GC coilovers help needed

[EndStar]

Ordering GC coilovers for my 280z in a couple days. I have KYB Excel-G struts coming in brand new. What's the highest spring rate I can run before I break things?

[MicroMachinery]

Might go check over at HybridZ.org. There's alot of information regarding Z cars over there.

[datzenmike]

Break things? well if wanting to approach the breaking point just throw away the springs, weld the strut in solid and use tire pressure for a suspension.

 

The 'rate' is in pounds per inch. A 150 lb/in rated spring will compress one inch for every 150 pounds placed on it. My Maxima strut springs (the Maxima is based on the zx platform so come comparisons with the Z car can probably be drawn here)were about 150 lb/in. My 710 springs were 100 lb/in. Just for fun I trimmed my 710 springs to equal the Maxima rate or looking at it another way a 50% increase for use when swapping them on to my 710.

 

I found the ride much stiffer/firmer and there was little risk of bottoming when the ride height was lowered. One hundred and fifty pounds per inch seems reasonable and comfortable to me, but probably not to others. Younger people can probably put up with a 'too stiff' suspension longer than older people.

 

Raced 510s run in the neighborhood of 300 lb/in springs and higher. Stock springs are 89 lb/in so that's way over 3X the rate. Note that this is for racing, and like most 'racing' ideas and equipment, they do not translate well for street use. Comfort is one of them. To enjoy driving any car, is 300 lb/in springs really any better than 200? or 175? At some point comfort and performance/enjoyment meet.

 

 

My advice is start low and increase gradually. Give yourself and the car time to get used to the ride. At some point you will say, meh... tired of pissing blood, it was better before. Put the last springs back on. I'm saying no one can tell you what rate you will like.

[EndStar]

Break things? well if wanting to approach the breaking point just throw away the springs, weld the strut in solid and use tire pressure for a suspension.

 

The 'rate' is in pounds per inch. A 150 lb/in rated spring will compress one inch for every 150 pounds placed on it. My Maxima strut springs (the Maxima is based on the zx platform so come comparisons with the Z car can probably be drawn here)were about 150 lb/in. My 710 springs were 100 lb/in. Just for fun I trimmed my 710 springs to equal the Maxima rate or looking at it another way a 50% increase for use when swapping them on to my 710.

 

I found the ride much stiffer/firmer and there was little risk of bottoming when the ride height was lowered. One hundred and fifty pounds per inch seems reasonable and comfortable to me, but probably not to others. Younger people can probably put up with a 'too stiff' suspension longer than older people.

 

Raced 510s run in the neighborhood of 300 lb/in springs and higher. Stock springs are 89 lb/in so that's way over 3X the rate. Note that this is for racing, and like most 'racing' ideas and equipment, they do not translate well for street use. Comfort is one of them. To enjoy driving any car, is 300 lb/in springs really any better than 200? or 175? At some point comfort and performance/enjoyment meet.

 

 

My advice is start low and increase gradually. Give yourself and the car time to get used to the ride. At some point you will say, meh... tired of pissing blood, it was better before. Put the last springs back on. I'm saying no one can tell you what rate you will like.

My Brother jser12 ran 250-200 and I drive his dime a lot, I thought it was a bit soft. Most z guys run 225-250 f&r I'm thinking 350-250 according to my bro. Just didn't know if having that high of rate will blow my struts

[graveltrapp]

Talk with Ground Control or the spring manufacturer you intend to go with. They will want to know how you intend to drive the car, and in most cases, offer  a number of options pertaining to there relaxed length so that they are properly captured in the strut assembly. Your new struts are most likely going to offer a increased amount of dampening which could be construed as a firmer ride thereby allowing you to stick with your stock springs.

I think micro m. had good advice which was to hit the forum that best addresses your model car.

[EndStar]

Talk with Ground Control or the spring manufacturer you intend to go with. They will want to know how you intend to drive the car, and in most cases, offer a number of options pertaining to there relaxed length so that they are properly captured in the strut assembly. Your new struts are most likely going to offer a increased amount of dampening which could be construed as a firmer ride thereby allowing you to stick with your stock springs.

I think micro m. had good advice which was to hit the forum that best addresses your model car.

I tried hybridz but never got an answer that wasn't 200-250 is plenty of spring rate

[EndStar]

and i have driven is a few different cars with different rates and set up, 

miata on really nice coilovrs at 400-275

vw on ricelands at 275-225  :no:  :no:  :no:

dime on GC at 250-200

dime was too soft, and miata was amazing, and well, ricelands are :fu:

so im thinking 350-250 will suit the z well for what i want, just afriad that might blow a strut, oh well, you guys were more helpful than hybridz

[datzenmike]

My Brother jser12 ran 250-200 and I drive his dime a lot, I thought it was a bit soft. Most z guys run 225-250 f&r I'm thinking 350-250 according to my bro. Just didn't know if having that high of rate will blow my struts

 

You need to drive a Z car. Miata, VW and dime are not the same thing.

 

The stiffer the spring the less strut travel. Less strut travel the less chance of 'blowing' it.

[Guest Rick-rat]

Nothing quite like asking for advice and not listening     :w00t:  But according to his profile he is 19 and already knows everything

[EndStar]

You need to drive a Z car. Miata, VW and dime are not the same thing.

 

The stiffer the spring the less strut travel. Less strut travel the less chance of 'blowing' it.

Yes i realize they are all different and all have different set ups, my bros dime will be closest to mine, at least set up wise. Because I'm going to try and get as low as potatosparkles one day, but I doubt anyone can do it better than him. This car will be slammed to shit, so it will have barely any travel, why I'm looking at 350-250

[EndStar]

Nothing quite like asking for advice and not listening :w00t: But according to his profile he is 19 and already knows everything

If I knew everything I wouldn't be here haha. I wanted to know if I blow struts with a spring rate too high. I've only been around Datsuns for 3 years and my z 6 months. I don't know shit, but I'm learning! Slowly.... Very very slowly.

[datzenmike]

The 510 weighs 2,100? What does your Z weigh? close to 2,900. 

[Ranman72]

a higher spring rate will only reduce the compression of the spring and not have anything to do with blowing the strut 

you might start bending control arms or breaking ball joints or lose fillings from your teeth if it is to stiff 

the thing that will blow your struts is running them fully compressed with little to n travel allowing them to bottom out or running them fully extended with to long and hard springs might blow the top of the strut tube apart

300 is probably good

I run 250 in the back of my 510 and it feels good

the z is heavier so you could run 300 and be ok

 

there are a few ways to set up suspension 2 of them are stiff springs and softer shocks so it isnt so jarring or softer springs and stiff shocks

if you want a stiff hard ride get stiff springs and stiff shocks

the struts you have chosen are decent but in my opinion a lower budget shock

tokiko blues are better and tokiko Illuminas are even better and adjustable     

[EndStar]

a higher spring rate will only reduce the compression of the spring and not have anything to do with blowing the strut

you might start bending control arms or breaking ball joints or lose fillings from your teeth if it is to stiff

the thing that will blow your struts is running them fully compressed with little to n travel allowing them to bottom out or running them fully extended with to long and hard springs might blow the top of the strut tube apart

300 is probably good

I run 250 in the back of my 510 and it feels good

the z is heavier so you could run 300 and be ok

 

there are a few ways to set up suspension 2 of them are stiff springs and softer shocks so it isnt so jarring or softer springs and stiff shocks

if you want a stiff hard ride get stiff springs and stiff shocks

the struts you have chosen are decent but in my opinion a lower budget shock

tokiko blues are better and tokiko Illuminas are even better and adjustable

Thank you, this is a great answer and one I was looking for. I know the kyb aren't as good, but its what I can afford for now. So I shouldn't have to worry about struts as long as I run it high compression and short spring. I was considering ordering my springs an inch shorter.

Thanks again, you too datzenmike, way more help than hybridz

[datzenmike]

Haven't looked but are your struts still fitted with the factory oil filled dampers??? If no and have already been replaced with incerts, read no farther.

 

If you have the oil filled struts, you can dump the old thin oil out and replace with motorcycle fork oil It comes in different weights like engine oils and thicker equals firmer action. Bike suspensions are 'tuned' this way. I put Bellray 20W in my Maxima struts and they are firm. Tried ATF in my sedan but I also only increased the spring to around 120. My wife drives it. One liter is under $20 and it will refill three struts.   

[EndStar]

The 510 weighs 2,100? What does your Z weigh? close to 2,900.

Yeah about, then again, no huge bumpers, no interior, no extra shit, so probly 2,500 I wanna weigh just to know. And I'm going with 350-250 and a 1" shorter spring