rc's opinion from rennteam re 997 turbo off throttle oversteer
08-02-2007, 04:09 PM
#16
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[QUOTE=ALPINE_997]In regards to Gradyex's comments - I "had" the wandering feel on the highway at speeds as low as 100mph. I have stated such and so have several others. Gradyex has this problem and I have been trying to help him with it as I am sorting it out and making small adjustments here and there to fix this wandering and squirmy feel.
QUOTE]
Alpine, I am not sure who of us here is the rule and who is the exception as far as the uneasy wandering feel people have describe.
I can just confirm that my car in stock suspension/alignment form is rock solid at speeds exceeding 170 mph (yes, mexico is close) and I was amazed how it felt like 100mph when it was really going over 170mph. During that stunt, the driver in the car behind me stated that my car was so low to the ground at those speeds that he swore it was going to touch the pavement even on a straightaway. I never experienced any of that wandering feel on the highway, it just goes like a bullet.
On the corners, we all know the car is no boxster but it goes faster around the same corners with less confidence inspiring feelings, that I agree with you.
Must be the extra 300 hp.
QUOTE]
Alpine, I am not sure who of us here is the rule and who is the exception as far as the uneasy wandering feel people have describe.
I can just confirm that my car in stock suspension/alignment form is rock solid at speeds exceeding 170 mph (yes, mexico is close) and I was amazed how it felt like 100mph when it was really going over 170mph. During that stunt, the driver in the car behind me stated that my car was so low to the ground at those speeds that he swore it was going to touch the pavement even on a straightaway. I never experienced any of that wandering feel on the highway, it just goes like a bullet.
On the corners, we all know the car is no boxster but it goes faster around the same corners with less confidence inspiring feelings, that I agree with you.
Must be the extra 300 hp.
08-02-2007, 05:17 PM
#17
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AAH986 - its the 300hp 
I really don't think its a rule but a handful do experience that high speed wandering from what I have read. This was resolve with my lower springs and perhaps the alignment. I didn't test it out with a new alignment so I can't say that it was just that.
I can say that with Gradyex that when we spoke I thought his tire pressure was a little high at warmed up temps. Probably a contributing factor to some of the wandering/floaty feel.
Gradyex can make comments with that since he changed the pressure. I also gave him my alignment specs to see if that would help him.
I need to live closer to Mexico. - the advantages in living in Cali
I need to find my Mexico
Are you totally happy with your Protomotive? Todd is a nice guy when i spoke with him.
I really don't think its a rule but a handful do experience that high speed wandering from what I have read. This was resolve with my lower springs and perhaps the alignment. I didn't test it out with a new alignment so I can't say that it was just that.
I can say that with Gradyex that when we spoke I thought his tire pressure was a little high at warmed up temps. Probably a contributing factor to some of the wandering/floaty feel.
Gradyex can make comments with that since he changed the pressure. I also gave him my alignment specs to see if that would help him.
I need to live closer to Mexico.
- the advantages in living in Cali I need to find my Mexico
Are you totally happy with your Protomotive? Todd is a nice guy when i spoke with him.
08-02-2007, 05:34 PM
#18
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My comments merely reflect my personal experience. Tire pressure, alignment, tires are key on this car. My 'hot' pressure jumped up ~15psi after one 20mn session!
I hope all of you get yours sorted out, the car is very safe and very fast stone cold stock.
I don't mind HR or any aftermarket peices, I just think merely adding springs may induce bump steer when the shocks bottom out. When the x73 is available, I will add it, no doubt.
I will post some vids, pocono is far from a smooth track, esp the infield.GL
C
I hope all of you get yours sorted out, the car is very safe and very fast stone cold stock.
I don't mind HR or any aftermarket peices, I just think merely adding springs may induce bump steer when the shocks bottom out. When the x73 is available, I will add it, no doubt.
I will post some vids, pocono is far from a smooth track, esp the infield.GL
C
08-02-2007, 07:27 PM
#19
Rennlist Member
There may be a pilot or wind tunnel jockey here who can elaborate why ground effect really works at 170, but not so well at 100:
GROUND EFFECT From Wikipedia, the free encyclopedia (abbreviated)
Because it is a function of the flow of air over and under the car, and because aerodynamic forces increase with the square of velocity, downforce increases with the square of the car's speed and requires a certain minimum speed in order to produce a significant effect. But some cars have had rather unstable aerodynamics, such that a minor change in angle of attack or height of the vehicle (for example, caused by a bump on the track or slipstreaming over a crest) has caused the car to experience lift, not downforce, sometimes with disastrous consequences. A notorious example of this was Mark Webber's Mercedes-Benz CLR in the 1999 Le Mans 24 hours, which flipped spectacularly after closely following a competitor car over a hump.
Two primary components of a racing car can be used to create downforce when the car is travelling at racing speed:
the shape of the body, and
the use of airfoils.
GROUND EFFECT From Wikipedia, the free encyclopedia (abbreviated)
Because it is a function of the flow of air over and under the car, and because aerodynamic forces increase with the square of velocity, downforce increases with the square of the car's speed and requires a certain minimum speed in order to produce a significant effect. But some cars have had rather unstable aerodynamics, such that a minor change in angle of attack or height of the vehicle (for example, caused by a bump on the track or slipstreaming over a crest) has caused the car to experience lift, not downforce, sometimes with disastrous consequences. A notorious example of this was Mark Webber's Mercedes-Benz CLR in the 1999 Le Mans 24 hours, which flipped spectacularly after closely following a competitor car over a hump.
Two primary components of a racing car can be used to create downforce when the car is travelling at racing speed:
the shape of the body, and
the use of airfoils.
08-02-2007, 09:07 PM
#20
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Are you totally happy with your Protomotive? Todd is a nice guy when i spoke with him.[/QUOTE]
Yes totally satisfied with protomotive, although you need to keep the octane above 93 if you want great improvement in performance and around 103 octane if you want a real crazy improvement.
I have a very early version of the tune and I heard he wrote a newer one that is supposed to be better even with lower octane gas.
Yes totally satisfied with protomotive, although you need to keep the octane above 93 if you want great improvement in performance and around 103 octane if you want a real crazy improvement.
I have a very early version of the tune and I heard he wrote a newer one that is supposed to be better even with lower octane gas.
08-02-2007, 09:43 PM
#21
[QUOTE=AAH986]
Dont forget weight differences (Turbo vs boxter/cayman) and the cars center of gravity. The HP differences are huge and Porsche wants to keep it that way (for good reason). I have read a lot of articles that place the Caymans handling capabilities as one of the best available today for a sportscar. Imagine if it did have 300 more HP? Nothing would touch it, including the 997 GT3. The car is simply perfectly balanced and makes a great track car right out of the box. This brings me to my second point:
Did Porsche intentionally surpress the 911 TT's handling qualities to not step on the sales figures of GT3's? Its possible but not likely IMO. The two cars are too different from each other and my guess is the turbo is going through first year "growing pains" relating to its new AWD setup. I totally respect your feelings Chris, but I just feel that the Turbos suspension needs further refinement. Since I don't track cars I cannot compare track vs street differences but each come with a different set of variables. The street suffers mainly from roads that are a far cry from the tracks but since I don't track my cars (yet) I cannot comment. I am simply stating my personal observations and nothing more. I hope that doesn't offend anyone because my intentions and goals are to make this car as close to perfect as possible. So far I have learned quite a bit thanks to the help of Alpine_997, who has gone out of his way to provide some answers but the process is not a quick one and we are not Porsche experts here nor claim to be. Is this the best Porsche can do for this car? To satisfy the majority of its customers YES. To satisfy car enthusiasts testing its capabilities ........I am afraid not. I would like to see what I can do to make it more conforming to my style of driving.
The results so far have been positive ones but I have not gone the whole nine yards (yet). First off make sure your cars alignment is dialed in to suit your needs and does not arrive with issues (like mine did). Secondly tire pressures of even 1 psi off make differences that I can literally feel. So far my cold tire pressures feel best at 33 psi front and 39 psi rear. I still am experimenting so that could change a bit but not by much. My car came with Bridstones. Just last night I added a set of spacers (7mm in front 15mm in rear using longer bolts) and the car feels a bit more planted around turns as well as the steering but I still need to test the car at higher speeds using different manuvers and different tire pressure settings. Visually, the car looks a lot better and lowering it might be an option if I can convince my neighbor to let me use his driveway to access my garage (mine is too steep). LOL! I think the next steps might be sway bars? springs? coil overs? Who knows? Someone needs to be our test pilot, so for me its Alpine (has more experience anyway). Eclou has also been helpfull and I am most appreciative. Anyway I am taking it a step at a time and testing the cheapest mods first. My front strut brace came in today from Fabspeed but I am not expecting miracles and will be surprised if I notice any improvement. I do it becauses its fun and I love getting my hands dirty. In time for those interested a few of us will report back which mods helped and which mods didn't.
Originally Posted by ALPINE_997
In regards to Gradyex's comments - I "had" the wandering feel on the highway at speeds as low as 100mph. I have stated such and so have several others. Gradyex has this problem and I have been trying to help him with it as I am sorting it out and making small adjustments here and there to fix this wandering and squirmy feel.
QUOTE]
Alpine, I am not sure who of us here is the rule and who is the exception as far as the uneasy wandering feel people have describe.
I can just confirm that my car in stock suspension/alignment form is rock solid at speeds exceeding 170 mph (yes, mexico is close) and I was amazed how it felt like 100mph when it was really going over 170mph. During that stunt, the driver in the car behind me stated that my car was so low to the ground at those speeds that he swore it was going to touch the pavement even on a straightaway. I never experienced any of that wandering feel on the highway, it just goes like a bullet.
On the corners, we all know the car is no boxster but it goes faster around the same corners with less confidence inspiring feelings, that I agree with you.
Must be the extra 300 hp.
QUOTE]
Alpine, I am not sure who of us here is the rule and who is the exception as far as the uneasy wandering feel people have describe.
I can just confirm that my car in stock suspension/alignment form is rock solid at speeds exceeding 170 mph (yes, mexico is close) and I was amazed how it felt like 100mph when it was really going over 170mph. During that stunt, the driver in the car behind me stated that my car was so low to the ground at those speeds that he swore it was going to touch the pavement even on a straightaway. I never experienced any of that wandering feel on the highway, it just goes like a bullet.
On the corners, we all know the car is no boxster but it goes faster around the same corners with less confidence inspiring feelings, that I agree with you.
Must be the extra 300 hp.
Dont forget weight differences (Turbo vs boxter/cayman) and the cars center of gravity. The HP differences are huge and Porsche wants to keep it that way (for good reason). I have read a lot of articles that place the Caymans handling capabilities as one of the best available today for a sportscar. Imagine if it did have 300 more HP? Nothing would touch it, including the 997 GT3. The car is simply perfectly balanced and makes a great track car right out of the box. This brings me to my second point:
Did Porsche intentionally surpress the 911 TT's handling qualities to not step on the sales figures of GT3's? Its possible but not likely IMO. The two cars are too different from each other and my guess is the turbo is going through first year "growing pains" relating to its new AWD setup. I totally respect your feelings Chris, but I just feel that the Turbos suspension needs further refinement. Since I don't track cars I cannot compare track vs street differences but each come with a different set of variables. The street suffers mainly from roads that are a far cry from the tracks but since I don't track my cars (yet) I cannot comment. I am simply stating my personal observations and nothing more. I hope that doesn't offend anyone because my intentions and goals are to make this car as close to perfect as possible. So far I have learned quite a bit thanks to the help of Alpine_997, who has gone out of his way to provide some answers but the process is not a quick one and we are not Porsche experts here nor claim to be. Is this the best Porsche can do for this car? To satisfy the majority of its customers YES. To satisfy car enthusiasts testing its capabilities ........I am afraid not. I would like to see what I can do to make it more conforming to my style of driving.
The results so far have been positive ones but I have not gone the whole nine yards (yet). First off make sure your cars alignment is dialed in to suit your needs and does not arrive with issues (like mine did). Secondly tire pressures of even 1 psi off make differences that I can literally feel. So far my cold tire pressures feel best at 33 psi front and 39 psi rear. I still am experimenting so that could change a bit but not by much. My car came with Bridstones. Just last night I added a set of spacers (7mm in front 15mm in rear using longer bolts) and the car feels a bit more planted around turns as well as the steering but I still need to test the car at higher speeds using different manuvers and different tire pressure settings. Visually, the car looks a lot better and lowering it might be an option if I can convince my neighbor to let me use his driveway to access my garage (mine is too steep). LOL! I think the next steps might be sway bars? springs? coil overs? Who knows? Someone needs to be our test pilot, so for me its Alpine (has more experience anyway). Eclou has also been helpfull and I am most appreciative. Anyway I am taking it a step at a time and testing the cheapest mods first. My front strut brace came in today from Fabspeed but I am not expecting miracles and will be surprised if I notice any improvement. I do it becauses its fun and I love getting my hands dirty. In time for those interested a few of us will report back which mods helped and which mods didn't.
Last edited by gradyex; 08-03-2007 at 03:05 AM.
08-03-2007, 12:44 PM
#22
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Sounds like a plan to me, the more information out there the better. Just be careful with the mods, as that can be a steep drop($)! I've decided to leave mine totally stock, unless/until porsche releases a suspension upgrade. The FS quiet sounds good, but I think I'll just leave it alone this time. GL
C
C
08-03-2007, 02:02 PM
#23
Rennlist Member
Originally Posted by TT Surgeon
Sounds like a plan to me, the more information out there the better. Just be careful with the mods, as that can be a steep drop($)! I've decided to leave mine totally stock, unless/until porsche releases a suspension upgrade. The FS quiet sounds good, but I think I'll just leave it alone this time. GL
C
C
