SSHORTT

I was pulled over the day on my way home after i bought my car for speeding, Even though i had the cruise control set just under the speedlimit (55). Well curious, after work (military police) me and a friend who was on duty used one of our radar guns and my car was going around 70 when i was showing 55! I called the guy and told him what had happened and if he had any problems like that, he said no and that the only thing that he thought might do that were the gears, which are 4.10's which he didnt mention when i bought the car! He also said that he still has the originals somewhere if i want them. So should i put the originals back in or have my car calabrated. I really cant afford this ticket or more so the insurance!He also said that the tires might be a size bigger!
Any help will be appreciated
Chris

unvc92camarors

stock tire size is 245/50/r16
i got some 235, 225/60/r16 if you want them
i'm just trying to get rid of them
they might help with your gear problem a little bit

RedHottG2

Just get your car programed and keep the 4.10s...here is a little more help for ya since I didnt know if you had a 93 or a 94-up car.

http://web.camaross.com/forums/showt...dakota+digital

Eliminator

I would keep the 4.10s they are nice to have, just get your PCM reprogramed. Look at www.madz28.com to program your PCM.

Jay-Roll

I went from 2.73's to 3.42's and had a similar problem. But mine was the opposite. If I was doing 55 it said I was really doing 65. If I was doing 75 it said I was really doing 92. So mine actually read higher than I was really going. I would think it would do the same with yours but further off. What is your tire size? If anything, yeah get a tune to fix your issue and your home free. What year is your car and what tranny M6 or A4?

SSHORTT

My bad.... the car is a 2000, SS A-4.

Injuneer

As noted in the post above, if you replace the stock gears with 4.10's and don't reprogram, the speedo would be indicating higher than actual speed. Depending on what gears your car is programmed for (you really ought to include a signature with year of your car and trans):

If your car came withe 3.42's and you installed 4.10's, at a true 70mph, your speedo would indicate 84mph.

Car had 3.23's, with 4.10's speedo would read 89mph

Car had 2.73's, with 4.10's speedo would read 105mph

So, you can see the 4.10s don't explain the speedo error.

Tire diameter would have to be increased from the stock 25.65" (assuming you have 4th Gen????) to over 30" to account for the error you are having, assuming the PCM was correctly adjusted for the 4.10s.

Jay-Roll

I was thinking. Is it possible the guy who previously owned the car thought 4.10's were getting installed but actually had a higher gear installed(3.42's for example). So he had the speedo calibrated for 4.10's when it should have been calibrated for 3.42's. Would that account for the speedo being the opposite?

Edit: You might have to pull the dif. cover off and count the teeth to find out for sure.

turbo_Z

Doing the math the only way the speed could be off is if like someone else mentioned... the previous owner THOUGHT the car had 4.10s put in so had the PCM programmed to recalibrate the speedo but the gears were never actually installed. Only problem is with what you described the original gears would have to be 3.23.. not 3.42. I guess you never said but I am assuming your car is a 6 spd. Also if you go and talk with the defense attorney you might be able to convince him/her to allow you to show proof of the cars false speedo readings and get the ticket dismissed... some DAs will allow this while others will not. But trust me this method works... I have gotten out of a ticket for intentionally changing my speedo calibration so the method is sound.

WestCoast96Z28

Yeah, something's wrong. Like everyone said above, lower gear ratio will make your speedo read higher than actual, not lower like in your case.

Now, I think I know the answer, but can you folks confirm? Won't the odometer be off as well. If the speedo is reading higher than actual, wouldn't the odometer always roll quicker, meaning it says you've got more mileage on the car than what's normal.

In SSHORT's case..that could be a good thing..he could drive drive 5000 miles and the odometer only reads 3929.

Jay-Roll

Yes that is correct. I have the same issue with my car and the speedo being off. I'm racking up more miles than I'm actually driving. I hate that part.