DG-FNR
20+ Year Contributor
- 234
- 62
- Oct 21, 2002
-
Geary,
NB, Canada
This is really a response to a privately-posted question, but the answer is worth sharing in public.
So then, what's the deal with Hypercoil springs?
Hypercoil does not make application-specific "lowering springs" like some other spring companies. They probably would wind you a custom spring that would fit in an OEM DSM application, but it'd probably set you back a couple of grand.
Instead, Real Racecars use a couple of common spring sizes, and Hypercoil makes springs that fit. The only exception is NASCAR, which uses a spring based on some late 60's GM OEM fitment - but because NASCAR is so big and so rich, that OEM fitment is now considered a "Real Racecar" fitment
Typically, a Real Racecar will use a spring that is either 2.5" in INNER diameter, or 2.25" inches in INNER diameter. An engineer has no real control over the OUTER diameter, because the OD is a function of the ID and the rate (stiffer springs use larger diameter wire)
They come in set lengths, from 3" to 12" by 1".
The big deal about Hypercoils is the extreme lengths they go to to ensure quality. A Hypercoil will never sag. A Hypercoil is guarenteed to be within 3% of it's indicated rate. Every single Hypercoil is rate-tested at the factory before it is shipped.
When you use a Hypercoil, you're using the exact same spring as an Indycar, CART car, WRC car etc etc etc. This is Real Racecar stuff. But because they have huge economies of scale, the springs are actually pretty inexpensive (in the ballpark of $60 per spring)
It's not very often that we get to use Real Racecar stuff and actually have it be CHEAP. Enjoy the opportunity!
To use Hypercoils on a DSM, you need to have a coilover kit - they will not fit without one. You also need coaxial upper spring hats (which has been discussed already)
What size depends on the ID of the spring hats, the length of the spring, and the rate you want. For Konis with native coilover hardware and appropriately-relocated snap ring grooves, that'll be 2.25" ID X 8" long by RATE. For most GC and EBAY-sourced stuff, 2.5" ID by 8" by RATE.
On my own car, I'm using 2.5" ID x 8" long X 900lbs/in on the front, and 2.5" x 8" long x 400lbs/in on the rear.
Something else that is helpful (heh) is the "helper spring" This is a flat-wound spring with minimal rate that is designed to collapse when the car's weight is applied to it, but expands when the wheel comes off the ground. It's useful to keep the spring from ratlling around on the perch in lowered applications. I use them on my car.
DG
Learn: http://autocross.dsm.org/books.html
So then, what's the deal with Hypercoil springs?
Hypercoil does not make application-specific "lowering springs" like some other spring companies. They probably would wind you a custom spring that would fit in an OEM DSM application, but it'd probably set you back a couple of grand.
Instead, Real Racecars use a couple of common spring sizes, and Hypercoil makes springs that fit. The only exception is NASCAR, which uses a spring based on some late 60's GM OEM fitment - but because NASCAR is so big and so rich, that OEM fitment is now considered a "Real Racecar" fitment
Typically, a Real Racecar will use a spring that is either 2.5" in INNER diameter, or 2.25" inches in INNER diameter. An engineer has no real control over the OUTER diameter, because the OD is a function of the ID and the rate (stiffer springs use larger diameter wire)
They come in set lengths, from 3" to 12" by 1".
The big deal about Hypercoils is the extreme lengths they go to to ensure quality. A Hypercoil will never sag. A Hypercoil is guarenteed to be within 3% of it's indicated rate. Every single Hypercoil is rate-tested at the factory before it is shipped.
When you use a Hypercoil, you're using the exact same spring as an Indycar, CART car, WRC car etc etc etc. This is Real Racecar stuff. But because they have huge economies of scale, the springs are actually pretty inexpensive (in the ballpark of $60 per spring)
It's not very often that we get to use Real Racecar stuff and actually have it be CHEAP. Enjoy the opportunity!
To use Hypercoils on a DSM, you need to have a coilover kit - they will not fit without one. You also need coaxial upper spring hats (which has been discussed already)
What size depends on the ID of the spring hats, the length of the spring, and the rate you want. For Konis with native coilover hardware and appropriately-relocated snap ring grooves, that'll be 2.25" ID X 8" long by RATE. For most GC and EBAY-sourced stuff, 2.5" ID by 8" by RATE.
On my own car, I'm using 2.5" ID x 8" long X 900lbs/in on the front, and 2.5" x 8" long x 400lbs/in on the rear.
Something else that is helpful (heh) is the "helper spring" This is a flat-wound spring with minimal rate that is designed to collapse when the car's weight is applied to it, but expands when the wheel comes off the ground. It's useful to keep the spring from ratlling around on the perch in lowered applications. I use them on my car.
DG
Learn: http://autocross.dsm.org/books.html
IT'S SO BOUNCY!!!! is almost always a shock/spring mismatch (sometimes because the car is sitting on the bumpstops, and bumpstops are really stiff springs)
!
