computer speed limit
Supporting Tuner
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From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
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St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Originally Posted by Y2Kvert4me
Actually, there is.
The PCM will only recognize speed readings up to 255mph.
Best of luck exceeding that!
The PCM will only recognize speed readings up to 255mph.
Best of luck exceeding that!
Le Mans Master
Joined: Sep 2003
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From: Jacksonville Florida
Originally Posted by Y2Kvert4me
Actually, there is.
The PCM will only recognize speed readings up to 255mph.
Best of luck exceeding that!
The PCM will only recognize speed readings up to 255mph.
Best of luck exceeding that!
I do know you can't set the cruise control above 165 mph.
Safety Car
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From: Making my plane take off from a treadmill
Originally Posted by CAJUNY2KC5
I do know you can't set the cruise control above 165 mph.
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Race Director
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From: Mustang OK
Originally Posted by rcmaben
Can anyone tell me the computer cutout top speed on a stock '04 coupe?
If you're referring to the the Rev Limiter it is around 6200 rpm for the LS1 engine and around 6600 rpm for the LS6 I believe. Just remember, the Rev Limiter only works when up shifting and not when down shifting.
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From: Gone
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St. Jude Donor '03
Clarification
I'm not sure if the same PCM is used in other vehicles, but that max speed is a programmable function (with a tuning tool, not via the DIC options).
This feature could be used to limit the top speed if you (or GM) wanted to, and if the PCM is used on other platforms, may well be used as a limiter....But for Corvettes, it is factory-set to it's highest point, which happens to be 255mph.
This feature could be used to limit the top speed if you (or GM) wanted to, and if the PCM is used on other platforms, may well be used as a limiter....But for Corvettes, it is factory-set to it's highest point, which happens to be 255mph.
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I don't think there is one. It's more a function of drag limitations than the computer I believe.
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From: New York NY
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St. Jude Donor '05
Originally Posted by JDs00PewterCoupe
I don't think there is one. It's more a function of drag limitations than the computer I believe.
Burning Brakes
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From: New Smyrna Beach Fl
let's start this over....... the rev limiter is set at a given RPM. It doesn't recognize speed. I believe all US manufactured cars & trucks have a speed limit programmed into there PCM's. It's usually set at the top speed rating for the STOCK tires. My C-1500 Silverado won't budge past 100 MPH, even though it's only turning 3'000+ RPM. The engine cuts out. Most Dodge's are set at 118 MPH, unless they have a factory equipped performance tire. The C5's PCM won't read over 255 MPH, but I believe the tires are rated at 252 MPH. So, if we go by that figure, the PCM is set at 252 MPH, max.
Le Mans Master
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From: Los Angeles
Originally Posted by Y2Kvert4me
Why does everyone say "drag-limited" anyways?
It's hp limited. It's easier to add hp and increase the top speed than it is to reduce drag.
It's hp limited. It's easier to add hp and increase the top speed than it is to reduce drag.
Also, "gear limited". 3.42 in 6th is around 260mph. I think a 4.10 is about 210mph.
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From: Gone
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St. Jude Donor '03
Originally Posted by SilverBullit02
let's start this over....... the rev limiter is set at a given RPM. It doesn't recognize speed. I believe all US manufactured cars & trucks have a speed limit programmed into there PCM's. It's usually set at the top speed rating for the STOCK tires. My C-1500 Silverado won't budge past 100 MPH, even though it's only turning 3'000+ RPM. The engine cuts out. Most Dodge's are set at 118 MPH, unless they have a factory equipped performance tire. The C5's PCM won't read over 255 MPH, but I believe the tires are rated at 252 MPH. So, if we go by that figure, the PCM is set at 252 MPH, max.
There are plenty of 200+ mph exotics that also run on Y rated tires. It is currently is the highest speed rating for any street tire.
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From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
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You are drag limited.
At 180+, the front of the C5 wants to lift off, unless you get some diffusers under the car and a wing on the rear for downforce.
So unless you have your pilots license, I don't see how you can exceed 200+mph and stay on the ground in a stock C5, no matter how much HP you have.
Aerodynamics is your friend at those elevated speeds.
At 500rwhp and 2.73:1 gears, I should be able to break 200mph - but I will never try it in my car. Not without serious aero modifications.
EG
At 180+, the front of the C5 wants to lift off, unless you get some diffusers under the car and a wing on the rear for downforce.
So unless you have your pilots license, I don't see how you can exceed 200+mph and stay on the ground in a stock C5, no matter how much HP you have.
Aerodynamics is your friend at those elevated speeds.
At 500rwhp and 2.73:1 gears, I should be able to break 200mph - but I will never try it in my car. Not without serious aero modifications.
EG
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From: San Diego, CA "leaf" "tee" "e"
Originally Posted by EnglandGreen
You are drag limited.
At 180+, the front of the C5 wants to lift off, unless you get some diffusers under the car and a wing on the rear for downforce.
At 180+, the front of the C5 wants to lift off, unless you get some diffusers under the car and a wing on the rear for downforce.
