**NEW** GT2 KW Competition 3-Way Suspension Installed
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Driving skill counts a lot. But in this forum the majority claims otherwise, most are always suggesting more mods or even accusing of cheating your claims.
I for one have had to send laptime data via email to a 6speedonline member as he did not believe how fast a PSS9 equipped Turbo can go around a certain track in the hands of amateur and thus pretty much accused me as a liar....
I also remember browsing a thread here where many people said it is impossible to make a Turbo as fast as Cup. Like something a 996 Turbo cannot be as fast as a Cup in Spa...Heh, once again it is due to driving skill.
Track 911 Turbos (Yep, I am talking about racing cars, as Cups are racing cars as well) have always been faster than Cups. Be it the 993 GT2's or the 996 GT2R's or even the 4WD Turbos such as Alzen's car. Most Professional Turbo Porsches beat even RSR's. For example Alzen 4WD 996 Turbo did Nordschleife+GP track in VLN competition traffic in 8.09min which is something like 6.40min for the Nordschleife part, you cannot touch that time even with GT3 RSR's! Jean is able to give a lot of more 993 Turbo/GT2 related evidence...
And you can make your car into race car if you have the means. Everything is possible with these cars if you are willing to spend. But remember the driving skill part. If we are talking about limited budget good example comes from Sweden where a track 996 Turbo (by Puppan, also shown in this forum) is faster than a 997 Cup. Obviously similar tires used.
And the tire question is so often forgotten here. In most cases here where one compares street cars (GT3,GT2, Turbo etc.) to Cups etc. and whether they were faster or not I have to look elsewhere...If one has new slicks and the other street car has R-tires there is no comparison. Always if there is talk about a surprising difference in speed between a street modded car and racing car it's about driving skill again. Slicks are in a different league due to their grip.
Ps. Manthey uses the best available spring rates for street 996 GT3 for Nordschleife and they use 350/975 rate in lbs/inch with their specced KW's. Hard rear seems to work well there...
But what do I know...
I for one have had to send laptime data via email to a 6speedonline member as he did not believe how fast a PSS9 equipped Turbo can go around a certain track in the hands of amateur and thus pretty much accused me as a liar....
I also remember browsing a thread here where many people said it is impossible to make a Turbo as fast as Cup. Like something a 996 Turbo cannot be as fast as a Cup in Spa...Heh, once again it is due to driving skill.
Track 911 Turbos (Yep, I am talking about racing cars, as Cups are racing cars as well) have always been faster than Cups. Be it the 993 GT2's or the 996 GT2R's or even the 4WD Turbos such as Alzen's car. Most Professional Turbo Porsches beat even RSR's. For example Alzen 4WD 996 Turbo did Nordschleife+GP track in VLN competition traffic in 8.09min which is something like 6.40min for the Nordschleife part, you cannot touch that time even with GT3 RSR's! Jean is able to give a lot of more 993 Turbo/GT2 related evidence...
And you can make your car into race car if you have the means. Everything is possible with these cars if you are willing to spend. But remember the driving skill part. If we are talking about limited budget good example comes from Sweden where a track 996 Turbo (by Puppan, also shown in this forum) is faster than a 997 Cup. Obviously similar tires used.
And the tire question is so often forgotten here. In most cases here where one compares street cars (GT3,GT2, Turbo etc.) to Cups etc. and whether they were faster or not I have to look elsewhere...If one has new slicks and the other street car has R-tires there is no comparison. Always if there is talk about a surprising difference in speed between a street modded car and racing car it's about driving skill again. Slicks are in a different league due to their grip.
Ps. Manthey uses the best available spring rates for street 996 GT3 for Nordschleife and they use 350/975 rate in lbs/inch with their specced KW's. Hard rear seems to work well there...
But what do I know...
As for driver skill, I think this thread has gotten a little off track.
100%...... driver ability and overall skill has so much to do with how well the car can perform, but in my case I am not stating I am a F1 driver or not........what I do want to know is that my car is not behaving as well as I expected and I want to get more out of it.......through careful and well reasearch and proven mods.
Just for the record, and to help clear up driver skill here (which I have never mentioned before and seems to many are coming to thier own conclusions here
, I have been tracking cars now for over 4+ years now and have done close to 300+ hrs on the track in both a 500RWHP M3 (which through much hard work have set it up to be very competitive within the P-circles and now a 500RWHP GT2, which is now also getting some serious respect, even from Cup Car owners. But most of my track time has been in the M3 which is such a different car to a GT2 in so many ways, hence all my questions about how to set my GT2 up to be as good as my M3 is, from that of stock.
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Good that you mention the M3 bit, because a lot of suspension dialing is constant from one make to the next. For example like I said about the rebound settings. Here is a chart that echos the same thing for BMW's.
As always though, trying is believing so give your way a try and if not, then this way might work. Either way, glad to see Turbo Porsche's going fast around the track.
As always though, trying is believing so give your way a try and if not, then this way might work. Either way, glad to see Turbo Porsche's going fast around the track.
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Just a quick update since attending my first track day of the year with the KW’s installed
The first was in January but it was a wet track so it did really count, but it was a fun day trying to control the car when the boost hit
http://www.youtube.com/watch?v=EVh4iFgWtX4
The day was wickedly hot with track temps up to and in excess of 35 degrees Celsius, so intake temps were not very good for fast times. However with that being said and given that this was the first real test of the new suspension (also it was not corner balanced until yesterday
), I am very happy to say that the car is heading in the right direction; the GT2’s previous best time was 56.43 and now is a 55.82, still along way to go with setting it up properly, but with a couple more tweaks and adjustments (and some good advice) over the next few track days I should be able to shave off another second or more 
…..well that’s the plan
Below is another car that attends the event, a Radical SR8, with a 55.19 wit as his best for the day. His best ever is a 52.93, so track temp definitely had a role to play in our times.
As a comparison the fastest 996 Cup Car (verified recorded time) does it in 53.48.
Car
Radical SR8
Lap Time
55.19
Date Recorded
11 Feb, 2010
Car
Porsche GT2
Lap Time
55.82
Date Recorded
11 Feb, 2010
Car
Porsche GT3 RS
Lap Time
56.93
Date Recorded
11 Feb, 2010
Question?? to other members that have similar set-ups and power, do you have find any Oversteer through fast or slow corners in the rear? I am fighting both brake oversteer and acceleration oversteer the later I can deal with just not the first? I have ideas about how to correct and will be trying them next event, just would like some input from others who have experienced the same and what they have done to correct this.
I am also looking at replacing all the bushes in the car with more solid ones i.e. Neoprene and getting some dog bones to stiffen up the rear a bit more.
Any comments or thoughts, before the next race day in March?
Cheers.
The first was in January but it was a wet track so it did really count, but it was a fun day trying to control the car when the boost hit
http://www.youtube.com/watch?v=EVh4iFgWtX4
The day was wickedly hot with track temps up to and in excess of 35 degrees Celsius, so intake temps were not very good for fast times. However with that being said and given that this was the first real test of the new suspension (also it was not corner balanced until yesterday
), I am very happy to say that the car is heading in the right direction; the GT2’s previous best time was 56.43 and now is a 55.82, still along way to go with setting it up properly, but with a couple more tweaks and adjustments (and some good advice) over the next few track days I should be able to shave off another second or more …..well that’s the plan Below is another car that attends the event, a Radical SR8, with a 55.19 wit as his best for the day. His best ever is a 52.93, so track temp definitely had a role to play in our times.
As a comparison the fastest 996 Cup Car (verified recorded time) does it in 53.48.
Car
Radical SR8
Lap Time
55.19
Date Recorded
11 Feb, 2010
Car
Porsche GT2
Lap Time
55.82
Date Recorded
11 Feb, 2010
Car
Porsche GT3 RS
Lap Time
56.93
Date Recorded
11 Feb, 2010
Question?? to other members that have similar set-ups and power, do you have find any Oversteer through fast or slow corners in the rear? I am fighting both brake oversteer and acceleration oversteer the later I can deal with just not the first? I have ideas about how to correct and will be trying them next event, just would like some input from others who have experienced the same and what they have done to correct this.
I am also looking at replacing all the bushes in the car with more solid ones i.e. Neoprene and getting some dog bones to stiffen up the rear a bit more.
Any comments or thoughts, before the next race day in March?
Cheers.
Congrats SAINT GT2 very nice vids,you got those guys in your pocket.You fly over the gt3's and with a litter more time you beat the best time of the gt3 cup,thats for sure.
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Saint, it just dawned on me that the huge gap in front/rear springs rates you are running might just be the oversteer culprit since you say it's doing it in high and low speed corners. In fact it could be the cause of the high speed braking wiggle.
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
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Yes, that's what makes it so quick, no rises as such and only one dip.
This one is one of the best, its a real drivers track and very famous in QLD.
This one is one of the best, its a real drivers track and very famous in QLD.
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Saint, it just dawned on me that the huge gap in front/rear springs rates you are running might just be the oversteer culprit since you say it's doing it in high and low speed corners. In fact it could be the cause of the high speed braking wiggle.
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
... Initially Loren I did think the front end would be a bit too soft.
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Saint, do you not agree with what bump and rebound is? Bump is how fast the springs compress, and rebound is how fast they uncompress. Higher settings of either means more resistance to compression or uncompression.
Is that where you disagree, or how it will work? I got my information from a professional race team, this is not off the top of my head.
Is that where you disagree, or how it will work? I got my information from a professional race team, this is not off the top of my head.
I am not here to beat my chest about who knows more about text book theory of what bump or rebound does on this thread, as anyone who has access to the web can find definitions to quote
, what I was interested in was suggestions/advice on how to correct my brake oversteer. But because you love theory, then here is some more for you to immerse yourself in…….
I epecially like the article on "Suggested Adjustment Procedures"
Let me quote a section;
"It should be noted that too much rebound on either end of the vehicle will cause an initial loss of lateral acceleration (cornering grip) at that end which will cause the vehicle to oversteer or understeer excessively when entering a turn. "
To me initial loss would refer to the place where you first noticed loss of grip, hence it after braking for me.
Also see the attached documents from various sources on the Net......
I hope these articles gives you some idea about what I was referring to.
All sarcasm aside, I have certainly learnt alot tonight from this discussion, I hope it helps others here
But until I am back on the track in March, I cannot tell you what the outcome is, however I will be more than happy to let you know......either way.
Because it's not about right or wrong but solving the oversteer problem
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Saint, it just dawned on me that the huge gap in front/rear springs rates you are running might just be the oversteer culprit since you say it's doing it in high and low speed corners. In fact it could be the cause of the high speed braking wiggle.
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
If you are running full stiff in front and full soft in rear, and still have this oversteer, your spring rates just might be the culprit. Obviously some other things to try are softening the rear sway and stiffening the front.
Keep track of your tire wear and tire temps if it gets to be too tough to pinpoint. They can give you a lot of information. And ALWAYS double check your settings for mistakes in maybe turning one **** further than the other from one side to the next. It's best to write them down and zero out to full soft and then adjust to make sure. Sometime people just have the ***** wrong on accident when they swear they turned them the wrong way.
BTW this is not questioning your **** turning skill. Just saying to double check.......
See post #61
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I think you misunderstood my suggestion. Adding a click or two of rebound (unless you are max or close to max) does not automatically put you in the range of too much. Your quote is not talking about subtle changes but rather over usage of one aspect of suspension tuning. I honestly do not see how you could take what I said and what I've presented and draw a conclusion like that.
Frankly I'm shocked at your sarcasm from someone trying to give you possible solution to your problem from half the world away. It's all going to be theory without having driven the car. Suspension tuning is just that, educated guesses based on theory. But the fact remains that small changes to rebound in such a way has a POSITIVE effect on reducing oversteer in many cases.
Anyways, good luck with it.
Frankly I'm shocked at your sarcasm from someone trying to give you possible solution to your problem from half the world away. It's all going to be theory without having driven the car. Suspension tuning is just that, educated guesses based on theory. But the fact remains that small changes to rebound in such a way has a POSITIVE effect on reducing oversteer in many cases.
Anyways, good luck with it.
No... I am not disagreeing with what each do...... what I am saying here is that a 2hr conversation with KW in Germany has taught me alot today and that my issue with brake oversteer has to with my rebound setting and needs to be backed off for my application.
I am not here to beat my chest about who knows more about text book theory of what bump or rebound does on this thread, as anyone who has access to the web can find definitions to quote, what I was interested in was suggestions/advice on how to correct my brake oversteer.
But because you love theory, then here is some more for you to immerse yourself in…….
I epecially like the article on "Suggested Adjustment Procedures"
Let me quote a section;
"It should be noted that too much rebound on either end of the vehicle will cause an initial loss of lateral acceleration (cornering grip) at that end which will cause the vehicle to oversteer or understeer excessively when entering a turn. "
To me initial loss would refer to the place where you first noticed loss of grip, hence it after braking for me.
Also see the attached documents from various sources on the Net......
I hope these articles gives you some idea about what I was referring to.
All sarcasm aside, I have certainly learnt alot tonight from this discussion, I hope it helps others here
But until I am back on the track in March, I cannot tell you what the outcome is, however I will be more than happy to let you know......either way.
Because it's not about right or wrong but solving the oversteer problem
I am not here to beat my chest about who knows more about text book theory of what bump or rebound does on this thread, as anyone who has access to the web can find definitions to quote
, what I was interested in was suggestions/advice on how to correct my brake oversteer. But because you love theory, then here is some more for you to immerse yourself in…….
I epecially like the article on "Suggested Adjustment Procedures"
Let me quote a section;
"It should be noted that too much rebound on either end of the vehicle will cause an initial loss of lateral acceleration (cornering grip) at that end which will cause the vehicle to oversteer or understeer excessively when entering a turn. "
To me initial loss would refer to the place where you first noticed loss of grip, hence it after braking for me.
Also see the attached documents from various sources on the Net......
I hope these articles gives you some idea about what I was referring to.
All sarcasm aside, I have certainly learnt alot tonight from this discussion, I hope it helps others here
But until I am back on the track in March, I cannot tell you what the outcome is, however I will be more than happy to let you know......either way.
Because it's not about right or wrong but solving the oversteer problem
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I think you misunderstood my suggestion. Adding a click or two of rebound (unless you are max or close to max) does not automatically put you in the range of too much. Your quote is not talking about subtle changes but rather over usage of one aspect of suspension tuning. I honestly do not see how you could take what I said and what I've presented and draw a conclusion like that.
Frankly I'm shocked at your sarcasm from someone trying to give you possible solution to your problem from half the world away. It's all going to be theory without having driven the car. Suspension tuning is just that, educated guesses based on theory. But the fact remains that small changes to rebound in such a way has a POSITIVE effect on reducing oversteer in many cases.
Anyways, good luck with it.
Frankly I'm shocked at your sarcasm from someone trying to give you possible solution to your problem from half the world away. It's all going to be theory without having driven the car. Suspension tuning is just that, educated guesses based on theory. But the fact remains that small changes to rebound in such a way has a POSITIVE effect on reducing oversteer in many cases.
Anyways, good luck with it.
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There is obviously some great information in this thread and I have gone down this same path recently. The settings that iLLM3 and Mikelly gave me were great starting points and given that I have 4 track days at Laguna under the Car's belt now, I thought I would contribute my thoughts:
My Car is now at -2.6 camber front, -2.2 rear. My toe at the front is 0 degrees (it was - 1/32nd but the turn in wasn't happening quickly enough for my liking) I might go to toe OUT if this doesn't sharpen it up more.. Rear toe is - 1/16th. I am shimmed to prevent caster issues and am not using adjustable shock mounts.
I have the Protrac/JRZ triple adjustables, with a spring rate of 600 lbs front and 800 lbs rear using Eibach Pro springs. I have adjustable RSR swaybars, with the front set to 1 position from full soft and the rear set to 1 position from full hard. I will post my ride height/Rake and corner balance figures as soon as my suspension guys SCARGO get them to me.
Initially with different settings (-2.0 front and rear camber and 1/32nd toe in in front) the car was not turning in as well as I would have liked and would push the nose (understeer) on the way out of a couple of corners at Laguna (turn 5 especially, which is an uphill turn, 3rd gear at about 80 mph)..
The corner exit push was made worse by getting on the gas hard.. if I feathered the throttle, the front end would grip better.. my interpretation was that the rear was squatting too much and there was a weight transfer to the rear, unloading the front and this was made worse by the fact that it's an uphill turn. Proof (in my mind) was that on downhill turns the car was near perfect (tuns 9 and 10 at Laguna were utterly brilliant.. I have never been able to go through them as fast as I can in this GT2) on downhill turns, the weight is on the front of the car.
So.. Changes were made, including putting 30 lbs more canister pressure in the rear (to increase the effective spring rate) and adding one click of low and high speed compression damping (to slow the transfer of weight to the rear under acceleration) and I also backed off my front low speed compression damping by 2 clicks and the high speed compression damping by the same amount. The theory being that this would allow the weight to transfer to the front more quickly .
Next session the Car was way better and the turn in had sharpened up, I could get on the power harder and earlier through the turns that it had been understeering on. One other issue. The car was WAAAAY better on a full tank of gas. again leading me to believe that the front needs as much weight on it as possible.
So.. I am off to Laguna again on the 4th and 5th for two days and will report back as to how the car handles now.. I am really, really picky about how my cars handle and have a ton of experience in suspension setup, mostly from my Motorcycle racing days. Cars are a lot more difficult and I am making one change at a time, then driving the car to see if it made it better or worse.
As it stands, this GT2 is a phenomenal piece of kit... My first time out in it I went 1.8 seconds a lap faster at Laguna than I had in either my 550 HP 944 Turbo with full Porsche Cup suspension all round and 275's front 335's rear, or my Corvette ZO6 with the same tire setup.
Here is some video from when the car WASN'T handling quite right... As a reference, the Corvette ZO6 in front of me that I passed (I took his line coming into the Corkscrew) is a 2600 lb, stripped out car, 550 hp, full coilover suspension and slicks and the driver is very competitive in his racing class...
http://www.youtube.com/watch?v=XK6zhvTEbAM
My Car is now at -2.6 camber front, -2.2 rear. My toe at the front is 0 degrees (it was - 1/32nd but the turn in wasn't happening quickly enough for my liking) I might go to toe OUT if this doesn't sharpen it up more.. Rear toe is - 1/16th. I am shimmed to prevent caster issues and am not using adjustable shock mounts.
I have the Protrac/JRZ triple adjustables, with a spring rate of 600 lbs front and 800 lbs rear using Eibach Pro springs. I have adjustable RSR swaybars, with the front set to 1 position from full soft and the rear set to 1 position from full hard. I will post my ride height/Rake and corner balance figures as soon as my suspension guys SCARGO get them to me.
Initially with different settings (-2.0 front and rear camber and 1/32nd toe in in front) the car was not turning in as well as I would have liked and would push the nose (understeer) on the way out of a couple of corners at Laguna (turn 5 especially, which is an uphill turn, 3rd gear at about 80 mph)..
The corner exit push was made worse by getting on the gas hard.. if I feathered the throttle, the front end would grip better.. my interpretation was that the rear was squatting too much and there was a weight transfer to the rear, unloading the front and this was made worse by the fact that it's an uphill turn. Proof (in my mind) was that on downhill turns the car was near perfect (tuns 9 and 10 at Laguna were utterly brilliant.. I have never been able to go through them as fast as I can in this GT2) on downhill turns, the weight is on the front of the car.
So.. Changes were made, including putting 30 lbs more canister pressure in the rear (to increase the effective spring rate) and adding one click of low and high speed compression damping (to slow the transfer of weight to the rear under acceleration) and I also backed off my front low speed compression damping by 2 clicks and the high speed compression damping by the same amount. The theory being that this would allow the weight to transfer to the front more quickly .
Next session the Car was way better and the turn in had sharpened up, I could get on the power harder and earlier through the turns that it had been understeering on. One other issue. The car was WAAAAY better on a full tank of gas. again leading me to believe that the front needs as much weight on it as possible.
So.. I am off to Laguna again on the 4th and 5th for two days and will report back as to how the car handles now.. I am really, really picky about how my cars handle and have a ton of experience in suspension setup, mostly from my Motorcycle racing days. Cars are a lot more difficult and I am making one change at a time, then driving the car to see if it made it better or worse.
As it stands, this GT2 is a phenomenal piece of kit... My first time out in it I went 1.8 seconds a lap faster at Laguna than I had in either my 550 HP 944 Turbo with full Porsche Cup suspension all round and 275's front 335's rear, or my Corvette ZO6 with the same tire setup.
Here is some video from when the car WASN'T handling quite right... As a reference, the Corvette ZO6 in front of me that I passed (I took his line coming into the Corkscrew) is a 2600 lb, stripped out car, 550 hp, full coilover suspension and slicks and the driver is very competitive in his racing class...
http://www.youtube.com/watch?v=XK6zhvTEbAM
Last edited by 80shilling; Feb 18, 2010 at 11:17 AM.
I would check your LSD out, and 0 toe as Dez mentioned, use my toe setup that I posted if you haven't, if you have? Not sure why, as I had a terrible experience with toe settings and that was a sweet spot for my setup and neutral in general for any car.
Another thought is that you are overheating those tires thus in the braking zone getting that squirm and less grip, happens after some consistent hot laps and trying to go faster and faster and brake later in the braking zone , also being too hard on brakes.. Too many different variables!
Anyway, great times and driving, try being a bit smoother in some areas next time or scrubbing off a little less speed then getting on gas sooner..
Last edited by iLLM3; Feb 18, 2010 at 11:11 AM.
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There is obviously some great information in this thread and I have gone down this same path recently. The settings that iLLM3 and Mikelly gave me were great starting points and given that I have 4 track days at Laguna under the Car's belt now, I thought I would contribute my thoughts:
My Car is now at -2.6 camber front, -2.2 rear. My toe at the front is 0 degrees (it was - 1/32nd but the turn in wasn't happening quickly enough for my liking) I might go to toe OUT if this doesn't sharpen it up more.. Rear toe is - 1/16th. I am shimmed to prevent caster issues and am not using adjustable shock mounts.
I have the Protrac/JRZ triple adjustables, with a spring rate of 600 lbs front and 800 lbs rear using Eibach Pro springs. I have adjustable RSR swaybars, with the front set to 1 position from full soft and the rear set to 1 position from full hard. I will post my ride height/Rake and corner balance figures as soon as my suspension guys SCARGO get them to me.
Initially with different settings (-2.0 front and rear camber and 1/32nd toe in in front) the car was not turning in as well as I would have liked and would push the nose (understeer) on the way out of a couple of corners at Laguna (turn 5 especially, which is an uphill turn, 3rd gear at about 80 mph)..
The corner exit push was made worse by getting on the gas hard.. if I feathered the throttle, the front end would grip better.. my interpretation was that the rear was squatting too much and there was a weight transfer to the rear, unloading the front and this was made worse by the fact that it's an uphill turn. Proof (in my mind) was that on downhill turns the car was near perfect (tuns 9 and 10 at Laguna were utterly brilliant.. I have never been able to go through them as fast as I can in this GT2) on downhill turns, the weight is on the front of the car.
So.. Changes were made, including putting 30 lbs more canister pressure in the rear (to increase the effective spring rate) and adding one click of low and high speed compression damping (to slow the transfer of weight to the rear under acceleration) and I also backed off my front low speed compression damping by 2 clicks and the high speed compression damping by the same amount. The theory being that this would allow the weight to transfer to the front more quickly .
Next session the Car was way better and the turn in had sharpened up, I could get on the power harder and earlier through the turns that it had been understeering on. One other issue. The car was WAAAAY better on a full tank of gas. again leading me to believe that the front needs as much weight on it as possible.
So.. I am off to Laguna again on the 4th and 5th for two days and will report back as to how the car handles now.. I am really, really picky about how my cars handle and have a ton of experience in suspension setup, mostly from my Motorcycle racing days. Cars are a lot more difficult and I am making one change at a time, then driving the car to see if it made it better or worse.
As it stands, this GT2 is a phenomenal piece of kit... My first time out in it I went 1.8 seconds a lap faster at Laguna than I had in either my 550 HP 944 Turbo with full Porsche Cup suspension all round and 275's front 335's rear, or my Corvette ZO6 with the same tire setup.
Here is some video from when the car WASN'T handling quite right... As a reference, the Corvette ZO6 in front of me that I passed (I took his line coming into the Corkscrew) is a 2600 lb, stripped out car, 550 hp, full coilover suspension and slicks and the driver is very competitive in his racing class...
http://www.youtube.com/watch?v=XK6zhvTEbAM
My Car is now at -2.6 camber front, -2.2 rear. My toe at the front is 0 degrees (it was - 1/32nd but the turn in wasn't happening quickly enough for my liking) I might go to toe OUT if this doesn't sharpen it up more.. Rear toe is - 1/16th. I am shimmed to prevent caster issues and am not using adjustable shock mounts.
I have the Protrac/JRZ triple adjustables, with a spring rate of 600 lbs front and 800 lbs rear using Eibach Pro springs. I have adjustable RSR swaybars, with the front set to 1 position from full soft and the rear set to 1 position from full hard. I will post my ride height/Rake and corner balance figures as soon as my suspension guys SCARGO get them to me.
Initially with different settings (-2.0 front and rear camber and 1/32nd toe in in front) the car was not turning in as well as I would have liked and would push the nose (understeer) on the way out of a couple of corners at Laguna (turn 5 especially, which is an uphill turn, 3rd gear at about 80 mph)..
The corner exit push was made worse by getting on the gas hard.. if I feathered the throttle, the front end would grip better.. my interpretation was that the rear was squatting too much and there was a weight transfer to the rear, unloading the front and this was made worse by the fact that it's an uphill turn. Proof (in my mind) was that on downhill turns the car was near perfect (tuns 9 and 10 at Laguna were utterly brilliant.. I have never been able to go through them as fast as I can in this GT2) on downhill turns, the weight is on the front of the car.
So.. Changes were made, including putting 30 lbs more canister pressure in the rear (to increase the effective spring rate) and adding one click of low and high speed compression damping (to slow the transfer of weight to the rear under acceleration) and I also backed off my front low speed compression damping by 2 clicks and the high speed compression damping by the same amount. The theory being that this would allow the weight to transfer to the front more quickly .
Next session the Car was way better and the turn in had sharpened up, I could get on the power harder and earlier through the turns that it had been understeering on. One other issue. The car was WAAAAY better on a full tank of gas. again leading me to believe that the front needs as much weight on it as possible.
So.. I am off to Laguna again on the 4th and 5th for two days and will report back as to how the car handles now.. I am really, really picky about how my cars handle and have a ton of experience in suspension setup, mostly from my Motorcycle racing days. Cars are a lot more difficult and I am making one change at a time, then driving the car to see if it made it better or worse.
As it stands, this GT2 is a phenomenal piece of kit... My first time out in it I went 1.8 seconds a lap faster at Laguna than I had in either my 550 HP 944 Turbo with full Porsche Cup suspension all round and 275's front 335's rear, or my Corvette ZO6 with the same tire setup.
Here is some video from when the car WASN'T handling quite right... As a reference, the Corvette ZO6 in front of me that I passed (I took his line coming into the Corkscrew) is a 2600 lb, stripped out car, 550 hp, full coilover suspension and slicks and the driver is very competitive in his racing class...
http://www.youtube.com/watch?v=XK6zhvTEbAM