scot w.
GNSperformance.com
- Joined
- Feb 19, 2005
I would like to start this off with a little information on what we’re doing to our GNS test T-Type and our goals then move into the build process with pictures. Our goal with this car is to frequent Autocross & Road courses while keeping a Track Ready Street Friendly handling car whether it be on the street, at the drag strip or on a closed course. Our motto is "Function is Everything"!
We chose Detroit Speed & Engineering’s full G-Body suspension package as the suspension for our GNS Test car. One thing about DSE, They are pounding their cars every weekend, customers are pounding their cars every weekend, and most of the time a DSE equipped car is winning and that alone made it an easy choice for us.
GNS Performance is now an Authorized Dealer for all DSE products. See us for Member discounts!.
We will start off with some basic measurements to give us a base to start with.
Here are a few basic numbers on our GNS test car:
Wheel base: 2746mm - 108.1in
Track: Front: 1486mm - 58.5in / Rear: 1466mm - 57.7in
Length: 5095mm - 200.6in
Width: 1819mm - 71.6in
Height: 1387mm - 54.6in
Drag Coefficient: 0.410 (Tested by GM)
Current Tire / Wheel sizes: Wheel make- CCW / 3-Piece
FRONT WHEEL: 18" X 9.5" - 4.75 Back Spacing
REAR WHEEL: 18" X 10.0" - 4.75 Back Spacing
FRONT TIRE: 255-35/18
REAR TIRE: 285-40/18
NOTE: No rubbing issues at all with stock suspension!! Went to Hotchkis lowering springs in the rear only and it dropped it perfectly 1". Got minor rubbing so I rolled the lips with the moldings.
A lot more info on wheels & fitment here:http://www.turbobuick.com/forums/br...-wheels/295464-18-ccw-wheels-scot-ws-car.html
Stock ride height from floor to wheel well lip w/CCW wheels:
FRONT: 25.5"
REAR: 27.75"
REAR ride height After installing the Hotchkis lowering springs = 26.75"
4-Corner Scaling: Done on (8/30/10)
Next we SCALED the car on all 4 corners to give us a weight on all 4 corners before installing the DSE suspension. After the installation we will re-scale the car to see how much weight was shaved and where. We will talk about front percentage when comparing weight percentages car to car and leave off the rear percent. The general goal with Pro-touring cars that are going to be competitive is to try and reach 50% front weight, but usually we only get to 53% to 51% at best.
Some like to do basic scaling with the driver, I prefer to scale it Without the driver just because the driver weight can vary depending on who it is or if there is a passenger. And you don't want to mess with placing 180to 200 lbs of weight in the car every time you do a corner balance.
When trying to even up cross weight you want to get as close to 50% as possible.
Here is what we had in the car had at Scaling..
* Full tank of gas just topped off!
* Nothing left inside the cars counsel /glove box, no floor mats.
* Nothing in the trunk.
* Tires at recommended pressure.
First we started with leveling the scales on the surface to make sure they were level before we started. This was done using a 6ft level across the scales, and then we jacked the car up in the center and lowered it onto the scales front & rear. With the whole car resting on all four individual scales we took measurements.
FRONT "CAR ONLY" :
* Left = 997 lbs
............................Total front "car only" = 1,953 lbs
* Right= 956 lbs
REAR "CAR ONLY"
* Left = 695 lbs
............................ Total Rear "car only" = 1,436 lbs
* Right = 741 lbs
Completed Percentages & Formula:
Front Bias: 1953 / 3389 = .57627 = 57.6%
Rear Bias: 1436 / 3389 = .42372 = 42.4%
The left front and right rear are heavier than they should be. The left side usually is heavier than the right, - "without driver". Next time we scale the car we will disconnect one end link on the front and rear anti roll bars when scaling, then connect them on the scales and shim them so they don't jack weight from one corner to the other. Doing this removes any unwanted bind the sway bars could be causing. Raising a spring perch on the LF corner will increase weight on the LF and RR corners.
Our left and right side weights add up to almost even, so by adjusting the heavy corners we should be able to balance them pretty close without driver.
Next post will be install pictures and more measurements.
SW.
Picture below is how the car sits now...
We chose Detroit Speed & Engineering’s full G-Body suspension package as the suspension for our GNS Test car. One thing about DSE, They are pounding their cars every weekend, customers are pounding their cars every weekend, and most of the time a DSE equipped car is winning and that alone made it an easy choice for us.
GNS Performance is now an Authorized Dealer for all DSE products. See us for Member discounts!.
We will start off with some basic measurements to give us a base to start with.
Here are a few basic numbers on our GNS test car:
Wheel base: 2746mm - 108.1in
Track: Front: 1486mm - 58.5in / Rear: 1466mm - 57.7in
Length: 5095mm - 200.6in
Width: 1819mm - 71.6in
Height: 1387mm - 54.6in
Drag Coefficient: 0.410 (Tested by GM)
Current Tire / Wheel sizes: Wheel make- CCW / 3-Piece
FRONT WHEEL: 18" X 9.5" - 4.75 Back Spacing
REAR WHEEL: 18" X 10.0" - 4.75 Back Spacing
FRONT TIRE: 255-35/18
REAR TIRE: 285-40/18
NOTE: No rubbing issues at all with stock suspension!! Went to Hotchkis lowering springs in the rear only and it dropped it perfectly 1". Got minor rubbing so I rolled the lips with the moldings.
A lot more info on wheels & fitment here:http://www.turbobuick.com/forums/br...-wheels/295464-18-ccw-wheels-scot-ws-car.html
Stock ride height from floor to wheel well lip w/CCW wheels:
FRONT: 25.5"
REAR: 27.75"
REAR ride height After installing the Hotchkis lowering springs = 26.75"
4-Corner Scaling: Done on (8/30/10)
Next we SCALED the car on all 4 corners to give us a weight on all 4 corners before installing the DSE suspension. After the installation we will re-scale the car to see how much weight was shaved and where. We will talk about front percentage when comparing weight percentages car to car and leave off the rear percent. The general goal with Pro-touring cars that are going to be competitive is to try and reach 50% front weight, but usually we only get to 53% to 51% at best.
Some like to do basic scaling with the driver, I prefer to scale it Without the driver just because the driver weight can vary depending on who it is or if there is a passenger. And you don't want to mess with placing 180to 200 lbs of weight in the car every time you do a corner balance.
When trying to even up cross weight you want to get as close to 50% as possible.
Here is what we had in the car had at Scaling..
* Full tank of gas just topped off!
* Nothing left inside the cars counsel /glove box, no floor mats.
* Nothing in the trunk.
* Tires at recommended pressure.
First we started with leveling the scales on the surface to make sure they were level before we started. This was done using a 6ft level across the scales, and then we jacked the car up in the center and lowered it onto the scales front & rear. With the whole car resting on all four individual scales we took measurements.
FRONT "CAR ONLY" :
* Left = 997 lbs
............................Total front "car only" = 1,953 lbs
* Right= 956 lbs
REAR "CAR ONLY"
* Left = 695 lbs
............................ Total Rear "car only" = 1,436 lbs
* Right = 741 lbs
Completed Percentages & Formula:
Front Bias: 1953 / 3389 = .57627 = 57.6%
Rear Bias: 1436 / 3389 = .42372 = 42.4%
The left front and right rear are heavier than they should be. The left side usually is heavier than the right, - "without driver". Next time we scale the car we will disconnect one end link on the front and rear anti roll bars when scaling, then connect them on the scales and shim them so they don't jack weight from one corner to the other. Doing this removes any unwanted bind the sway bars could be causing. Raising a spring perch on the LF corner will increase weight on the LF and RR corners.
Our left and right side weights add up to almost even, so by adjusting the heavy corners we should be able to balance them pretty close without driver.
Next post will be install pictures and more measurements.
SW.
Picture below is how the car sits now...
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