How can I increase the stock springs "rate"?

[laze1]

How can I increase the stock springs "rate"? Is there any way to do this with spacers or some other magic potion?

Also, are stock springs linear or progressive rate springs?

Dumb question I suppose?, but I am trying to engineer my car for NASA TTC class. If I can get some some extra spring rate in the front (and rear maybe), I will might go back to stock springs and save some points..However I will likely have to do it anyways to get back into TTC from TTB.

BTW: I have a 2006 Grand Touring.....currently with a Hotchkis TVS and SPL front camber arms. I plan to keep the sway bars even if i go back to stock springs all around.

Thnx!

[Fluid1]

Why do you need a stiffer spring rate? There's nothing you can do to the OEM springs.....
IIRC, the OEM springs are linear.

Give this a read:
http://www.swiftsprings.com/products-sport_springs.html

I'd think about prepping the car for TTB +19

[laze1]

The biggest change I felt with the Hotchkis springs was the I had significantly less front end nose-dive during threshold braking.....I would like to raise the springs rate some to prevent nose-dive.....

[laze1]

I was wondering if NASCAR style spring "rubbers would work??

Originally Posted by Fluid1

Why do you need a stiffer spring rate? There's nothing you can do to the OEM springs.....
IIRC, the OEM springs are linear.

Give this a read:
http://www.swiftsprings.com/products-sport_springs.html

I'd think about prepping the car for TTB +19

[Fluid1]

Originally Posted by laze1

The biggest change I felt with the Hotchkis springs was the I had significantly less front end nose-dive during threshold braking.....I would like to raise the springs rate some to prevent nose-dive.....

Koni Yellows with adjustability are what you need. Check the other thread, I laid out what I think could be the best bet for you. There's more than 1 way to skin a cat.

[racerbob4]

spring rubbers

[laze1]

thnx

Originally Posted by Fluid1

Koni Yellows with adjustability are what you need. Check the other thread, I laid out what I think could be the best bet for you. There's more than 1 way to skin a cat.

[first350]

some of the autoX guys have 3-way adjustable shocks - IIRC there's 2 settings for compression and 1 for rebound...the 2 setting for compression are a fast and slow rate, the fast rate can be used to effectively simulate a higher spring rate; that may help, but I think those shocks are fairly $$$.

[betamotorsports]

It could be argues in NASA TT that modifying the stock springs (cutting) is a point modification. Adding a spring rubber or longer bump stops (progressive urethane) would be a no point mod.

[laze1]

Yes, all good suggestions below..

However, this is a "points game" that I am playing..so anything that adds points is out of the question right now. I am trying to stay in TTC and NOT have to spend any extra money. I run NASA TT for fun, nothing more...
I will spend money on expendables (tires/rotors/pads/etc) and as little as possible for go-fast stuff.

This is a major reason I want to keep my front SPL Camber Arms,,,i have already purchased them, they add the camber I need to go faster, and the fully adjustable camber helps to even out/maximize my tire wear on the track and street.

The camber arms alone are 4 points, However, I think they are worth it for my situation!

BTW: This car is my DD! (with 2 blood-sucking kids in college)

[Fluid1]

I disagree about the camber arms. But oh well, good luck

[laze1]

Hey Fluid1,

Your ideas are very good and helpful! I like your suggestions, and have learned from them.. Thnx!

I may try your ideas at a later date or different car...your view in this scenario on using springs in lieu of sway bars to control the car is very enlightening...I understand that better now. Of course you have to look at the entire package (spring/shocks/bars/tires/alignment/track conditions) when tuning...and I am trying to get there..just gonna take a little while.

So, I have given up on trying to get back into TTC with my +7 point starting penalty. It will cost me more money to do so and will likely NOT go any faster. So I think I will just buy some big sticky tires and drive my ass off in TTB. And have a bunch of fun...

BTW: As stated before, I would like to "place" in any class that I run in, but frankly that isn't gonna happen for awhile because of the driver.

I have to learn how to get that last second of time from any setup to be competitive in TT. I am currently 2 seconds slower than a winning time of 1:22 @ a track like Roebling Rd, 1:50 to a winning 1:47 @ Barber. So I am close! Better/bigger/sticker tires will obviously help some..but I have to learn to use that extra traction.....and put down the magic lap when it counts.

Note: These wining time do NOT include "ringers" that show up from time to time. So @ Barber a Grand Am RX8 race car with Grand Am driver shows up and runs a 1:43 in TTB...WTF...He was just using the weekend as a test day for an upcoming Grand Am race @ Barber...but totally tilted the "curve".....

Note: Here in the SE Region, M3s "own" TTC, and sometimes TTB,,,but Zs are "competitive"...but not gonna win day-in, day-out...

[Fluid1]

If you want to be competative, just research what the faster guys are driving in both TTB and TTC. If you can produce a setup to be more competative in one or the other, that would be the clear cut solution, if I were you.
I have hinted from the start that I don't think TTC is the place for you car. I mean, I drive a Base, which is lighter than your car, and has no limited slip. I can add an aftermarket limited slip for what, +3 points? Even at that point, my car is lighter and has a better LSD, and is -4 points from your car Stock.

[Fluid1]

One issue with going "bigger, wider and stickier" with the tires is the heavy point penalities.

I could use 12 points on Tires only if I run Kuhmo V710 in 275 trim.
Or I could use 6 points on tires only if I run the 888's in 245

While the Kuhmos would be much faster than the 888's on the same 9.5" rim, unless you have the right suspension and camber setup, you're not using all that nice expensive rubber anyway, and those 6 saved points may be better used on something like a new front bumper with brake ducting, lightweight mods in certain areas to get a better balance, sways, camber arms, anything.


Did you ever track your car with the OEM stock swaybars?

[betamotorsports]

I can add an aftermarket limited slip for what, +3 points?

Nope, aftermarket LSD is a +1 mod on a base 350Z because the Enthusiast is on the same line as the Base and it came with a LSD. Already had that confirmed by Greg.

[laze1]

Yep, i ran a couple of track days 100% stock..I didn't like the body roll or nose dive.

Note: I had a S2000 before the Z, the change was massive. I almost thought I had made a mistake buyin the Z. But I like it now and am comfortable at speed in it..very confident.

Also, I wasn't the same driver as I am now..I have about 30 track days now, about 15 in the Z. Somewhere around track day #20...I figured out how to drive! My speed has continued to steadily improved to the point that I decided to try NASA TT last month (Barber). I finished 4th out of 6 in TTB and about 20th out of 30 overall. So was not the slowest guy on the track, but clearly not the fastest, even in class.

So, I am ready to go back and try it in near stock config for TTC and see how that works. Again, all this is just for fun and hopefully a beer mug or 2

Originally Posted by Fluid1

Did you ever track your car with the OEM stock swaybars?

[Fluid1]

I hear ya man. I'll most definitely be in TTC