Spring Rates Question? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

jgalewsk · 11-04-2013, 08:59 PM

I've been looking at spring rates lately of different suspension setups and I'm a little confused. Any insight would be awesome!

Here are spring rates that I have found through research here on Camaro5:

Stock V8:
165 lbs/in front
370 lbs/in rear
45% front to rear ratio

Pfadt lowering springs:
210 lbs/in front
395 lbs/in rear
53% F/R ratio

BC BR coilovers and Pedders XA coilovers:
448 lbs/in (8kg/mm)
560 lbs/in (10kg/mm)
80% F/R ratio

Here is the link to another thread that I found some of the spring rates: http://www.camaro5.com/forums/showthread.php?t=234954

The F/R ratio is bolded because that is what is causing my confusion... Is there any reason that the F/R ratio changes so much when moving to coilovers? ~50% to 80%?!

jgalewsk · 11-08-2013, 12:48 PM

Anyone?

BullF-16 · 11-08-2013, 01:52 PM

I know JusticePete can answer here but i think he's busy at SEMA

jgalewsk · 11-08-2013, 03:57 PM

I figured that's why I haven't seen him responding lately... In the meantime, I guess we will see if anyone has any insight.

BullF-16 · 11-08-2013, 05:17 PM

Quote:

Originally Posted by jgalewsk

I figured that's why I haven't seen him responding lately... In the meantime, I guess we will see if anyone has any insight.

I do know my last trip down to visit Pete for my camber plates and ZL1 sways he had me swap out the 8kg front and 10kg rear coils to 12kg all around on the supercar coilovers. Pretty impressed with the upgrade. My kidneys hate me btw!

jgalewsk · 11-09-2013, 12:59 AM

Quote:

Originally Posted by BullF-16

I do know my last trip down to visit Pete for my camber plates and ZL1 sways he had me swap out the 8kg front and 10kg rear coils to 12kg all around on the supercar coilovers. Pretty impressed with the upgrade. My kidneys hate me btw!

Snickerdoodle also put 12kg springs on all 4 corners. I messages him earlier to get his opinion. The characteristics of handling during hard cornering must change when that front to rear ratio changes so drastically... I mean 12kg front to 12kg rear is obviously 1:1 ratio. Stock is more like a 9:20 ratio...

jgalewsk · 11-27-2013, 01:11 PM

bump... (I'm guessing Pete is still busy?)

VR Baron · 11-27-2013, 07:52 PM

Quote:

Originally Posted by jgalewsk

bump... (I'm guessing Pete is still busy?)

Think so.

sting808 · 11-27-2013, 10:11 PM

The higher front spring rate helps reduce nose dive under extreme braking/corning at a price. The ride becomes stiffer. The adjustable dampening helps the bound/rebound.

I ran the Pedders stock 8KG and went to 10KG to reduce front nosedive in Auto-X. My car has added front weight due to DeWitt radiator, FI, suspension, etc. Overall car weight is much heavier due to sub box, added mods, and tons of dynamat.

At 10KG and 28mm solid front swaybar, the front suspension does not give if you press down. I can imagine 12KG. This would be great for auto-x and road track, but bad for a DD, unless you want a compressed spine.

Instead of focusing on the numbers, prioritize your needs and weigh the consequences. BC/Pedders can use softer springs if you want the flexible adjustability, but stock ride quality, as with other brands, too. With drag, you want FR-to-RR weight transfer, so softer springs. Autox and road racing want more stable, firmer ride, so a more balanced stiffer spring based on weight distribution. DD/Street may want a lower stance, but OE ride, so OE like spring rate, but shorter height. If you keep OE spring rate and lower spring height, you may bottom out, so many lowering springs are typically slightly stiffer than stock. This is a very general/layman approach to suspension spring rate. I'm sure the suspension manufacturers can provide a better explanation and correct any of my inaccuracies.

VR Baron · 11-27-2013, 11:42 PM

Pete did say that the 8/10 kg springs with the coilovers were the best balance for the 5th gen. I'm still learning and tunning the setup on the supercars. I have to say, when I'm down in the 8-10 setting range, and I have gone softer yet,which is for the street, the ride is better then drop springs and only a little firmer then stock on smooth roads. Over patched asphalt and bumps it is firmer(springs) but so controlled and solid, much better then Hotchkis springs, which are good riding for a drop spring.
Even with stiff springs, as long as the shock valving is adjustable, especially bound and rebound, you can get a good solid comfortable ride, or crank it up for auto x or road course!

11-04-2013, 08:59 PM	#1
jgalewsk Drives: 2013 Summit White Camaro 2SS RS 1LE Join Date: Oct 2012 Location: Lafayette, LA Posts: 278	Spring Rates Question? I've been looking at spring rates lately of different suspension setups and I'm a little confused. Any insight would be awesome! Here are spring rates that I have found through research here on Camaro5: Stock V8: 165 lbs/in front 370 lbs/in rear 45% front to rear ratio Pfadt lowering springs: 210 lbs/in front 395 lbs/in rear 53% F/R ratio BC BR coilovers and Pedders XA coilovers: 448 lbs/in (8kg/mm) 560 lbs/in (10kg/mm) 80% F/R ratio Here is the link to another thread that I found some of the spring rates: http://www.camaro5.com/forums/showthread.php?t=234954 The F/R ratio is bolded because that is what is causing my confusion... Is there any reason that the F/R ratio changes so much when moving to coilovers? ~50% to 80%?!

11-08-2013, 01:52 PM	#3
BullF-16 USAF retired! Thank God! Drives: 2011 1SS, 1LT red,1LT/RS SGM 98Z28 Join Date: Jul 2011 Location: North Texas Posts: 2,799	I know JusticePete can answer here but i think he's busy at SEMA __________________ HKE LSX427(Mast blk lbl 305 6bolt LS7heads, PatG231/246 blower cam, RWHP/TQ: 1281/1133 SNL Performance Custom Twin PT6766 BB turbos 4 to 25psi selectable on the Boost Leash controller, Squash dual 400LPH/ID2000s, ALKY 4 gal meth, Autometer AFR/Bst/oilpres/oiltemp/fuelpress gauges, Pedders Justice road crs pkg: All HD bushes, supercar 12kg coil overs, supercar ZL1 sways, camber plates all setup by JusticePete! :Gforce 9" 35spline S-Trac, 1500hp Outlaw axles, 3.5"alum DS, Monster Triple disc; 4xForgeline 19x10.5 4xBridgestone 305/30R19 RE-11, CTS-v calipers/rotors/Cobalt friction XR1/3 pads

11-27-2013, 11:42 PM	#10
VR Baron SoCal Camaro5 Race Team Drives: 2021 Shadow Grey Camaro 2SS 1LE Join Date: Mar 2010 Location: SO CAL Posts: 14,287	Pete did say that the 8/10 kg springs with the coilovers were the best balance for the 5th gen. I'm still learning and tunning the setup on the supercars. I have to say, when I'm down in the 8-10 setting range, and I have gone softer yet,which is for the street, the ride is better then drop springs and only a little firmer then stock on smooth roads. Over patched asphalt and bumps it is firmer(springs) but so controlled and solid, much better then Hotchkis springs, which are good riding for a drop spring. Even with stiff springs, as long as the shock valving is adjustable, especially bound and rebound, you can get a good solid comfortable ride, or crank it up for auto x or road course! Last edited by VR Baron; 11-27-2013 at 11:53 PM.

11-08-2013, 12:48 PM	#2
jgalewsk Drives: 2013 Summit White Camaro 2SS RS 1LE Join Date: Oct 2012 Location: Lafayette, LA Posts: 278	Anyone?

11-08-2013, 03:57 PM	#4
jgalewsk Drives: 2013 Summit White Camaro 2SS RS 1LE Join Date: Oct 2012 Location: Lafayette, LA Posts: 278	I figured that's why I haven't seen him responding lately... In the meantime, I guess we will see if anyone has any insight.

11-27-2013, 01:11 PM	#7
jgalewsk Drives: 2013 Summit White Camaro 2SS RS 1LE Join Date: Oct 2012 Location: Lafayette, LA Posts: 278	bump... (I'm guessing Pete is still busy?)

11-27-2013, 10:11 PM	#9
sting808 Drives: 2010 SS RS Join Date: Apr 2009 Location: Honolulu, Hawaii Posts: 930	The higher front spring rate helps reduce nose dive under extreme braking/corning at a price. The ride becomes stiffer. The adjustable dampening helps the bound/rebound. I ran the Pedders stock 8KG and went to 10KG to reduce front nosedive in Auto-X. My car has added front weight due to DeWitt radiator, FI, suspension, etc. Overall car weight is much heavier due to sub box, added mods, and tons of dynamat. At 10KG and 28mm solid front swaybar, the front suspension does not give if you press down. I can imagine 12KG. This would be great for auto-x and road track, but bad for a DD, unless you want a compressed spine. Instead of focusing on the numbers, prioritize your needs and weigh the consequences. BC/Pedders can use softer springs if you want the flexible adjustability, but stock ride quality, as with other brands, too. With drag, you want FR-to-RR weight transfer, so softer springs. Autox and road racing want more stable, firmer ride, so a more balanced stiffer spring based on weight distribution. DD/Street may want a lower stance, but OE ride, so OE like spring rate, but shorter height. If you keep OE spring rate and lower spring height, you may bottom out, so many lowering springs are typically slightly stiffer than stock. This is a very general/layman approach to suspension spring rate. I'm sure the suspension manufacturers can provide a better explanation and correct any of my inaccuracies.