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I find this very interesting. I was talking to a cop the other day, and he mentioned something about radars and license plate. Do you know why you have to have a license plate in the front of your car. Did u know law enforcement use the license plate as a wall to bounce the radar laser back to the gun? If you dont have a front license plate, the gun wont be able to recieve the laser back because there isnt anything to reflect the laser back. Very interesting? or is he jus bullshiting wit me, i dunno but when i find out more ill let you know
 

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What the cop was trying to communicate is that he uses the front license plate as a **target**. Since most license plates are white, it provides an easy target on all vehicles to lock onto. Lasers are able to bounce off of a white surface more easily than another colored surface. I have read that cops have a difficult time "locking" onto a black car.
 

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To me... Logic... doesnt make sense with the front liscense plate thing. Its really a target rather than just a liscense plate. On my V1... I get Ka band 'pings', which imo would reflect back to the officer. I think the officer you were speaking to was coming up with random bullshit to sound intelligent. But... just a bullshitter. 8)
 

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keckman said:
What the cop was trying to communicate is that he uses the front license plate as a **target**. Since most license plates are white, it provides an easy target on all vehicles to lock onto. Lasers are able to bounce off of a white surface more easily than another colored surface. I have read that cops have a difficult time "locking" onto a black car.
I thought it was more how reflective the material is insteado f what color it is. I remember a Car and Driver article from a few years ago about this. THey said it was hard for a car that had no shiny spots on the front to be picked up accurately, but it was simple to pick up a car with alot of chrome on the front.
 

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CA is the anal parent of the vehicle code. You have to have your front plate because you have to (identification purpouses)--it's that simple. As for using the laser, the front plate is an easy target: usually white, flat, and coming straight at the cop.
 

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Discussion Starter #9
You Think?

stick said:
CA is the anal parent of the vehicle code. You have to have your front plate because you have to have to (identification purpouses)--it's that simple. As for using the laser, the front plate is an easy target: usually white, flat, and coming straight at the cop.
That's what i thought at first, California was the analist on vehicle codes, but take a quick look at the Mass General Law Chapter 90, Masschusetts it pretty much beating CA now. Since the governor screwed up on the budget, they are finding new ways to bring up revenue, and they figured since more and more of us are out on the road why not make laws they will make money on these things.

no more altered exhaust, cant lower car no more then 2 inch from stock or put more gross weight on car. No tinting i believe, since they were anal about my stock window. No shaving door handles. Whole bunch of others shit.
 

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LadyLexusIS300 said:
it sounds believable, but what happens if they scann the car from the side?

You cant get shot from the side. Radar only works from in front or in back.

Think about it. If he shot you from the side, you car has NO acceleration fromt he side. So the speed would read 0mph.
 

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to clear up a little confusoin...in the first post the eminence is referring to laser, not traditional radar. The front plate gives the cop a good target to aim his laser gun at since it is a better reflective surface than the front end of your car since it is flat and typically rather shiny compared to the rest of your car. The shinier and more reflective it is the better it will reflect the laser giving the cop a better chance of getting a reading on you. If you have a lot of chrome on the front of your car, the cop can get a reading from farther away or be able to lock in quicker. That is one of the reasons I didn't mount my front plate.

The cop can still get a reading without a front plate, it just may take an extra second or two which could be enough time for you to slow down after the V1 starts screaming at you. If you are close enough to the cop though it won't matter, and hopefully your v1 picked up the laser when he was getting another car.

Having a front plate or shiny plate doesn't make a difference to a radar gun.
 

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Discussion Starter #12
gun

thats correct, Massachusetts doesnt use radar guns, they use something called Lidar guns, i dunno whats the differnce
 

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Where I live, they don't require the front plates. However the cops aim for your headlights first with the laser gun and then to the hood for a last resort. That could also be a reason why blacked-out headlights are illegal here.
 

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The front license plate has nothing to do with radar... you can pick up bicycles on radar.... they certainly don't have a front plate
 

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If you don't have a front plate they will usually target your headlight. They can get a quicker lock on your plate but the headlight works almost ws well.
 

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Heres a post I put up on another site...

Just to share my experiences.

My brother is a cop and we've had quite a bit of time to play with his radar against my Valentine 1 and my old Whistler.

First off you cant run two radar detectors in the car at once. Cheap radar detectors "leak" and they give false readings to good ones. If you get a random 1 beep (usually at a certain set interval of time (10-20s)) of K or Ka band its usually someone elses radar detector. Also, all these products give off interference and having them both in the car at once doesnt work. They hinder each others performance. Thus the reason why speedlabs and other test sites test them independently, not together.

If the cop has his radar on constant and is sitting there pretty much any detector will pick him up. Most of the random speed traps are conducted this way. The Valentine 1 detector gave warning almost a mile away. Whistler just before I saw my brother's car. One thing to note. A cop cant use RADAR in heavy traffic. In-car radar you dont point and shoot, its just mounted or aimed sensors. So if cars are too close to each other theres no way to get a certain cars speed. This is only the case with moderate - heavy traffic.

In light traffic if the cop is using instant onradar (flipping it on whenever he sees a car with the radar set to MAX HOLD, this locks the highest speed read on his display so when you hit the brakes it doesnt really matter) If you get lucky enough to see him in time and SLAM on the brakes the radar sometimes detects too high a discrepancy in responses of speed readings and wont register a speed right away, giving you time to slow down. This is nearly extinct in the newer units and its hard to pull off on all. My Whistler didnt detect instant on until I could see the cop, and it was too late. My Valentine One warned me almost everytime unless I was the only car on the road in which there was no reminence to pickup.

If a cop uses laser in heavy traffic its allowed. Laser is usually used in the form of a standalone gun. The gun has a target and the speed is displayed in the viewfinder. Laser will instantly get your speed. Whistler didnt detect me getting shot with laser once for some erason. My brother aimed it at where my front plate should be and it never went off. The Valentine one went off when he would shoot me or the car in front of me. Usually giving me sufficient time to slow down. I was actually impressed with it. With no front plate the cop has to aim at your headlight to get your speed with a laser. If he doesnt do it just right due to the curveture of the headlight it wont go back to him. I take the front plate ticket anyday over a speed and the cop isnt gonna pull you over for a front plate ticket while hes speed trapping. Just this morning state police were trapping with laser. I saw the guy follow my car with the gun. My radar bleeped 4 times as he kept shooting me.


NOTE: Radar works from behind or infront. It does not work from the side.

I drive to work 40 miles everyday on a highway. I cruise at about 90-100mph the whole way. I see cops usually everyday. So far i havent gotten caught because theres always cars in front of me and my V1 gives me plenty of warning. I got nailed once in the dark by instant on radar with no other cars on the road on my way back from geneseo. Get a V1 and dont speed unless theres other cars on the road and youll be fine. If you guys have any questions please ask.
 

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Eminence said:
I find this very interesting. I was talking to a cop the other day, and he mentioned something about radars and license plate. Do you know why you have to have a license plate in the front of your car. Did u know law enforcement use the license plate as a wall to bounce the radar laser back to the gun? If you dont have a front license plate, the gun wont be able to recieve the laser back because there isnt anything to reflect the laser back. Very interesting? or is he jus bullshiting wit me, i dunno but when i find out more ill let you know
That is only true for black cars (or so I've been told). In Ohio it's required for you to have a front plate, but a cop isn't going to pull you over for it unless he's already got you on the side of the road for something else.

That is, unless it's a jerky cop. :)
 

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radar uses the doppler principle. the more of an angle you are to the johnny when passing by, the slower the speed, if you go by him completely perpendicular to his gun position, your speed will read 0. if at a 45 degree angle, it will read much lower than actual.
if you are doing 100mph, next to a larger vehicle that is doing 50, the johnnies gun is going to pick up the greatest source of reflection, that being the larger vehicle.

i don't run a license plate, and i angle my intercooler upward. if i didn't have an intercooler, i would angle my radiator upward. this helps weaken the returning signal. next time i paint my front bumper i'll be mixing lead in with the paint, which absorbs the radio waves to an extent.

try searching on the doppler principle or doppler effect. someone who knows a fair amount about doppler in a different way, is probably Wxman, i'll send him this link

-gte








LadyLexusIS300 said:
it sounds believable, but what happens if they scann the car from the side?
 

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IS300GTE said:
radar uses the doppler principle. the more of an angle you are to the johnny when passing by, the slower the speed, if you go by him completely perpendicular to his gun position, your speed will read 0. if at a 45 degree angle, it will read much lower than actual.
if you are doing 100mph, next to a larger vehicle that is doing 50, the johnnies gun is going to pick up the greatest source of reflection, that being the larger vehicle.

i don't run a license plate, and i angle my intercooler upward. if i didn't have an intercooler, i would angle my radiator upward. this helps weaken the returning signal. next time i paint my front bumper i'll be mixing lead in with the paint, which absorbs the radio waves to an extent.

try searching on the doppler principle or doppler effect. someone who knows a fair amount about doppler in a different way, is probably Wxman, i'll send him this link

-gte








LadyLexusIS300 said:
it sounds believable, but what happens if they scann the car from the side?
Damn, that is something to think about. :-?
 

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IS300GTE said:
radar uses the doppler principle. the more of an angle you are to the johnny when passing by, the slower the speed, if you go by him completely perpendicular to his gun position, your speed will read 0. if at a 45 degree angle, it will read much lower than actual.
if you are doing 100mph, next to a larger vehicle that is doing 50, the johnnies gun is going to pick up the greatest source of reflection, that being the larger vehicle.
This only is true with laser radar. Other forms of radar can still pick up your speed from any angle relatively accurately.

i don't run a license plate, and i angle my intercooler upward. if i didn't have an intercooler, i would angle my radiator upward. this helps weaken the returning signal. next time i paint my front bumper i'll be mixing lead in with the paint, which absorbs the radio waves to an extent.

try searching on the doppler principle or doppler effect. someone who knows a fair amount about doppler in a different way, is probably Wxman, i'll send him this link

-gte
The Doppler effect is what's responsible for the difference in a sound as it passes you by. Lets say we take a race car and have it run by us at a constant RPM. As the car approaches us, the sound of the engine has a certain pitch (or scientifically speaking is at a certain frequency). Once the car passes by the pitch, or frequency, lowers and the sound is not as 'high' of a note. This is causes by the 'buildup' of soundwaves in front of the object and the spreading out of them behind. Think of soundwaves as the ripples in water after something hits the water. If you continueously hit the water while moving at a constant rate in one direction, the ripples infront of you will bunch up and get closer while the ripples behind will not be as close together (the frequency of the ripples infront is higher than that of the ripples behind it).
 
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