JoshH
July 21st, 2007, 04:34 AM
So I was sitting here today just playing around with EFI Live. I decided to take a look at the "Speedo" tab. I opened up the paramaters and noticed the following:
{H0101} Vehicle Speed Sensor Pulses per Mile:4000
{H0103} Final Drive Ratio: 4.10
{H0104} Trans Output Shaft Revs/Mile: 423
{H0136} Tire Revolutions Per Mile: 682
{D5061} Transfer Case Ratio: 2.7
I know some of this stuff is wrong, like the final drive ratio, but that isn't what's bothering me. The thing that bothers me is the fact that these numbers don't even make sense with each other. I'm going to have to make some assumptions on what these things mean. That may be part of what's leading to my confusion, but I doubt it.
Of course H0136, H0104 and D5061 are self explanatory, but the other two I can only make a faily well educated guess on what they mean. I'm guessing H0101 is the total number of times a tooth passes by the VSS during one mile of travel. I'm also guessing that H0104 is the total number of revolutions the output shaft (I'm forced to assume the output shaft is the shaft coming out of the back of the transmission that the driveshaft, 2wd, or transfer case, 4wd, hooks up to) would make during one mile of travel.
Using those obvious values and the assumed meanings we should be able to divide H0101 by H0104 and come up with the total number of teeth on the speed sensor "wheel", or whatever it's called. Unfortunately it doesn't quite work out right. If you divide H0101 (4000) by H0104 (423) you come up with 9.456. I don't quite see how you can have a fraction of a tooth. It doesn't make much sense to me, but it gets even stranger. If you were to take H0136 and multiply it by H0103 you should come up with the total number of revolutions the driveshaft makes in one mile of travel which, according to the assumptions I've made, should be the same as H0104. So if you do the math you come up with 2796.2, but that is no where near the value of H0104 (423).
Does anyone know what is going on with this table? The reason I'd like to get it figure out is because I'd like to tune my shifting, but I noticed the shift speeds in my stock programming are not even close to being accurate. For instance, my WOT 2-3 shift speed is set stock at 32 mph, but it doesn't actually occur until closer to 45. I think it is being thrown off by the inaccuracies in this table, but I don't know how to adjust it.
I am thoroughly confused. Can anyone shed some light on this for me?
{H0101} Vehicle Speed Sensor Pulses per Mile:4000
{H0103} Final Drive Ratio: 4.10
{H0104} Trans Output Shaft Revs/Mile: 423
{H0136} Tire Revolutions Per Mile: 682
{D5061} Transfer Case Ratio: 2.7
I know some of this stuff is wrong, like the final drive ratio, but that isn't what's bothering me. The thing that bothers me is the fact that these numbers don't even make sense with each other. I'm going to have to make some assumptions on what these things mean. That may be part of what's leading to my confusion, but I doubt it.
Of course H0136, H0104 and D5061 are self explanatory, but the other two I can only make a faily well educated guess on what they mean. I'm guessing H0101 is the total number of times a tooth passes by the VSS during one mile of travel. I'm also guessing that H0104 is the total number of revolutions the output shaft (I'm forced to assume the output shaft is the shaft coming out of the back of the transmission that the driveshaft, 2wd, or transfer case, 4wd, hooks up to) would make during one mile of travel.
Using those obvious values and the assumed meanings we should be able to divide H0101 by H0104 and come up with the total number of teeth on the speed sensor "wheel", or whatever it's called. Unfortunately it doesn't quite work out right. If you divide H0101 (4000) by H0104 (423) you come up with 9.456. I don't quite see how you can have a fraction of a tooth. It doesn't make much sense to me, but it gets even stranger. If you were to take H0136 and multiply it by H0103 you should come up with the total number of revolutions the driveshaft makes in one mile of travel which, according to the assumptions I've made, should be the same as H0104. So if you do the math you come up with 2796.2, but that is no where near the value of H0104 (423).
Does anyone know what is going on with this table? The reason I'd like to get it figure out is because I'd like to tune my shifting, but I noticed the shift speeds in my stock programming are not even close to being accurate. For instance, my WOT 2-3 shift speed is set stock at 32 mph, but it doesn't actually occur until closer to 45. I think it is being thrown off by the inaccuracies in this table, but I don't know how to adjust it.
I am thoroughly confused. Can anyone shed some light on this for me?