PD,
To answer some of your questions, I am not sure what the rack is originally out of. They would not tell me as which I understand. It comes with an electric driven power steering pump. It was marketed for MG's.
The ratios are very close to the Pantera which is a good start.
I would not push this on anyone as I have not driven the car with it and will not drive the car for some time. I am not sure it would be a simple bolt on as. The rack will need some modification to start with.
I am addressing the Pantera suspension from scratch. I will be fabricating new uprights and new a-arms to get the geometry the way I want it.
There are several things to consider when making these these types of changes and it's hard to address all of them in this fashion.
I also believe people are changing racks which may not have the pivot points in the right location which will mess up the suspension geometry. In fact this replacement Rack for the MGB being sold has inner ti-rod pivot point 1.5" off the original MGB rack. I don't think MGB owners are considering this but I think a light weight small car such as that will have less of an impact.
One issue I want to resolve with the geometry of the suspension is the fact that the inner ti-rod pivot and the outer ti-rod pivot are not inline with the suspension pivot points. They should not only be inline but also point to the instant center (which basically means their angle should follow the angular deviations of the a-arms.
What this means is if the rack is in the proper location and the inner ti-rod length is correct, you can correct for bump steer and you can control Ackerman BUT>>>>
The current bump steer fix changes the ark where bump steer is fixed, bump droop is magnified and other issues arise. The ti-rod points further away from instant center and the geometry gets worse even though you have fixed one problem.
This is all fine as it is the best "easy fix". I am trying to take it a step further.
I cannot begin to understand the reasoning for the way they have set up the geometry and the best glues I have is it is a compromise for various reasons.
My goal it to get all these things aligned as they should be so I can make changes and so I can (Here is the key) Understand the changes I am making.
Despite what some have said, the Pantera does have Ackerman built into the geometry. It comes from the angle the ti-rod attaches to the upright.
My goal is to get the pivot points back the way they should be, t-rods pointing the way they should be locate the rack at the proper location. In doing so I will have room to move the rack back and forth for Ackerman. Bump steer will be designed out from the start.
There are several things going on in the uprights and determining the SAI. We have different wheel and tires then what came on the car. All this will take out most of the scrub with many other considerations.
It's all one big puzzle but you see it's not a simple rack change.
Gary
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