Okay here is the situation:

I have a 1993 car, so I have speed density. I have the 2.97 first gear in the trans and I put 4.10:1's in. The speedometer reads a lot quicker than what I am going. I.E. for example, I am going about seventy and the speedometer reads about ninety. If my computer reads off of how fast I am going as well as incoming air, etc, how would this affect the air\fuel mix. What else would this affect? What do you guys think?

Thanks in advance, Jay

PS -- Is there any harm done in driving like this for awhile?

I forgot to add one more thing, it does throw a ses that says that the VSS is malfunctioning and that my right bank o2 sensor is lean.

 

So what are your opinions? I know for a fact that it has to be leaning it out some because the computer threw a right bank lean code. Tell me what you think.

Thanks in advance,

Jay

 

i have no idea, but how bout you just get a speedo recalibration tool, that way your not putting on additional false milage on your car

 

Man, I have tried to even find one to buy but I can't!

I have another thread in the for sale section. I can't seem to find a SLP speedo recalibrator box to buy anywhere. I looked at thunder racing but I couldn't find it on their website. I can't find anyone that sells them anymore.

If anyone knows please let me know.

Thanks,

jay

 

crappy, do you have a chip yet? if you get one burned you may consider getting it burned for the correct gear set. sorry i cannot help you further

 

I don't think it would have any affect on your air/fuel ratio at all. You can drive around with it like that no problem, I did the same thing when I put 3.73's in. The speedo read high, thats all. It will obviously add a lot of miles on the odometer though, which sucks.

 

The speed in speed-density is not MPH from the speedo.... its RPM.

The computer knows the volume of the cylinder, so it multiplies the volume of the cylinder x RPM/2 X volumetric efficincy. Then it checks the IAT and MAP sensors and calculates the air density, so it con convert CF/M to LB/M.

Speedo calibration box:

Dakota Digital Speedo Interface

 

Thanks for everyone's help. I will be ordering one from dakota digital in a few minutes! Injuneer, you 'da man. Thanks, I would be lost without you guys' help!

Jay