can the yellow box solve this problem
- Thread starter SAAD5745
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SierraFlyer
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Hi Frisbee,
The yellow box simply cuts into the speedo wire. It counts the number of electrical pulses coming in and puts out some percentage of pulses to correct the speedo to read the correct speed.
It is not really complicated to adjust but it takes some time. The steps are hook up your yellow box. Then go for a ride with a GPS velcro'ed to the take near the speedo. Remember what speed the gps is reading and what the speedo is reading at the same moment. Take those two numbers and calculate the ratio (ie. divide the smaller into the larger). Now refer to the yellow box instructions and set the switches to that ratio. Now go for a ride again and check the GPS against the speedo. They should match. Hint - The higher the speed you take the sample at, the smaller the error will be at high speeds. In other words, a 1 mph error at 20 mph turns into a 10 mph error at 200 mph. But if you have a 1 mph error at 100 mph turns into a 2 mph error at 200 mph. So go as fast as you feel comfortable to get the speeds to calculate the ratio.
Disclaimer - I have not done this yet so my calcs may be a little off.
A I am going to do the same to mine soon so here is the calculations to get close. First correct for the stock speedo error. My stock speedo is about 7 mph faster @ 100 mph than the bike is really going. 100 mph on the speedo is really only 93 mph on the road. That is just about 7% fast. So you would want to adjust the yellow Box output DOWN 7% (Your ratio would be about .93 ... 1 -.93 =.07 or 7%). Your speedo would then read 93 while going 93mph. Cool!
Now to correct the speed for the new 220 mph face plate, we do the exact same thing. Looking at the problem we find that when you were doing 185 mph through the neighborhood before, you are now reading 209 mph (13.07% faster). You are not going any faster and the needle is pointing to the same place but the scale is smaller. So we need to slow the speedo pulses DOWN again. The math is 209/185 = 1.1297, or 12.97%. But remember that is in addition to the 7% you alread have applied to correct the "Suzuki" error. Both are reductions in speedo pulses out of the yellow box so just add them together. 7 + 12.97 = 19.97% Down. The yellow box can correct something like 28% up or down from input pulse frequency so we are within the capability of the yellow box.
This should get you really close to where you need to be as a start. Then you can fine tune it by repeating the process one more time, in case your speedo has a different error from mine. Remember that you have to keep the adjustments so far and just add or substract the new percentage from that. This should get you far closer than stock error without doing the last adjustment. But check it to be sure I didn't screw up my math and subtract when I should of added??
Good luck!
The yellow box simply cuts into the speedo wire. It counts the number of electrical pulses coming in and puts out some percentage of pulses to correct the speedo to read the correct speed.
It is not really complicated to adjust but it takes some time. The steps are hook up your yellow box. Then go for a ride with a GPS velcro'ed to the take near the speedo. Remember what speed the gps is reading and what the speedo is reading at the same moment. Take those two numbers and calculate the ratio (ie. divide the smaller into the larger). Now refer to the yellow box instructions and set the switches to that ratio. Now go for a ride again and check the GPS against the speedo. They should match. Hint - The higher the speed you take the sample at, the smaller the error will be at high speeds. In other words, a 1 mph error at 20 mph turns into a 10 mph error at 200 mph. But if you have a 1 mph error at 100 mph turns into a 2 mph error at 200 mph. So go as fast as you feel comfortable to get the speeds to calculate the ratio.
Disclaimer - I have not done this yet so my calcs may be a little off.
A I am going to do the same to mine soon so here is the calculations to get close. First correct for the stock speedo error. My stock speedo is about 7 mph faster @ 100 mph than the bike is really going. 100 mph on the speedo is really only 93 mph on the road. That is just about 7% fast. So you would want to adjust the yellow Box output DOWN 7% (Your ratio would be about .93 ... 1 -.93 =.07 or 7%). Your speedo would then read 93 while going 93mph. Cool!
Now to correct the speed for the new 220 mph face plate, we do the exact same thing. Looking at the problem we find that when you were doing 185 mph through the neighborhood before, you are now reading 209 mph (13.07% faster). You are not going any faster and the needle is pointing to the same place but the scale is smaller. So we need to slow the speedo pulses DOWN again. The math is 209/185 = 1.1297, or 12.97%. But remember that is in addition to the 7% you alread have applied to correct the "Suzuki" error. Both are reductions in speedo pulses out of the yellow box so just add them together. 7 + 12.97 = 19.97% Down. The yellow box can correct something like 28% up or down from input pulse frequency so we are within the capability of the yellow box.
This should get you really close to where you need to be as a start. Then you can fine tune it by repeating the process one more time, in case your speedo has a different error from mine. Remember that you have to keep the adjustments so far and just add or substract the new percentage from that. This should get you far closer than stock error without doing the last adjustment. But check it to be sure I didn't screw up my math and subtract when I should of added??
Good luck!
Thanks . I do understand that . Whats a yellow box ? Did you change your faceplate ? I figure that it might be just as easy to see what speed differance is and remember them . It sounds like its only 12 - 15 mph differance per 100 mph , counting suzukis 7% . So all I really got to do is add 6 mph every 50 mph to my speed and I should be very close .
SierraFlyer
Registered
The "yellow box" is a little yellow palstic box that costs about $100. You mount it behind the dash under the cowl behind the headlights near where the harness plugs into the back of the dash. The Box has four wires coming out of it and a row of tiny micro switches on one side. The switches are for the error adjustment. The wires are power and ground, and speed sensor input and speed corrected output. Very simple.
I have not put it in yet but plan to soon. I find it really annoying to have error on the speedo. I can't really know if I was speeding or not when the cop says I was. Probably was.....
Try this link to see one: http://www.blackrobotics.com/
I have not put it in yet but plan to soon. I find it really annoying to have error on the speedo. I can't really know if I was speeding or not when the cop says I was. Probably was.....
Try this link to see one: http://www.blackrobotics.com/
SierraFlyer
Registered
Oh yes I forgot, The error is not fixed at 5 mph or so. It is linear from "0", meaning at 0 mph there is zero error. but at 50mph there is 3.5mph error and at 100 there is 7mph error: and at 150 mph there is 10.5 mph error and so on. The error DOES get bigger with higher speeds. The microcomputer in the yellow box counts sensor pulses and then outputs a percentage of input pulses to the dash. It can put out more or less pulses than input depending what you need to correct for.
In every case I have read or heard the speedo reads faster than actual speed so we have to subtract the error not add it. The way I work it now is that riding along at 70mph on the speedo in a 65 speed limit is legal. Somewhere around 72 indicated is actually going just over 65mph on the radar.
In every case I have read or heard the speedo reads faster than actual speed so we have to subtract the error not add it. The way I work it now is that riding along at 70mph on the speedo in a 65 speed limit is legal. Somewhere around 72 indicated is actually going just over 65mph on the radar.
Thanks . So in reality all you really have to worry about is don't go above 70 -72 mph and you won't be speeding on the freeway . I understand how the differance increases with speed . Will the yellow box change the odometer reading ? I'll double check my speed with someone next to me , until I can fix it with the box .
SierraFlyer
Registered
Yea frisbee, thats what I did. Just ride up next to someone on the freeway and look on their car dash for the speed. Be careful because you're in their blind spot though. I was surprized at how different every car is also. After half a dozen cars you will get an average error. These are pretty close to accurate. GPS is exact.
The trouble with 70mph is that you are still in first gear! In 6th the RPM would be about 3400 RPM if you have the stock sprockets. I have trouble staying under 90 most of the time.
And yes the yelow box will correct the odometer. The way it works is similar to mechanical Speedo's. The input pulses drive the odometer and the speedo is linked to it by some ratio of gears of electronics depending on what type it is. Fix one and the other is fixed automatically.
Another thing I didn't say but you probably alread figured out is that if you install the yellow box and gauge faces at the same time, you only need to do one speed run and caluculations to get the rough correction ratio. I broke it up in two steps just to show how it is done. But it dosen't need to. In the future, you can redo the ratio each time you change gearing or sprockets or install lower profile tires, etc.
The trouble with 70mph is that you are still in first gear! In 6th the RPM would be about 3400 RPM if you have the stock sprockets. I have trouble staying under 90 most of the time.
And yes the yelow box will correct the odometer. The way it works is similar to mechanical Speedo's. The input pulses drive the odometer and the speedo is linked to it by some ratio of gears of electronics depending on what type it is. Fix one and the other is fixed automatically.
Another thing I didn't say but you probably alread figured out is that if you install the yellow box and gauge faces at the same time, you only need to do one speed run and caluculations to get the rough correction ratio. I broke it up in two steps just to show how it is done. But it dosen't need to. In the future, you can redo the ratio each time you change gearing or sprockets or install lower profile tires, etc.
