03threefiftyz

iTrader: (25)

I ran OEM compression bushings last year, but swapped in the whitelines a few weeks ago. If we don't get 2' of snow on Thurs and more on the weekend, I plan to run the car during a little Evo TnT this Sunday. I'll report back.

SnoXRacer183

iTrader: (3)

I will probably be getting some coilovers/shocks/springs for my car here pretty soon. I do not, nor will I have money for Penske/AST/Moton (real shocks) anytime soon in my life.

Of all the "cheap" options, Fortune Auto 510s sure put off the vibe that the company actually knows what they are doing. They will "custom" build their chinese shocks, dyno them to match, and install custom spring rates. I know these are low quality shocks, but they should do better than running stock suspension correct?

I just dont see the advantage of running the Koni Yellow or Bilstein HDs with springs that are lower, but nearly the same spring rates as stock for the same price as these 510s (racer discount). Are there springs out there that I'm missing that would actually be an improvment for the Koni/Bilstein? The shocks themselves would be better with Koni/Bilstein, but it seems like with the Z, the higher spring rates and roll stiffness is more important than "better shocks" and soft springs.

Am I wrong in assuming these low rate coilovers "custom" built with 1000/800 springs, would be a better choice than Koni/Bilstein?

Z1NONLY

iTrader: (2)

Not sure about those coilovers...

My new Koni's should come in tomorrow. I intend to eventually get the old Koni's revalved for whatever stiffer springs I decide to go with.

For now, the "soft" RSR's will have to do the job with new off-the-shelf Koni's. (410lbs/345lbs)

I can say that Koni's + RSR's + Hotchkis sways > Stock suspension.

03threefiftyz

iTrader: (25)

You can see if Jeff Wong (ProParts) will valve you some yellows, but you are still probably looking at 1500, even you start with used yellows. I hated the twin tube Koni's on my car, though. Had a few different companies do them, they always leaked and lacked sufficient adjustment range. You can buy single MCS's for about 2200 right now (I think). Not a big fan of singles, but they are modular, so you can upgrade to doubles or triples without having to replace the whole unit.

Z1NONLY

iTrader: (2)

Ouch!

Glenn350zHR

iTrader: (5)

Mike I sent the koni yellows that i picked up for 100$ to ProParts. having them revalved and reconditioned for 1000/800 springs along with front coilover sleeves. estimated price quote i got was around 800$. should know the exact cost in a week or two when they are complete. 4-6 week turnaround time.

Slaloms

I'll also suggest people check with ProParts on building a 28 series setup out of used components. If they have parts in inventory, you can get a killer solution for a very reasonable price.

SnoXRacer183

iTrader: (3)

So what happens to the dynamics of a 350Z when you start to "even" out the spring rates. Lets say you went 700/500 springs and you moved the car to a 700/700 set up? what effect with that have on our cars?

03threefiftyz

iTrader: (25)

On a square tire set-up, it will be snappy and pretty hateful on corner exit, unless you run a lot of front bar. At that point, the roll stiffness will be too high for STU car IMO. I run a staggered set-up. Same tire, but wider wheel in back, but if I didn't, I would drop the rear spring about 50lbs to "bring it back inline". On top of that, I would probably drop the rear a touch. I run a little more rake (compared to BP), which loosens the car up even more. On an ST car, I'd start with a relatively level F/R ride height and 200lbs stagger to start.

SnoXRacer183

iTrader: (3)

Ok so I’m kinda confused...

-Stock 350Z comes with spring rates 340F/410R (ish). Front tires are 225, rear are 245. The car stock has a tendency towards understeer. Call it 40% F grip/ 60% rear grip car balance

-When you stiffen the rear of a car it moves grip to the front, and the car starts to move towards oversteer. Also, putting a square tire set up…like a 265 on all 4 corners will also give the front more grip, so the back end will again feel more towards oversteer. With my 275 NT-01s on my stock suspension, the car feels pretty damn neutral. Call this square tire set with stock springs a 50% F / 50% R balance.

-You fast SCCA guys run a square tire set up (285 STU/ 315 BSP), but have moved spring rates to like 1100F/800R. Do you the chassis dynamics change that much at the higher spring rates with wide grippy tires, that you need to dial out that much oversteer? In my theory in my head, you went square tires to get the car 50%F/50% R, and then changed spring balance to get the car back to 40% F/ 60% R.

Or is there more to the spring rate changes that I’m over simplifying?

I'm just having a hard time wrapping my head around using such high front spring rates compared to my square tire/stock suspension set up and how I think that feels. It's not that I dont believe you, just trying to gain some knowledge for myself before I go an order a suspension that I'm not going to like...

03threefiftyz

iTrader: (25)

It is not so much the oversteer as the lack of corner exit grip...

...also I run more than 800lb on the back of the BSP car.

Z1NONLY

iTrader: (2)

I have heard that stiffening the front helps maintain static camber and thus improves grip.

I have not ran enough A/B (from soft front to stiff front), to be able to attest to this phenomenon, but the owner of the BRZ I'm co-driving at Dixie used the stiffest bar he could find up front, and the car was actually loose the first time I drove it. (I was getting throttle oversteer at the bottom of 3rd...in a BRZ.)

03threefiftyz

iTrader: (25)

I think both BP and I have found a big bar, on its stiffest setting, to be relatively hateful...

...I never go above the second hole from softest on the hotchkis front bar, and don't use a rear bar at all.

AznSky

iTrader: (12)

Sorry wrong thread

Z1NONLY

iTrader: (2)

I think your springs probably take care of increasing roll stiffness?

I'm one hole back from stiffest setting on my Hotchkis bar, but then I'm only running 345lb springs up front.

The rear is set to the middle on the bar, with 415 or so springs.

I try to keep the shocks toward the middle of their adjustment range, but the rear is a little stiffer and the fronts are set a little softer.

03threefiftyz

iTrader: (25)

I can't fathom autocrossing a 350z in ST/SP/SSM on springs that soft. I hate my car with a rear bar....

SnoXRacer183

iTrader: (3)

What is the characteristic of the car you dislike with a rear bar?

03threefiftyz

iTrader: (25)

Corner exit traction is sooooooooooooooooooooooooooooo much better without the bar. I can't get on the power as early, even on big hoos, with a rear bar. I am not all that fast into a corner (need to work on it), but I make up a lot of time on other BSP cars getting out of the corner.

steidz

iTrader: (8)

Any recommendations for rear springs with the open end pitched? My Hyperco's are closed down on the bottom end. This is giving me a too much ride height even after taking out the bottom rubber and cutting the top mount down.

So where are you guys finding your springs are what type of rear mount are you using.

I have the ohlin dfv and upped the spring rates as much as possible with the stock valving. New springs are 750 front and 525 rear.

03threefiftyz

iTrader: (25)

Get a shorter rear spring?