hey does anyone have custom spring rates on their coilovers? i am buying a set of bc coilovers and they offered custom spring rates so just wondering whats a good set up or should i just leave it
thanks

 

stiffest available
because racecar.

for real tho, I'm about to buy BC's and I'm getting the stiffest available.
why go for something close to stock?
plus, with the rear being stiffer than the front, you can lift off oversteer even more so

 

also, if you like to be low, you'll bottom out with soft springs! get the stiffs!

 

Can you tell me the rate lol

 

^they only offer a few rates....
what are your options?

and if I "tell you" a rate, what makes you so sure that I am right, or if thats what you want anyway?
I can see it now, "bitch ass justin, told me to get these and now it sucks!"

what are your goals?
does anything I said interest you?

 

I would also vote stiffest available

I have a set of Tein Street advance, they don't have 'custom' coils, but I do have them maxed out stiff, I love they way they feel, zero complaints, but I wouldn't mind a little stiffer if I had the option

Edit: I lied, I have the rear full stiff and the front a few clicks back.


Everything you say interests me

 

Well I want to slam it and I want it to be comfortable its not for tracking and the spring rate the site said I can choose any rate do you guys know what's the spring rate bc comes with?

 

He said up to 12k and lowest is 6k

 

so, why did you chose the BC's over the others, if you dont know what any of the features mean??
and thank you, I knew the rates were set up as on option. you can only pick out 2 sets.

maybe you should google "spring rates" to see how they will affect your ride.
you dont even know why you want stiffer springs, thus, you'll be disappointed when they do come in.

 

the reviews on bc and tein were the best but on tein you can't go as low so i decided to go with bc, i know 2 people with bc coils and they want to change springs so its a bit stiffer thats why i wanted to see what you guys have to compare to and the shop selling it told me stock bc coils come with 12k in the front and 6k in the rear

 

You have to understand what spring rate affects and what you want out of a set of springs.

First and foremost, you have to find out if your particular coilovers retain full stock suspension stroke or if you lose stroke the lower you get. This is the absolute most important factor in both ride quality and in performance, and also it's a big factor in the spring rate. If I were in the market for coilovers, I would avoid the ones that lose suspension travel as the car is lowered. The suspension isn't just there to keep you comfortable, it's there so the tires remain in contact with the road over rough roads, bumps, etc, and to set the front-rear handling balance.

Keeping the car off the bumpstops should be your highest concern and you can do so by retaining suspension stroke and/or properly matching the springs and shocks. Avoiding the bumpstops means the car will stick to the road better over bumps and I'm not talking just large bumps. It will also give a nice ride because you're not hitting the bumpstops. You can go with a softer spring. With reduced travel you have to go with a stiffer spring to avoid the hitting the bumpstops. It's a win-win, better performance and more comfortable. These cars have very little stroke from the factory and you really can't afford to lose any without going with stiff springs.

If you hit the bumpstops around a corner say in the rear, you now have infinite stiffness in the rear which will cause the car to be very tail happy. Not in a good way, it will cause snap oversteer before you realize what happened and it will cause unpredictable behavior, especially at high speeds.

If your set of coilovers reduces suspension travel as you lower the car, going with stiff enough springs to keep it off the bumpstops can help not only performance but also comfort. You will feel small bumps more but you won't "crash" over large bumps.

Overall traction (tires) will also determine how stiff the springs need to be. My old suspension was fine on regular tires but once I put sticky tires on it, the handling went to crap. It became unpredictable and dangerous. Around a hard corner near the limit it would be cornering fine and then hit the rear bump stop whether from body roll or from a bump and it would go very sideways very quickly. I slide around all the time but this is not a nice pretty slide. It slides which reduces traction and the suspension unloads off the bumpstop causing the rear end to stick again. Once it sticks it bottoms out and slides badly again. It's a twitchy, sliding, nightmare.

Performance wise, ask yourself what a stiffer spring does for you. Surprisingly very little. Tires are what determine ultimate traction, springs mostly control the dynamics. The TL has great suspension geometry and goes into negative camber when the body rolls. In other words, the tire's contact patch stays flat on the road even when the car is leaning. Body roll does not increase weight transfer as most think. So what do springs do? They affect dynamics. Ideally as you enter a corner you want the car to settle into the corner quickly and take a set. Shocks are also important for this and should be matched to your spring rate. Stiffer will help the car to feel sharper and it will be harder to upset as you transition from one direction to the other or hit the brakes in a corner. Actual skidpad g-force will be affected little by stiff springs, that's mostly in the tires.

There's no reason to go super stiff in the TL, especially for a street car. You gain very little if anything and you give up ride comfort

Now the other important factor that most overlook when choosing springs..... Handling balance. Does the car push or is it loose? Entering a corner, would you rather have the rear end slide out first or would you like the front tires to slide first, causing the car to go off course by going wide in a corner. Manufacturers set cars up to understeer (front tires breaking free first) because it's considered safer. Most people can't control the rear end sliding out but when the front breaks free, letting off the gas or just losing a little speed will allow you to regain traction and it takes little to no skill. I personally prefer just a little oversteer.

Regardless of whether you prefer oversteer or understeer, you still want both the front and rear ends to lose traction at about the same time. If one end of the car slides out prematurely, you're losing traction too soon and your cornering limit is reduced. If you get springs that increase understeer (stiffer front springs in relation to the rear springs), no matter how stiff they are and no matter how good it seems like the car handles, take it to it's limit and you're not going to be able to corner as quick as you did with the stock suspension, the front tires will slide prematurely. Cars set up wrong with the balance off and with stiff springs give a false sense of security. They will feel like they handle great, causing the driver to take corners faster than normal and then they find out the hard way that the car does not corner as well as stock. Same if the rear springs are overly stiff. It's just like adding too stiff of a rear swaybar, the car becomes tail happy.

The leads me to swaybars... Plan out your mods in advance. If you know you're going to use a stiff rear swaybar and no plans to go to a stiffer front swaybar you might want springs with a little more front stiffness. The easiest way to approach it is to keep the front to rear stiffness ratio close to stock and fine tune the handling balance with aftermarket adjustable swaybars.

I can't recommend a spring rate not knowing the setup. If your setup retains the stock or near stock suspension travel, you're going to be fine with softer springs, anywhere from stock rate to however high you want to go. If not, you need to go stiffer.



If you want a spring rate that will get the car to truly handle well under real world conditions and you want it to be reasonably comfortable:

Try to get a coilover that retains full suspension travel (ask the manufacturer).

Pay attention to the front to rear spring rate ratio for handling balance.

Look at the big picture- All suspension and tire mods like swaybars, shocks, tires, etc, should be viewed as a package and compliment one another.

Get a spring that's stiff enough to keep it off the bumpstops but not overly stiff.

 

Yup, pretty much that.

 

Good write up IHC. I learned some stuff.

 

Search his username on here and you'll find a wealth of info on everything.