty wild witha 4 cyl. judging by the rampage i am sure it will fly.






This is on the daytona I had the tie rods on top at first cause thats the way the taper was it got much better moving them underneath. I need the stuff you have But I don't know the thread size of the dakota inner tie rod ends. There is a bump steer kit available for mustangs that looks just like your set up but uses a tapered bolt.
Posted By: '72CudaRacer

Re: Bump steer in rwd daytonas - 02/26/11 01:56 AM

Quote:

here is what the tie rod looks like on my daytona. i dont have a MP kit but it is similar. i am using the one that we make so the rack may be located a little different not sure .

looked at some of the pictures you posted of the daytona. that will be pretty wild witha 4 cyl. judging by the rampage i am sure it will fly.





Please, do yourself a favor. You should put a flat washer between the head of the bolt and the rod end to prevent bolt pull through in case of a rod end failure. Thanks,
Brian Dunnigan
Posted By: dirt

Re: Bump steer in rwd daytonas - 02/26/11 04:34 AM

that picture was taken while i was figuing out what i was doing. I have since used a washer there. I also found that the ackerman is much better if the locatian of the tie rod end is moved closer to the wheel. I have made an adapter to do that and also space the rod end down at the same time. i have pretty much eliminated bump steer problems.

you will probably end up with the rod end about 3/4 to 1" sopaced down from the factory mounting arm. I used the mustang bump steer kits on the daytonas and it worked fine. i had something i mocked up in the last picture that amounted to the same thing. drill a 5/8 hole through the spindle arm and use a 5/8 rod end with a sleeve , 5/8 threads on one end and 9/16 on the other , to match the rack tie rods . you will need the sleeve to make it reach the spindle.
it makes the tie rod longer than it should really be but its really not bad, you could probably get a extension if you wanted to get it perfect.
dont move the spindle tierod end mounts closer to the rack to shorten the tie rod your tires will squeel when you make a turn , the ackerman will be all screwed up. The tie rods should be shorter but thats not the major problem. moving the end closer to the wheel will actually make an inprovement, i know because thats what i eventually did on my car.
Posted By: Rampage16v

Re: Bump steer in rwd daytonas - 08/26/11 11:44 PM

Thanks for the reply. This is on the daytona, I have factory tierods underneath so far.
I just have to find some rod ends that will thread onto the rack!
Quote:

here is what the tie rod looks like on my daytona. i dont have a MP kit but it is similar. i am using the one that we make so the rack may be located a little different not sure .

looked at some of the pictures you posted of the daytona. that will be pretty wild witha 4 cyl. judging by the rampage i am sure it will fly.




Posted By: dirt

Re: Bump steer in rwd daytonas - 08/27/11 08:57 PM

/when i was using a dakota rack i just ordered a bump steer kit from summit racing for a mustang 2 rack and it worked. my dakota rack had 9/16 threads on it, the later dakota racks were larger on the ends.
Posted By: Rampage16v

Re: Bump steer in rwd daytonas - 06/10/12 12:22 PM

Ok thanks. I'm finally getting to the point now to get to that.
http://www.youtube.com/watch?v=EvFciB2ZkvQ&feature=youtu.be

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