Date: Sun, 27 Nov 2011 09:56:23 -0500
Reply-To: Derek Drew <derekdrew@DEREKMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Derek Drew <derekdrew@DEREKMAIL.COM>
Subject: Re: Setting Corner Spring Rates -- Nissan 2012
In-Reply-To: <CAAj276wDF6mUZu-c7k8EZc57Sv4TS41QmRoWa0q_+2BBUwFg5A@mail.g
mail.com>
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<font size=3>Bozo engineering too? <br><br>
Nissan GT-R 2012<br>
------------------------<br>
<a href="http://drivemagazine.co.za/wp-content/uploads/2011/11/2012-Nissan-GT-R-Silverstone.jpg">
<br>
</a>The updated, 2012 Nissan GT-R has been revealed. The new model has
even more power spewing forth from its engine bay, unique asymmetric
suspension settings for right hand drive models, and a rear view camera
is now standard.<br><br>
The GT-R even has different spring rates and rear suspension geometry
from one side to the other to account for the weight of the driver. It’s
a typically meticulous job by the GT-R’s chief engineer Mizuno-san and
his team of GT-R obsessives.<br><br>
The GT-R’s transaxle gearbox sits just to the right of the main
propshaft, which means in right-hand drive form it carries 50kg too much
corner weight on that side of the car. This has been addressed by adding
spring rate and damper support to the right front of the car, and
removing it from the front left. The actual pivot position of the
respective sides has been adjusted too. <br><br>
The GT-R’s 3.8L twin-turbocharged V6 engine’s peak power output has been
upped to 550PS/404kW @ 6 400rpm. Maximum torque has also been boosted,
now climaxing with 632Nm between 3 200 – 5 800rpm. Although the peak
figures are the drawcard, power and torque delivery is equally important
for actual performance. Engine response and torque has therefore been
improved when at mid and low speed. Power at high rpm has also been
optimised. In essence, the power and torque curves are better.<br><br>
These improvements have been achieved thanks to a variety of tweaks.
Intake efficiency has been refined, and air flow resistance has been
reduced. Exhaust emissions have also been reworked, and new exhaust
valves have been employed. Further honing has been applied to the valve
timings, the air-fuel mixture ratio and the ignition timing.<br><br>
======================================<br><br>
<br>
At 06:54 PM 11/26/2011, you wrote:<br>
<blockquote type=cite class=cite cite="">Sorry to say but the best bet
is redistribution of weight in/on your<br>
charriot. Spring rate changes the amount load transfer and shocks
the<br>
timing of that transfer, the rates you were showing would make us
tight<br>
push on corner entry ,loose at apex and tight/push on corner exit with
the<br>
roundy round dirt cars we ran. Keep your left and right springs
balanced<br>
with the same rate to prevent awkward handling differences between left
and<br>
right turns,you may put more or less of a split between front and
rear<br>
which will only change handling on acceleration and braking<br>
<br>
Velma 82diesel 1.6 na westy<br><br>
On Nov 26, 2011 10:04 AM, "Don Hanson"
<dhanson928@gmail.com> wrote:<br><br>
On Sat, Nov 26, 2011 at 4:43 AM, Derek Drew
<derekdrew@derekmail.com> wrote:<br><br>
> Nobody seems to real...<br>
The most important part of setting up a vehicle for optimum
handling is<br>
corner weights. The ride height has to be adjusted properly
to achieve<br>
optimum corner weight distribution. Until the ride height is
properly<br>
adjusted, nothing else will make any predictable and consistent<br>
difference. You could put 300lb springs LF/RR and 1000lb ers
RF/LR...and<br>
still not even up the actual tire load if the ride height is not<br>
optimized. Wheel alignment, too, is totally dependent on ride
height<br>
adjustment. Suspensions work as a System...changes to one part of
the<br>
system affect the rest of the parts of the system...Corner weight and
ride<br>
height are very interdependent....You adjust your corner weight by
changing<br>
the ride height...and of course standard suspension on a Vanagon is
not<br>
very easily adjustable.<br><br>
Spring rates: First, you must have the load at the tires
adjusted to<br>
optimum....that is where you can start calculating the spring rates
you<br>
want....Using the body work to measure ride height is not very
accurate.<br>
To be accurate, one needs four scales and a very very level spot to
set<br>
up. The ride height needs to be measured at some chassis point that
is<br>
close to the suspension axis of movement..... As little as 1/16th of
an<br>
inch change in ride height can transfer a hundred lbs of tire load
from<br>
corner to corner.....A few hundred lbs of tire load makes a huge
difference<br>
in how a vehicle will respond in low traction situations. You
simply<br>
can't expect to get any meaningful improvement in vehicle behavior
by<br>
willy-nilly swapping of springs of different rates, without first
getting<br>
it evened up on it's tires....Period.<br><br>
In the original post, it was mentioned the LR/RF had a hugely
bigger load<br>
than the two opposite corners, right? Think of your dining
room<br>
table...the one that rocked on it's legs till you stuck that
matchbook<br>
under one leg (or more properly cut the longer legs down). Now,
think of<br>
those legs ...If you make the two lower corner legs out of 6x6
timbers,<br>
they still would be too short. If you say..."hey, these tall
legs, they<br>
are holding up 200lbs of food and drink, I better make them from angle
iron<br>
to carry this big load"....they will still be too long and the table
will<br>
still rock and spill your wine....<br><br>
Heavier springs/lighter springs...change the springs very much and
you<br>
will need to change the shock action, too.
Dampers/Dampeners...whatever,<br>
the shocks control how quickly the springs compress and extend.<br><br>
Suspension art is really fascinating and quite a
study.</blockquote>
<x-sigsep><p></x-sigsep>
_______________________________________________<br>
Derek
Drew
<br>
Washington DC / New York<br>
derekdrew@derekmail.com<br>
Email is best normally but...<br>
PHONE: 202-966-7907 (Call the number at left normally)<br>
(alt/cell for diligent calling only): 703-408-1532<br><br>
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