Little bit of a dilemma ordering shocks and springs for this new setup.
My old Ridetech 4link setup had 2.5”ID 12” springs with 185 lb spring rate and seemed pretty damn stiff then and now even installed these on the speedtech setup.
Now speedtech is recommending;
QA1 DD417 shock. 5/8 bearing 1.25 width and a 10 inch 300 lb spring
strange recommended this setup https://www.strangeengineering.net/product/double-adjustable-drag-racing-coilover-shocks-4-64-stroke.html/
i am confused on what to do.
carbuff
04-30-2024, 10:15 AM
I suggest doing "the work" to measure for exactly what you need, or barring that start with Speedtech's suggestion.
By the work, what I mean is you need to assemble everything, locate the axle at the ride height you desire, and then measure the center to center for the 2 shock mount points. That will determine the length of the shock you need at ride height. Once you know that, then you decide which manufacturer of shock you want to use. Call them and tell them the measurement. You also should pay attention to the bump / compressed length (ie: what is the shortest length the shock will need to be under compression) as well as the extended length (not as critical, but the maximum length the shock would be under full extension).
The way the shock is made will determine the length of the spring based on how much adjustability the shock body allows for the adjuster. It's likely you would need different length springs for different shock/coilover manufacturers.
In addition, I highly recommend you consider these zero-rate helper springs and what they call 'spring dividers' (the long ones) as well as a set of coilover spring thrust bearings. They make like easier down the road if you want to adjust corner weights and when you have the car in the air with the axle at droop. Here are links to what I'm referring to:
Zero-Rate Helper Springs (https://www.pegasusautoracing.com/productselection.asp?Product=1876)
Spring Dividers (these actually keep the spring aligned before compression at full extension) (https://www.pegasusautoracing.com/productselection.asp?Product=1877)
Thrust bearings (https://www.summitracing.com/parts/aaf-all64210)
Hopefully all of this helps with some guidance.