gibson Posted May 30, 2004 Report Share Posted May 30, 2004 I did a top speed test with my car the other day.I went flat out for about 45 seconds and the needle was stuck at 240 kmh (150 mph). The car felt great,just some wind noise. What confuse's me is that the rpm's was just 4700 ! I have done this with other cars and when you hit top speed with them the rpm,s are just under redline. There must be some of you here that have tried it,what was your rpm's ? (I can also tell you after cleaning the car today that the bugs really get stuck on it at that speed Link to comment Share on other sites More sharing options...
Cupillac Posted May 30, 2004 Report Share Posted May 30, 2004 I did one last year and if I recall correctly I was just at redline when it hit around 240Kmh also, then the rpms went back to about 5000. Pretty much the same thing. "Cadillac, it's not a car, it's an obsession" -W.Kingdon Link to comment Share on other sites More sharing options...
JasonA Posted May 31, 2004 Report Share Posted May 31, 2004 I did a top speed test with my car the other day.I went flat out for about 45 seconds and the needle was stuck at 240 kmh (150 mph). The car felt great,just some wind noise. What confuse's me is that the rpm's was just 4700 ! I have done this with other cars and when you hit top speed with them the rpm,s are just under redline. Something doesn't seem right. Mathematically, 150 mph with 235/60/16 tires and the 3.71 final drive should be in the neighborhood of 5500 rpm. I'm not sure why your tachometer would be reading that much lower...unless you have a seriously different-sized tire. But to answer your other question, no, the engine isn't necessarily at redline at a car's top speed. There are three methods (that I can think of) of achieving a top speed. 1) Aerodynamically. My '95 Nissan Truck has a theoretical top speed of way over 100 mph, but the little 4-cylinder engine just doesn't have the umph to move the big brick through the air that fast. The actual top speed is somewhere between 90 and 100 mph, which isn't close to redline in top gear. 2) Redline. Sometimes, you run out of gears when your car keeps accelerating. Redline in an STS would equal about 160 mph or higher. The engine doesn't quite have the power to get there, but if it did, your top speed would be higher than it is. This is what I refer to as the "theoretical" top speed, like I mentioned earlier with my truck. At redline in top gear, my truck would be going well over 110 mph, but the engine runs out of breath much sooner. 3) Electronic controls. The SLS is electronically-limited to 112 mph because of the OE tires. Some STSes are limited to 130 mph, if they had H-rated tires from the factory. Those that had Z-rated tires were limited to 150 mph. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
dankhts Posted May 31, 2004 Report Share Posted May 31, 2004 On the STS, the car's computer restricts the top end speed. You won't achieve max RPM in high gear even if you're going down a hill with the wind behind you. My '96 STS goes about 138 - 139 MPH - I gorget what the RPM was, but it was less then 5000. Link to comment Share on other sites More sharing options...
Greg P. Posted May 31, 2004 Report Share Posted May 31, 2004 I did a top speed test with my car the other day.I went flat out for about 45 seconds and the needle was stuck at 240 kmh (150 mph). The car felt great,just some wind noise. What confuse's me is that the rpm's was just 4700 ! I have done this with other cars and when you hit top speed with them the rpm,s are just under redline. There must be some of you here that have tried it,what was your rpm's ? (I can also tell you after cleaning the car today that the bugs really get stuck on it at that speed Where do you find a place to drive that fast? Link to comment Share on other sites More sharing options...
Bob D Posted May 31, 2004 Report Share Posted May 31, 2004 My '93 STS pulls a third to fourth gear shift at 6500 rpm, 130 mph. It climbs right up to 145mph at about 5500 rpm. Although it does seem to be hitting a wall there, it felt as if it has a little left to go...maybe. I've done this a couple of times out on a lonely flat road through ranch land, in the middle of the day. '93 STS.. opened, dropped, wide...fast. Link to comment Share on other sites More sharing options...
gibson Posted June 1, 2004 Author Report Share Posted June 1, 2004 I did a top speed test with my car the other day.I went flat out for about 45 seconds and the needle was stuck at 240 kmh (150 mph). The car felt great,just some wind noise. What confuse's me is that the rpm's was just 4700 ! I have done this with other cars and when you hit top speed with them the rpm,s are just under redline. There must be some of you here that have tried it,what was your rpm's ? (I can also tell you after cleaning the car today that the bugs really get stuck on it at that speed Where do you find a place to drive that fast? Late evening on a empty highway outside of Stockholm (Sweden).I would not do this unless it was not totally safe for other cars/people. Link to comment Share on other sites More sharing options...
phillydude Posted June 1, 2004 Report Share Posted June 1, 2004 3) Electronic controls. The SLS is electronically-limited to 112 mph because of the OE tires. Some STSes are limited to 130 mph, if they had H-rated tires from the factory. Those that had Z-rated tires were limited to 150 mph. How would one tell what was issued as the OEM tires (which would theoretically tell me what the max speed chip is set for)? I haven't gotten around to checking it "for real" yet... but I will soon. Link to comment Share on other sites More sharing options...
Ranger Posted June 1, 2004 Report Share Posted June 1, 2004 How would one tell what was issued as the OEM tires (which would theoretically tell me what the max speed chip is set for)? I haven't gotten around to checking it "for real" yet... but I will soon. Check the tire sticker on the driver side door jam. Link to comment Share on other sites More sharing options...
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