High speed instability

Chubbs

Well-Known Member
Like you, I'll have to check tonight. They sure looked level, but I've never put a gauge on them. I'll get pics and post them up later.

Thanks for the help to everyone involved. These forums are great for troubleshooting.
 

Gtstorey

Goblin Guru
You also might want to try increasing castor also to add stability. I'm not sure that the DF recommended way of determining castor is accurate enough to give an absolute value, although it is likely good enough to compare changes in caster.
 

Chubbs

Well-Known Member
A couple of things...

First, my tie rods are actually angled up just slightly toward the wheel. However, I'm unsure how to get them any lower.

Which leads to my next issue, my set up is not exactly as the factory setup is, as I have the tie rod mount in the upper hole in the front, and the lower hole in the rear. This is going to put the actual tie rod end link at the lowest position possible, unless I drill some additional holes.

The only thing I could do would be to swap the aluminum Mount brackets from left to right, since they are actually slightly tapered. That would put the tie rod a little lower, and therefore a little more level.
 

Attachments

Desert Sasqwatch

Goblin Guru
Trying a suspension simulator can help better understand how it should be set up properly and see how bumpsteer occurs. This one is free and a works reasonably well.


The key is to have the tie rods (some call them toe rods) to travel in the same arc as the rest of the front suspension. That technically translates to no bumpsteer, all things considered.
 

Chubbs

Well-Known Member
Oh, and caster is set at 8.5 degrees both sides, as per factory recommendation. It's hard to say if that's accurate or not, but I at least did it as they described.
 

Lonny

Administrator
Staff member
Try increasing your caster to 10 degrees you will need to reset your camber and toe. This should help get rid of bump steer.

Have you replaced the rubber rear control arm bushings with the Moog steel spherical bushings?

Also is there any chance you have the toe link rack installed upside down?
 

Gtstorey

Goblin Guru
Lonny,
Any chance the DF rear control arms will be ready by next spring. I’m trying to decide if I want to get the Moogs for my almost new control arms. If your adjustable ones will be ready next spring, I’ll likely just wait and get those.
 

Gtstorey

Goblin Guru
Attached is a picture of my set up. Front one on top hole, rear drilled slightly lower than stock bottom hole. On one side the drilled hole overlapped the stock hole so I added a plate to lock it down.

What is Lonny calling the toe rack link? If he’s talking about the steering rack, can it be installed more than one way?
90C557E1-DF04-4AC0-B91A-C7B38E6CFDA2.jpeg
 

Lonny

Administrator
Staff member
I would like to say that I will have the new rear suspension production ready for sure by next spring, but time just send to fly by.

We are getting close to finishing the the instructional video cars. This will free up a lot of time.

I have finished redesigning the rear suspension and as soon as the material arrives I will fabricate two prototypes for testing. This should happen in the next few weeks and will give us a better idea of a production time frame.

20211027_191259.jpg
 

DCMoney

Goblin Guru
I would like to say that I will have the new rear suspension production ready for sure by next spring, but time just send to fly by.

We are getting close to finishing the the instructional video cars. This will free up a lot of time.

I have finished redesigning the rear suspension and as soon as the material arrives I will fabricate two prototypes for testing. This should happen in the next few weeks and will give us a better idea of a production time frame.

View attachment 28162
This makes my week! Looks awesome! Know you don't have the engine/transmission mounts shown yet but are you planning on adding mounting options for the sway bar?
 

DCMoney

Goblin Guru
Lonnys rear suspension and subframe replaces the OEM subframe, control arms, knuckle etc. Currently there is nothing shown for mounting the sway bar to the new subframe, but its also missing the engine/transmission mount was well.

 

Gtstorey

Goblin Guru
I didn't realize that he had changed the design to no longer use the oem subframe. Maybe it will be available both ways? I'm afraid of what the cost may be if it requires a new subframe.
28174
 

RobC76

Well-Known Member
Fabricated upright as well. This is next level improvement. I like how he’s engineering so that hopefully everyone that wants to purchase subframe for exhausting cars can. Good stuff.
 
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