Suspension for improved lap time...
 

Afternoon all...

In case you didn't know, I'm a fan of road courses and lapping the 370z.

I, however, do not know what suspension change would make the biggest improvement in lap times without making the 370's ride rock hard.

I was thinking of adding front camber arms. Was also thinking of adding coilovers to make an improved time. Would coils help lap times???

Thanks all!

check the suspension section of the forum for ideas

Brakes & Suspension - Nissan 370Z Forum

Wanted to see if lap times can be lowered without lowering past OEM.
- I got the impression ya had to lower to improve lap times?

You should be able to get better lap times even without lowering. Having stiffer springs and shocks valved for the springs will help the car transition better which should result in an improvement.

If you are still running factory front camber you're going to see a big difference right there by going aftermarket and dialing in more camber.

Start with these....

Autocross to Win (DGs Autocross Secrets) - Suspension
https://www.youtube.com/watch?v=hGZRairqHNI

There's a next to brand new SPL front arms for sale right now, if op is considering that.

Question for the gurus: would increasing front positive caster and negative camber simultaneously be better than increasing just front camber? My simple understanding is increasing positive caster helps create negative camber when the wheels turn. I ask because, in my mind, wouldn't severe negative camber (like a -3 or even more) reduce straight line braking performance?

Oh yeah... I'm leaning pretty heavy towards SPL Front camber arms - SPL FUA Z34.

While I'm sure that high neg. camber will decrease straight line braking performance due to decreased tire contact patch, I can't think of any time in my autox car that I've ever thought "I need more brake". Granted that's autox vs. HPDE but I have to imagine that whatever you lose braking you more than make up for in cornering speed. fwiw I run -3 deg. up front on mine.

Thx gomer. Just to clarify, my comment wasn't a disagreement to your suggestion. I am just really interested to know whether caster adjustment can create meaningful gain in negative camber.

If you go high on neg camber, then you can't be low on ride height because camber gain in bump (eg: dive under braking) will really screw with the contact patch.

I put 10 degrees of caster into my race car (70's historic Pommy sports car) so I could pull back the camber a bit and still get camber gain with steering input to help with turn and not kill the inside of the tyre under braking, but I have to install stealth power steer (actually electric power hook - hidden up under the dash).

This "sort of" translates to the Z34, keep neg camber around 3 or 3.5 (max) and push caster up a degree or two - this will help with turn and power steer will deal with increased steering effort with increased caster.

With the Z34, camber gain in bump (as the car dives under braking) can be significant if the car is low (real low). The rate of camber increase grows with bump. The only way to counter this is really stiff front spring which will kill grip which is not desirable.

It is all about finding the sweet spot and it can be very small ... BJ from Doran Racing noted on this form somewhere where a 1mm change in ride height "transformed" to Z34 RC they were running at the time, and finding the right compromise "at the limit" can involve small changes.

It is all a trade-off and the more adjustable and less compliant the suspension becomes, the less "daily-capable" a vehicle becomes.

SWMBO will not get into my car now because it is simply too harsh for her !! but that has its own benefits as well

To answer the OP question, increasing front caster can actually reduce the level of camber required to get the car to "turn". For me, I started at 3 neg camber when I installed SPL FUCA and then played with caster to get the level of turn I wanted - I am using 265/35R18 r-specs because I could not see the need to go bigger at present.

I have a full SPL suspension waiting to go on my car. That said, my recommendation would be:

- Front sway bar, full stiff
- SPL Front Camber Arms (-2.5 camber to start)

You want to go + on the caster. I have my Nismo set at -2 camber, and +6 caster. Next alignment will be caster set at +7. The more +caster, the more camber you will get when turning the wheel. So you don't have to run alot of camber.

This is from the Toyo website for the R888's.

Operating Temperature: 160°F to 220°F
Hot Inflation Pressures: 32 to 38 (psi)
Camber: -1° to -3°
Caster: As much positive as possible

You can't have both. The farther you go one way. The worst it becomes the other way. Pick your poison.

I'm surprised that you don't already have camber arms. As much as you talk about tracking the Z. ;)

Osbornsm, what shocks do you have?


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