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Okay, everyone give me their inputs. Is it just me? My STI is fully broken in. I really expected soo much more from this car, as far was GForce. I mean, when i stomp on the car, it accelerates alright, and its fast too. But I cant feel any Gforce throwing me back to my seat, nor can anyone sitting in passenger seats. Now my GSX, you can feel it, all day long, and it had less horsepower. Dont get me wrong, the car is fast, and is to my likings, just that I expected soo much more from power wise because of all the hype and advertisements that Subaru makes with hp on this car. This is my first time owning a Subaru, and still getting use to how the car is and the engine setup. I've owned many import cars in my life, and has been modifying cars since 92. All Acuras, hondas, and mitsubishis. So I have lots of experience in modifying cars, but when it comes to Subarus, the setup, turbos that come with the subaru, or whatever, i am new to it. Can you all tell me if your STI is the same? or is it just mine? It almost feels like there is no turbo. Any inputs would be nice.
 

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Chance to get STi vs. 350Z

The fact that you can't feel a sudden rush of power is what you are noticing. This is an extremely good thing. The torque curve of the STi engine is very flat and linear. There are no peaks where the power is lacking and then suddenly kicks in. Getting this kind of wide flat torque curve out of a turbo charged engine is very difficult and quite an accomplishment. The best thing about this is the usable power is very high at almost all rpms.

I kinda missed the sudden turbo rush, but I certainly didn't miss the lag issues :D Besides, if you put a boost controller and downpipe on, you will feel the rush and the car will be even faster.
 

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The 'g force' you are describing is exactly that....a change in acceleration. If you are still gaining speed at the same speed you were from the start, you effectively have no acceleration.

You're into a second order equation. If you're car was gaining speed at a higher rate (mile per hour PER SECOND) then you would feel a g-load. gravity = acceleration = change of velocity per time = change of displacement per time per time.
 

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CloNeGTS said:
The 'g force' you are describing is exactly that....a change in acceleration. If you are still gaining speed at the same speed you were from the start, you effectively have no acceleration.

You're into a second order equation. If you're car was gaining speed at a higher rate (mile per hour PER SECOND) then you would feel a g-load. gravity = acceleration = change of velocity per time = change of displacement per time per time.
Wait a minute. What do you mean by still gaining speed at the same speed you were from the start? That would mean you are in fact accelerating, since there is a change of rate of speed. If you accelerate slower, you'd feel less of a force, but it would still be there. Only if you're at a constant velocity, then the rate of change is zero (dv/dt = 0) Of course you'd feel a g-load at a higher rate of acceleration. You'd feel more g-load because by definition it is an acceleration.
 

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Wait up! A "g" refers to specific acceleration, 9.8m/s^2 or 32.2 ft/s^2. Speed is the measure of change in position, acceleration is a measure of change in speed. One "g" is when your change in speed is that of what the gravity of the planet Earth would accelerate an object in a vacuum at sea level. "Jerk" is the measure of rate of change in acceleration.

Of course, no car experiences constant acceleration. Otherwise, there would be no such thing as a top speed. Most cars experience an slight increase, peak, and then decrease in acceleration in every gear. The largest acceleration the car will experience is usually in 1st gear, because the low gear allows the most engine torque to be applied to the drive wheels. "Low end torque" means that the acceleration peak occurs at a lower speed in each gear. This could be stated as "getting faster more quickly." The rush you may be expecting occurs in cars with not as much reletive low-end-torque, where the engine essentially plays catch-up as the acceleration peak occurs at a higher speed.
 

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my head hurts now. :cry:

I know why it's better and faster, and I know I like how smooth it is, but I sure can't explain it. :D
 

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I was assuming constant acceleration, in which you would still feel g-force. Therefore, 0-60 in 4.8 seconds equals an average acceleration of about 0.57g. Surely you'd feel that! If you're talking about change in acceleration, ie, acceleration that is a function of time, then perhaps the STi has a rate of acceleration that is closer to constant that other similarly-equipped cars. I dunno, haven't driven one yet.
 

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Considering that not even the STi can make linear acceleration, you actually feel much more than .57 at some point. I think it was the graph in R&T that showed a peak acceleration right around 1 g (maybe more, maybe less; it was a small picture) slightly after launch in the STi. Yes, you can feel that, but you also experience 1 g of acceleration everytime you move against the Earth. Hop one inch into the air, and you will experience a constant 1 g of acceleration from takeoff to landing. Of course, hopping one inch doesn't make you feel like you are rocketing down a drag strip in a muscle car. This is a bad example, in a way, in that if you experience 1 g of acceleration horizontally, the force applied to your body is 1.7 times that of sitting still (1/1^.5).

That makes me think that the stiffer suspension in the STi may also have alot to do with the seat-of-the-pants meter. If you measure your acceleration by the force pushing you straight back into your seat (paralell to the vehicle), then a car with softer suspension would, by leaning further back during that acceleration, change the direction that gravity itself applies to you body, thus artificially inflating the feeling of acceleration. Ok, that's a run-on sentence. Anyway, that's the same reason that those "rides" at some theme parks (such as the "Back to the Future" ride at Universal Studios) can make you feel like you are accelerating quickly or even falling, without ever moving your center on mass more than a few inches. A device like that really goes to show how inaccurate your butt is in the accurate measure of acceleration.
 

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The suspension has a big deal to the seat of the pants feel. My wifes minivan feels like it is going like a bat of hell when you stand on it because of the soft suspension. Likewise when you apply her brakes easily the nose dives about 6". When you stand on her brakes I fell like I am going to "fall" out the windshield. Now with a performance car the chassis is much more stable during these manuvers and so for a seat of the pants feel there is less movement. I also race go-karts which have no suspension and there is even less movement even though there is a lot more g-force being felt.
 

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I guess what I was saying is what he is describing is a feel of change in acceleration. If a car is constantly gaining 5 MPH per second, it would just be a linear acceleration. Since F=MA, a constant acceleration is going to give you a constant force. This would be the same as sitting your butt in a chair...you don't feel anything...you are just being pushed up against by the chair. Same with a constant acceleration. As crazytrain mentioned, jerk is the change in acceleration. That will make you feel something.

I didn't quite say what I was trying to....crazy helped out. Does that make any sense?
 

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CloNeGTS I think I know what you're saying. You'd feel the force only when the force is first applied, until your body reacts and balances that force. If that force is steadily increased, ie, a time-dependent acceleration, your body has to continually react...this is the sensation that you're talking about, right?
 

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That's my thoughts anyway. I'm guessing you would get used to a constant force of any kind, just as you do gravity. The force is still there and you are still accelerating, but it isn't quite the feeling of the change in acceleration as mentioned before.

But anyway....back to the beginning of the question....the reason the car feels slower is because of the nice flat torque curve. There aren't as many differences in the acceleration, it's very constant. But don't worry...it's fast alright!
 

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man you cant feel anything? This is mine and my friend's first turbo car and after our first race we had to go into chikfila and grab a drink and sit and chat for a while we were shakin so bad lol. I love the feel of the car and it feels fast as crap to me, but then again I've never had or been in a turbo car. Enjoy!

Robert~
 

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Discussion Starter #17
UPDATE - doh.

Fellas, i appreciate all your inputs. Like i said before, dont get me wrong, this car is fast as hell and i love it. If i could sleep in it, i would. Its just that I didnt understand why slower cars have a force pushing you back while this car is faster and it doesnt. Thats what i didnt get. But with all said, I think all of you pretty much answered my question, although some answered in ways i couldnt understand. I talk a little different i guess, plain english, not scientific language. So i had to think a little, while i tried to understand what you guys were telling me. :D I wanted to know why I didnt feel the G Force, not HOW g Force is created. :D thanks to all you who gave me some input.
 
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