Cutting stock springs
02-02-2012, 11:50 AM
#16
Everyone's saying don't cut stock springs but nobody's saying why. (will cutting it change the spring rate?) will it make the ride bouncy? stiff? etc??
This is just a curious question.... Not planning on cutting mine, I'm on Eibach's and perfectly happy with them.
02-02-2012, 12:31 PM
#17
As an engineer I would say that things are designed the way they are for a reason. They are designed to withstand a myriad of situations/conditions/environmental hazards after lots of math, physics, and simulation work. When you modify a part you change the design parameter of the part and so all that math, physics, and simulation that went into the part design is pretty much out the window. What's left is variability and unpredictability. So if you want to cut a spring, by all means do so, but know that you are introducing a huge uncertainty risk into the safety and handling of your car.
02-02-2012, 12:48 PM
#18
Here's my dilemma,
I installed the Eibach lowering springs this weekend and although the new stance looks awesome the ride quality is not good. It's very stiff now... and when passengers are in the car they actually comment how rough the ride is and when I now go some speed bumps my exhaust scrapes. It's a trade off I cannot accept so I am thinking my only option is to go back to my original springs?
Here's the question, would it be "ghetto" to cut off say 1/2- 3/4's of an inch from the stock springs? If so, can anyone recommend a different spring that lowers the car about an inch but is not so harsh and will let me have passengers in the car?
FYI- the lowering springs are the only thing done to the car, I'm on stock rims
and tires.
Thanks
I installed the Eibach lowering springs this weekend and although the new stance looks awesome the ride quality is not good. It's very stiff now... and when passengers are in the car they actually comment how rough the ride is and when I now go some speed bumps my exhaust scrapes. It's a trade off I cannot accept so I am thinking my only option is to go back to my original springs?
Here's the question, would it be "ghetto" to cut off say 1/2- 3/4's of an inch from the stock springs? If so, can anyone recommend a different spring that lowers the car about an inch but is not so harsh and will let me have passengers in the car?
FYI- the lowering springs are the only thing done to the car, I'm on stock rims
and tires.
Thanks
They werent made for that short of a stroke.
Either wait a week or two to see Konis results on 370Z springs working on the G37.
Alternatively, try the Swift springs, I hear they are a little more gentle, they have a high rate, which would lead me to think you still wont be happy.
02-03-2012, 10:12 AM
#20
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I ended up just going back to the stock springs for now.. but I did notice that the Eibach springs that were sent to me were for a coupe and not a sedan? I'm thinking that is why my ride was so rough...
02-03-2012, 10:48 AM
#21
I don't know what the numbers are for cars, but for bikes, there is a recommended difference in height between unloaded suspension, bike with no rider, and bike with rider in full gear/accessories. The latter is called total sag. The idea is to position the suspension such that it doesn't bottom out, nor does it fully extend when in use. Preload on the springs (front and back) is used to make this adjustment. If you're using mismatched springs for your vehicle, you'll either get too much suspension movement that the shocks can't dampen (BB, proper use of the word in this context I think), or the springs will be so stiff that deflection will be minimum and ride exceptionally harsh.
Before blindly installing any suspension upgrade, do some research and find out what the various spring rates are, and how they relate to your particular application.
Before blindly installing any suspension upgrade, do some research and find out what the various spring rates are, and how they relate to your particular application.
02-03-2012, 11:26 AM
#22
why not get adjustable coils? A more expensive route but if you want to drop and not have the discomfort of springs, spend a little more money and get height adjustablilty and a smoother ride overall.
Bad ride was my one fear so I went coils over springs this time around. Always had springs on my other cars. Will never buy springs again. Coils and night and day better than springs.
Bad ride was my one fear so I went coils over springs this time around. Always had springs on my other cars. Will never buy springs again. Coils and night and day better than springs.
02-03-2012, 11:43 AM
#23
This link contains more technical data on the eiback p/n 6399.140
Eibach Springs : NEWS : INFINITI G35X SEDAN 2007-08
PK=Prokit, OE=what came on the car.
Eibach Springs : NEWS : INFINITI G35X SEDAN 2007-08
PK=Prokit, OE=what came on the car.
TECHNICAL INFORMATION
FRONT:
OE rate: Linear 61 N/mm (348 lbs/in)
PK rate: Progressive 40-96 N/mm (228-547 lbs/in)
Tubing: Yes
Bump-stop: OE
Dust boot: New Eibach Springs dust boot
Damper: OE
OE wheel center to fender: 402 mm (15.8 in)
PK wheel center to fender: 367 mm (14.4 in)
Front Alignment:
OE Camber = -0.35 (+/-0.75 deg)
OE Caster = 4.0 (+/-0.75 deg)
OE Toe = 0.04 (+/-0.04 deg)
PK Camber = -1.7 deg
PK Caster = 4.7 deg
PK Toe = 0.04
PRO-KIT will require PRO-ALIGNMENT kit 5.72130K installed to adjust alignment to OE specification.
Approximate installation time: 1.0 hr
REAR:
OE rate: Linear 67 N/mm (382 lbs/in)
PK rate: Progressive 65-93 N/mm (371-530 lbs/in)
Tubing: None
Bump-stop: OE
Damper: OE
OE wheel center to fender: 388mm (15.3in)
PK wheel center to fender: 360mm (14.2in)
Rear Alignment:
OE Camber = -0.25 (+/-0.55 deg)
OE Toe = 0.11 (+/-0.11 deg)
PK Camber = -1.7 deg
PK Toe = 0.11 deg
PRO-KIT will require PRO-ALIGNMENT kit 5.72265K or 5.72260K installed to adjust alignment to OE specification.
Approximate installation time: 1.0 hr
FRONT:
OE rate: Linear 61 N/mm (348 lbs/in)
PK rate: Progressive 40-96 N/mm (228-547 lbs/in)
Tubing: Yes
Bump-stop: OE
Dust boot: New Eibach Springs dust boot
Damper: OE
OE wheel center to fender: 402 mm (15.8 in)
PK wheel center to fender: 367 mm (14.4 in)
Front Alignment:
OE Camber = -0.35 (+/-0.75 deg)
OE Caster = 4.0 (+/-0.75 deg)
OE Toe = 0.04 (+/-0.04 deg)
PK Camber = -1.7 deg
PK Caster = 4.7 deg
PK Toe = 0.04
PRO-KIT will require PRO-ALIGNMENT kit 5.72130K installed to adjust alignment to OE specification.
Approximate installation time: 1.0 hr
REAR:
OE rate: Linear 67 N/mm (382 lbs/in)
PK rate: Progressive 65-93 N/mm (371-530 lbs/in)
Tubing: None
Bump-stop: OE
Damper: OE
OE wheel center to fender: 388mm (15.3in)
PK wheel center to fender: 360mm (14.2in)
Rear Alignment:
OE Camber = -0.25 (+/-0.55 deg)
OE Toe = 0.11 (+/-0.11 deg)
PK Camber = -1.7 deg
PK Toe = 0.11 deg
PRO-KIT will require PRO-ALIGNMENT kit 5.72265K or 5.72260K installed to adjust alignment to OE specification.
Approximate installation time: 1.0 hr
02-04-2012, 01:23 PM
#24
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Even Honda guys don't do this anymore... lol, I don't understand the logic in spending X-amount of dollars for a g37 and then cheaping out on suspension.
02-04-2012, 05:08 PM
#25
The springs are progressive....you can't just shorten them and expect good results. You are changing the spring geometry in doing so. They also seat in the struts a certain way and will no longer fit correctly. My h&r springs were low and not too harsh. But to do it right you should do coils or a spring and strut combo
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