Speed Tech Front End, QA1 Coil Overs and Harsh Ride

[old66tiger]

The ride in my 66 GTO is a bit harsh with the Speed Tech parts and the QA1's. I have 550 lb springs and to get the height right, I have the coils adjusted to about 2" from the top end of the shock adjustment. Are these springs just too soft such that the coils are compressed too much? Should I be into 650 lb springs?

[dhutton]

In my experience too much preload gives a rough ride. Is the shock roughly centered in its travel at ride height? If it is I would try a higher spring rate.

Nick from Chassisworks posted a pdf here that shows how to calculate the correct spring rate:

https://www.pro-touring.com/showthre...ge2&highlight=

Don

[marolf101x]

Or you can just type in the vehicle info into our spring rate calculator and it will give you 3 options (cruiser/daily driver; performance driving; racing).

Also, do not dismiss the shock as being part of the issue. The shock can make a car ride too soft or too stiff. Do you have adjustable shocks? If so, where are you in the adjustment range?

[killer69]

Or you can just type in the vehicle info into our spring rate calculator and it will give you 3 options (cruiser/daily driver; performance driving; racing).

Also, do not dismiss the shock as being part of the issue. The shock can make a car ride too soft or too stiff. Do you have adjustable shocks? If so, where are you in the adjustment range?

That would have been my first question?
The 550 lb spring is the heaviest one available at this time.
you can always call Speedtech direct to discuss. WE don't bite.