This thread is for spring rates for all available springs on Maximas/I30/I35s. Post away, and I will update this top post as new submissions arrive. Hopefully one of our moderators will sticky this so it can become a solid reference material.

Please specify spring brand, car year, linear or progressive rate, and whatever rate is available.

1st Generation Maxima

2nd Generation Maxima

3rd Generation Maxima

BlehmCo coilovers
Front: 450 lb/in
Rear: 450 lb/in


4th Generation Maxima

OEM SE springs (linear) estimated:
Front: 250 lbs/in
Rear: 250 lbs/in

OEM GLE/GXE springs (linear) estimated:
Front: 200 lbs/in
Rear: 200 lbs/in

Eibach (progressive)
Front: 166-257 lbs/in
Rear: 166-343 lbs/in

Tokico (progressive)
Front: 111-225 lbs/in
Rear: 148-295 lbs/in

TEIN High-Tech ("H-Tech") (progressive)
Front: 180 lbs/in
Rear: 250 lbs/in

TEIN S-Tech (progressive?)
Front: 200 lbs/in
Rear: 280 lbs/in

TEIN Basic Damper Coilover (linear?)
Front: 390 lbs/in (7 kg/mm)
Rear: 340 lbs/in (6 kg/mm)

5th Generation Maxima (thanks to DrKlop for compiling)

Eibach Pro-Kit
Front: 139-188 lbs/in
Rear: 194-295-346 lbs/in

Vogtland:
Front: 134 - 194 lb/in (working range 170 - 194 lb/in)
Rear: 205 – 377 lb/in (working range 220 - 270 lb/in)

Tein H-tech:
Front: 180 lbs/in
Rear: 290 lbs/in

Tein S-tech:
Front: 200 lbs/in
Rear: 270 lbs/in

Progress Technology:
Front : 165 lbs/in
Rear : 250 lbs/in
(according to a different, unconfirmed source the rates could be 165-250 lbs/in in the front and 179-285 lbs/in in the rear.)

Canuck Motorsports..Progressive rate
front initial rate 125 (high rate not supplied)
rear (probably linear) rate 320

6th Generation Maxima

Infiniti I30

Infiniti I35

 

Do we have any OE rates for comparison?

Norm

 

For those trying to compare the 9kg/7kg or 8kg/6kg, etc. Front/Rear rates of coilovers with lowering spring rates, the following was provided by Larrio:

 

The overall conversion is so close to 56 lb/in for every Kg/mm that a calculator is hardly necessary.

If anybody is interested, I have a little (~570k) conversion software called 'Convert.exe', into which I've added the Kg/mm <=> lb/in and a few other metric/English conversions.

Norm

 

Or just Google "conversion" and in 5 seconds you have your answer since there are myriad conversion sites.

Spring rates for 4th gen (source: TEIN website):

TEIN High-Tech ("H-Tech") (progressive)
Front: 180 lbs/in
Rear: 250 lbs/in

TEIN S-Tech (progressive?)
Front: 200 lbs/in
Rear: 280 lbs/in

TEIN Basic Damper Coilover (linear?)
Front: 390 lbs/in (7 kg/mm)
Rear: 340 lbs/in (6 kg/mm)

Josh, if you trust it, you can copy some 4th gen spring rate info from http://maxmods.dyndns.org/index.php?MaximaSprings

 

Ground controls sleeve coilover default rates are 450 front an unknown "proprietary" rate in the rear, that I estimate to be 350lbs (since Eibach ERS springs are only available in increments of 50lbs/in).

 

BlehmCo coilovers for 3 gen... 450/450.

 

didn't realize there was such a thing. Learn something new every day.

 

A couple of confirmations: TEIN S-Techs are progressive-rate, and TEIN Basic coilovers are linear-rate.

 

Wow, the stock springs are linear?

 

most stock springs are linear, except in higher-end cars. That makes them more predictable to handle, cheaper to make......

 

Don't know if this is true but I've been assuming it is for the past 4 years. For $50 one could test em by I've spent enough already on silly baselines.

GXE model OEM springs are 200LB/IN linear rate.
SE model OEM springs are 250LB/IN linear rate.

http://forums.maxima.org/showpost.ph...18&postcount=2

 

my rears say 150 of some proprietary rate. the fronts are 450. pretty big difference if you ask me...

 

they aren't 150 trust me, that's softer than stock and they sure as hell ain't softer than stock lol. GC won't tell what the rate is though because they say it took a long time to develop, etc.

 

I've never understood that position. It's not like anybody is requesting the specific design dimensions that were chosen to end up with that rate (so that the design could be copied for the cost of a phone call vs having to buy one set of springs - ???). Just the end result, like the "drop" numbers that are so readily available. Why the rate number would need to be considered any more sensitive than the "amount of drop" makes little sense.


Norm

 

which is why GC is not very popular with the racing crowd.....who mostly sway toward Eibach, who are happy to tell you the rates that you're getting. GC's are for the "import tuner" crowd who are more interested in looking good, which is why the "amount of drop" is always the #1 stat. Not saying that some GC setups don't perform well, but it's always gonna be a guessing game with them.

general spring rule: No rate availabe = no buy.

 

You do know that GCs use Eibach ERS springs I assume. You can get whatever rate you want, a non proprietary rate, but the default rate in the rear some big secret. The fronts springs are normal Eibach ERS nomenclature, model number indicates the spring length, diameter, rate, etc.

 

hmm thats really odd. makes me think about getting another set of different springs. although it feels fairly solid on tight turns.

 

I remember seeing 4th gen oem se springs as 120f 200r
Also the SE rear springs are the stiffer ones, the fronts are the same between models. (they do differ between transmissions),

I emailed them CMS directly for these numbers:

Canuck motorsports spring rates:

04+: 190 front 340 rear
00-03: 125 front 320 rear
95-99: 125 front 255 rear
89-94: 170 front and rear
all are in lbf/in and progressive rate.


Also Ground Controls rear springs are in metric units. I belive my GC rears are 64 N/mm which is equal to 365lbf/in. The fronts are in standard units, mine are 450 lbf/in. To read GC ERS springs the 1st number is the length, the 2nd is diameter, and 3rd is spring rate ie:
0800.250.0350 is an 8" long spring, 2.5" diameter, and 350 ibf/in


Spring rate conversions:
http://wwwrsphysse.anu.edu.au/~amh11..._conversio.htm
http://www.onlineconversion.com/foru...1110951659.htm

To Convert lbf/in to N/mm (Pounds-force per inch to Newtons per millimetre)

lbf/in x 0.175 = N/mm, Example: 100 lbf/in x 0.175 = 17.5 N/mm

To Convert N/mm to lbf/in

N/mm x 5.714 = lbf/in or N/cm x 0.5714 = lbf/in

To convert ibf/in to kg/mm (Pounds-force per inch to Kilograms per millimetre)

ibf/in x 0.0791 = kg/mm

 

If S-Techs are progressive why is there only one rate listed for front and rear (each)?

 

thats the highest rate they go.

 

I called H&R and they said they don't test spring rates because it wouldn't be comparable to the way other companies test their spring rates

 

You shouldn't be posting in this thread, post in one of the general 5th gen suspension threads. Or better yet, go comment on some threads in the Members' Rides forum until you can make a new post.

 

bump for updates

 

Boss Chen coilovers: 8 kg/mm front 6 kg/mm rear. This is for 4th gen but I believe the 5th gen come with the same. And I think Larry will use different spring rates if you so request.

 

Anyone have OEM specs on a 2002 SE spring rates? I don't see them posted.

 

1995-2001 Progress Technology Coilovers

Front: 450lbs - 8kg/mm
Rear: 350lbs - 6kg/mm

Linear rate springs

 

You know this always bothered me--stock 4th gen rates are NOT 200F/R GLE and 250F/R SE. That is WAY too stiff relative to all the aftermarket options, which are ALL significantly stiffer than stock. In addition, the front and rear spring rates are going to differ due to the fact that the front is significantly heavier and you generally want the front wheel rate to be higher than the rear wheel rate to dial in more understeer for cars off the factory.

My guess is the fronts are around 100lb/in and rears are like 70, this is probably way more accurate than 250/250. I could feel the front of my 4th gen lift when it had stock suspension and I got on it.

 

Agreed, but that's the only thing published from late 90's I've seen. I'll have my OEM springs off in a couple weeks, shouldn't be hard to throw one or two 50lb salt blocks on the end of one and get a decent compress figure.

 

I dunno, my coilovers are over 400 lbs/in in front and they feel only about twice as stiff as stock...

 

You are either dead wrong or all the other spring rates are wrong. Eibachs are the stiffest or close to the stiffest spring out there, and you're going to say that they're softer than or equal to stock? Have you RIDDEN in a stock Maxima?

Bottom line, no offense but a hunch as to "about twice as stiff" is not good enough to base any argument on. I could go over reasons but they should be obvious.

 

Ya man except you're basing your opinion on the same hunch! In fact, you're trying to deny the numbers because of the way your suspension feels to you. Not very scientific.

My car was on stock SE suspension for a while. I don't believe I've spent much time in a GLE or GXE but I assume they feel like any other sedan from that era. However, I was on Illuminas and H-Techs for a couple of years between the stock suspension and coilovers.

 

Morpheus and JSutter were both spot on. While changing tires I pulled one of the front struts off. The spring measured is about 10yrs old and bought used so I can't verify if it's an SE or GLE. With 50lbs it compresses .67" and 100lbs is .95". Anybody got a loose rear spring laying around?

 

Thanks for measuring, Bejay. According to JSutter's post above, the front springs are the same among all trim levels but the SE rears are stiffer. So the question is actually whether those are auto or 5-speed stock springs. And at 10 years old I wonder how much it's softened.

 

Spring rates don't soften over time, unless perhaps there has been enough corrosion to reduce the wire diameter. Otherwise, softening a spring would require a change in the basic material stiffness property, an increase in the mean coil diameter, or an increase in the number of active coils. I don't think so.

But they can take a permanent 'set' due to (over)loading, which gives a similar appearance. That's an "energy per unit volume" thing where the energy comes from the weight supported and the amount of spring deflection (including how far it moves during bump conditions).

The contribution to suspension ride stiffness provided by the control arm bushings may have dropped over that length of time though.


Norm

 

Forgot these particular springs have only been installed half those years as I usually run in just winter. They definately haven't taken a "set" as I still have 5-6 finger wheel gap up front.

 

what does it mean when a springs rate is 'linear'? also are there stats on what the stock spring rates on a 5/5.5 gen are yet? i'm just curious

 

Linear means as the spring compresses the rate stays the same. Progressive rate springs get stiffer, ie the rate increases, as they compress.

Coilover springs are typically linear.
Drop springs are typically progressive.

To spot the difference look at the coils. If they are all the same distance apart then the spring is linear. Progressive springs have coils closer together. As the ones closest together, which are softer, start touching those coils become 'dead' if you will. Then the higher rate coils take over. This gives you a decent ride on the street. Once you start carving the corners the higher rates take over and give you the sporty ride and keep you off the bump stops.

3rd, 4th, and 5th gen front springs all look very similar. Id bet they are all within 30-50 in/lb of each other. 4th and 5th gen rear springs are pretty close too.

 

Almost there.

Coil spacing doesn't have much to do with the rate of any individual coil. Closer-spaced ones just bottom out against each other sooner (takes less spring compression to become "dead"). Fewer active coils = stiffer spring.

More or less, there are two kinds of variable rate springs.

One has coils of only two distinct spacings and the transition from soft to stiff occurs rather abruptly when all of the closely spaced coils bottom out at about the same amount of spring compression. It's probably better to think of these as being "bi-linear", or having two distinct and linear rates. Either - or, with nothing useful in between.

The other is a true progressive that has some sort of uniform variation going on. Gradually changing the close coil spacing is one way to achieve this.

Most lowering springs sold as "progressive" are probably closer to "bi-linear".


Norm

 

Yea that makes more sense. I forgot as you remove or cut coils the spring becomes stiffer.