ive read that its better to have a higher spring rate in the front rather than the rear like 10/8.

while others say having spring rates the same front and rear would be fine such as 10/10.

i still don't get which to go with? is either fine for a 350z, just wanted to lower the car for a daily driver.

any help will help. thanks.

 

If the purpose is "looks" for a daily driver dont worry about it. If you have specific needs, autocross for example, then you can look at alternative spring rates. Remember if you go with a spring that is higher than OEM, the ride will be less comfortable.

 

Daily driver spring rate balance doesn't matter, I would go for the most comfortable coilovers you can find.

 

Look into the Bilstein coilovers. It's $$$ though.

 

Oem spring rates are,....

2003-2004
314/342

2004.5+
314/427

For someone that know's the car is a daily driver, consider 560/448 as your practical limit.

As far as front to rear rate balance, it's ok lower or even. As rear rates get beyond 500lbs in rate, you'll find the car more willing to rotate on less then smooth daily driver road surfaces. Lower rear rate setups exist to extract more rear grip do to the car's weak oem limited slip and because the car has built in anti dive and anti squat elements whereby the lower rear rate helps keep the rear more planted (like being able to roll into the throttle sooner when comming out of the hole or corner).

IMO I would look into

Eiback Pro-S
Spring rates Front 485lbs to 525Lbs Rear: 240Lbs to 548Lbs (progressive springs)

Bilstein Pss Montube
Spring rates 370/240-420 (progressive rear)
(no point in adjustable damping, with the Bilstein Pss10 bad things happen when you turn up the damping anyhow).


If you have to have adjustable damping, I would go with either
Kw Variant 2 Twin tube, rebound adjustable
Spring rates Front 485lbs to 525Lbs Rear: 240Lbs to 548Lbs (progressive springs)

Cusco Zero2 Monotube, adjustable damping, full height adjustable
Spring rates 560/392

HKS III Non Sport Monotube, adjustable dampners, full height adjustable
Spring rates 448/448

Tein CST Monotube construction, adjustable dampners, full height adjustable
392/392

Just to say it
Tokico D-spec shock and spring package 350Z DSK512
Spring rates 375f/375r - Linear Springs
Drop 1"/1.5"

 

Spring rates are insanely subjective. Every car is different, everyone drives different road conditions, has different ideas on whats comfortable/acceptably stiff, etc. Even 2 Z's, driven on similar roads, with the same spring rates can ride drastically different. 10k/7k might not be bad with OEM bushings, but on another car with spherical bearings instead of bushings and differently valved shocks, 10k/7k might be murder for some people.

I've driven a hellaflush Altima that was on 12kg/mm springs all around and it wasn't even uncomfortable. I've driven Civics with 9kg/mm and it was way too stiff. I've ridden in Z's with spring rates from 7kg to 15kg... I wouldn't go more than 11-12kg/mm but that's just me.

What are your plans for the car?

 

what is your main goal?

do you want to dump the car?

do you want a moderate daily ride height that is comfortable to ride in?

i have hipermax iii's non sport and have no complaints. rides like stock only a bit stiffer and better. obviously you have dampening control to make it stiffer if you wish.

 

Of course I bring to the discussion the fact that I have tested the following

314/342 oem 2003 350Z suspension
358/375 Tein H-tech oem 2003 350Z shocks
375/375 Tokico D-spec springs koni yellow shocks
375/342 Tokico D-spec springs front oem Z rear springs on cut down oem upper seats Koni shocks
448/342 Tein tapered springs 70mm-90mm custom spring seats oem rear spring on cut down oem upper seats Koni shocks
448/427 Tein tapered springs oem rear springs on cut down oem upper seats Koni shocks
560/342 Generic 65mm ID spring pillowball upper mounts custom lower spring seat oem rear springs on cut down oem upper seats Koni shocks
560/427 Generic 65mm ID spring oem rear springs on cut down upper seats Koni shocks
560/500 Generic 65mm ID spring TomsMotor sports adjustable rear springs
560/427 Truechoice Phase IV coilovers front oem rear spring on cut down upper seats Koni yellow rear
650/427 Truechoice Phase IV coilovers front Hypercoil spring oem rear spring on cut down oem upper seats Koni yellow rear
448/427 Truechoice Phase IV coilovers front generic 65mm ID spring oem rear spring on cut down oem upper seats Koni yellow rear
370/240-420 Bilstein Pss9 coilover
370/427 Bilstein Pss9(testing linear rear spring vs as delivered Bilstein progressive rear spring)
560/500 Pss9 revalved Swift 70mm ID springs Toms Motorsports adjustable rear coilover springs
560/450 Pss9 Revalved Swift 70mm ID springs custom linear spring seats for Eibach ERS rear springs
560/392 Ohlins PCV coilovers
560/427 Ohlins PCV coilovers oem rear spring on cut down upper seats
370/392 Ohlins PCV coilovers custom inserts to run 70mm front spring (wanted to test behavior when undersprung in the front, VERY short test)

So my subjective opinion brings a little something to the table and I have run all the above dampers on the dyno, plus a few I was loaned to test.

 

^ Now just need a list of all those coilovers with lap times and I can make my decision

 

someone else's lap times are not indicative of a successful suspension

 

I know this is an old thread but rather than starting a new one i figured id keep it goin.
Would a spring rate of 13k front and 6k rear be good on stance gr+ as a daily driver? Im goin to try and not have any wheel gap on my car and run 19s currently on stocks.

 

That's what I run on my track car, I would drop to the standard 12/5 setup, but really I would get something other than Stance. I would also look I yo an EOM spring mounted setup.

 

ha long time lurker and my question seemed to fit into this thread. (mostly cause of Gsedan35s comparisons) I keep noting that none of the lowering springs offerings changed their (rear)rates after nissan revised the suspension on the 04.5+ cars, is that mostly because that was the ONLY suspension change? I don't need full coilovers on this car, was actually looking at Koni yellows and getting a set of springs until I found an offer for a lightly used H&R setup. I know the rates on those are still a mystery, but for the price I think I can bank on brand reputation as for my goals for the car it's a weekend toy mostly. street driven. I don't autocross anymore and las time i was out on VIR was just for parade laps unfortunately lol. Bu I still enjoy a spirited drive and want a slight lowering. )usual lowering spring range 1"-1.5") part of me wants to put more aside and do the Koni yellows and pick my spring rate mostly because i don't want softer than the revised spring in the rear...

 

i went with the eiback prokit and tokico d-specs...i am happy with it. like the adjustability of the d-specs. alot of my friends run the koni yellows and they seem to be stifffer... they have i think 4 click adjustment and the tokico are a **** that turns so you can adjust in 1/4 incraments.

i have mine 2 full turns out from full stiff... comfortable enough for daily but stiff enough when gettin on it