130 Or Bust

[3100gagt]

OK so i was rollin with my friend's MX-6 V6 5-spd doin like 90 in my 99GT while my car was left in 3rd gear!!! just messin with him then we hit it and i slid by him completely by 110MPH then we rolled to 130MPH and my car hit fuel cut.?

Now the car was in 3rd gear I think, not paying attention to cluster while doing over 120 then the cut & I looked and i was at 130.Headers helped out so much it like stopped going at 125 before.

Now was that the gov. hiting or did i hit redline in 3rd?
Anybody know? if not i will have to try it again and see.

[eric99gt]

uhhhhhh....it's controlled by the PCM.

[3100gagt]

what is?
the car wont shift by itself if manualy put in 3rd
did anyone hit the gov?

[Lythium]

Never heard of a GA goin over 120 without shuttin off. And 130 in 3rd gear, in a GA especially, sounds kinda wierd.

[rabidpanda69]

But it's not gonna pass the top speed set by the pcm. The only way to do that is go down a hill.

[JoeyK]

Mine don't cut out till around 134, I don't know where you guys are getting this 120mph figure from unless you're referring to 1998 & down?
I've heard from alot of people saying they can hit 130. give or take a few, before hittin the cut off.

[rabidpanda69]

I never gave a figure of any kind ;) I just mean to say that it topped out because of the pcm, not because of third gear redline. If you felt it quickly stop accelerating then the gov. hit. If just kinda held the speed and rpm's then it was redline or I supposed it might bounce of the rev limiter.

[Korbendallas68]

Not to be a party pooper but, 130 on the open road? Save it for the track.

[JoeyK]

Good, then don't be a party pooper & leave it alone.;)

Yes Panda, it surges something terrible when it hits the limiter. This was on 469, which is an outer loop around Ft Wayne, IND. which seems to be something the city built for the future. There doesn't seem to alot of traffic on it in the daytime let alone at ngiht, granted I've never been on it during rush hour but the loop is way bigger than the city it surrounds.There isn't a soul on it in wee hours in the morn. Or atleast 2 to 3 in the morn. was around the time I was running at a full clip. I won't even say why or the little P.C. police here will get all bent out of shape.:lol: Anyways, that how & when I found out where mine capped off. It took a while past 120 to reach it I might add.

[eric99gt]

Alright, here's the facts. The 99 and up GAGT is electronically limited to 126MPH. If you say you've gone faster you're either lying or your speedo is off. Once you hit that speed the PCM cuts fuel to the injectors therefore limiting your top speed.

[buckeyejack]

Mine stoppes at 120 mph. Even going down hill it won't hit 126.
120 ,that's it. Shifts into overdrive right at 118 , goes 2mph more and rev limiter comes in.

[3100gagt]

it was 130
before my headers i had it to 128 but it seemed to take forever to get it there, then i let out. i will take a pic next time and post it.

My tires are V rated so im good in that dept. till 150MPH
The MX-6 was doing 130 also and my car was past his. so I dont know

when the cut hit i completely let off cuz i had to get off the exit anyway in like 500ft.

are there any charged guys out there that would heve some more insite, you know they can still pull over 120

My 96 hit gov @105

Heck i will just have my friend take a pic of the speedo while im doin 130
Will try this weekend!!!

[Matt95GT]

Originally posted by 3100gagt
it was 130
before my headers i had it to 128 but it seemed to take forever to get it there, then i let out. i will take a pic next time and post it.
...

Heck i will just have my friend take a pic of the speedo while im doin 130
Will try this weekend!!!

Obviously you aren't listening...

Originally posted by eric99gt
Alright, here's the facts. The 99 and up GAGT is electronically limited to 126MPH. If you say you've gone faster you're either lying or your speedo is off. Once you hit that speed the PCM cuts fuel to the injectors therefore limiting your top speed.

The gauges are not the most accurate or consistent measurement instrument. Example... the speedo on my 94 is nearly 4 MPH off as timed by radar. I also watched the tach on my 95 climb to 6700 RPM, which is impossible, rev limited to 6500 and the digital tach readout on my S-AFC confirms it. Same with the 900 RPM idle that shows as 1200 RPM on the tach gauge.

Pics of your inaccurate gauge prove nothing. Don't bother.

[soccerplayer21]

even before my s.c i could get mine up to 136 137, on a race track of course im not tryin to hit a bump n die on a street

[wild_card_06]

I don't know where you came up with a 126mph limiter. I have had my GT at 140 on flat ground. Its bone stock, and I haven't hit a limiter I'm just to scared to go any faster but I know it can.

[JoeyK]

Originally posted by eric99gt
Alright, here's the facts. The 99 and up GAGT is electronically limited to 126MPH. If you say you've gone faster you're either lying or your speedo is off. Once you hit that speed the PCM cuts fuel to the injectors therefore limiting your top speed.

Chill out & lsten before you get so harsh. No one likes to be called a liar when they are telling the truth- simply put.
The limiter varies, why I do not know. There seems to be about a 10mph range where you could fall into it. - Yes, things such as different tire sizes & badly calibrated speedo's can play a factor. But I do not believe my speedo is that far off. (8 mph)I've heard different claims for years now & when someone tells me they wen't over your 126 figure (Again, don't know where that comes from unless it's just your experience with your car- if so it does not mean every car is identical.) I believe them because I've been over it myself.

[Matt95GT]

This discussion is a moot point unless actual speed has been verified via radar, GPS, or other means besides the speedometer.

Originally posted by JoeyK
Chill out & lsten before you get so harsh. No one likes to be called a liar when they are telling the truth- simply put.

How is stating the facts harsh? :???2:

[JoeyK]

Calling people liars is harsh. Especially when the person doing so does not know the facts himself.

Why is it a moot point? All that is being stated is what the speedo reads topped out. I don't think anyone here would argue that there are variables such astire/wheel ciombo's & or bad speedo calibration. But I highly doubt a speedo is gonna be off 8mph. Otherwise I'd be picking up tickets left & right & I'd be ticked off everyday I go to work & people are doing 27 in a 35.

If I have to explain electonics manufacturing to you all I will at a later time when I have time. I & many others I've talked to have a theory as to why the limiters vary.(The guy who clued me/us in on what could make the diff. worked for Delphi.)

[ntl5002]

Doesn't it have something to do with what tires you have on your car when it's new?

[Korbendallas68]

Are stock tires able to handle 130mph??

[ntl5002]

Some, I think it depends on the tire/wheel package for the car. That's what I think determines the governor. The manufacturers don't want you to go faster than or get close to the rating on the tire and have something go wrong and get sued over it.

[SCGA1]

Originally posted by 3100gagt
it was 130
before my headers i had it to 128 but it seemed to take forever to get it there, then i let out. i will take a pic next time and post it.

My tires are V rated so im good in that dept. till 150MPH
The MX-6 was doing 130 also and my car was past his. so I dont know

when the cut hit i completely let off cuz i had to get off the exit anyway in like 500ft.

are there any charged guys out there that would heve some more insite, you know they can still pull over 120

My 96 hit gov @105

Heck i will just have my friend take a pic of the speedo while im doin 130
Will try this weekend!!! As stated, GA GT's are electronically-limited to 126 mph. Unless you have a PCM tune or a chip that eliminates the governor, you were not exceeding 126 mph.:cool:

[jayhawk]

Originally posted by ntl5002
Some, I think it depends on the tire/wheel package for the car. That's what I think determines the governor. The manufacturers don't want you to go faster than or get close to the rating on the tire and have something go wrong and get sued over it.

Bingo. Because I bought the super ghetto SV1 Sunflower, my speed limit is 108. :(

[dballz]

GT is governed to 128, and I believe the SE is limited to 108. Its been dicussed MNAY times

[RocketFast321]

Originally posted by ntl5002
Doesn't it have something to do with what tires you have on your car when it's new?

The 99+ GT tires are able to go like 140mph (I belive)
The 99+ Se tires are 120mph

[Korbendallas68]

Originally posted by dballz
GT is governed to 128, and I believe the SE is limited to 108. Its been dicussed MNAY times

:agree:

[3100gagt]

M 81 mph 130 km/h
N 87 mph 140km/h Temporary Spare Tires
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars,GAGT's

My grand am GT 1999 calls for V-rated tires OEM on the door sil
Done with the tire conversation.

Guess i will have to see and take my speedos word for it and let it at that..

[SilverGA2001]

I'm going to agree with Joey. I've shown an indicated 134 before (mine will not exceed 121 or so in Drive, but keep it in 3rd to the floor, and it passes it every time :dunno: ). Whether it's doing it or not isn't what I'm saying/claiming. It was indicated. For sure though, I'd absolutely love to be clocked (hopefully not by law enforcement... :lol: ) while doing it to find out the true read. And if I trusted anyone else enough, I'd have them pace me in the Formula, and compare the two readings.

Anyway, I haven't done this in a very long time. :)

[eric99gt]

Originally posted by JoeyK
Calling people liars is harsh. Especially when the person doing so does not know the facts himself.

Why is it a moot point? All that is being stated is what the speedo reads topped out. I don't think anyone here would argue that there are variables such astire/wheel ciombo's & or bad speedo calibration. But I highly doubt a speedo is gonna be off 8mph. Otherwise I'd be picking up tickets left & right & I'd be ticked off everyday I go to work & people are doing 27 in a 35.

If I have to explain electonics manufacturing to you all I will at a later time when I have time. I & many others I've talked to have a theory as to why the limiters vary.(The guy who clued me/us in on what could make the diff. worked for Delphi.)

I wasn't exactly referring to anyone here. I was just saying in general because we all know there are a lot of BS artists out there. The limiters do not vary from car to car. Have you ever looked at the computer settings in a 99+ GA. Everyone I've looked at has the injectors shutting down at 126 MPH, which has been 3. This has been confirmed by sources on the GAGT boards back when we had a GM engineer lurking around. I don't know why you think it would vary. GM doesn't just randomly plug in numbers to each of their PCM's with the OBD2 programming. When you get to those speeds the needle can be thrown off a lot. It's that simple. Until somebody actually gets measured going that fast in a stock PCM GA using calibrated equipment there are no real facts. I've given you facts.

[JoeyK]

Let me start by saying this isn't even close to being worth arguing over anymore. No big deal. Let me just leave you with this; yes, I would 100% agree that all the programming is the same. I would bet my life that things such as capacitors, diodes, transistors, etc. are not identical on every cars electronics systems. I'm not just talking the pcm here either. Lots vary in the manufacturing process & there are control points set for specs. As long as they stay in the control points parts will vary. When they do it does not mean the programming command is going to be translated with 100% acuration to get the exact result the program commands.
If you think everything is manufactured indectical then you are very mistaken. This is where we in theory, figure this variation lies.

[eric99gt]

No argueing. Just convo. I could beleive that. But with such infintesmal differences in parts I find it hard to believe that that would cause such a huge difference. Isn't it more realistic to believe that the speedometer is not calibrated properly at those speeds. I guess would could agree to disagree.

[JoeyK]

That's cool. I just figure mine is miost likely a combo of both. As I said, I cannot see the speedo calibration being off that much but it could be off anywhere from 3 to 5 mph at that point.

[Ackbar00]

Mine gets to about 130 in the 1/4 mile.:cool:

[eric99gt]

Great :roll2:

[Brandon]

ive ran gps in mine while having gone at higher speeds ( i stopped at 95mph) and the gps and the speedometer were reading the same.... 95 mph....

thats all i am going to comment on though :) ive had it upto 113 and that was fast enough for me!

[99GrandAMSE]

Originally posted by Ackbar00
Mine gets to about 130 in the 1/4 mile.:cool:

... 9 MPH short according to the ET you listed :lol:

[XoticGA]

So :uhh: what happens at 128 mph? The car just shuts off or what?

[Ackbar00]

Originally posted by 99grandamse
... 9 MPH short according to the ET you listed :lol:

Guess you missed this part....

"on the brakes"

[99GrandAMSE]

Originally posted by Ackbar00
Guess you missed this part....

"on the brakes"

Nah, I didn't miss anything ... remember that!

[SilverGA2001]

Originally posted by XoticGA
So :uhh: what happens at 128 mph? The car just shuts off or what?


Where ever that top speed may be for the person... 126...128... indicated 134.. whatever, the car just goes no faster. If like mine, it'll hold the speed, but simply won't go any faster. I've never had anything exciting happen, no rev limiter engage, no choking, no surging. It's very boring the way it happens.

[ntl5002]

When I hit 110 it scared the crap out of me because I was accelerating then all of a sudden I wasn't. I thought I broke something but this was before I remember cars have the limiters.

[jayhawk]

Originally posted by 99grandamse
Nah, I didn't miss anything ... remember that!

PWn3D JU!!!1111ELEVEN11!!!

[99GrandAMSE]

... mine has the 112 MPH limiter :( ... and when it hits, it simply feels like you took your foot off the accelerator even though you didn't :(

[MantaGreen97]

Originally posted by 3100gagt
Now the car was in 3rd gear I think, not paying attention to cluster while doing over 120 then the cut & I looked and i was at 130.Headers helped out so much it like stopped going at 125 before.

Now was that the gov. hiting or did i hit redline in 3rd?
Anybody know? if not i will have to try it again and see.

Just a note about the 3rd gear issue, GAs with automatics are safe up to their maximum (electronically limited) speed in 3rd gear, you don't need to be in 4th to get to "top" speed.

As for the speedo error, it shouldn't be very large. At least not on 96+ cars. The IPC (Instrument Panel Cluster) gets its information the same as the PCM/BCM does--via the VSS (Vehicle Speed Sensor). If your tyres are a little smaller than the original ones (in overall rolling circumference I mean not having anything to do with wheel diameter) than the original ones, the VSS will be overreading (meaning you'll get a slightly higher indicated than actual speed. With tyres that are larger overall, you'll get the opposite.

Still that is beside the point of the indicated speed error I suppose. Simply put a properly functioning IPC and VSS, assuming tyres that have perfect circumference for the vehicle's calibration (meaning the VSS pulses exactly the number of times per unit distance that it was designed to), the IPC should not be in error any more than +/- 2 MPH, I'd say.

That said there are other things that can contribute to indicated speed error. One being the angle of which you are reading any analog sweep guage as is the speedometer in our cars. Another simply being the IPC isn't working 100% perfectly and is off by a little bit (this could be caused simply by wear over time, or by removing and replacing needles as could be the case with installing gauge overlays).

The end point is when the PCM (or BCM as GM seems to be calling it these days) sees a VSS that indicates a speed greater than or equal to the cutoff speed in its programming it will initiate its fuel cutoff strategy. The signal the PCM is getting is the same as the IPC receives so the only discrepancy between the two is how the IPC will display the speed.

As for where the limiter actually is is another story. For 99+ GAGTs it is supposed to be 126MPH as mentioned and 108 or so for SEs. It seems that this actually varies in practice however. It might be that some people's IPCs err enough at higher speeds that the VSS is pulsing one thing and the IPC shows another, however I doubt that many IPCs would actually be flawed in such manner.

The best way to tell the actual speed of the vehicle is by properly calibrated radar or other external means. The best way to verify if either the VSS or IPC is reading incorrectly is to use that speed measured, connect an OBD-II scanner and see the actual pulses/sec and convert that to speed. Then compare that to the actual speed shown by radar and then the indicated speed shown by the IPC to see where and how much any error occurs.

In any case I'm sure that the majority of people will find that the limiter engages at an indicated speed reasonably close to what it is supposed to be limited to (i.e. 108 MPH for 96-98s and 99+SEs and 126 MPH for 99+ GTs).