Recomended settings for track use ?

[retro_al]

Could somebody recomend some settings for a 350z de, spring rates, camber etc I have all the adjustable links, I know it varies to which track you drive but just some base settings would be nice

 

Thanks Al

[Ekona]

No such thing, depends on the driver.

 

What suspension are you running? What geo setup have you got now? How do you like your car to handle? What tyres? How far are you willing to compromise for track if you're also using it on the road?

[GodISmE]

-3 front, -2,5 rear camber, 1/16 toe out F, 1/8 toe in R (total), car lowered by 1-1.5 inch, 13 mm rake.

Spring rates: I run 14/9kg and the rear is too stiff so I think 14/7 would be ideal.

Depends on the tires though - I'm on semislicks.

 

Anyone else? I'm curious about the coilover spring rates.

Edited February 20, 2017 by GodISmE

[RobPhoboS]

Al - it's a can of worms you're opening without much info on your part

Is this a daily driven car that you're going to drive on track a handful of times ?

Or is this a car that's going to see the track a few times a month but needs to be driven there ?

Or is it an out and out track car that's stripped, with a cage etc?

[MeisterR]

Looking at those rate (14/9), a true coilover system in the rear?

That would be okay if you are using an inboard springs setup.

On true coilovers, that 9kg is way way too much.

 

The problem is more with the damper valving.

On the track, you should be within the first few clicks of the damping adjustment if the damper were valved correctly.

The problem is, those are data that only the guy that build the suspension know (or should know).

 

It is a big can of worm, and really the only person that can advice is if they have the damper dyno in their hand.

Otherwise, a springs rate may work well on one damper setup, but the same springs rate will not work on another damper setup.

 

Everything have to work together, and the person providing the parts should have the answer.

 

Jerrick

[djtimo]

-3 front, -2,5 rear camber, 1/16 toe out F, 1/8 toe in R (total), car lowered by 1-1.5 inch, 13 mm rake.

Spring rates: I run 14/9kg and the rear is too stiff so I think 14/7 would be ideal.

Depends on the tires though - I'm on semislicks.

 

Anyone else? I'm curious about the coilover spring rates.

 

Good straight answer this... -2.5 may be too much if running big power. Im at -1.5 rear camber.

 

This will get you somewhere close. Corner weight will also help keep the car feeling nice in both left and right handers.

[GodISmE]

This season I'm lowering the rear camber to -2 and changing the rear springs to 6k. Right now even with the rear ARB removed it's still too stiff. I am not sure if I need to revalve the damper if I go down by more than 2k? Need to check with Stance but I think going down (softer springs) should be ok.

-3 at the front is perfect with r888 255/35/18 so I am keeping this setting.

Edited March 2, 2017 by GodISmE

[MeisterR]

This season I'm lowering the rear camber to -2 and changing the rear springs to 6k. Right now even with the rear ARB removed it's still too stiff. I am not sure if I need to revalve the damper if I go down by more than 2k? Need to check with Stance but I think going down (softer springs) should be ok.

-3 at the front is perfect with r888 255/35/18 so I am keeping this setting.

 

Ah right, it is Stance coilovers.

You won't really need a revalve, you basically are just losing the top end of the adjustment and all the response of the damping.

Because going to a softer springs rate makes that top end of the adjustment over critical damping, and it isn't something you want to use.

 

When we done coilovers for the 350Z, we run a 10/5 setup.

 

So I would say around a 12/6 or 14/6 will be around the right setup for it.

When you have a coilovers rear, the springs rate become a lot more sensitive.

There will be a huge jump from 9kg to 6kg in terms of wheel frequency.

 

But if the setup was flawed to begin with, it is difficult try to make something work.

I would say go for a softer springs will be the first try, after that I would say it will be more effort than it is worth.

 

Jerrick

[GodISmE]

Thanks for your reply. Not sure if I understand you correctly - do you mean that with 3k softer springs I will only be able to make use of a limited damper adjustment range (it's 16 clicks right now)? Which end though - they most stiffest settings?

[MeisterR]

Thanks for your reply. Not sure if I understand you correctly - do you mean that with 3k softer springs I will only be able to make use of a limited damper adjustment range (it's 16 clicks right now)? Which end though - they most stiffest settings?

 

If you imagine that each springs rate have a "Maximum" amount of damping force you can use with that springs rate.

If you go over that MAX amount, then your damper is stopping the springs from moving, and that is a bad thing.

You can go softer because you don't always run on the road at the MAX setting.

 

So For example, a damper is valved at a range, the softest will be the max value for a 4kg/mm springs, and the stiffest will be the max value for a 10kg/mm springs.

 

Say it is paired it to a 9kg/mm springs.

With a 9kg/mm springs, you can run between the 5kg/mm setting to the 9kg/mm setting.

 

Now you change the damper to a 6kg/mm springs.

You can only run between the 4kg/mm to the 6kg/mm setting.

What that mean is any adjustment from the 6kg/mm damping to the 10kg/mm damping is over the MAX amount, and therefore should not be used.

 

Another issue is that a damper function it's best at their stiffest setting, because they provide the best "control".

So say you have a 6kg/mm springs.

 

You can dial a damper that was valved for 10kg/mm to the force for a 6kg/mm springs.

However, it will performance completely different from a damper that was valved for 6kg/mm that is dialled to full stiff.

 

If you are running at full stiff, I would guess that you are probably running over the MAX amount anyways and your wheels probably are not generating the amount of grip that it could of with a properly dialled set of suspension.

 

Jerrick

[GodISmE]

They say here that it's ok to even go up by 2k without revalving and it won't have an impact on the ride quality. Does this change anything? So for 9k spring that range would have been something like 7k to 11k, no? What does it mean for me in practical terms when I hit the track with those 6k springs - that I will have no damper adjustment at the rear and it won't really make a difference whether it's 0 clicks or 16 clicks?

 

EDIT. I've just checked with their technical support - they say the valving range is 6k to 10k.

Edited March 6, 2017 by GodISmE

[MeisterR]

They say here that it's ok to even go up by 2k without revalving and it won't have an impact on the ride quality. Does this change anything? So for 9k spring that range would have been something like 7k to 11k, no? What does it mean for me in practical terms when I hit the track with those 6k springs - that I will have no damper adjustment at the rear and it won't really make a difference whether it's 0 clicks or 16 clicks?

 

EDIT. I've just checked with their technical support - they say the valving range is 6k to 10k.

 

Uh... Damper dyno or it mean nothing.

 

Springs rate does affect ride quality, but the damper is the main thing that control it.

I can have a very soft springs, with a extremely harshly valved damper, and the ride will still be unbearable.

Everything works together, you can't just isolate a part out and go "it is fine to change that".

 

So lets put it this way, say you run full stiff (as you do now), and you put that 6kg/mm springs on and run the same damping adjustment.

Your rear will be over critical, and that mean it will jack itself down if you hit bumps continuously.

That mean your rear will just sink until it is resting on it's bump stop.

The result is that you will have a rear that is unpredictable, and could "snap" out on you at anytime.

 

If you soften the adjustment, you may just get to the point where your damper will work with the springs.

However, because of the soft damping adjustment, it won't load the tyres like it is suppose to.

What that mean is you get this "sluggish" response as your damper isn't pushing your tyres to get it to heat up and generate traction.

Safer than the wheel snapping out on you, but far from ideal on how a car on track want to utilise it's tyres.

 

Remember, the only thing on the car that generate traction is the tyres.

The suspension's job is to get that tyre to generate as much traction as it can.

That is why you got to look at how changes in the suspension affect the tyres, you cannot just go I want it stiffer and just throw a 16kg/mm springs on.

Or in your case, I want it softer and just throw a softer springs on.

 

However, given what you said, if you have no other choice.

I would say that 6kg/mm springs will be the best option because I know for a fact that a 9kg/mm springs in the rear is way too stiff.

 

Jerrick

[GodISmE]

Well, I guess I will just have to test it on a track - I have two options for softer rear springs and can test both at no extra cost: 6k and 8k. I'll start with 6k with the ARB put back on (softest setting) and I'll see how the damper reacts. If I will be losing traction at the rear during transitions and no damper adjustment will help, I'll switch to 8k. If 8k is going to be ok (in theory it should as it's pretty close to 9k and it's actually the middle of the valving range), I'll switch to 16k at the front to balance it out. It should be fine, I like a stiffer ride and apart from Nordschleife, most of the tracks I will be driving on are pretty flat.

 

Just out of curiosity, what's actually involved in revalving coilovers? Can this be done at any suspension tuning shop or does it have to be done by the manufacturer?

Edited March 7, 2017 by GodISmE

[RobPhoboS]

Just out of curiosity, what's actually involved in revalving coilovers? Can this be done at any suspension tuning shop or does it have to be done by the manufacturer?

 

There are videos on youtube of people doing it themselves.

[MeisterR]

Well, I guess I will just have to test it on a track - I have two options for softer rear springs and can test both at no extra cost: 6k and 8k. I'll start with 6k with the ARB put back on (softest setting) and I'll see how the damper reacts. If I will be losing traction at the rear during transitions and no damper adjustment will help, I'll switch to 8k. If 8k is going to be ok (in theory it should as it's pretty close to 9k and it's actually the middle of the valving range), I'll switch to 16k at the front to balance it out. It should be fine, I like a stiffer ride and apart from Nordschleife, most of the tracks I will be driving on are pretty flat.

 

Just out of curiosity, what's actually involved in revalving coilovers? Can this be done at any suspension tuning shop or does it have to be done by the manufacturer?

 

Due to the motion ratio of the 350Z rear suspension design, I would say 6kg/mm is about as high as I want to go.

You will just have to see, chances are that it might be okay but you just end up running the damper soft.

 

Re-valving is pretty simple actually, it is just a bunch of "shims" that sit onto of a piston that affect the force it generate.

But a monotube damper require a few specialist tool, and not many people have that.

And of course, you will need a damper dyno or you will have no idea what you have actually done.

 

Jerrick

[RobPhoboS]

Note:

My comment was just so he could see what's involved - not to try it out himself

GodISmE - check out this channel, loads of videos getting technical but easy to follow if you're interested:

https://www.youtube.com/channel/UCKaREq3sxDXcdeRtq4Fbukw

[retro_al]

Sorry guys I forgot about this thread, thanks for all the replies

 

Okay so my car is just a weekend car and hopefully to be used on a handful of trackdays ( I'm doing raf marham in april )

 

So the car already has bc coilovers but I have no idea on spring rates, the damping can be adjusted at the top soft/hard

 

I have had the car fully polybushed with superpro bushes, also new eibach front and rear anti rollbars, and adjustable camber arms front and rear.

 

Wheels are 10.5 on the rear with 295 30 19 yokohama AD08R tyres and 255 30 19 on the fronts

 

Kazz 1.5 way lsd , and the usual ds2500 brake pads and race fluid.

 

When I had the parts fitted I asked for 2 deg camber on front and rear,but I'm wondering if I need to change this (hence post)

 

Anyway I'm sure I will find out soon enough at marham just how it handles, then I suppose I can get some adjustments done after.

 

 

Thanks Al