Thread: Need help deciding spring rates for a daily driven B13 SE-R

I am going to be ordering Fortune Auto 500 Series coilovers w/Swift Springs for my 1992 Nissan Sentra SE-R in the next few days, but need help in choosing the spring rates.

Fortune Auto's standard spring rates for the car are 8K front / 4.5K rear.

Mike Kojima, and a whole host of old-schoolers seemed to agree that 6K front / 4K rear was the upper limit of what was tolerable on the street, and recommended having that ratio front vs rear. I drive a good 20,000+ miles a year on the street.

As I was talking with the guy who I was ordering from, he mentioned if anything, he'd probably recommend bumping the rear up to 6K and leaving the front at 8K due to the weight on the front of my chassis, but admitted he wasn't really familiar with my chassis. He also mentioned that Fortune Auto designed these for the street, so those rates should be ideal, particularly for the front.

I also noticed a LOT of people on these forums seem to be running higher spring rates than was recommended 10-20 years ago - and many bumping the rear spring rates even higher than the front.

I'm a little lost to all of this, as this will be my first coil over setup.

Any recommendations / explanations? Thanks!

it depends how much travel is available at resting ride height, type of bumpstops, and how the strut is valved.

if its actually a good strut with digressive valving and a lot of low speed bump, i'd use a 5kg front and a 4.5-5kg rear
if its like a bc racing coil where it has little no low speed damping and low of high speed compression, i'd use a 6kg front and 5kg rear
if its high quality shock with a lot of travel, you can get up to 8-10kg rates and still feel the same as the softer 5kg-6kg springs.

spring rates are tough to choose, a lot is dependant on subjective ride quality, and quality of the shock and its damping curve.

more rate in the rear will help the car rotate more. i like to run more spring frequency in the rear on fwd/awd cars, it will give a flatter ride when hitting bumps, quicker weight transfer and feel more neutral in cornering at the expense of some rear stability.

if ur just putting around town with a lot of bad potholes, i'd stay around 4-5kg front, 4-5kg rear and not dumped.
if ur dumped you need more spring to stay off the bumpstops, which is the biggest contributor to the bumpy ride feeling

Thanks for the reply! Unfortunately, as I really needed to get them coming to me, I've already ordered a set.

They are Fortune Auto's 500 series, so they are a digressive valving. I went with 6K front, 4K rear with Swift springs.
Judging by your comments, I probably would've wanted to go a bit higher in the rear. I suppose when it comes time to rebuild them, I can up the rears to 5K - or maybe increase things all around.

I'm not sure if I will drop the car at all. If I do, I'll probably try 1.25" front, 1" rear - but maybe the spring rates I went with won't allow for that.

Anyhow, I'll see how my decisions went in a few weeks!