Feb 3, 2004 7:18:35 PM
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Carlos from Spain
- Rennteam Moderator
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- Loc: Spain. , Spain
- Posts: 21148, Gallery
- Registered on: Feb 9, 2003
- Reply to: Bilal
Re: You won't believe this.... SL600 0-60 in 3.6
Bilal, you Daimler-Chrysler passion and enthusiasm clouds you 
Lets compare the SL55AMG vs and the GT2 (since the same would apply to the SLR vs CGT comparisons)
In a STRAIGHT-LINE, when cruising at high speeds or doing a top speed test the SL55AMG will give you a very stable and secure "feeling" maybe even more than the GT2 since it may "feel" more nervous, but this is a subjective sensation of stability that does not correspond with reality because the minute you have to brake hard or try to make the car change direction you will find you actually have much less stability than the GT2 hence the GT2 can take corners faster at high speed w/o running off the road for example, correct?
This is why the SL55AMG may lead you to believe its more stable than the GT2 when cruising at high speed, but so will a Greyhound bus, but in reality its the other way around than what you "feel" :
- the heavier mass (not same as weight) of the SL55 at speed causes it to have a greater inertia, so it wants more to keep going in the same direction and not want to change more, that will make the car less susceptible to small influences to change direction such as cross winds and bumps giving a sensation of stability, like tha car is on rails. But only in straight line, since that same desire to keep going straight will work against you when you have to decelerate or turn into the curve, so when stability really matters you have less.
- the SL has the same drag coeficcient that the GT2 but it has positive lift (bouyancy) while the GT2 is designed with negative lift. So the higher the speeds, the SL55 will wnat to raise/lift and float as opposed to the GT2, that will greatly reduce your grip and contact to the ground.
- The SL55 is designed with less downforce than the GT2, which while less downforce helps high speed acceleration and top speed due to the less drag, it will also have less "weight" at high speed, so the GT2 uses that drag to help stick the car to the ground. And more important, the downforce also work in the corners since it adds weight but not the negative effects of mass in the corners such as centrifugal force, weight transfer, etc. This is one of the most important aspects in high speed stability and grip, thast why is so valued in F1's and allows them to achieve such lap times. If they brake a little piece of the front lip for example during the race, their lap curve speeds will drop greatly. Due to their need and use of downforce (and the open wheel design) an F1 has the same aerodinamic drag as a BUS!
- The SL55's steering is lighter and more numb than a GT2's, this makes the car more confortable to drive and also gives you a sense of stability, but actually what its doing is filtering out the feedback from the steering and wheels in the shape of vibration and nervousness, and this feedback is necessary to maintain a greater control of the car since it lets you know what the car is doing, the weight transfers, the grip of the wheels, the exact direcction of the car, etc and hence greater "real" stability, though it may "feel" more nervous. LAck of steering feedback is one of the thing that drives me nuts the most from a car, along with body roll.
- the suspension and chasis setup of the SL55 are softer and more confortable than the GT2 which will filter out the irregularities of the road giving you the sensation of floating and "pose" but actually the softer and longer travel setup the less grip, handling and stability, especially at high speeds, due to the greater inertias involved.
- The SL55 has a higher center of gravety than the GT2, while it gives it a greater ground clearance its also makes it less stable and increases the weight transfers at speed.
- The SL55 is designed with greater sound insulation than a GT2 therefor blocking the enviromental clues of feeling of speed leading you to believe you are going slower than what you really are giving you the sensation of stability. Buts is a fake sensation from blocking you from the outside of the car. For some people it means more confort, for me it means less pleasure.
The same can be appplied when comparing an SLR with a CGT. Or these are the same reasons why a lighter DTM CLK version is more stable at high speed than the street CLK-AMG car, though it may not "feel" that way to the average driver, but the sportcar driver will interpret the right clues of stability and will feel the DTM as more stable though more nervous. So when I hear comments in a mag that a SL55 feels like its going slower and more stable than a Murc, thats not necesary a good thing, and the writter may want to get a different job.
I can't believe this post is so long, somebody else can probably say the same thing only needing a couple of lines... sorry
Lets compare the SL55AMG vs and the GT2 (since the same would apply to the SLR vs CGT comparisons)
In a STRAIGHT-LINE, when cruising at high speeds or doing a top speed test the SL55AMG will give you a very stable and secure "feeling" maybe even more than the GT2 since it may "feel" more nervous, but this is a subjective sensation of stability that does not correspond with reality because the minute you have to brake hard or try to make the car change direction you will find you actually have much less stability than the GT2 hence the GT2 can take corners faster at high speed w/o running off the road for example, correct?
This is why the SL55AMG may lead you to believe its more stable than the GT2 when cruising at high speed, but so will a Greyhound bus, but in reality its the other way around than what you "feel" :
- the heavier mass (not same as weight) of the SL55 at speed causes it to have a greater inertia, so it wants more to keep going in the same direction and not want to change more, that will make the car less susceptible to small influences to change direction such as cross winds and bumps giving a sensation of stability, like tha car is on rails. But only in straight line, since that same desire to keep going straight will work against you when you have to decelerate or turn into the curve, so when stability really matters you have less.
- the SL has the same drag coeficcient that the GT2 but it has positive lift (bouyancy) while the GT2 is designed with negative lift. So the higher the speeds, the SL55 will wnat to raise/lift and float as opposed to the GT2, that will greatly reduce your grip and contact to the ground.
- The SL55 is designed with less downforce than the GT2, which while less downforce helps high speed acceleration and top speed due to the less drag, it will also have less "weight" at high speed, so the GT2 uses that drag to help stick the car to the ground. And more important, the downforce also work in the corners since it adds weight but not the negative effects of mass in the corners such as centrifugal force, weight transfer, etc. This is one of the most important aspects in high speed stability and grip, thast why is so valued in F1's and allows them to achieve such lap times. If they brake a little piece of the front lip for example during the race, their lap curve speeds will drop greatly. Due to their need and use of downforce (and the open wheel design) an F1 has the same aerodinamic drag as a BUS!
- The SL55's steering is lighter and more numb than a GT2's, this makes the car more confortable to drive and also gives you a sense of stability, but actually what its doing is filtering out the feedback from the steering and wheels in the shape of vibration and nervousness, and this feedback is necessary to maintain a greater control of the car since it lets you know what the car is doing, the weight transfers, the grip of the wheels, the exact direcction of the car, etc and hence greater "real" stability, though it may "feel" more nervous. LAck of steering feedback is one of the thing that drives me nuts the most from a car, along with body roll.
- the suspension and chasis setup of the SL55 are softer and more confortable than the GT2 which will filter out the irregularities of the road giving you the sensation of floating and "pose" but actually the softer and longer travel setup the less grip, handling and stability, especially at high speeds, due to the greater inertias involved.
- The SL55 has a higher center of gravety than the GT2, while it gives it a greater ground clearance its also makes it less stable and increases the weight transfers at speed.
- The SL55 is designed with greater sound insulation than a GT2 therefor blocking the enviromental clues of feeling of speed leading you to believe you are going slower than what you really are giving you the sensation of stability. Buts is a fake sensation from blocking you from the outside of the car. For some people it means more confort, for me it means less pleasure.
The same can be appplied when comparing an SLR with a CGT. Or these are the same reasons why a lighter DTM CLK version is more stable at high speed than the street CLK-AMG car, though it may not "feel" that way to the average driver, but the sportcar driver will interpret the right clues of stability and will feel the DTM as more stable though more nervous. So when I hear comments in a mag that a SL55 feels like its going slower and more stable than a Murc, thats not necesary a good thing, and the writter may want to get a different job.
I can't believe this post is so long, somebody else can probably say the same thing only needing a couple of lines... sorry
.
