l30thelion

iTrader: (3)

I run in NASA H3 (hope to move up to TT some time this year) and am trying to set my car up for time trials. After a 2-day event at Homestead w/ NT01s, the outside edge of the front tires really took a beating. I've also read that negative camber is really a must for the Z and would like to know what would be more beneficial, adjustable arms or springs?

I'm thinking that springs w/ 1" drop (e.g the Eibach Pro-Kit) would provide a lower CG and some negative camber, while the adjustable arms would allow for far more negative camber. I'm not sure which change would be best.

Thoughts?

BTW, springs are +2 while adjustable arms are +4.

Thanks


Current Setup
Shocks: Koni Sports +3
Tires: NT01 255/40/17 +7
Sways: Hotchkis F/R +2
Brakes: StopTech 13" Front +2

Total: +14 Points

Billhyco

iTrader: (14)

why not do both ?

betamotorsports

iTrader: (1)

Driving style has a lot more to do with how the tires wear then suspension settings. Slow in, fast out.

I've run my basically stock 2006 350Z at a number of open track events and tire wear was fine. My co-driver at a a Speedventures event was pro racing driver and combined we had 6 hours of track time. Erik's last few laps of the day beat the NASA TTC lap record for the track. Tire temps were hotter on the outside front (stock -1 front camber) but not bad. Tire wear was fine.

Slow down on corner entry and squeeze on the car through the apex and out the exit.

l30thelion

iTrader: (3)

Unless my math is off, "both" would bump me up to TTB, I'd like to stay in TTC.



I agree that driving style has a lot to do with it. I felt I was often turning-in early or going in a little too hot then scrubbing off speed, and not able to stay/squeeze on the throttle through the turn as much as I probably should have for better times. I guess it's a patience thing. I'll definitely think about and work on it at the next event.

That being said, I'm still curious about what would be the better modfication? Some folks on the forum run quite a bit of negative camber (-3 front) and say they've had great results.

betamotorsports

iTrader: (1)

More front negative camber helps. An alternative solution is offset upper control arm bushings which are a no point mod in NASA TT and Solo2 BSP legal. Hippie on this site and I have machined sets for our own cars. I'm thinking about making a few sets and selling them but I haven't finished testing yet. I've been able to get an additional 1 degree of negtive camber to a -2 total in front. I just need to make sure they hold up. Maybe by the end of summer I'll know.

laze1

iTrader: (17)

I need these BAD,,,I am having to run TTB since I run SPL camber arms to get the camber needed for R-Comps to work well.

laze1

iTrader: (17)

What model Z are you running?

Note: I have a Grand Touring, and it has a +7 point penalty to start with in TTC!

2006 350Z Grand Touring (Brembos) TTC +7
275-40-17 RA1 all around +5 ,a up 20MM over TTC base +4
After market springs +2 non-OEM springs +2 (hotchkis TVS)
After market sway bars +2 non-OEM Sway bars +2 (hotchkis TVS)
After market Front upper control arms (camber arms) +4 (SPL F & R arms)

everything else stock (shocks, engine, aero, interior)

So a total of 24 points

If I go to 255 tires, that takes me back to 20..but still must move too TTB..right? I would still need to make 1 more change....likely the springs since they are "street springs" with very little drop or spring rate change. and I have run successfully without them..and that would take me to 18 points and back in TTC...but changing springs is a PIA...and would not happen till the winter re-build period...

The darn camber arm deal is killing me...............

l30thelion

iTrader: (3)

My Z is an 03 Enthusiast, so relative to people running the Grand Touring or Track model Z, I dont get +7 for brakes and running a heavier car w/ VDC (can you turn it off completely?) which from what understand is really more of a hindrance on track.

It seems that the way the rules are set up now, the only models that work if you want to stay in TTC are the Base and Enthusiast. But there may be a reason for the way they classed it, I'm just not sure I get it.

Back to my original question, would the camber arms be worth the +4 vs the springs +2? If I go w/ springs it would put me at a total of +16 which would allow me to move up to stickier rubber if I want to in the future (255/40/17 V710/Hoosier/Hankook). Springs are also cheaper from what the research I've done. I'm leaning towards the springs at this point.

betamotorsports

iTrader: (1)

Springs.

In another thread I list my mods and I'm going to trade 30mm in tire width to get back enough points to upgrade the springs.

betamotorsports

iTrader: (1)

FYI... the factory 2006 springs have a higher rate then the Hotchkis TVS spriings. For NASA TT you're better off with your stock 2006 springs.

laze1

iTrader: (17)

The Hotchkis are higher spring rate in front than the stocks...the rears are softer than stock...The Hotchkis springs really do help with nose-dive under hard braking...but I my have to remove them to get back some points....I really want to keep my camber arms if at all possible

Hotchkis:
Front Front 9/16" (15mm) Drop
340 lbs/in

Rear 3/4" (19mm) Drop
330 lbs/in


Oem springs 350Z 2004.5/2005 (found 04 car's that have the revised susp.)
Front:314 Rear:427

Oem springs 350Z’s 2003/2004
Front:314 Rear:342

laze1

iTrader: (17)

I have done a "Yaw-rectomy", and removed the yaw sensor for track days...that is the only way to kill it completely

laze1

iTrader: (17)

I may be crazy, but being able to run BIG camber has really improved the handling on my car...GREAT turn in and grip...almost too much....but I get much better tire wear with camber up front..about 3 deg front,( 2 deg rear).

I run the SPL front and rear arms..you really don't need the rear arms if you are anywhere near stock ride hidth..you have alot of adjustment in the rear....almost ZERO in the front

Note: I run a square wheel/tire setup..17x10 w/275-40 RA1...and rotate my tires alot

I have to run my rear sway bar on soft, and still get a little loose,,,so I adjust my tire pressures when that happens..I run about 2-4 lbs less in the rear on tracks/situations when I get oversteer/loose...I may stick my stock rear sway bar back on for some tracks..I also may use LESS rear camber to resolve this issue also. I have already tried going up on the front bar but didn't like the way it felt.

And better rubber is ALWAYS A GOOD THING! Having adjustable camber lets you get all you can from good rubber.

betamotorsports

iTrader: (1)

Oops, you're right regarding the front spring rates.

ke0ki2k

iTrader: (2)

its a natural habit everyone starts off with. ya just gotta break it. coming in hot and trail braking the hell out of the car is ok if the corner is like a type 3 (at the end of the straight and leads to more corners, a corner you can "sacrifice" to an extent) just really focus on getting the car whoa'd up enough to make a LATE turn in and unwind those hands as you squeeze throttle onto the straights if its a type 1 (turn that leads onto a highspeed straight)...not making up much time in the corners, its the straights that really matter the most.

id do some more aggressive springs (Nismo T2 springs come to mind) and have it alligned at a shop with a good rep with local Autox guys. if youre doing TT the 690 pound/inch nismo springs will keep the car a little flatter than the regular springs out there, you may want to have the Konis revalved sometime soon after though.

Gsedan35

iTrader: (10)

While I can't see running any progressive spring that is mild in rate, that will roll over and play dead into the bump stop's. I also don't see the T2 springs as the answer here either and least not in the bigger picture. Even with the Koni's revalved, you run smack into issues with insuffecient mid and high speed compression damping because of their twin tube contruction. Not so much a issue for BSP, where your not likely to get into mid and high speed chassis events. In time trials, you will. Monotube 2812's exist for this very reason, though are too costly to recommend here.

IMO, only way I would do the T2 spring is with Bilstien HD's that you have revalved. I would not automatically send them to Bilstein so much as I would find a local shop that is willing to let you point to elements on the shock dyno that you wish to change.

Another thought, has anyone confirmed Cobb's claim that their linear springs are +15% to 2004.5 oem springs? Confirmed as in taking a dial caliper to the springs or put them on a rate testor?

Stack

You all are way over thinking/engineering this... please take what John says to heart:

Ask for an instructor that can give you some TT specific coaching... tell him or her what your tires are doing and what you're looking to do.

Hell... come up to Carolina Motorsports Park June 20-22, I'll hook you up with a good instructor that'll help you get the most out of what you've got now.

ke0ki2k

iTrader: (2)

didnt know twin tubes had problems like that :/ what about TcKline Koni's? still problems with compression?

I was wondering about the Cobb springs too....you might wana look into some coilovers OP lol or be a gangster and buy Motons and wrap em with some 900 lb/inch ERS springs :]

Anybody ever run Penske 8760's?

l30thelion

iTrader: (3)

The event at homestead was my first in about 8 months so I was very nervous the first session (I was slowest and couldn't pass a MazdaSpeed 3 Wagon!!). It was also my first time on the NT01s, Sways, and StopTechs (ST43 pads all around). It took me a couple of sessions to get used to the incredible braking force of this setup. I mean the stopping power is INSANE! And now I know what people mean when they say that modulating the brakes can be tough w/ race pads.

Fortunatley NASA FL Region now has "stand-by" instructors for anyone who would like some input. This really made a HUGE difference for me. The instructor gave me some input, didnt really say I was doing anything terribly wrong, and for me it gave me that nudge of confidence that I think I needed after not being at an event in a while. NASA FL Region really ROCKS!

The second day I asked one of the fastest TTC Z drivers, Luis J, to ride w/ me. He said I needed to turn-in a bit later in some corners and really try to stay on the throttle once I get on it. Also, I needed to sacrifice the last corner before the front straight a bit more to get on the throttle earlier. So yes the things that some of you have advised are dead on.

Thanks everyone for your input!

ke0ki2k

iTrader: (2)

true lol we want to take someone new to road racing & put him on some quadruple adjustable motons haha...we are, to quote Jeremy Clarkson, "ambitious...but rubbish"