jmill96Z

iTrader: (3)

I was just wondering how muh is too much? How will a steep rake effect the weight transfer of the car. I'm asking b/c my car has a pretty decent rake, and I think it could be hurting the transfer.

GregWS6&z28

iTrader: (8)

good question. I'm wondering this also since I installed some qa1's. I would think that you wouldnt want the front more than an inch lower than the midpoint between the line from the front wheel to the back wheel. no more than 2" of rake. it should help MPH due to drag but you will probably lose weight transfer potential

tektrans

iTrader: (23)

On my old set up I found that a steeper rake definately hurt my weight transfer. Car
60'ed much better after decreasing the rake.

jmill96Z

iTrader: (3)

So, are we talking 1 or 2 degrees?

dlove

iTrader: (23)

my front is about a 1/2 inch lower than the rear.

i think when its really low the car won't transfer weight untill the front is above the centerline. correct me if im wrong

RAGENZ28

iTrader: (5)

I like the front of the car 1" lower than the rear.

getusumws6

iTrader: (9)

as stated above you want the front and rear within 1" of each other, for best results.

Rogue86

iTrader: (14)

Also, something to consider is if you have access to a set of scales (any local chassis shops or decent circle track racers should have them) scale your car.

Setting your front-rear and left to right weight bias will determine where your ride height needs to be.

Per the directions for scaling your car as per Madman in the September 2007 issue of GM High Tech, you want 10-20lbs more weight on the right rear corner of the car. In a NA application you want 51% weight bias to the front and in a power adder car 53% to the front. The sway bars should be disconnected during the scaling process and reattached afterwords in a nuetral position, putting no preload in the chassis.

jmill96Z

iTrader: (3)

I have been thinking about buying a set of scales for that reason alone. I have been looking for a way to apply aircraft weight and balance principles to my car. So, in theory it is all based on canter of gravity. I take the reading from each scale, along with it's location (arm) in reference to the reference datum (imaginary line at the nose of the car). What we're looking at is weight x arm = moment(rotational force in inch/lbs)

Example:
If I have one scale under each tire with the following weights

LF 1234
RF 1256
LR 876
RR 825

The arm for each front tire is measured in inches from the tip of the front bumper. Let's say the front scales are at 22" and the rears are at 210 ( BS # for example only)


here's how I figure the car's CG

LF 1234 x 22= 27148
RF 1256 x 22= 27632
LR 876 x 210= 183960
RR 825 x 210= 173250

Add weight and moment and calculate arm (point at which CG is)


car weight is 4191
car moment is 411990
Claculated CG nose to tail is moment/weight=arm
Calculated CG is 98.1 inches from the nose of the car


I don't know if this is even relevant after typing it all out. If someone who has scaled their car, and wants to shoot me some real #'s and measurements I can see if it really works.

Rogue86

iTrader: (14)

WOW... I can't really follow all that, but I think you are making it wayyy to hard on yourself. Set you bias up front to rear and set up the right rear 20lbs heavier than the left rear and you are good to go.

dochall22

iTrader: (6)

I dunno about performance but i think it makes the car look awesome. my car had eibachs all the way around lowers 1.5 or more, and i just swapped a set of v6 springs in the rear and now it looks f'n sweet

jmill96Z

iTrader: (3)

It's really hard to explain over the net. I can do this stuff in about 10 minutes if the car is on scales. The reason people put their battery in the back is to change the center of gravity. I can use my program at work, or do it by hand in a couple of minutes to figure out the exact shift in CG without weighing the car again.


I'm going to do some testing this year at the track to see if I can't find out if this stuff actually works or not.


Maybe I am overthinking this, but I think it could be usefull to dialing in a chassis.