300zxtt update and suspension=Q45

[Q45tech]

Why lowered Q may actually roll more even with stiffer springs:

The ball joint has been replaced with another spherical bearing with a long shank attaching it to the spindle. This relocates the control arm lower, which raises the front roll center back to nearly its stock location.

The roll center, by the way, is the imaginary point in space the body rolls about in a turn. When the car is lowered, the roll center is lowered as well. The distance between the roll center and the car's center of gravity is called the roll moment, and the roll moment is basically the lever arm Isaac Newton used to make the body roll in a turn. When lowering a multi-link car, the roll center usually drops more than the center of gravity does, which makes the roll moment longer, causing more body roll. Even though the overall center of gravity is now lower, the torque making the car lean in a turn and causing weight transfer to the outside wheels is greater. Since the SPL lower arms raise the roll center back up, they reduce the roll moment, reducing roll and weight transfer to the outside wheels. Pretty cool, huh? This goes a couple of levels beyond your typical bolt-on suspension kit.

Our current setup is -2.5 degrees camber in the front with 9 degrees caster and zero toe, and -1.25 degrees camber with 0.125-inch toe-in in the rear.

http://www.sportcompactcarweb....t300z/http://www.splparts.com/

[elwesso]

great, something else for me to buy!!!!!

Interesting info though tech...

[irax]

Roll Center is your best friend. We went thrugh a long disccusion about this on one of the drift forums about what a proper roll center will do for you. The thing is if you have a propper roll center you wont need so stiff springs, stock spring rate is usualy really good for all-round road racing/auto-x its just stock ride hight isnt. And when you dont properly lower vehicles (Reads:"With out adjusting toe,caster,camber and roll center") you can get more body roll then stock.

Q45tech

Q: Which 300zx arms can we use on the G50? just the upper? or is lower usable too? What about the rears?

[elwesso]

Im sure the lower control arms can be used.. I know for a fact the uppers, tension rods, and all the rear links can be used.

[sijoko]

The Z32 lower control arms will work in the rear for sure.

I am pretty sure the front ones are also the same.

The SPL stuff is probably the greatest value for aftermarket suspension parts. Way cheaper than ordering anything from Japan.

Another way to adjust the roll center is to use spacers to push the wheels out. This will raise the roll center slightly.

[irax]

Another way to adjust the roll center is to use spacers to push the wheels out. This will raise the roll center slightly.

I don't think so. Spacers will adjust the foot print but not the roll center so much...

[66mgb]

Looking at these Sportline vs SPLAre they comperable to the SPL's?

http://cgi.ebay.com/ebaymotors...ZWDVW

[redmanfx]

These lower pro arms are only $627...........



red

[elwesso]

They may be comparable but for an extra $20 shipped or so, you can have the SPL which are guarnteed quality, and youll be buying from a NICO sponsor.

SPL are 342 shipped, those are $320 shipped....

[irax]

These lower pro arms are only $627...........



red

those are the s13/14 lca's not the z32 lca's that they show in the artcle

*edit* are the arms in the article a new designe? i like the idea of tubular and not boxed...

[sijoko]

I don't think so. Spacers will adjust the foot print but not the roll center so much...

When the center of the tire contact patch is moved, it will affect the roll center. It will be slight but nevertheless there is a change.

If the wheel is moved out, then the line drawn from the instantaneous center to the center of the tire contact patch will be longer which results in the roll center moving up slightly.

[redmanfx]

The picture of the SPL Lower arms I posted are indeed for the 90-99 Z32. Straight from their website.

red

[Q45tech]

Anyway the post was about lowering and how simple changes in complex suspension often make matters worse or at least some aspects worse.For sure every change from oem will increase the harshness and vibration transmission into the steering wheel and seat.

What you gain from simple spring lower is never much but after you have optimized the sway bars 28/20, plus Tokico HP series, it is the only cheap mod out there.

With some 245/255 tires all around in a higher than 95 load index and oem soft fast wearing 160-200 rating......even the 94-96 came new with 200.

[irax]

the best suspension change you can do is wheels and tires, propper offsets, width and compound will make the best bang for the buck.

[Q45tech]

It is assumed that Q45 members would be utilizing tires at least of oem performance [less than 200 treadwear index] and quality, [at or greater than 95V rating] unfortunately this is rarely the case.

Any wheel significantly [more than a few pounds] heavier than oem is a down grade in performance any shims added to make a wheel fit is a downgrade due to lower heat conductivity of such shims.

[midnightsliding]

quick question.. dose and one know if the (Z32) solid subframe and diff bushings will work on a G50s subframe.

[elwesso]

They will.

[midnightsliding]

wow that ur then man wes...

[jamesmost]

quick question.. dose and one know if the (Z32) solid subframe and diff bushings will work on a G50s subframe.

did that a while back car is solid and direct w/ bushings