Best way to eliminate understeer
06-20-2020, 10:02 AM
#31
Three Wheelin'
Thread Starter
Look I appreciate the suggestions on driving, but I can manage that part. The reality is if a student were to ever tell me that xyz car forum suggested they drive their car a certain way I would tell them to forget everything they read and we would start from scratch. The problem taking suggestions from forums on driving is one, you have no idea what experience level the people making the suggestions have, they could simply have done a handful of DEs. Two forum suggestions are just guesses about a persons driving abilities and are nothing more without actually seeing the person drive.
Car setup suggestions are the same, if someone says xyz is the only way to drive this car, those are suggestions and may not match someone’s driving style, if this were not true all IRL racers would run the exact same setup.
Now were forums can be useful is if someone has enough data/seat time to know how they want to change their car (I want the car to rotate better mid-corner). There are typically many ways and one or two best ways, forum guys typically have good feedback as has been shared on this thread.
But driving suggestions are going in one ear and out the other, which is why I tried to be very specific on what I was looking for. If someone has significant experience and ever wants to meet up at an event and hop in the car, I would 100% be up for that.
Car setup suggestions are the same, if someone says xyz is the only way to drive this car, those are suggestions and may not match someone’s driving style, if this were not true all IRL racers would run the exact same setup.
Now were forums can be useful is if someone has enough data/seat time to know how they want to change their car (I want the car to rotate better mid-corner). There are typically many ways and one or two best ways, forum guys typically have good feedback as has been shared on this thread.
But driving suggestions are going in one ear and out the other, which is why I tried to be very specific on what I was looking for. If someone has significant experience and ever wants to meet up at an event and hop in the car, I would 100% be up for that.
06-20-2020, 10:13 AM
#32
Nordschleife Master
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I don't really get this. Lowering would increase front end negative camber,correct?\
RE: Driver Mod Comment
I would actually go out on a limb and say it is either equipment (tires, old suspension parts, alignment or etc.) or driver error if ones is experiencing bothersome understeer in a 997.2. My GTS had a bit of understeer when I picked it up in October that I had not really experienced in 997.2s. I put new tires on it, had it aligned and whalla . . . back to neutral.
Not saying this is the case at all with OP, but I have seen PCA certified instructors that could not drive for shyte. I had one dang near put my car into a wall at Barber with me in it and I saw him wreck someone else’s car about a year later.
Most instructor ties are about a good 9/10s driver and are very much still learning themselves. The 10/10s guys are usually racing on weekends and it literally takes that level of dedication to develop and hone driver skills. There is not enough track time with a half dozen HPDEs per year to develop sufficient car control skills to be at 10/10s on a consistent basis.
RE: Driver Mod Comment
I would actually go out on a limb and say it is either equipment (tires, old suspension parts, alignment or etc.) or driver error if ones is experiencing bothersome understeer in a 997.2. My GTS had a bit of understeer when I picked it up in October that I had not really experienced in 997.2s. I put new tires on it, had it aligned and whalla . . . back to neutral.
Not saying this is the case at all with OP, but I have seen PCA certified instructors that could not drive for shyte. I had one dang near put my car into a wall at Barber with me in it and I saw him wreck someone else’s car about a year later.
Most instructor ties are about a good 9/10s driver and are very much still learning themselves. The 10/10s guys are usually racing on weekends and it literally takes that level of dedication to develop and hone driver skills. There is not enough track time with a half dozen HPDEs per year to develop sufficient car control skills to be at 10/10s on a consistent basis.
06-20-2020, 10:17 AM
#33
Three Wheelin'
Thread Starter
I don't really get this. Lowering would increase front end negative camber,correct?\
RE: Driver Mod Comment
I would actually go out on a limb and say it is either equipment (tires, old suspension parts, alignment or etc.) or driver error if ones is experiencing bothersome understeer in a 997.2. My GTS had a bit of understeer when I picked it up in October that I had not really experienced in 997.2s. I put new tires on it, had it aligned and whalla . . . back to neutral.
RE: Driver Mod Comment
I would actually go out on a limb and say it is either equipment (tires, old suspension parts, alignment or etc.) or driver error if ones is experiencing bothersome understeer in a 997.2. My GTS had a bit of understeer when I picked it up in October that I had not really experienced in 997.2s. I put new tires on it, had it aligned and whalla . . . back to neutral.
Again “neutral” is somewhat subjective and based on driving style/preferences. You could be right on the tires though, they are 3 seasons old and are Pilot Sports which while decent are not a real track focused tire
06-20-2020, 10:27 AM
#34
Nordschleife Master
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BTW, the moron PCA certified instructor that almost totaled us and my car tried traili brake the high speed S right before the tunnel at Barber. This was a corner that did not need trail braking, in a car that did not need trail braking (I had fastest lap in that make and model at Barber) by an “instructor” that did not know how to trial brake or when to trail brake. His sensation of a push/nderateer or desire to trail brake that corner was DRIVER ERROR.
i have a video of path we left in grass going up a 300 foot hill and stopping feet from the properrtycwall. We missed hitting another part of the property wall at 90 mph plus by a very short distance.
i posted this video on another thread of my running same or slightly quicker lap than a certified instructor in a car that should be 5 to 10 seconds quicker than car I was in.
https://rennlist.com/forums/997-foru...l#post16712572
i have a video of path we left in grass going up a 300 foot hill and stopping feet from the properrtycwall. We missed hitting another part of the property wall at 90 mph plus by a very short distance.
i posted this video on another thread of my running same or slightly quicker lap than a certified instructor in a car that should be 5 to 10 seconds quicker than car I was in.
https://rennlist.com/forums/997-foru...l#post16712572
06-20-2020, 11:19 AM
#36
Three Wheelin'
Thread Starter
BTW, the moron PCA certified instructor that almost totaled us and my car tried traili brake the high speed S right before the tunnel at Barber. This was a corner that did not need trail braking, in a car that did not need trail braking (I had fastest lap in that make and model at Barber) by an “instructor” that did not know how to trial brake or when to trail brake. His sensation of a push/nderateer or desire to trail brake that corner was DRIVER ERROR.
i have a video of path we left in grass going up a 300 foot hill and stopping feet from the properrtycwall. We missed hitting another part of the property wall at 90 mph plus by a very short distance.
i posted this video on another thread of my running same or slightly quicker lap than a certified instructor in a car that should be 5 to 10 seconds quicker than car I was in.
https://rennlist.com/forums/997-foru...l#post16712572
i have a video of path we left in grass going up a 300 foot hill and stopping feet from the properrtycwall. We missed hitting another part of the property wall at 90 mph plus by a very short distance.
i posted this video on another thread of my running same or slightly quicker lap than a certified instructor in a car that should be 5 to 10 seconds quicker than car I was in.
https://rennlist.com/forums/997-foru...l#post16712572
I really appreciate the great suggestions I did get and will definitely start with tires and likely sway bars. As I learn the car a bit better and go through setup I will be sure to share back.
06-20-2020, 11:19 AM
#37
Rennlist Member
Get a set of GT3 LCA's to allow more negative camber up front. The Stock LCA's only max out around 1.25 and you'll wear out the outer shoulders of the tire. This indicates where the weight is going.
Set it to about 2.5 for a decent balance of track and street.
Set it to about 2.5 for a decent balance of track and street.
06-20-2020, 12:37 PM
#38
Again, these cars are not setup optimal for performance driving, hence different setups on the GT cars. I will definitely check toe, on the S2K you needed toe to not kill yourself.
I am not really interested in the “driver mod” suggestions. It isn’t arrogance it is just that I am confident in my abilities, between sitting in the right seat and driving, I would venture to say i have had more seat time than most people. I am probably a bigger critic of my driving than most and admit I can most definitely gain more experience with the car, but it does not handle how I want, which is why I made the thread. While I understand very well how to tune a suspension, I recognize there are many ways to skin a cat some better than others, so that was the real intent is to figure out the best way on a 997.
I am not really interested in the “driver mod” suggestions. It isn’t arrogance it is just that I am confident in my abilities, between sitting in the right seat and driving, I would venture to say i have had more seat time than most people. I am probably a bigger critic of my driving than most and admit I can most definitely gain more experience with the car, but it does not handle how I want, which is why I made the thread. While I understand very well how to tune a suspension, I recognize there are many ways to skin a cat some better than others, so that was the real intent is to figure out the best way on a 997.
06-20-2020, 12:50 PM
#39
Sway bars is always everybody's first mod because it is cheaper/easy but I recommend starting the other way because you will end up there anyway and may not need to change the bars. If you track you will definitely want front gt3 lower control arms. This car likes half a degree more negative camber up front relative to rear. Keep adding more until you see the tire wear you like keeping the front half a degree more. For 80% street and 20% track I like -2 front and -1.5 rear. You will also see significant changes with small rear toe adjustments and this should be your first change. I like zero toe front and 1 to 1.5mm toe in each side for a rear total of 2 to 3mm toe in which is a lot less than factory. My car rotates very easily and is on the side of slight oversteer everywhere with those settings unless I aggressively unload the front. I also have bilstein pss9 coilovers for corner balance. Be careful if you lower as it can mess up the rear roll center as you mentioned. Best way to lower the rear is with different subframe bushings to maintain geometry. Once you are driving the rear of this car at the limit you will want solid rear dogbones. When you really lean on the backend all the rubber in the upper dogbones flex a lot and it's hard to feel what the tire is doing. Then finally sway bars for fine tuning if needed.
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VT Blue (06-23-2020)
06-20-2020, 01:12 PM
#41
Sway bars is always everybody's first mod because it is cheaper/easy but I recommend starting the other way because you will end up there anyway and may not need to change the bars. If you track you will definitely want front gt3 lower control arms. This car likes half a degree more negative camber up front relative to rear. Keep adding more until you see the tire wear you like keeping the front half a degree more. For 80% street and 20% track I like -2 front and -1.5 rear. You will also see significant changes with small rear toe adjustments and this should be your first change. I like zero toe front and 1 to 1.5mm toe in each side for a rear total of 2 to 3mm toe in which is a lot less than factory. My car rotates very easily and is on the side of slight oversteer everywhere with those settings unless I aggressively unload the front. I also have bilstein pss9 coilovers for corner balance. Be careful if you lower as it can mess up the rear roll center as you mentioned. Best way to lower the rear is with different subframe bushings to maintain geometry. Once you are driving the rear of this car at the limit you will want solid rear dogbones. When you really lean on the backend all the rubber in the upper dogbones flex a lot and it's hard to feel what the tire is doing. Then finally sway bars for fine tuning if needed.
06-20-2020, 01:34 PM
#42
06-20-2020, 01:52 PM
#43
Three Wheelin'
Thread Starter
I am with you on this topic. I have 10+ years of multiclass/endurance/sprint racing. I love my c2S but it’s an understeer pig. I am not interested in throwing parts at the car other than some civilized spring rate coilovers (Stock susp is 15 years old). I am thinking to start a slight toe out in the rear and a set of 245F/285R track tires. I hope you didn’t sell your s2000. I will never sell mine!
. Thanks for the info, I will start there and see how it is!
Thanks for the good info
06-20-2020, 02:27 PM
#44
www.tarett.com. But I don't recommend this unless you have coilovers to properly set rake. Stock C2S height is pretty much optimized for the suspension geometry. Subframe bushings would be one of the last mods I would do.
06-20-2020, 08:12 PM
#45
- understeer indicates you front end is losing grip before your rear end given your current driving style
- you fix this by adding more grip up front or decreasing grip in the rear
- ways to add grip up front include aero (splitter), more tire (run square set-up), run a less stiff anti roll bar, run lower tire pressure (more optimal tire pressure) in the fronts, more negative camber, less toe ( I wouldn't go over zero)
- conversely, you can add a stiffer bar in the rear, run slightly high pressure in the rear to decrease grip. I'd personally never run toe greater than zero in the rear
- you can also change you driving style, maybe use more trail breaking (or lift mid corner :-) )
- you fix this by adding more grip up front or decreasing grip in the rear
- ways to add grip up front include aero (splitter), more tire (run square set-up), run a less stiff anti roll bar, run lower tire pressure (more optimal tire pressure) in the fronts, more negative camber, less toe ( I wouldn't go over zero)
- conversely, you can add a stiffer bar in the rear, run slightly high pressure in the rear to decrease grip. I'd personally never run toe greater than zero in the rear
- you can also change you driving style, maybe use more trail breaking (or lift mid corner :-) )