Chaps I have a mk2 that has the MC Wilkinson powered rack and pinion system installed. It uses a modern electric pump to power the rack. I bought the car as it is very good condition and has a massive history file etc etc etc. My intention was to use it for sprits and track days and general road use/trips to lemans etc.
In trying the car out the steering and general behaviour is fine and parking etc is great with the power assistance BUT! when I try to drive it fast it is difficult to negotiate bends and corners my initial though was a lot of oversteer and I need to do some ore testing before I can give a better description. I jut wondered if anyone who has made this conversion can give any advice on alignment or suspension set up angles.
Best regards
Phil D
I’ve only read about the Wilkinson R&P units. As I understand it they have a speed sense to vary the boost depending on road speed.
If you’re having problems with too much turn in at speed, then it may be that your speed sense control circuit isn’t adjusted correctly.
Did it come with an installation manual, and does it detail any speed adjustment or sensors?
To much oversteer Phil !! how much engine power are you feeding in?
To much toe in and / or not enough castor return.
I assume you have checked both.
Peter B.
As far as I am aware there is no speed sensing capability. The car is a 3.4 which s not producing what it should as its down on compression (90 psi) on one cylinder. I have not yet measured any settings. not sure what I should have either with this set up.
I run a 3.8S with a ZF rack and pinion conversion. From what I know, and from my car, the front suspension of the Mark II, S Type, and 420 is not designed for a R & P system due to the built in geometry. The impact of this is that the Ackermann effect is lost with the R & P set up. The result of his is that the front wheels do not turn side to side with an increasing toe out as you move off the straight ahead position. The increasing toe out is needed as the outer wheel must scribe a larger radius circle than the the inside wheel. This causes the tires to scub as turn at a ever tighter circle. To test, put you car in a flat surface such as a parking lot and make a turn at full lock and see if the tires scrub. After much measurement and head scratching I do not believe there is a solution to this short coming yet having said that, I will remain with the R & P as the overall precision of steering is good and there are no leaks! To my knowledge there are no alignment specs that can totally overcome this issue. The downside of the R & P setup is a larger turning circle and premature tire wear. If any one has engineered a solution I would love to hear about it.
Thankyou John, I will investigate further and report back
07714 759198
Phil,
I have an XJ rack on M&C mounts on my S Type. The best alignment settings I have found are 1-1.5 degrees of negative camber and 2-3 degrees of castor. This is with 205 VR tires on 6 inch V-12 E wheels. I have no problems cornering. How do you like the electric PAS pump ?
Paul
I was hoping you would reply Paul as I couldn’t find your previous posts where you gave the settings. Currently I have 185 x 15 with Blockley tyres. I haven’t driven the car enough due to the dreadful weather we have had since Christmas when I bought the car but that will change shortly. The electric PAS seems ok and for general trips the system if fine. one quick question do you have the 205 section tyres on all 4 corners? when I tried that on a previous mk2 the rears would touch the wheel arches (not the spats) but I guess the etype wheels might have a better offset?
Hi Phil,
I have 205s all aorund, the offset of the 6 inch wheels fits under the stock S Type arches. Tires make a huge difference. Do you have a generator or an alternator ? I have a 55 amp alternator married to the PAS pump, but I am considering fitting a 100 amp alternator and A/C.
50 amp alternator
07714 759198