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#181
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Thread Starter
The weight is their biggest weakness no doubt for handling, but it doesn't hurt braking very much because of the GT3 6 piston fronts, and 350mm discs at each corner of my car. Tires presently are Nito NT01's. Upgraded turbos{500whp} give wonderful acceleration. I also upgraded all my suspension to adjustable control arms, Moton Clubsports, GT3 control arms, bigger sways and TRG droplinks. It's got -2 degrees camber front and rear and is corner balanced. This combination of upgrades has reduced the understeer as much as possible for this car's weight. Sorry for the mod list, just thought it might give a better idea of how the car is set up.
I find the most difficult part of driving it is the transition from quickly attained speed to intense braking for the next corner, and not over braking, lather, rinse,repeat, as you say. I need to get more flow into it. How can I apply the "momentum car " theory to help this situation?
I find the most difficult part of driving it is the transition from quickly attained speed to intense braking for the next corner, and not over braking, lather, rinse,repeat, as you say. I need to get more flow into it. How can I apply the "momentum car " theory to help this situation?
Last edited by Veloce Raptor; 05-22-2011 at 09:03 PM. Reason: spelink and tiepoz
#182
Rennlist Member
450/700 spring set at present. I have heard that 600/800 would be better. I wouldn't want a 1000 pounder at my stage of the game. How much difference would a spring change make?
#183
The Penguin King
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Before you go about changing springs, you might look at your alignment. A lot of folks run more negative camber up front than on the rears. If you took your front camber up to -2.5, and left the rear alone, you would address at least some of the understeer issue.
#184
Rennlist Member
Thread Starter
i agree with mglobe on this. In addition, what higher rate springs do, among other things, is give you flatter cornering with less body roll. This in turn gives you more usable contact patch in corners and less dramatic weight transfer. In conjunction with your Motons, the car will be a lot more responsive at turn in and a lot more balanced and un-dramatic in the entire cornering sequence IMO.
#185
Rennlist Member
I think Mglobe was talking to increase camber slightly to 2.5 degrees, especially if he is on the soft side to begn with.
Going to a stiffer spring, can actually increase or cause oversteer, even though you might reduce body roll. This is what the "tuning as a system" part is all about. flatter cornering, less body rolll doest always equal "more responsive at turn in". Many times, soft, with some body roll gives the most responsive turn in. Adding camber to this set up would then allow for more contact patch to match the body roll. the less dramatic weight transfer can be achieved by stiffer bump on the shocks .
Going to stiff on springs or sway bar settings makes your car feel like a go cart on the streets, with all the things you are saying, but on the track, it can be a pushing disaster. This is the art of set up.
One GREAT example is the local SCCA ITE Camaro that was just destroyed last month. it started out as easy pickings for most of us due to its weight, but high level of hp. it just couldnt handle. with some advice at the track to soften things way UP. they removed the front and rear swaybar , and did some testing. 3 seconds were found even though it was rolley polley. turn in was amazing, and lots of neutral grip. reducing the spring rates, and lowering the swaybar settings and suddenly, it was handling as well as the comp coupe vipers and had the power to match. sad it was killed off in an accicent, just as they figured it all out after 8 years of evolution!
Going to a stiffer spring, can actually increase or cause oversteer, even though you might reduce body roll. This is what the "tuning as a system" part is all about. flatter cornering, less body rolll doest always equal "more responsive at turn in". Many times, soft, with some body roll gives the most responsive turn in. Adding camber to this set up would then allow for more contact patch to match the body roll. the less dramatic weight transfer can be achieved by stiffer bump on the shocks .
Going to stiff on springs or sway bar settings makes your car feel like a go cart on the streets, with all the things you are saying, but on the track, it can be a pushing disaster. This is the art of set up.
One GREAT example is the local SCCA ITE Camaro that was just destroyed last month. it started out as easy pickings for most of us due to its weight, but high level of hp. it just couldnt handle. with some advice at the track to soften things way UP. they removed the front and rear swaybar , and did some testing. 3 seconds were found even though it was rolley polley. turn in was amazing, and lots of neutral grip. reducing the spring rates, and lowering the swaybar settings and suddenly, it was handling as well as the comp coupe vipers and had the power to match. sad it was killed off in an accicent, just as they figured it all out after 8 years of evolution!
i agree with mglobe on this. In addition, what higher rate springs do, among other things, is give you flatter cornering with less body roll. This in turn gives you more usable contact patch in corners and less dramatic weight transfer. In conjunction with your Motons, the car will be a lot more responsive at turn in and a lot more balanced and un-dramatic in the entire cornering sequence IMO.
#186
Rennlist Member
Thread Starter
Going to a stiffer spring, can actually increase or cause oversteer, even though you might reduce body roll. This is what the "tuning as a system" part is all about. flatter cornering, less body rolll doest always equal "more responsive at turn in". Many times, soft, with some body roll gives the most responsive turn in. Adding camber to this set up would then allow for more contact patch to match the body roll. the less dramatic weight transfer can be achieved by stiffer bump on the shocks .
#187
Steering wheel should be held approximately 9 & 3 for all corners, IMO, unless you are turning the wheel more than 180 degrees. I have not found a corner on any track yet where I have to take my hands off the wheel, although I have by no means been to every track. However, in the paddock, or when you are using incredibly high steering angles at low speed (autocross perhaps) shuffling is sometimes the only way to go. Yes, closer to the wheel on track than on the street--more control, less fatigue, easier to steer with palms/fingertims rather than arms/shoulders.
#188
Rennlist Member
shuffle steering is bad and can usually be a cause of a lot of accidents when the car gets a little out of shape directionally . pros can cheat or drive around this, but at the edge road racing, by having the hands always at 9 and 3 or 10 and 2, the neutral point, as far as the brain goes, and level of steeing input is intrinsically known. as soon as you move your hands around, that mental "0" point is reset and you might have no idea where the "0" point is. it becomes an advantage exiting turns and fethering power, with steering input. if you cheat up, you get a little more leverage, can induce more oversteer by putting too much input, and get lost in the correction. Its just a real bad habit that I like to stop from the very first session if Im instructing.
+1 on the above. I frequently hear the term shuffling, as a student or with a stock steering wheel you may want to repostition your hands at 6 and 12 after your downshift is completed for tight turns. Your hands are in positioned at 3 an 9 without getting crossed up thru the corner. From a physical stand point it also keeps your scapulae firmly against the seat back ( where as if you get crossed up, you pull your loaded shoulder away from the seat and get some thoracic rotation) your not fighting the forces of the car and can thus feel what is happening with the car. I think this is why you get this synergistic good feel, but there are limited circumstances that require it.
#189
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Bob I am going to add this edit to your statement because I think in a 911 this is more appropriate language.
In faster corners, it is sometimes useful to breathe the throttle to give the front end more grip at turn-in.
High speed turns may not requite you to lift completely off the throttle especially in 911s. I like to use the term breathe on the throttle because it is better defines how much movement to use on the throttle pedal. 50% throttle to 30% throttle is a breathe and 50% to 0% is a lift in most people's eyes.
In faster corners, it is sometimes useful to breathe the throttle to give the front end more grip at turn-in.
High speed turns may not requite you to lift completely off the throttle especially in 911s. I like to use the term breathe on the throttle because it is better defines how much movement to use on the throttle pedal. 50% throttle to 30% throttle is a breathe and 50% to 0% is a lift in most people's eyes.
If a driver is dropping throttle (lifting completely and violently) to horse the car around, there's something wrong.
If you can feel a weight shift or trajectory change with a credit card's thickness change in throttle input, you're close the the limit and doing well.
There is no car that cannot be driven quicker by someone else...
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-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
#191
Rennlist Member
There is also a way test the general effect of a stiffer spring, and that would simply incorporate the sway bar settings. a stiffer swaybar increases the spring rate on one side, but jacks down the car's opposite wheel. over bumps, it can be upseting, but over bumps that both wheels see, there is no effect.
having the bump set at the highest level that doesnt rattle your teath, is a good starting poing. . Rebound settings gernally as much, for a track that doesnt jack the car down. (i.e. if too bumpy of a track, the shock never gets a chance to extend fully and you end up going lower and lower, or called "jacking down" which is bad)
Its probably the most interesting subject matter, because there are so many factors and trade offs. bump, (high speed , low speed) rebound, sway bar (front to rear) spring rates, suspension geometry, etc. all revolving around the driver capabilty and style. thats why the perfect set up for Pat Long might not be as good as one for another driver.
I guess the main queston is really more about what is the end goal.
.
having the bump set at the highest level that doesnt rattle your teath, is a good starting poing. . Rebound settings gernally as much, for a track that doesnt jack the car down. (i.e. if too bumpy of a track, the shock never gets a chance to extend fully and you end up going lower and lower, or called "jacking down" which is bad)
Its probably the most interesting subject matter, because there are so many factors and trade offs. bump, (high speed , low speed) rebound, sway bar (front to rear) spring rates, suspension geometry, etc. all revolving around the driver capabilty and style. thats why the perfect set up for Pat Long might not be as good as one for another driver.
I guess the main queston is really more about what is the end goal.
.
I will let the true suspension experts here, such as Larry Herman and Chris Cervelli, comment on using stiffer springs, both for better & worse. In addition, adding bump (compression) is not optimal in many cases. Rather, having as little bump & as much rebound as the car will take (given a decent track surface, etc.) often yields better results. Not always, but often. And with a stiffer spring, the shocks can be set softer for more compliance over bumps, curbs, etc.
#192
Mark Wrote: s[QUOTE]huffle steering is bad and can usually be a cause of a lot of accidents when the car gets a little out of shape directionally . pros can cheat or drive around this, but at the edge road racing, by having the hands always at 9 and 3 or 10 and 2, the neutral point, as far as the brain goes, and level of steeing input is intrinsically known. as soon as you move your hands around, that mental "0" point is reset and you might have no idea where the "0" point is. it becomes an advantage exiting turns and fethering power, with steering input. if you cheat up, you get a little more leverage, can induce more oversteer by putting too much input, and get lost in the correction. Its just a real bad habit that I like to stop from the very first session if Im instructing.[/Q
It is the instructors assessment of the student if this technique could be executed safely by the student in addition to the other areas of focus. My student yesterday at the IMSA course at Pocono, was locked out at turn 5 and was unable to get the car to apex. We elected not to use the 12 and 6 reposition but discussed it's merits and application at perhaps one corner at several of the courses in the Atlantic east coast. By setting your hands at 12 and 6 you intrinsically retain where the "0" point is and can place the car where desired with throttle and steering input. Steering input remains constant relative to the desired placement of the car. I believe the original question posted was relating Oak Tree at VIR and yes this is a corner where this can be of help.
I know personally going through the ranks that many a chief instructor with many regions have suggested this technique. But again I will preface driver and corner specificity, just as left foot braking has it's merits at certain times in directing car position and attitude. In RTR our last two chiefs use this technique as does Larry. All accomplished drivers in there own right, but none are pro's. For the right driver it is something in the skill set to be utilized, granted on a limited basis.
It is the instructors assessment of the student if this technique could be executed safely by the student in addition to the other areas of focus. My student yesterday at the IMSA course at Pocono, was locked out at turn 5 and was unable to get the car to apex. We elected not to use the 12 and 6 reposition but discussed it's merits and application at perhaps one corner at several of the courses in the Atlantic east coast. By setting your hands at 12 and 6 you intrinsically retain where the "0" point is and can place the car where desired with throttle and steering input. Steering input remains constant relative to the desired placement of the car. I believe the original question posted was relating Oak Tree at VIR and yes this is a corner where this can be of help.
I know personally going through the ranks that many a chief instructor with many regions have suggested this technique. But again I will preface driver and corner specificity, just as left foot braking has it's merits at certain times in directing car position and attitude. In RTR our last two chiefs use this technique as does Larry. All accomplished drivers in there own right, but none are pro's. For the right driver it is something in the skill set to be utilized, granted on a limited basis.
#193
Rennlist Member
i would advice not to guess much on any of those topics - usually generic forum advices do not work well at all when you look to solve your own particular issue. I also think turbo car setup will not be same with generic NB gt3 setup I personally know a bit about. you need to find good mechanic who knows enough about setting up AWD turbo cars for track and check his opinion. or disconnect front drive completely and follow setup rules for GT2 cars.
This brings another topic to my head. Be advised on group buys also. You may save money compared to your local shop but you are only cheating yourself. They local shop or the shop you buy the majority of your stuff from is there for a reason if they are worth their salt. They are there to help you remain a customer of theirs. They are there to help you become a better driver and have a fun reliable car. In order for them to do this they need to make money too. Make them earn that money by buying the parts from them and letting them help you tune them. I have seen group buys a lot for suspensions or data systems where the group buy vendor doesn't support the product past the point of sale or they can't support it because they don't understand the specifics of the car it goes on. This does no one involved a favor. All it does is start headaches for the buyer and their shop because they shop lost a valuable sale.
Sorry for my $.02 rant on this. As I was typing the first response it brought up my idea on the second.
#195
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Go fast Paolo. Be gentle with your steering inputs. See you in a couple weeks.
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.