Corner Balance Numbers. Air Cooled Crowd Chime In Pls
08-08-2017, 11:06 PM
#1
Burning Brakes
Thread Starter
Corner Balance Numbers. Air Cooled Crowd Chime In Pls
So I got a set of scales and i'm tinkering with the car in the garage. Just played with it for a while (been in the garage long enough that my wife thinks im hiding a girlfriend in there) and got the following weights. Considering air cooled handling dynamics, do i need to have a bit more weight on the LR tire to help with right turns considering most track i go to have a lot more right handers than left handers or do i need to stop her and pronounce Mission Accomplished.
FL 585 FR 596
RL 804 RR 814
F vs R weight distribution 42.2% vs 57.8%
L vs R 1389lbs 49.6 vs 1410lbs 50.4
Cross weights are dead on at 1400 lbs
Eugene
FL 585 FR 596
RL 804 RR 814
F vs R weight distribution 42.2% vs 57.8%
L vs R 1389lbs 49.6 vs 1410lbs 50.4
Cross weights are dead on at 1400 lbs
Eugene
08-09-2017, 12:37 AM
#3
I know nothing about air cooled but some common mistakes in scaling are:
lack of flat floor
forgetting to detach 1 side of sway bars
forgetting to inflate to proper pressures
not setting ride height
not dealing with suspension stichion (especially with rubber bushings)
lack of driver's weight in driving position
lack of 1/2 of "race" distance fuel load
lack of flat floor
forgetting to detach 1 side of sway bars
forgetting to inflate to proper pressures
not setting ride height
not dealing with suspension stichion (especially with rubber bushings)
lack of driver's weight in driving position
lack of 1/2 of "race" distance fuel load
08-09-2017, 12:45 AM
#4
Burning Brakes
Thread Starter
I know nothing about air cooled but some common mistakes in scaling are:
lack of flat floor
forgetting to detach 1 side of sway bars
forgetting to inflate to proper pressures
not setting ride height
not dealing with suspension stichion (especially with rubber bushings)
lack of driver's weight in driving position
lack of 1/2 of "race" distance fuel load
lack of flat floor
forgetting to detach 1 side of sway bars
forgetting to inflate to proper pressures
not setting ride height
not dealing with suspension stichion (especially with rubber bushings)
lack of driver's weight in driving position
lack of 1/2 of "race" distance fuel load
08-09-2017, 12:19 PM
#5
Three Wheelin'
Corner balance
Another thing to include is driver weight. Looking at your numbers, I'm guessing you did not include as the drivers side is usually heavier.
Here is how I set my target corner weight (with driver weight in car).
Derermine left side weight (LF + LR) and right side wt (RF + RR)
Determine front to rear weight distribution, ie front axle/total wt and rear axle/total wt. (I will use 40/60% here):
Target weights:
LF = Left side wt X 40% front split
RF = Right side wt X 40% front split
LR = Left side wt X 60% rear split
RR = Right side wt X 60% rear split
I know that there are a few ways that people use, but I like this one
Here is how I set my target corner weight (with driver weight in car).
Derermine left side weight (LF + LR) and right side wt (RF + RR)
Determine front to rear weight distribution, ie front axle/total wt and rear axle/total wt. (I will use 40/60% here):
Target weights:
LF = Left side wt X 40% front split
RF = Right side wt X 40% front split
LR = Left side wt X 60% rear split
RR = Right side wt X 60% rear split
I know that there are a few ways that people use, but I like this one
08-09-2017, 01:26 PM
#6
Three Wheelin'
What kind of car do you have?
It appears that you have completed a basic CB, including accounting for the parameters mentioned by Mr. fatbillybob.
And of course, all this assumes you have moved any weight you can into strategic positions.
I have a 911 GT car. It weighs about 2150 without a driver (that includes about 250-300 pounds of strategically-placed ballast).
I use tire pressures that are based on quali, not race conditions. Same for fuel levels. I also set ride height and alignment based on these quali parameters as well. So the entire basic set up is biased toward quali.
I haven't done anything to determine how different things would be with racing fuel levels and tire pressures-- I suppose I can quantify that the next time I do set up, which is coming soon. I'd guess the difference is likely to be small with this kind of car.
Beyond the basics, it is possible to start making further adjustments to target specs based on more subtle variables, like those specific to certain tracks, et cetera. For example, folks that race at places like Lime Rock and Fontana may take into account some track-specific variables.
For many applications, much of this fine tuning is "in the noise."
It appears that you have completed a basic CB, including accounting for the parameters mentioned by Mr. fatbillybob.
And of course, all this assumes you have moved any weight you can into strategic positions.
I have a 911 GT car. It weighs about 2150 without a driver (that includes about 250-300 pounds of strategically-placed ballast).
I use tire pressures that are based on quali, not race conditions. Same for fuel levels. I also set ride height and alignment based on these quali parameters as well. So the entire basic set up is biased toward quali.
I haven't done anything to determine how different things would be with racing fuel levels and tire pressures-- I suppose I can quantify that the next time I do set up, which is coming soon. I'd guess the difference is likely to be small with this kind of car.
Beyond the basics, it is possible to start making further adjustments to target specs based on more subtle variables, like those specific to certain tracks, et cetera. For example, folks that race at places like Lime Rock and Fontana may take into account some track-specific variables.
For many applications, much of this fine tuning is "in the noise."
08-09-2017, 05:16 PM
#7
Burning Brakes
Thread Starter
Actually those numbers are with me sitting in the car. My helper was reading the scales as i sat there. Adjustments were made after each reading. The reason why i think there's such an even split between left and right side and the slightly better than 40/60 weight distribution is the fact there's a 200 lbs ballast in the passenger floor board to make race weight. Car itself is very light, around ~2375 lbs
Looking at your method below, I'm good to go. I would get spot on numbers. I'll go once over and make sure i'm getting the same results today.
Looking at your method below, I'm good to go. I would get spot on numbers. I'll go once over and make sure i'm getting the same results today.
Another thing to include is driver weight. Looking at your numbers, I'm guessing you did not include as the drivers side is usually heavier.
Here is how I set my target corner weight (with driver weight in car).
Derermine left side weight (LF + LR) and right side wt (RF + RR)
Determine front to rear weight distribution, ie front axle/total wt and rear axle/total wt. (I will use 40/60% here):
Target weights:
LF = Left side wt X 40% front split
RF = Right side wt X 40% front split
LR = Left side wt X 60% rear split
RR = Right side wt X 60% rear split
I know that there are a few ways that people use, but I like this one
Here is how I set my target corner weight (with driver weight in car).
Derermine left side weight (LF + LR) and right side wt (RF + RR)
Determine front to rear weight distribution, ie front axle/total wt and rear axle/total wt. (I will use 40/60% here):
Target weights:
LF = Left side wt X 40% front split
RF = Right side wt X 40% front split
LR = Left side wt X 60% rear split
RR = Right side wt X 60% rear split
I know that there are a few ways that people use, but I like this one
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08-09-2017, 05:24 PM
#8
Burning Brakes
Thread Starter
The car is a 86 3.2 Carrera. Tire pressures were set up as if i was running hot pressures on the track 32 psi all around. 3/4 Fuel. It's pretty light as everything unnecessary was stripped out. As I mentioned above it does have a 200lbs balllast in the passenger footwell/floor which i think is keeping things pretty balanced from left to right with me in it.
I think further adjustments based on specific track would be beyond my expertise. Not sure how for example to change the corner weight specific to Lime rock where you're doing all right hand turns. I initially thought more weight on the left would help with that track but I'm not sure to be honest. I just wanted to get to a good spot that works well for these cars for most of the Northeastern tracks and go from there
I think further adjustments based on specific track would be beyond my expertise. Not sure how for example to change the corner weight specific to Lime rock where you're doing all right hand turns. I initially thought more weight on the left would help with that track but I'm not sure to be honest. I just wanted to get to a good spot that works well for these cars for most of the Northeastern tracks and go from there
What kind of car do you have?
It appears that you have completed a basic CB, including accounting for the parameters mentioned by Mr. fatbillybob.
And of course, all this assumes you have moved any weight you can into strategic positions.
I have a 911 GT car. It weighs about 2150 without a driver (that includes about 250-300 pounds of strategically-placed ballast).
I use tire pressures that are based on quali, not race conditions. Same for fuel levels. I also set ride height and alignment based on these quali parameters as well. So the entire basic set up is biased toward quali.
I haven't done anything to determine how different things would be with racing fuel levels and tire pressures-- I suppose I can quantify that the next time I do set up, which is coming soon. I'd guess the difference is likely to be small with this kind of car.
Beyond the basics, it is possible to start making further adjustments to target specs based on more subtle variables, like those specific to certain tracks, et cetera. For example, folks that race at places like Lime Rock and Fontana may take into account some track-specific variables.
For many applications, much of this fine tuning is "in the noise."
It appears that you have completed a basic CB, including accounting for the parameters mentioned by Mr. fatbillybob.
And of course, all this assumes you have moved any weight you can into strategic positions.
I have a 911 GT car. It weighs about 2150 without a driver (that includes about 250-300 pounds of strategically-placed ballast).
I use tire pressures that are based on quali, not race conditions. Same for fuel levels. I also set ride height and alignment based on these quali parameters as well. So the entire basic set up is biased toward quali.
I haven't done anything to determine how different things would be with racing fuel levels and tire pressures-- I suppose I can quantify that the next time I do set up, which is coming soon. I'd guess the difference is likely to be small with this kind of car.
Beyond the basics, it is possible to start making further adjustments to target specs based on more subtle variables, like those specific to certain tracks, et cetera. For example, folks that race at places like Lime Rock and Fontana may take into account some track-specific variables.
For many applications, much of this fine tuning is "in the noise."
08-09-2017, 06:46 PM
#9
Three Wheelin'
Cool. That car sounds pretty light... I see that you have a very lightweight driver.
As I stated, mine is a less than 2000 pounds without the ballast or driver.
I am sure that if/when you become motivated, you can network to some relatively local resources to learn what subtle things you may be able to do for further refinement. For example, depending on your application and potentially, class rules, you may be able to take out more weight in parts, and place it back in as ballast in better spots.
I have a bunch of local resources with decades of Porsche pro racing experience. They can tell me what subtle tweaks work best for Sears Point, Laguna Seca, et cetera.
Two further suggestions...
Consider acquisition and study of Fred Puhn's How to Make Your Car Handle. I refer to mine often. The car on the cover is one that some of my local resources helped develop and support.
Consider what potentially might be even more strategic ballast placement. When I did my ballast project, I wanted to add weight in front. I wound up with a stack of plates in the smuggler's box (about 40 pounds) and a stack in the passenger footwell. I even have a stack that emulates my cool shirt box for conditions when I am not using it.
One of our racers, a very clever attorney and accomplished driver, modified a 911 front belly pan so he can add tuning/ballast weights in various locations along the car's transverse axis up front. Easy and clever.
As I stated, mine is a less than 2000 pounds without the ballast or driver.
I am sure that if/when you become motivated, you can network to some relatively local resources to learn what subtle things you may be able to do for further refinement. For example, depending on your application and potentially, class rules, you may be able to take out more weight in parts, and place it back in as ballast in better spots.
I have a bunch of local resources with decades of Porsche pro racing experience. They can tell me what subtle tweaks work best for Sears Point, Laguna Seca, et cetera.
Two further suggestions...
Consider acquisition and study of Fred Puhn's How to Make Your Car Handle. I refer to mine often. The car on the cover is one that some of my local resources helped develop and support.
Consider what potentially might be even more strategic ballast placement. When I did my ballast project, I wanted to add weight in front. I wound up with a stack of plates in the smuggler's box (about 40 pounds) and a stack in the passenger footwell. I even have a stack that emulates my cool shirt box for conditions when I am not using it.
One of our racers, a very clever attorney and accomplished driver, modified a 911 front belly pan so he can add tuning/ballast weights in various locations along the car's transverse axis up front. Easy and clever.