scot w.
GNSperformance.com
- Joined
- Feb 19, 2005
Up-Date
Sorry for the long delay on updating this thread but we have been very buisy lately and still trying to fit in more testing. We have been doing some involved testing in efforts to achive a nicely ballanced G-body for the autocross and Roadcourse. We will get pretty involved here on some topics such as "Torsional Rigidity", Drag co-efficiant, Etc. so if you plan on actually competeing in an Autocross or on a Roadcourse you might want to follow along.
We are now the Buick vendor for DSE (Detroit Speed & Engineering) bringing you a Fully bolt-in Pro-touring suspension for the G-Body cars. We are in the process of installing a complete DSE G-Body suspension on the GNS test car early next week. We will be documenting the complete install by video & pictures. Soon as we are done we will edit everything into a nice video and post it for everyone.
To get prepared for this install we have done A LOT of priliminary testing and measurements in stock form and as it sits now.
To begin we will add the beginning Stock ride heights and with the Hotchkis rear lowering springs.
STOCK Ride height measurements were:
* FRONT = 25.5"
* REAR = 27.75"
With HOTCHKIS Lowering springs in rear:
* REAR = 26.75" (Perfect 1" Drop)
Next we SCALED the car on all 4 corners (on 8/30/10). 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 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 without 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 close to 50%.
Here is what 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 recomended presure.
We started with leveling the scales on the surface to make sure they were level before we started. Then we jacked the car up in the center and lowered it onto the scales front & rear. With the whole car resting on all for 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". I will now disconnect one end link on the front and rear anti roll bars when scaling next time, then connect them on the scales and shim them so they don't jack weight from one corner to the other. 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.
We won't be bothering with scaling the car again untill the new DSE suspension is on then once that is finished we will go back and re-scale the car with exactly the same gas and disconected sway bars and see what we come up with and go from there.
SW.
Sorry for the long delay on updating this thread but we have been very buisy lately and still trying to fit in more testing. We have been doing some involved testing in efforts to achive a nicely ballanced G-body for the autocross and Roadcourse. We will get pretty involved here on some topics such as "Torsional Rigidity", Drag co-efficiant, Etc. so if you plan on actually competeing in an Autocross or on a Roadcourse you might want to follow along.
We are now the Buick vendor for DSE (Detroit Speed & Engineering) bringing you a Fully bolt-in Pro-touring suspension for the G-Body cars. We are in the process of installing a complete DSE G-Body suspension on the GNS test car early next week. We will be documenting the complete install by video & pictures. Soon as we are done we will edit everything into a nice video and post it for everyone.
To get prepared for this install we have done A LOT of priliminary testing and measurements in stock form and as it sits now.
To begin we will add the beginning Stock ride heights and with the Hotchkis rear lowering springs.
STOCK Ride height measurements were:
* FRONT = 25.5"
* REAR = 27.75"
With HOTCHKIS Lowering springs in rear:
* REAR = 26.75" (Perfect 1" Drop)
Next we SCALED the car on all 4 corners (on 8/30/10). 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 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 without 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 close to 50%.
Here is what 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 recomended presure.
We started with leveling the scales on the surface to make sure they were level before we started. Then we jacked the car up in the center and lowered it onto the scales front & rear. With the whole car resting on all for 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". I will now disconnect one end link on the front and rear anti roll bars when scaling next time, then connect them on the scales and shim them so they don't jack weight from one corner to the other. 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.
We won't be bothering with scaling the car again untill the new DSE suspension is on then once that is finished we will go back and re-scale the car with exactly the same gas and disconected sway bars and see what we come up with and go from there.
SW.
