How fast does your Grand AM go???

[BubbaTheHut]

I have toped out my stock grand am gt 03' at 125-126mph. What kind of speed are others getting?

I never seemed to hit any kind of speed limiter. What speed does it kick in?

[bandit307]

I can do 213km/h, Then i het my govern its the end of 3rd gear.

[lagetur]

If my car didnt sound like it was gonna fall apart i would push it past 100 and find out.

[BubbaTheHut]

213 is quick, what kind of mods do you have done to your car?

[bandit307]

Pretty much nothing. Exaust, and minor details nothing for dramatic horse power gains.

And my exaust isnt even catback just new muffler and tips.

You know i said 213 KM/H Right. not MPH

[rainbowbriteboy]

I dont push it....ive never taken my car past 90.

Same reason as Matt.

[bandit307]

My car is pretty solid i dont think its gona fall apart i just always think my tranny is gona blow up again. F-in 4t45e piece of $hit.:pissed2:

[cabdisaster]

120 ish then the limiter kicked in , this was with out the dhp

[PontiacGA]

120+ (burried the speedo) and smooth as silk. JET chips are good for something.:roll2:

[eric99gt]

Originally posted by BubbaTheHut
I have toped out my stock grand am gt 03' at 125-126mph. What kind of speed are others getting?

I never seemed to hit any kind of speed limiter. What speed does it kick in?

126 mph

[Xeiros]

I'd say 95mph, and waiting for my car to blow up the whole time.

[ttah8]

i have an SE and I cut-off at 107, but if I get DHP...no more limiter which means I can be a speed demon.

[Brandon]

did 113 and that was as fast as i needed

[BubbaTheHut]

i did realise that it was KPH, but its still fast. Adding exaust must help break the 130mph mark. and thats what i am looking for.

[slowbird]

I hit the govenor once or twice before I got the new PCM.

I haven't gone near that kind of speed since...I'm not really interested in stressing my car like that.

1/4mile is enough for me.

[Bjornboy81]

Originally posted by bandit307
Pretty much nothing. Exaust, and minor details nothing for dramatic horse power gains.

And my exaust isnt even catback just new muffler and tips.

You know i said 213 KM/H Right. not MPH Unless the govener is deifferent in the Canadian cars (which I doubt) how did you do 132 MPH in a car that is limited at 126??? You don't have the limiter removed do you?

[Colin]

adding exaust must help break the 130mph mark. and thats what i am looking for. And the point of this is :???:

[Matt95GT]

^ x2. And exhaust has zero to do with the speed governor.

[matt rupke]

96 2.4 se rev limiter at 105 and not even 4k on the tach, i know theres more after that

[BubbaTheHut]

i know exaust has nothing to do with the govener, I would have to get it repregromaded/chiped. I was jw how fast other people where getting there cars. Previously i could only get it to 120ish but for some reason now it does 125/126. i was just curious if other people where getting it that fast also

[Bjornboy81]

Originally posted by BubbaTheHut
i know exaust has nothing to do with the govener, I would have to get it repregromaded/chiped. I was jw how fast other people where getting there cars. Previously i could only get it to 120ish but for some reason now it does 125/126. i was just curious if other people where getting it that fast also previous to what?

[ihatemygrandamg]

Well I hit 126mph in my 99 GT, then the gov kicked in. Im looking to get a DHP but not for that reason. I dont realy speed like that I see no need to. If you wanna drive like that hit a track.

[tejohnson]

Can't say I am brave enough to go past ~140. Perhaps after the latest improvements I may...

[Jibo]

170 or 172 KM/H, did it once, hit the governor, had pleanty of tach left, but really now, why int he world would you EVER need to go that fast, have never gone nearly that fast since. Just no need for it


Bjornboy81 wrote
Unless the govener is deifferent in the Canadian cars (which I doubt) how did you do 132 MPH in a car that is limited at 126??? You don't have the limiter removed do you?

I am fairly certain it is the same limitation between the US and canada, if the governor is not removed, there is no way he was going that fast

[Eden]

I've done 125, and still pulled, that's as high as my speedo goes, but my rpm's were at 3800, of a total 5500, so I still had room to move.

[Foxy]

Where were you guys doing this!?

Speedos are usually optomistic... when I had my STi on the track, the speedo said 125 or so; the GPS said 118. Even at lower speeds, there's still about a 4% error.

[slowbird]

Originally posted by Foxy
Where were you guys doing this!?


There isn't any real point to this thread...it's just here.

Like Ladybugs....they serve no real purpose...but we tolerate their exisitance....cause they are pretty.

[BubbaTheHut]

There is no real purpose to this thread, its just fun.

[xxbackhillxx]

143mph

[bandit307]

Unless the govener is deifferent in the Canadian cars (which I doubt) how did you do 132 MPH in a car that is limited at 126??? You don't have the limiter removed do you?

No i dont have it removed. Is there a actuall speed govern in the 2000 GA's? I dont know its about 5900rpm 3rd gear so maybe its a rev limiter.

All i know is i hit 213km/h. Not trying to sound like my car is awsome cause its mine its just thats what i did.

[VanishingImage]

107 then the limiter kicked in. Pretty lame it wouldn't even let it go to the 110 that my speedo reads up to,3mph??? comon:lol:

I know they do that mainly because of the tires that come on the cars factory aren't rated for high speeds and some other factors.

[cole454]

105 = speed limiter

[archillasvante]

112 mph = limited

[ChevelleSSLS6]

105 is still slow. But then again I'm a wild child. Only on empty highways scouted for hazards and fuzz first.

[ecks57]

ladybugs do have a purpose they eat aphids off of plant leaves cuz aphids eat plant leaves (learned that when i was hella young) lol

[ZACH]

Originally posted by Foxy
Where were you guys doing this!?

Speedos are usually optomistic... when I had my STi on the track, the speedo said 125 or so; the GPS said 118. Even at lower speeds, there's still about a 4% error.

I would believe a speedo over a GPS anyday, The sensor for the speedo is in the tranny, the sensors for the GPS is located hundreds of miles away on several satalites then the GPS does a bunch of math to figure it out. The Speedo only does one calculation.

If all you people plan on or have removed the limiter, make sure you replace the absolutely most important thing on your car, the TIRES. make sure the tires are rated for higher than the speed you are going. And absolutely do not go over the speed limit ;)

128mph Limited : Tires rated for 149mph

[eric99gt]

Either way it's a known fact that speedos on average read 5% higher than the true speed.

[Foxy]

Originally posted by ZACH
I would believe a speedo over a GPS anyday, The sensor for the speedo is in the tranny, the sensors for the GPS is located hundreds of miles away on several satalites then the GPS does a bunch of math to figure it out. The Speedo only does one calculation.

Guess how the speedo senses your speed? It calculates it by measuring how many times your wheels spin. Guess what affects that? Tire circumference. Guess what? If your tire isn't exactly the right size, your speedo is off. Getting non-stock tires, having not exactly the right pressure, how worn the tires are (going from 9/32" to 2/32" tread depth definately affects the circumfrence of the tire!), and so on all affect how your sensor will report your speed. Besides that, the manufacturers generally will indicate a higher than actual speed.

The sensors for the GPS is on your handheld unit. The GPS satellites merely beam down signals and your GPS unit in your car/hand measure the time it took the signal to get there and trilaterate. Study GPS; it's a very fascinating subject and amazing that it works - the signal that you receive, for instance, is thousands of times weaker than background radiation noise - and yet the handheld units can pick it up! I worked with GPS for my master's thesis; we had units that could measure down to the centimeter (thought my project didn't use them; I just got to play with them a bit). My handheld unit is good down to about a tenth of a MPH given a good signal.

[TA^Guy]

GA hit the limiter at 126ish
Xtreme hit the limiter at 98ish
My Z28 I had over 150mph (buried the speedo at 110).
A guy I worked with and I did the math from the tire diameter of a BFGoodrich Comp TA (255/50RZR16), 2.73:1 rear gearing and final drive of a TH700R4 by my 5600rpms. :)
My bike, well the speedo read 182mph when I backed off due to traffic on the track. :)

Foxy is correct, a GPS unit can pinpoint the location the size of a dime on a map.

Speedos are usually off a good 4-8%. And thats right from the factory with brand new rubbers.

I was once told that if a manufacture were to sell cars with the speedo reading to low (saying you are going slower than you actually are) they can be fined because the speedo is part of the saftey equipement in operating the vehicle at a safe speed. So to make sure they are in complience the speedo will typiclaly read faster than you are actually traveling.

Think your speedo is correct?

Barrow or rent a GPS unit and test it for yourself, I'm sure you'll be surprised.

Infact there are companies that sell speedo correction units for motorcycles.
Originally posted by ChevelleSSLS6
105 is still slow. But then again I'm a wild child. Only on empty highways scouted for hazards and fuzz first.
Damn right it is.

105mph and I'm still in first gear!

WOOT!

[slowbird]

I stand corrected on the Ladybug thing.




Ummm...I've gone by those radar "Your speed" signs that tell you how fast you are going and they seem right on the buck with my speedo.

[ZACH]

Yes a GPS can measure to the nearest 1/100th of a foot, but not yours and none of them will come even close to that when you are moving. The ones that measure that accurately are used for surveying and cost somewhere between 10 and 30 thousand.

I am not saying that speedo's are accurate, I,m just saying they are more accurate than a handheld GPS. The average GPS today can only measure to the nearest 15ft (if WAAS capable, which most are), and that is when you are standing completely still with completely clear sky around, not when you are moving. And being that a GPS works based on recieving several different signals from things that are hundreds of miles away there are many more factors that create possible errors.

I know on the handheld GPS I use, it shows you the measurement of how accurate you are at that moment, and very rarely do I see it say that I am more accurate then 20ft.

[Foxy]

Zach,

Do you know how GPS's calculate that 20ft accuract circle? Do you know how GPS's calculate velocity? Hint - it's not necessarily r=d/t.

For my thesis, I researched GPS velocity with a Garmin RINO 120 GPS (http://www.garmin.com/products/rino120/). The velocity accuracy depended on the exact course that was being tested - smaller, curvier paths were less accurate. For a straight path (like driving a car down a highway), the GPS was dead on (within the accuracy of my measuring tools, which measured down to a 1/10th of a MPH) about 45% of the time, and within .3 mph something like 90% of the time.

So, if you want to believe your intuition that they aren't very accurate, that's fine. I'll believe my hands on, instrumented research.

[ZACH]

SO how does a GPS measure speed then if not by r=d/t. Because thats what speed is, d/t

What other way is there to calculate speed?

I am asking seriously because I want to know, I know its sound like I'm being a smart ass, but I'm really not.

I'm not trying to get anything started and may be we should start a new thread because this is getting off topic.

[Foxy]

Most use a combination of r=d/t but primarily rely on Doppler shift from the radio signals. To oversimplify, The GPS sats transmit on a very, very, very specific frequency. Any relative movement to those satellites results in a change in the frequency. The position of the sats are very very well known. By figuring out the Doppler Shift (and angle to the satellite, but you know that already if you're tracking it), you can determine velocity pretty precisely.

[ZACH]

I did'nt realize there was a seperate function going on, I just assumed that they tracked your distance and time and gave you answers based on that. And since your position is only within 15ft at best, then your getting a possible error of 30ft between 2 points. But your saying there is a seperate signal used to track movement? That still sounds a little weird to me, it must still be using some form of d/t even if its distance of the wavelength of the signal, which is what it sounds like you are saying.

This is just way to complicated of a thing to be discussing like this, but you said you have thesis that you wrote on the topic?, I'd be interested to read it. I do site surveying on a pretty regular basis, and we are considering getting a GPS unit. We have a handheld Garmin, but 15ft accuracy is not close enough for what we do. We use a total station for our surveys.

[Foxy]

Argh, my reply vanished..

There's not a separate signal. It's the same signal put out by the GPS, but due to the relative motion of the satellite to the receiver, the signal appears to have a different wavelength/frequency. Google "doppler effect." It's the same reason why an ambulance driving at you with its siren on sounds different as it comes closer and closer, passes you, and drives away. The siren is making a constant frequency sound, but due to its motion, the waves going towards you are compressed and are perceived as being higher frequency.

This is a formula you can use to determine your relative motion:
http://upload.wikimedia.org/math/c/b/f/cbf559a7831c3641030f9824d7390ce4.png

Fs is the frequency of the source signal (for GPS, the L1 carrier wave is 1575.42 Mhz)
Fr is the frequency that the receiver perceives it is receiving (say, 1575.4252)
Vs is the velocity of the source signal (the satellite moves at a precisely known velocity - for the medium earth orbits of the GPS satellites, it's about 10245 mph)
Vr is the velocity of the receiver.
c is the speed of light (this is known)
n is the unit vector from the satellite to the receiver (this is known because you're tracking the satellite).

So, you have only one unknown - the velocity of the receiver. You don't need your exact location to determine your velocity. Radar guns work on the same doppler effect principle.

In practice, the GPS receivers combine that formula above with r=d/t, pass all this through a Kalman Filter (basically an algorithm that smooths out noisy/erratic input data into a smooth curved output stream, based on feedback from the system) - so you're not getting your exact instantaneous speed - but as I found, in practice, it's pretty accurate.

As for my thesis, I didn't work on GPS, but I used it very heavily, so I had to learn a bunch about it. It's like I used GPS as a tool to achieve my goal, but I had to learn about my tool and see what it was capable of so I would know if it was suitable or not. I'd post my thesis, but it has my real name and other identifying information that I'd rather not associate with my screen-name.. gotta preserve that pseudo-anonymity :) I'll PM you some more info, though.

[nino_neg]

the limiter kicks in at about 113 on my se.
neone reprogram theirs?

[gerald]

108 on a dead highway at 10.30 at night on the way home from work.

[eric99gt]

210 mph....

[Colin]

Originally posted by eric99gt
210 mph.... :glasses2:

[Matt95GT]

:horse:

http://www.gaownersclub.com/forum/showthread.php?threadid=50907