jgordon

hey guys,i just had a new pcm installed,and programmed,and had only 1
key,they programmed 2 keys,car runs great,but i have 3.73 gears,and i
did not think to tell them what i had,does that really matter?

Z28KLR

Your speedo (and odometer) will read a bit high until you invest in a tuner or speedcal device to recalibrate. But otherwise, no it will drive just fine.

jgordon

that is good to know,the speedometer was off before the new pcm,5mph fast,so with
the new pcm,it would still be the same? thanks

Z28KLR

Go to www.paladinmicro.com, click on the "tools" tab and then click on "gear calculator". Put your info in (rear tire size, transmission etc) and you can compare the differences in vehicle speed at an identical engine rpm and gear.

Just off the top of my head I'm guessing that with 3.73's the speedo will read about 20mph high at 50mph. With these sort of things it's always a percentage.... So it won't be a consistent high speedo reading; at 30 mph it may only read 10 or 15 high, and at 75mph it may read 25 or 30 high.

jgordon

so i guess that i am only 5mph fast,and odometer is off 1 tenth for every mile,
that something was already done to make it that close?

Z28KLR

If the odometer is off by 0.1 per mile, then your speedo is off by 10%.

So at an indicated speed of 50, your actual would be 45. At 60, actual is 54. At 70, actual is 63. Etc, etc.....

An easy way to verify is download a free gps app for your phone and try it while driving.