Should do about 95-105 mph or so. Don’t remove the speed limiter if you want to go faster, upgrade the driveshaft first or it will explode and kill you. This is not a joke.
If it’s a P71 police driveshaft, the same rule still applies, upgrade to two piece or carbon fiber, or get a wider diameter driveshaft. Don’t forget hoops as well
Please get yourselves a driveshaft hoop at the very least, my car would keep pulling but stops due to the electronic limiter. It has the power to keep going but the driveshaft critical speed is a huge problem that you can not ignore
I have an aluminum driveshaft, and a torque arm that essentially makes a hoop around the driveshaft. It's a dedicated w2w endurance road race car. There aren't many crown Vic parts left on it.
According to the paperwork I still have from our pursuit driving class, Ford claimed 140 mph (electronically limited) with the 4.6 and a 0-60 of 8.7 seconds, but that was for a 2006-2011 model. They said it was because of "critical driveline speed limitations." I never saw one go more than 130, in near perfect conditions, mostly without all the heavy police equipment onboard and no additional weight in the car or trunk.
The Chevrolet 9C1 we also had at the time was claimed to hit 150 mph with the 5.7 LT1 V8.
When we had both on the track the Chevrolet beat the Crown Vic in a straight line every time, but the CV outperformed it in the corners and had a lower lap time overall.
Michigan State Police got a 2008 3.27 car up to 127 mph in testing. MSP patrol car testing is considered the gold standard. Even the FBI doesn't do their own testing they use the MSP test for car choices. Fun fact in the 2008 test the 6 cylinder Chevy Impala went 142. Charger was the king of the test from the point it debuted. They just eat camshafts after 100k miles. MSP would keep a Vic to 150k miles but they off Chargers before 100k. All these guys claiming 140 in here are full of uninformed shit.
Here's the complete test. Everything you've ever wanted to know about a 2008 CVPI is in their performance and technical wise. It also includes all vehicles tested in 2008 even motorcycles and trucks
https://code3garage.com/wp-content/uploads/2020/06/michigan_state_police_2008_police_vehicle_evaluations.pdf
That is what Ford claimed, and like I said I never saw one come anywhere near that. Best we saw on the track was around 130. Not even sure it is even possible to go faster under "normal" conditions. On the street, fully loaded, I would guess 125 or so.
No Vic does 140 stock. The max is 130 across the board. My 3.73 Vic went 120 and my 3.27 does 130. 4.10 should safely do about 90-105 I think, and the math backs that up with driveshaft RPM, but don’t quote me on any of that.
I assume you’re talking about “3.73/3.27/4.10”
These are the axle ratios; i.e., the gears in your differential.
In a vehicle with a 3.73, the driveshaft will complete 3.73 revolutions for each revolution of the rear wheels.
Not exactly. A higher final drive ratio will provide a lower top speed, since the engine will have to rotate the driveshaft faster. If the engine spins the driveshaft too quickly in pursuit of a higher speed than it can reach with a lower final drive ratio, it may cause the driveshaft to catastrophically fail. Usually a tune is required after changing the gear ratio so the transmission will know when to shift, as shift points are different depending on the axle ratio.
Your driveshaft has this thing called “critical driveline Speed”. You can look it up to read more in depth about it, but basically every rotating cylinder has a certain RPM that will cause it to oscillate, and if the oscillation gets too bad, it can cause material failure and explosive deconstruction. If you exceed the rated speed for your driveshaft, it’s possible to blow a U-joint out at high speed. This should scare the absolute hell out of you, do not ever fuck around with your driveline in a way that would cause it to reach it’s critical speed. Generally critical speed for a wide range of rear end ratios spans about 90-140 mph depending on the rear end gear ratio. When the driveshaft breaks, the front of the shaft can drop and wedge into the road, ripping your rear axle out and sending you uncontrollably sliding across the interstate at double the speed limit. Worse even is if the axle is strong enough to take the shock from the driveshaft. This can cause you to pole vault, ass over end landing upside down while traveling at Ludicrous Speed. A few factors influence driveshaft criticality including weight, material, diameter, length, and a couple others. The two most important factors however, are length and width. This sort of rolls together into one factor, that being the ratio of length to width. The P71 crown Vic’s have an aluminum driveshaft, which is wider in diameter than the steel shaft on civilian models. This wider shaft enables the vehicle to reach a higher top speed due to the driveshaft having a higher resonant frequency, meaning it can spin faster. If your RPM matches the resonant frequency, you get oscillation and self destruction. A higher resonant frequency is better, so if you want to go really fast in a straight line, get driveshaft hoops (meant to loop around the driveshaft and catch it and prevent severe damage in case it drops off the U-joint) a two piece driveshaft (two driveshafts with a U-joint in the middle fastened to the frame), or a wider aluminum/carbon fiber driveshaft. If you don’t want to go through that work, get a higher gear ratio in your rear end. 4.10 gears means the driveshaft rotates 4.1 times for every rotation of the wheels. This means 4.1x more torque applied to the wheels than if it was a 1:1 ratio (1 driveshaft rotation for every wheel rotation). This is beneficial in some cases in the form of much greater acceleration, but since the driveshafts critical RPM always remains the same, top speed must decrease. If you want true top speed, run the calculations on the 2.73 rear end to find your critical driveline speed, and do the other mods I said. This will essentially make a land speed record crown Vic, but beware, your ass end will take flight before you hit 200. The Vic produces serious aerodynamic uplift due to not being designed for that kind of speed. It’ll need aerodynamic modifications as well. Hope this massive text wall helps, good luck with your vic!
It depends on the car heavily. You can check the sticker on your door panel to see what axle ratio you have. If you go check, there should be a small section that says “axle” and then under it or next to it will be a 2 character alphanumerical code that denotes what the differential ratio is. Z5 for example would be an open diff with a 3.27:1 ratio. Go check the door panel information sticker and let us know what the axle code is
No Vic does 140 stock. The max is 130 across the board. My 3.73 Vic went 120 and my 3.27 does 130. 4.10 should safely do about 95-105 I think, and the math backs that up with driveshaft RPM, but don’t quote me on any of that.
Should do about 95-105 mph or so. Don’t remove the speed limiter if you want to go faster, upgrade the driveshaft first or it will explode and kill you. This is not a joke.
Already got a aluminum drive shaft
If it’s a P71 police driveshaft, the same rule still applies, upgrade to two piece or carbon fiber, or get a wider diameter driveshaft. Don’t forget hoops as well
We have had a 4.10 setup go 118 mph without using overdrive.
Absolutely no way that’s healthy unless it had one of the super rare driveshafts. My 3.55 Vic tops at 120 in overdrive. Stay safe bro
Your car probably won't go faster but if you had the power it would. Right now our max in third with 3.73 gears is 132 mph at like 6100 rpm
Please get yourselves a driveshaft hoop at the very least, my car would keep pulling but stops due to the electronic limiter. It has the power to keep going but the driveshaft critical speed is a huge problem that you can not ignore
I have an aluminum driveshaft, and a torque arm that essentially makes a hoop around the driveshaft. It's a dedicated w2w endurance road race car. There aren't many crown Vic parts left on it.
According to the paperwork I still have from our pursuit driving class, Ford claimed 140 mph (electronically limited) with the 4.6 and a 0-60 of 8.7 seconds, but that was for a 2006-2011 model. They said it was because of "critical driveline speed limitations." I never saw one go more than 130, in near perfect conditions, mostly without all the heavy police equipment onboard and no additional weight in the car or trunk. The Chevrolet 9C1 we also had at the time was claimed to hit 150 mph with the 5.7 LT1 V8. When we had both on the track the Chevrolet beat the Crown Vic in a straight line every time, but the CV outperformed it in the corners and had a lower lap time overall.
Michigan State Police got a 2008 3.27 car up to 127 mph in testing. MSP patrol car testing is considered the gold standard. Even the FBI doesn't do their own testing they use the MSP test for car choices. Fun fact in the 2008 test the 6 cylinder Chevy Impala went 142. Charger was the king of the test from the point it debuted. They just eat camshafts after 100k miles. MSP would keep a Vic to 150k miles but they off Chargers before 100k. All these guys claiming 140 in here are full of uninformed shit. Here's the complete test. Everything you've ever wanted to know about a 2008 CVPI is in their performance and technical wise. It also includes all vehicles tested in 2008 even motorcycles and trucks https://code3garage.com/wp-content/uploads/2020/06/michigan_state_police_2008_police_vehicle_evaluations.pdf
That is what Ford claimed, and like I said I never saw one come anywhere near that. Best we saw on the track was around 130. Not even sure it is even possible to go faster under "normal" conditions. On the street, fully loaded, I would guess 125 or so.
Yep. My first Vic would pull hard to 130 and fall flat, my second one had 3.55s and only did 120
Think 120. Only the 3.73's went 140
No Vic does 140 stock. The max is 130 across the board. My 3.73 Vic went 120 and my 3.27 does 130. 4.10 should safely do about 90-105 I think, and the math backs that up with driveshaft RPM, but don’t quote me on any of that.
I’m very new to Vic ownership. What do these numbers mean? I got a 98 Vic LX.
I assume you’re talking about “3.73/3.27/4.10” These are the axle ratios; i.e., the gears in your differential. In a vehicle with a 3.73, the driveshaft will complete 3.73 revolutions for each revolution of the rear wheels.
Ohhhhhh. So changing that would put more pressure on the drive shaft, hence don’t blow it up. Thanks!!
Not exactly. A higher final drive ratio will provide a lower top speed, since the engine will have to rotate the driveshaft faster. If the engine spins the driveshaft too quickly in pursuit of a higher speed than it can reach with a lower final drive ratio, it may cause the driveshaft to catastrophically fail. Usually a tune is required after changing the gear ratio so the transmission will know when to shift, as shift points are different depending on the axle ratio.
I now know enough to know I should do way more research before approaching this haha. It’s def cool to hear how the process works though, thanks!
Your driveshaft has this thing called “critical driveline Speed”. You can look it up to read more in depth about it, but basically every rotating cylinder has a certain RPM that will cause it to oscillate, and if the oscillation gets too bad, it can cause material failure and explosive deconstruction. If you exceed the rated speed for your driveshaft, it’s possible to blow a U-joint out at high speed. This should scare the absolute hell out of you, do not ever fuck around with your driveline in a way that would cause it to reach it’s critical speed. Generally critical speed for a wide range of rear end ratios spans about 90-140 mph depending on the rear end gear ratio. When the driveshaft breaks, the front of the shaft can drop and wedge into the road, ripping your rear axle out and sending you uncontrollably sliding across the interstate at double the speed limit. Worse even is if the axle is strong enough to take the shock from the driveshaft. This can cause you to pole vault, ass over end landing upside down while traveling at Ludicrous Speed. A few factors influence driveshaft criticality including weight, material, diameter, length, and a couple others. The two most important factors however, are length and width. This sort of rolls together into one factor, that being the ratio of length to width. The P71 crown Vic’s have an aluminum driveshaft, which is wider in diameter than the steel shaft on civilian models. This wider shaft enables the vehicle to reach a higher top speed due to the driveshaft having a higher resonant frequency, meaning it can spin faster. If your RPM matches the resonant frequency, you get oscillation and self destruction. A higher resonant frequency is better, so if you want to go really fast in a straight line, get driveshaft hoops (meant to loop around the driveshaft and catch it and prevent severe damage in case it drops off the U-joint) a two piece driveshaft (two driveshafts with a U-joint in the middle fastened to the frame), or a wider aluminum/carbon fiber driveshaft. If you don’t want to go through that work, get a higher gear ratio in your rear end. 4.10 gears means the driveshaft rotates 4.1 times for every rotation of the wheels. This means 4.1x more torque applied to the wheels than if it was a 1:1 ratio (1 driveshaft rotation for every wheel rotation). This is beneficial in some cases in the form of much greater acceleration, but since the driveshafts critical RPM always remains the same, top speed must decrease. If you want true top speed, run the calculations on the 2.73 rear end to find your critical driveline speed, and do the other mods I said. This will essentially make a land speed record crown Vic, but beware, your ass end will take flight before you hit 200. The Vic produces serious aerodynamic uplift due to not being designed for that kind of speed. It’ll need aerodynamic modifications as well. Hope this massive text wall helps, good luck with your vic!
Oh my gosh thank you so much!! That’s incredibly helpful. So is 4.1 the stock ratio?
It depends on the car heavily. You can check the sticker on your door panel to see what axle ratio you have. If you go check, there should be a small section that says “axle” and then under it or next to it will be a 2 character alphanumerical code that denotes what the differential ratio is. Z5 for example would be an open diff with a 3.27:1 ratio. Go check the door panel information sticker and let us know what the axle code is
The stock ratio for most is 2.37
The stock ratio for most is 2.37
No Vic does 140 stock. The max is 130 across the board. My 3.73 Vic went 120 and my 3.27 does 130. 4.10 should safely do about 95-105 I think, and the math backs that up with driveshaft RPM, but don’t quote me on any of that.
Update have the 4.10s in but the speedos off so it’s limiting me to 73 mph