Heavy steering

I have a superformance mk2 with 225-60-15 Avons At higher speeds the steering is very heavy slower speed is not bad. At higher speeds you have to pull on the steering wheel pretty hard. i have had this car for eight years and love it almost 9000 miles
 

Terry Oxandale

Skinny Man
Could this be excessive caster? Also, is it hard to turn (harder at speed vs parking), or is it heavy in that it is sluggish, or not light and nimble, at speed?
 
This is probably due to gyroscopic reaction. Not much you can do to change it except reduce the rotational inertia with lighter wheels and tires.
 

Randy V

Admin
Lifetime Supporter
Please post up your alignment readings from the shop that did it.
Also - does your steering wheel self center when you go around the corner and relax your grip on the wheel?
 
Could this be excessive caster? Also, is it hard to turn (harder at speed vs parking), or is it heavy in that it is sluggish, or not light and nimble, at speed?
caster is built in from factory it is heavy but responsive you have to have alot of muscle also keep your self in the seat
 
Is this a recent development? Have you checked the condition and tightness of the nylon cups in the lower ball joints?
 

Ian Anderson

Lifetime Supporter
Do you have canards fitted?
Single or double nostril?
What is the rake of the car? Front 1/2 inch lower than rear?
Perhaps it is creating a lot of front downforce

ian
 

Neil

Supporter
Do you have canards fitted?
Single or double nostril?
What is the rake of the car? Front 1/2 inch lower than rear?
Perhaps it is creating a lot of front downforce

ian
Here is MIRA wind tunnel data on a GT40 that John Horsman gave me:

As raced at Le Mans in 1969. Front : 295 lbs LIFT, Rear : 49 lbs LIFT, at 0 degrees yaw angle and at 200 mph.
 
This is probably due to gyroscopic reaction. Not much you can do to change it except reduce the rotational inertia with lighter wheels and tires.
Gyroscopic or caster are the likely culprits, as it is speed dependent. Down force would only decrease your camber (make it more negative, top in) and increase your toe in. I suspect the suspension was designed to become more stable at high speeds, thus the heavy steering.

If you can reduce the caster, it might help. The more caster you have, the more you have to lift the front end to make it turn.

Please let us know what you figure out!
 
[QUOTE

If you can reduce the caster, it might help. The more caster you have, the more you have to lift the front end to make it turn.

Please let us know what you figure out!
[/QUOTE]
Caster is non adjustable on SPF as on originals. Only changing the a arms will alter caster. SPF caster is high at 6-7 degrees. As stated above greater caster increases high speed stability at cost of heavier steering. I don't understand OP stating steering heavier at high speed, but less at low. My SPF has heavy low speed steering, but lightens up with speed.
 
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