Is 1kg/mm change in springs significant?

[Bronze MFP]

After x-mas i'm planning on purchasing coilovers. I kinda had my heart set on the Nismo R-tune setup, it has 8kg/mm springs up front and 7kg/mm springs rear. Only problem with them, is they are pricey (~1500 bux) and I have no clue if the struts are rebuildable or replaceable. SPL parts' KTS coilovers feature an 8kg/mm front spring and a 6kg/mm rear spring, are ~1100 bucks and the dampers are replaceable. So, will that 1kg/mm springrate change in the rear be noticable? Thanks in advance.

[hannibal]

IMO, I dont thnik you would feel it, especially on the rear.

[Exar-Kun]

Yeah, you can notice it...

if you had said 1lb/in I would say no.

don't buy coilovers based on spring rate alone man....Different spring rates are better suited for differnet purposes, etc.

Take a look at what YOU want to do with the car, search around for someone who knows howto set up a car for your purposes, or ahs set their own car up and done well, and go from there...-chet

[InsanityInc]

1kg/mm is a fairly large difference. Keep in mind that a lot of street cars have 1kg/mm springs or LESS. A lower rear springrate will be worse at keeping the back end on the ground, so if you want to OMGDRIFTJDMTYTE, then you'd want a lower rate in the back.

[crzycav86]

You wrote just the opposite.

A stiffer rear spring rate will tend to increase oversteer. Thus, if you want ultraJDMdoriftotyt3... get stiffer rear y0.

[Nismo_Freak]

1kg/mm is a fairly large difference. Keep in mind that a lot of street cars have 1kg/mm springs or LESS. A lower rear springrate will be worse at keeping the back end on the ground, so if you want to OMGDRIFTJDMTYTE, then you'd want a lower rate in the back.

I can't think of one car made that has a 1kgf/mm spring rate. That's equal to a 56 lb. spring.

[InsanityInc]

You wrote just the opposite.

A stiffer rear spring rate will tend to increase oversteer. Thus, if you want ultraJDMdoriftotyt3... get stiffer rear y0.

No. Stiffer spring rates improve road holding, if they weakened road holding, why would anyone go to stiffer springs? So, if you have stiffer springs in the back, they're going to hold to the road better than the front during lateral acceleration, meaning it's going to be harder to induce oversteer.

Quote »I can't think of one car made that has a 1kgf/mm spring rate. That's equal to a 56 lb. spring.[/quote]That's probably because you generally don't see the spring rates listed for non-sports cars. Most cadillacs (especially older ones) have incredibly soft springs.

[Bronze MFP]

The car is a daily driver, but will see autocross and HPDE events, the only other system I was considering was the Tein Flex, but in all honesty i've heard great things about KTS coilovers. oh and insanity... a higher spring rate in the rear does increase oversteer.

[Nismo_Freak]

That's probably because you generally don't see the spring rates listed for non-sports cars. Most cadillacs (especially older ones) have incredibly soft springs.

A Cadillac has higher spring rates than any 240... it's just "soft" because it has 4500 lbs. of car pressing down on it.

No. Stiffer spring rates improve road holding, if they weakened road holding, why would anyone go to stiffer springs? So, if you have stiffer springs in the back, they're going to hold to the road better than the front during lateral acceleration, meaning it's going to be harder to induce oversteer..

Incorrect, a harder spring just reduces the amount of roll and resulting suspension bump when compressed. When you hit bumps it will not compress and absorb the bump, it will simply skate over it which is a loss of traction.

[crzycav86]

No. Stiffer spring rates improve road holding, if they weakened road holding, why would anyone go to stiffer springs?

So let me remove the coilovers from my car, and replace them with solid steel rods. Zero suspension travel has got to give me f1-style handling, because it'd be so stiff... right?

[Exar-Kun]

No. Stiffer spring rates improve road holding, if they weakened road holding, why would anyone go to stiffer springs? So, if you have stiffer springs in the back, they're going to hold to the road better than the front during lateral acceleration, meaning it's going to be harder to induce oversteer.

That's probably because you generally don't see the spring rates listed for non-sports cars. Most cadillacs (especially older ones) have incredibly soft springs.

]

Read the FAQ....Also, you're the first to earn my new picture for those who Don't read the faq before making a comment.

[p00t]

alright guys.. i dont think we need to correct him 3 times...

[llamabeta]

]

Read the FAQ....Also, you're the first to earn my new picture for those who Don't read the faq before making a comment.

Ahahaha. Nice.

InsanityInc, please do review the many helpful posts on this forum as well as the many web pages out there talking about supension setup\dynamics.

Exar-Kun and Nismo_Freak are some of the best resources for this particular knowledge.

[MarkEmark]

After x-mas i'm planning on purchasing coilovers. I kinda had my heart set on the Nismo R-tune setup, it has 8kg/mm springs up front and 7kg/mm springs rear. Only problem with them, is they are pricey (~1500 bux) and I have no clue if the struts are rebuildable or replaceable. SPL parts' KTS coilovers feature an 8kg/mm front spring and a 6kg/mm rear spring, are ~1100 bucks and the dampers are replaceable. So, will that 1kg/mm springrate change in the rear be noticable? Thanks in advance.

What are you planning on doing with your car?

I have the KTS coilovers...and I couldn't imagine that anyone would ever want anything stiffer...even on the softest settings they're plenty stiff, but perfectly streetable. I haven't had them adjusted to max stiffness for the dampening but I can imagine that they'd be unbearably stiff for anything except pure track racing. And yes, like everyone said, stiffer springs in the rear will induce oversteer compared to softer springs. That said, go with KTS. They OWN.

[chmercer]

i want gr-6 in 12/10 with the camber bracket.... i could run super slammed all the time and not rub, lol

[Nismo_Freak]

i want gr-6 in 12/10 with the camber bracket.... i could run super slammed all the time and not rub, lol

Gay.

[Exar-Kun]

and you could overload your tires traction just by sneezing at the wheel instantaniously! yay!

[nismofly]

^^^

that might make for interesting entertainment

[Ace 2.0]

sorry to post whore but how would Tanabe sustec pro DD's work out they have 10\8 springs.

[eddiec]

the whole package needs to be tuned together. what good is stiff spring if the damper is not able to dampen out the oscillations. and that is what a "shock/strut' is for is to dampen the springs "springyness". so if one was to purchase a set of coilovers hopefully the company selling them has matched the damper valving to corresponding spring rate. i cant speak for the hi-dollar setups, but the k-sports i have do not have enough damping for the supplied rear spring rate. they came with 5kg for the rear and its either too hard (skating, loss of traction) or too soft (bouncy, understeerish). this is after adjusting the damping through the entire range of adjustability.

so its not about the stiffest springs your backside or dentures, for the geriatric crowd, can hadle. its about having properly tuned dampers capable of handling the spring rate you desire for the setup you wish to run. obviously a drift setup would differ from a drag or auto-x setup.