How much rake is too much?
Thread Starter
10 Second Club
iTrader: (3)
Joined: Feb 2006
Posts: 2,554
Likes: 1
From: Movin' On Up
How much rake is too much? 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.
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
Trending Topics
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.
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.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo Thread Starter
10 Second Club
iTrader: (3)
Joined: Feb 2006
Posts: 2,554
Likes: 1
From: Movin' On Up
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.
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.
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.
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
Thread Starter
10 Second Club
iTrader: (3)
Joined: Feb 2006
Posts: 2,554
Likes: 1
From: Movin' On Up
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.
