Wired 24/7

iTrader: (2)

Hi guys -

I need help deciding what my suspension options are for my setup in the near future will be.

Like the sig says, SF Challenge 19x9.5 and 19x10.5, 255 / 285 tires. (I'll get back to you guys with the offsets)

I will have the fenders cut/rolled if necessary.

My biggest criterium is, I cannot have too much drop. The driveway where I wash my car is extremely steep, I have scraped before going up there.

My other criterium is, I do not want to spend a lot of money... because I kinda blew a lot on the rims you see...

Option 1: Stock suspension. The "wheel gap" isn't that big of a deal to me. At least not yet.

Option 2: Something like Tein S-tech or Tein H-tech springs. Good springs with minimal drop. Neither of these springs should give me alignment problems (is that right?). But -- my question is, will they ruin my shocks over time?

Option 3: Some kind of basic coilover. Speaking of basic, Tein Basic would probably be fine. Adjustable height, that's good too. The only bad news is I haven't riden in anyone's car who has these coilovers, and I'd like to get a better idea of the ride quality before I commit to something this expensive. Any volunteers for a test drive? B-Unit?

Z1 Performance

iTrader: (564)

RSR springs but heavily backordered

Alberto

iTrader: (14)

In your case, where you dont want to much of a drop, and dont want to ruin your shocks over time I think you have 1 clear choice. The Hotchkis springs-they drop like almost 1", and the rears are slightly softer than stock, and the fronts are slightly stiffer. They did this to get rid of the Z bounce. They handle better than stock, look better, are dirt cheap, you can realign without the aid of camber/toe kits, and it wont kill your shocks over time Add in some Hotchkiss sways and you'll have a great handling Z.....

Wired 24/7

iTrader: (2)

I really appreciate the recommendation!

So, basically any springs that drop under 1" will be ok for my shocks? Or does the spring rate affect the shocks as well?

Do you prefer the Hotchkis over the Tein S-tech (similar drop) just because of the spring rates?

Thanks again!

Wired 24/7

iTrader: (2)

(accidental click!) =\

mgl

iTrader: (10)

im running 255s and 285s in the rear with tein basics.
don't know exactly how much i'm lowered, but i'm happy with the way they feel.
no cutting or rolling of the fenders needed. although i will probably lower the rear a little more so maybe i will need to in the future, but i sure hope not.

Alberto

iTrader: (14)

I would go with Hotchkis. I almost switched from my JIC's to those springs(for drag race purposes), and every review Ive read on them people love them. The fact that they are not that much stiffer in front and softer out back would help me sleep better at night in regards to shock life. They where designed to be used with stock shocks, if you add aftermarket shocks it would be that much better, but thats up to you.....glad I could help.

Wired 24/7

iTrader: (2)

For the Hotchkis sways, do you think the stiffest setting in front and rear would be acceptable for street?

Would stiff F / stiff R give me too much understeer, should I go with medium F and stiff R?

Thanks again in advance.

palepony

iTrader: (8)

wired

a number of variables are going to determine your oversteer/understeer characteristics

as i posted in some other recent spring threads that you were involved in

you have a 2005 make year, which has a higher rear spring rate than the 2003-2004 make years. the hotchkis are similiar to the 2003-2004 spring rates, but the hotchkis rear is quite different than the 2004.5+ make years

2003 OEM
front 310-314 lb/in rear 342-350 lb/in

2005 OEM
front 310-314 lb/in rear 427 lb/in

hotchkis
front 340 lb/in rear 330 lb/in

by going hotchkis springs, you will increase front spring rate and drop the rear spring rate by nearly 100lb/in. this will increase understeer as compared to your current setup (2005) much more than it would affect an owner of a 2003-2004 Z. note: the hotchkis would work well for alberto's drag purposes as it would be easier to shift weight to the rear for traction. again, it really depends on what you want your suspension to do.

the RSR springs are more similiar to your current setup and have a modest drop (agree with Z1 that RSR are a good choice)

also...
you have increased the difference between your front and rear tires. OEM 225 front 245 rear, a 20mm difference. you 255front 285 rear, a 30mm difference. this will also increase understeer

as for your sway bar question
the beauty of adjustable sways are that you can adjust them! to dial in your steering characteristics. however, choose your springs first to change the characteristic of your handling, then tweek with the sways, rather than vice-versa
also, change one thing at a time, drive, evaluate, and then make decisions. if you change multiple things at once its more difficult to dial in

hope that helps

pp

Wired 24/7

iTrader: (2)

Clearly though, the Hotchkis sways and springs were engineered together as a pair, to produce good results in performance specific to the 350z.

I like the RS-R option, however I like the price of the Hotchkis better, and RS-R does not make sways to go with their springs. (AFAIK from looking at their website).

What I'm talking about is with the Hotchkis sways they are clearly designed to help minimize understeer, due to their stagger in stiffness from Front to Rear.

palepony, I appreciate your advice and it has made me a more informed consumer.

However I like to look at things from a different point of view (maybe it is my engineering background that makes me want to find the easiest solution that works, lol).

I would rather put everything on at once, because then the only degree of freedom to adjust is the sways. In other words, I will install everything, using a "best guess" estimate of the sways setting. Then if I am having issues with over/understeer, I can adjust the sways. If that doesn't help, I will look into other springs.

Since Hotchkis springs are cheaper, I'd rather do this BEFORE getting the more expensive RS-R springs and then realizing the Hotchkis springs would've been fine if I had just adjusted the swaybars correctly.

So my question regarding swaybar stiffness is aimed at people who have them installed already.

The website here

http://www.hotchkistuning.com/cgi-bi...atalogno=22413

gives the swaybar stiffnesses compared to stock. As you can see, they're staggered from the factory, the rear is stiffer than the front at each setting (soft, medium, firm or whatever).

I am thinking firm / firm for the time being, and if the ride is too uncomfortable or there's too much understeer I will probably change it to medium / medium.

The reason I asked if firm/firm would be too much understeer is because the stagger is different.

firm firm would be +63% stiffer F / +146% stiffer R
med med would be +32% stiffer F / +92% stiffer R.

palepony

iTrader: (8)

wired

i like engineers!

Don't get me wrong. I think your making a good choice. As I've said in other threads, many are pleased with the hotchkis springs/sways.

It's more the fundamentals of suspension dynamics that i'm trying to convey. Mostly to illustrate where you are now with your current suspension (OEM springs, sways, tires), and where you will go with your choices.

I'm not here to bash or promote a certain manufacturer's product but to clarify the changes in your suspension behaviour by your choices. Again, the hotchkis springs/sways are a good choice (? did I say that already? )

The hotchkis sways/springs were engineered with the 2003-2004 springs/shocks/bounce in mind as far as I can tell. Obviously, contacting hotchkis directly will give more accurate information on their R+D than me . You have a 2005 shock/spring combo which is different, so the change in your handling will be different.

RSR doesn't necessarily have to make coorosponding sways if you know how each component from different manufacturers adjust your suspension. Many people mix and match their components to get what they want. Again, it's what you want your suspension to do.

I have to agree with this comment. to quote you..... "What I'm talking about is with the Hotchkis sways they are clearly designed to help minimize understeer, due to their stagger in stiffness from Front to Rear.". The sways do give some moving room in how the car handles by their adjustability. However, "mantra", for what's it's worth, is that adjust your handling with springs then tweek with sways.

The counter the above arguement ---> Once you go to high spring rates ie. >400 lb/in, many coilover manufacturers have elected for lower spring rates in the rear than front. This includes truechoice/unitech (extensive R+D), tanabe, zeal, cusco, ?others. There seems to be a point that rear traction becomes a problem approx 425lb/in and trades off with changing the understeer characteristic. For example, the cusco combination has understeer promoting springs and sways that promote oversteer to balance. With the spring rates we are talking about, this doesnt seem to apply, but a cutoff seems to have emerged.

btw. you're correct that going to med/med would reduce understeer compared to firm/firm on the hotchkis sways. the beauty is you can continue to adjust as needed, for the extreme example front soft rear firm would further reduce understeer (adjust as needed! )

only here to help, not to dissuade you

more than happy to help, but if i'm pissing you off, more than happy to shut up too

pp