Spring rate question
 

I'm stupid so, I'll get to the point:

9k/6k springs rates vs 10k/8k on coilovers.
9k/6k is what they originally come in and 10k/8k is what they were custom ordered as.

What does it mean (in lamens terms) and what does it change for me?

Obviously driveability is important but handling is not #1 (I'm not auto-crossing my car). I bought them for the drop.

Thanks (don't hate me)

Its a figure identifying how much weight is required to move the spring a specified distance.

In your instance original rate is 9kg to move the front spring 1mm and 6kg to move the rear 1mm. While the ordered rate is 10kg to move the front spring 1mm and 8kg to move the rear spring 1mm.

Those are some fairly stiff springs and you are going to feel bumps a lot more.

Cheers

Andrew

I dont think it is in your best interest to get stiff coilovers if all you want is a drop.

10/8 will more likely oversteer (tail-end breaks free first) than the 9/6. What this means is that you may have to disconnect the rear sway bar on one side (or just remove the whole thing) if you want safe handling.

And yes, 10/8 is a lot for a primarily street driven car.

What sway bars are you running?

I bought imput1234's coilovers, obviously the height he was riding on is my goal.

I'm on the stock sway bars.

I can change the coils if I want obviously but would rather not "waste" money...

I hope I really don't regret this lol

Or the opposite may be true if you follow Eric Meyers advice

OE = 156#/in front 116#/in rear

9/6 = 503#/in front & 335#/in rear

10/8 = 559#/in front & 447#/in rear


Those are fairly stiff rates for street tires, but not unheard of ...

The shock valving will play more into how stiff it feels on the street than these rates. If you're trying to go really low then stiff rates are required to keep it from bottoming out. Going really low is just for looks, handling suffers down there.

.

Well, my experience says 10/8 will oversteer with OEM bars on street tires. 10/8 is a stronger rear bias than stock (or should I say a weaker front bias); the numbers you post above prove that.

Of course, the final handling also depends on alignment, wheel/tire choice, rake, etc. But if you make typical choices in the other areas - no stagger on the tires, similar negative camber front & rear, not too much toe-in on the rear, I predict oversteer with OEM bars. The OP may never experience it, depending on how he drives, but the potential is there.

Again, detatch the rear sway and perhaps it will be workable.

To the OP: There's nothing wrong with running the coilovers as you will be receving them with the 10/8 rates. I'd simply advise finding a reasonably safe place to determine how the car handles (an autocross is ideal for that; also, while you are there find an experienced RX-8 driver and let them drive it; listen to their advice) and if it oversteers, detatch the rear sway and see how that changes things.

If it still oversteers another trick is to lower the rear a little (a turn or two) without changing the front. This will take some of the rake out, which won't look as cool. But it can help reduce oversteer.

Good luck and have fun with it! Don't be afraid to experiment.

tein cruse master is for street they only use 5/3, just get some lower spring rate but keep the 10/8 may be later you want to do autocross you could always change it back and you could always mix and match, like 8/5.