Stock and Aftermarket Springs
If you are interested in dropping your car with lowering springs, at least know what your stock rates are, and those of the aftermarket product you are looking to get. Spring rates measure how "stiff" the springs are, measured in lbs/inch. Drop is how much lower your car will be compared to stock ride height.
The chart below was posted by chickracer over 2 years ago and shows the stock b15 spring rates. To the best of my knowledge, the 1.8s still uses the same rates as the GXE, and I don't think the SE-R or SpecV rates have changed for '04 or '05.
***The chart link is gone, so I only know some of the rates from memory***
154F/247R - SpecV (all years)
134F/212R - SE-R (5spd/auto) and SE (w/PP)
134F/190R - 2.5S/LE/SE (w/o PP)
123F/190R - 1.8S/GXE/XE
Here are the spring rates and (drop) of the most popular aftermarket lowering springs. Understand that you really don't want to drop too much, and the rates should be higher than stock to compensate for less wheel travel:
180F/300R (1.2"F/1.0"R) Eibach Pro-Kit (gen2 #6362.140)
200F/333R (1.6"F/1.6"R) Eibach Sportline (gen2 #EIB4.6263)
168F/258R (1.3"F/1.1"R) Tanabe NF210
174F/258R (1.8"F/1.8"R) Tanabe DF210
207F/314R (1.3"F/1.1"R) Tanabe GF210
170F/270R (1.3"F/1.1"R) Tein S-Tech
154F/246R (0.9"F/0.6"R) Tein H-Tech
190F/280R (1.2"F/1.0"R) Swift Sport
230F/290R (1.5"F/1.5"R) Goldline
190F/240R (1.7"F/1.5"R) Progress a.k.a Intrax
172F/274R (1.6"F/1.6"R) Vogtland
280F/230R (2.0"F/2.0"R) Megan Racing
150F/190R (2.0"F/2.0"R) Sprint
???F/???R (1.5"F/1.5"R) B&G
???F/???R (1.5"F/1.4"R) H&R
I would stay away from Sprint because the drop is too low and rates too soft. Also, you really should know the rates of the lowering spring you are putting on your car, not knowing the spring rate is like not knowing the width of a tire. You need to know the rates to setup the suspension properly!
Also, here are the numbers for the Ground Control coilover sleeves, don't bother using these on stock dampers, the rates are too high. Use with Koni Sport for best results.
375F/300R (~1.0"-2.5"F/~0.5"-2.5"R) Ground Control (interchangable front and back)
Complete Coilover Systems
For more information visit my b15 suspension writeup at:
http://www.southern-shift.com/forums/viewtopic.php?t=1001
Nismo S-tune Kit
Spring Rates: 185F/300R (progressive, meaning this is just the MAX rate)
Swappable Springs: NO
Ride Height Adjust: NO (fixed at 1.0"F/0.6"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: NO
Upper Mounts Incl?: YES
Install Difficulty: LOW (pops right into car)
Street Price: $800
Tein Basic
Spring Rates: 336F/336R (linear)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (1.0"-2.4"F/0.5"-2.3"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: NO
Upper Mounts Incl?: NO
Install Difficulty: MEDIUM (reuse stock upper mounts)
Street Price: $800
Koni/Ground Control
Spring Rates: 375F/300R (linear)
Swappable Springs: YES (+/- 25 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (no notches, ~2 full turns from soft to stiff)
Upper Mounts Incl?: NO
Install Difficulty: VERY HIGH (reuse stock upper mounts, front strut housing, properly install GC)
Street Price: $850
Tein SS
Spring Rates: 336F/280R (linear, some use 392R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (1.0"-2.4"F/0.8"-2.3"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (16 way, 32 with EDFC)
Upper Mounts Incl?: NO
Install Difficulty: MEDIUM (reuse stock upper mounts)
Street Price: $1100
KSport
Spring Rates: 392F/280R (linear)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (36 way)
Upper Mounts Incl?: YES
Install Difficulty: LOW
Street Price: $850
JIC FLT-A1
Spring Rates: 392F/280R (linear, several use 336R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Twin Tube Nitrogen Gas
Damper Adjustment: YES (5 way)
Upper Mounts Incl?: YES (pillowball w/front camber adjustment)
Install Difficulty: LOW
Street Price: $1150
JIC FLT-A2
Spring Rates: 392F/280R (linear, several use 336R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Mono Tube Nitrogen Gas
Damper Adjustment: YES (15 way)
Upper Mounts Incl?: YES (pillowball w/front camber adjustment)
Install Difficulty: LOW
Street Price: $1750
One quick note: Stay away from B&G coilovers. Just ask David, I believe his exact quote was "overall they were the worst things I have bought for my car and I wish I could get my money back".
Lowering your car
When it comes to lowering your car, you either do it the right way, meaning using quality parts and making sure you install them correctly, or you don't do it at all. As a general rule, no aftermarket spring alone is really designed to work well with stock shock absorbers (or dampers) over an extended period of time. Dampers are a wearable part like brake pads and tires...eventually you have to switch them out after using them with stock springs anyway. The design of our suspension does not allow a lot of drop on stock dampers, and even modest lowering will cause premature wear. How soon your dampers go depends on things like what springs you use, but also your driving style or what the road surfaces are like in your area.
The main reason stock dampers should not be paired with almost all lowering springs is wheel travel. Anytime you drop your b15 on stock dampers you will lose wheel travel and bottom out more often. A really bad example is using 2" lowering springs with stock dampers. Because the stock dampers are too long for the shorter springs, the car at rest has the shock piston almost completely compressed...to the point where you can't even push down on the car because there is no shock travel. Not only will this kill your dampers in no time, it may also cause damage to other suspension components.
It is popular to only use lowering springs because it's cheap and looks so damn good. But you cannot escape the fact that our factory shock absorbers are tuned by Nissan engineers to work specifically with the factory springs, switch only one piece out, and the car just won't work right after a while. It's like using tires that are way too small for your rims, technically they may fit, but you might damage the rims and other suspension pieces and experience ride quality issues.
Here's what Koni has to say about this:
So now imagine what any lowering spring will do to the factory struts. Get the point?
Which product should I get?
Save up your money and definitely get a coilover system like Nismo S-tune or Tein Basic. They are ideal suspension setups, because the dampers and springs are matched to each other by engineers to give you the best balance between performance, ride quality and durability.
Using Koni Sport "Yellows" (which have stronger adjustable internal valving versus factory) to Ground Control sleeves is another route that has proven fairly popular for a number of users on this board. Once installed CORRECTLY (shortening the front konis, possibly relocating the front spring perch, choosing the right length and rate ERS springs, using the correct GC top hats, replacing plastic thrust bearings with metal b13 ones, revalving the konis to match the spring rates, adding external adjustability in the rear, etc.) the Koni/GC setup is arguably the BEST performance setup for the B15 Sentra.
If you want a VERY LOW drop, like 2" and still have decent ride quality, get the Tein Basic, you won't regret it. It is infinitely better than using lowering springs. If you want a slight drop, better performance, a quality ride, and an extremely easy install get the Nismo S-tune. For under $1000, these are the only two products I would personally put on my car.
Where can I get these aftermarket suspension products?
www.shox.com
www.performancenissanparts.com
www.sportcompactonly.com
www.ptuning.com
Feel free to ask any questions in this thread or PM me.
If you are interested in dropping your car with lowering springs, at least know what your stock rates are, and those of the aftermarket product you are looking to get. Spring rates measure how "stiff" the springs are, measured in lbs/inch. Drop is how much lower your car will be compared to stock ride height.
The chart below was posted by chickracer over 2 years ago and shows the stock b15 spring rates. To the best of my knowledge, the 1.8s still uses the same rates as the GXE, and I don't think the SE-R or SpecV rates have changed for '04 or '05.
***The chart link is gone, so I only know some of the rates from memory***
154F/247R - SpecV (all years)
134F/212R - SE-R (5spd/auto) and SE (w/PP)
134F/190R - 2.5S/LE/SE (w/o PP)
123F/190R - 1.8S/GXE/XE
Here are the spring rates and (drop) of the most popular aftermarket lowering springs. Understand that you really don't want to drop too much, and the rates should be higher than stock to compensate for less wheel travel:
180F/300R (1.2"F/1.0"R) Eibach Pro-Kit (gen2 #6362.140)
200F/333R (1.6"F/1.6"R) Eibach Sportline (gen2 #EIB4.6263)
168F/258R (1.3"F/1.1"R) Tanabe NF210
174F/258R (1.8"F/1.8"R) Tanabe DF210
207F/314R (1.3"F/1.1"R) Tanabe GF210
170F/270R (1.3"F/1.1"R) Tein S-Tech
154F/246R (0.9"F/0.6"R) Tein H-Tech
190F/280R (1.2"F/1.0"R) Swift Sport
230F/290R (1.5"F/1.5"R) Goldline
190F/240R (1.7"F/1.5"R) Progress a.k.a Intrax
172F/274R (1.6"F/1.6"R) Vogtland
280F/230R (2.0"F/2.0"R) Megan Racing
150F/190R (2.0"F/2.0"R) Sprint
???F/???R (1.5"F/1.5"R) B&G
???F/???R (1.5"F/1.4"R) H&R
I would stay away from Sprint because the drop is too low and rates too soft. Also, you really should know the rates of the lowering spring you are putting on your car, not knowing the spring rate is like not knowing the width of a tire. You need to know the rates to setup the suspension properly!
Also, here are the numbers for the Ground Control coilover sleeves, don't bother using these on stock dampers, the rates are too high. Use with Koni Sport for best results.
375F/300R (~1.0"-2.5"F/~0.5"-2.5"R) Ground Control (interchangable front and back)
Complete Coilover Systems
For more information visit my b15 suspension writeup at:
http://www.southern-shift.com/forums/viewtopic.php?t=1001
Nismo S-tune Kit
Spring Rates: 185F/300R (progressive, meaning this is just the MAX rate)
Swappable Springs: NO
Ride Height Adjust: NO (fixed at 1.0"F/0.6"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: NO
Upper Mounts Incl?: YES
Install Difficulty: LOW (pops right into car)
Street Price: $800
Tein Basic
Spring Rates: 336F/336R (linear)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (1.0"-2.4"F/0.5"-2.3"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: NO
Upper Mounts Incl?: NO
Install Difficulty: MEDIUM (reuse stock upper mounts)
Street Price: $800
Koni/Ground Control
Spring Rates: 375F/300R (linear)
Swappable Springs: YES (+/- 25 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (no notches, ~2 full turns from soft to stiff)
Upper Mounts Incl?: NO
Install Difficulty: VERY HIGH (reuse stock upper mounts, front strut housing, properly install GC)
Street Price: $850
Tein SS
Spring Rates: 336F/280R (linear, some use 392R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (1.0"-2.4"F/0.8"-2.3"R)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (16 way, 32 with EDFC)
Upper Mounts Incl?: NO
Install Difficulty: MEDIUM (reuse stock upper mounts)
Street Price: $1100
KSport
Spring Rates: 392F/280R (linear)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Twin Tube Hydraulic
Damper Adjustment: YES (36 way)
Upper Mounts Incl?: YES
Install Difficulty: LOW
Street Price: $850
JIC FLT-A1
Spring Rates: 392F/280R (linear, several use 336R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Twin Tube Nitrogen Gas
Damper Adjustment: YES (5 way)
Upper Mounts Incl?: YES (pillowball w/front camber adjustment)
Install Difficulty: LOW
Street Price: $1150
JIC FLT-A2
Spring Rates: 392F/280R (linear, several use 336R)
Swappable Springs: YES (+/- 56 ft/lbs)
Ride Height Adjust: YES (~1.0"-2.5"F/~0.5"-2.5"R) (can adjust overall damper length)
Damper Type: Mono Tube Nitrogen Gas
Damper Adjustment: YES (15 way)
Upper Mounts Incl?: YES (pillowball w/front camber adjustment)
Install Difficulty: LOW
Street Price: $1750
One quick note: Stay away from B&G coilovers. Just ask David, I believe his exact quote was "overall they were the worst things I have bought for my car and I wish I could get my money back".
Lowering your car
When it comes to lowering your car, you either do it the right way, meaning using quality parts and making sure you install them correctly, or you don't do it at all. As a general rule, no aftermarket spring alone is really designed to work well with stock shock absorbers (or dampers) over an extended period of time. Dampers are a wearable part like brake pads and tires...eventually you have to switch them out after using them with stock springs anyway. The design of our suspension does not allow a lot of drop on stock dampers, and even modest lowering will cause premature wear. How soon your dampers go depends on things like what springs you use, but also your driving style or what the road surfaces are like in your area.
The main reason stock dampers should not be paired with almost all lowering springs is wheel travel. Anytime you drop your b15 on stock dampers you will lose wheel travel and bottom out more often. A really bad example is using 2" lowering springs with stock dampers. Because the stock dampers are too long for the shorter springs, the car at rest has the shock piston almost completely compressed...to the point where you can't even push down on the car because there is no shock travel. Not only will this kill your dampers in no time, it may also cause damage to other suspension components.
It is popular to only use lowering springs because it's cheap and looks so damn good. But you cannot escape the fact that our factory shock absorbers are tuned by Nissan engineers to work specifically with the factory springs, switch only one piece out, and the car just won't work right after a while. It's like using tires that are way too small for your rims, technically they may fit, but you might damage the rims and other suspension pieces and experience ride quality issues.
Here's what Koni has to say about this:
Having owned a set of Konis for four years now, I can tell you that they much stronger than the factory struts. Despite this, they did bottom out with Eibach Prokit springs which offer one of the most conservative drops on the market. This point highlights the fact that our cars have very little shock travel to begin with.Koni North America said:
So now imagine what any lowering spring will do to the factory struts. Get the point?
Which product should I get?
Save up your money and definitely get a coilover system like Nismo S-tune or Tein Basic. They are ideal suspension setups, because the dampers and springs are matched to each other by engineers to give you the best balance between performance, ride quality and durability.
Using Koni Sport "Yellows" (which have stronger adjustable internal valving versus factory) to Ground Control sleeves is another route that has proven fairly popular for a number of users on this board. Once installed CORRECTLY (shortening the front konis, possibly relocating the front spring perch, choosing the right length and rate ERS springs, using the correct GC top hats, replacing plastic thrust bearings with metal b13 ones, revalving the konis to match the spring rates, adding external adjustability in the rear, etc.) the Koni/GC setup is arguably the BEST performance setup for the B15 Sentra.
If you want a VERY LOW drop, like 2" and still have decent ride quality, get the Tein Basic, you won't regret it. It is infinitely better than using lowering springs. If you want a slight drop, better performance, a quality ride, and an extremely easy install get the Nismo S-tune. For under $1000, these are the only two products I would personally put on my car.
Where can I get these aftermarket suspension products?
www.shox.com
www.performancenissanparts.com
www.sportcompactonly.com
www.ptuning.com
Feel free to ask any questions in this thread or PM me.