Steering & Suspension Mods.

[campbellr2007]

Having spend a fair bit of time reading through the numerous posts on the steering and suspension mods it's time for me to begin to tackle them. I have listed the mods below outlining what I intend to do. I would welcome any comments.

Bumpsteer - The car has sierra suspension with the tall mushrooms. I plan to cut the steering rack mounting tubes down to measure 100mm. This is based on Sidebodcar's latest reply to a post. The section to be cut on the top of the tube in order to allow the rack to sit lower. Advice I have read is to use a circlip to get an even cut and to use the off-cut as a spacer on the bottom. I also need to check for clearance between the chassis upright and the UJ on the rack. - Other than that I am not aware of any other mod required to resolve the bumpsteer issue.

Front Camber - To be set to vertical at full droop then wind the top ball joint out a full 4 turns to introduce slight positive camber at full droop. When on the ground I understand this then reverts back into negative camber.

Front Caster - First step is to set the bottom wishbone as far forward as possible by removing the packing washers from the rear of the wishbone mount and placing them to the front. Next is to do the opposite at the top wishbone. Should cut away any of the top wishbone mounting tube at the front to allow the wishbone to move back further ? - if yes then how much of the tube should be removed ? Other than this I am not aware of any further mods that are required.

Rear Camber My understanding is that I should not use the middle hole as instructed by the build manual but use the lower hole to mount the outer rear wishbone. This would reduce the camber slightly in a negative direction by lowering the outer side of the wishbone.

Rear Toe in/Toe out. - My understanding is that there are two options to optimize this. The first is to have the rear hub assembly inner face machined or alternatively to slot the inner rear wishbone mounts allowing the wishbone to be set further forward than the standard settings. - On this one I had not planned to do either and to live with the standard set up for the time being.
I would welcome comments on the wisdom of this and what the likely negative impact I will experience buy carrying out all the other mods but not this one?

If I have missed anything else I should be looking at during the build then I would welcome any suggestions but I think from reading the forum I have covered the known improvements.

Many thanks in advance for any replies.

Regards

Ronnie.

[Purple AK]

Might be worth checking with Pilgrim first to make sure they haven't already introduced these simple mods into the chassis build


Sorry. Carry On

[chedz]

hi ronnie,
an excellent summary of the mods. I have all of them done to my car (living near pete helps). For the caster mods you should keep 1 small washer and one large between the rubber of the bush and the chassis to stop any chaffing. For trimming the chassis tubes down at the top, just cut as much as you can off but leave a little stub (I left about 2mm) to give room for washers not to rub the upright and give you a bit left to file perfectly square.

One thing that is VERY IMPORTANT to check after the caster mods...
You will be changing the at rest angle of the bottom ball joint, I found with the max caster this joint had very little movement remaining available in the backwards direction, this could cause problems so I angled the ball joint base plate in the same direction by putting a couple of washers under the back 2 fixing bolts. You may not need this as I went for extreme caster to get through SVA, but please check this.
You'll find a summary of some of the mods on the site in my signature, its still a work in progress though.
Good luck and come back with any questions or improvements you come up with.
cheers
g.


good luck with the mods, you'll be amazed at the difference they make.

[Stu J]

Can I just say you have probably saved anyone else having to search past threads on this subject, and you have hit the nail on the head... well done.

My only tuppence worth, is that I left 1mm after the weld on the top wishbone mounting tube, and one tip I found very useful was to put jubilee clips around the steering rack tubes. When you have marked the tube this hint gives a perfect line to cut/grind in order not to go too far or not level.

[campbellr2007]

Well that the front end all but done. Having access to a pit made life easier. The best money I ever spent when building the garage. Hope to complete the rear this weekend.

Thanks for the comments guys

Ronnie.

[Sidecarbod]

Hi Ronnie,

Doing all the mods that you have suggested will make a big difference to the way the car handles.

As to your question regarding the whether the rear toe out mod will make a big difference....well it does make a difference but not a big one. I noticed that the rear end 'bobbled' about a bit less on bumpy roads but to be honest you can leave that mod until you've put some miles on the car, you can then decide whether you have a rear end issue or not. (Tyre wear will be worse without the mod).

Noel's car has all the mods apart from the rear tow done to it and he described the difference as "profound!!"

Make sure that the front toe is set to zero and that the rears are NOT used to set the fronts up. If the front toe is not right then all your effort will be wasted.

Regards,

Pete

[Rowly]

I just finished doing the front end Mods, Bumpsteer & camber reset.
as described in various posts.
I am well pleased with the result, I set the Toe to zero, as near as I could, using a Laser level. I will take it in to my local Garage to have it checked out.
Thanks to all for advice posted. it was a great help!!