Speedo Correction for the 100

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i use my aftermarket GPS too, but the ScanGuage II allows you to factor in a % which will then show the correct speed.

I haven't altered my ScanGuage (coz i rely on the GPS) but it's pretty easy to do.

My tyres are Cooper STTs 265x75x16.
Factory were Dunlop Grandtrek ATs 275x70x16.

and at 98km/h ScanGuage II reading is actually 100km/h on the GPS which is generally our highway speed limit. Doesn';t sound like i should care, but speed cameras (they call them "road safety cameras" now) we get only like a 3 - 5 km/h allowance and get fined. That tolerance is less than what the factory says is acceptable...but the Govt says they are fighting a road death toll. Revenue raising is what it is.

hope that helps
peter

3-5 km/h ?? thats it?

i was doing 21 over... thought the flow of traffic was 65 (in a 55), apperently I was really doing 76. Which isn't bad becuase i got pulled over in a group of people and the guys that were flagged down infront were doing 96 in a 55 when they got radar'd.

Still dont think i was doing 76, i know a difference between 65 and almost 80 mph. oh well, s*** happens
 
2000UZJ

yep. it sucks. i was coming back from Geelong on the Princes Highway....i'd been to ats4x4 to get a quote.....yes i could have called on the phone and got a quote but due to leasing the beast (i own it now) i needed to rack up some k's (kms)

some mf was on my bumper (@$$) and i was in the fast lane...so i accelerated a bit, so he could go on his way and i moved into the next lane.

106 km/h was on some speed camera. It was "adjusted" to 103. $140 friggin dollars. My first fine in f'ing 18 years. 103 in a 100? And i get fined for that? fek.

Toyota and every manufacturer (we are talking about a 2005 car...it might have changed since then...but) have a friggin 10% tolerance on the speedo in terms of what is shown vs actual ....but no not my f'ing Victoria State Government.

i found out later i could have sent a "letter" outlining my fantastic driving record and requested that i get let off. Suggested by the state car registration place Vic Roads.

I just paid it and lost 1 demerit point. fek
peter

ps as the edit reason says, i didnt have a GPS at the time or the ScanGuage II. I was just looking at the speedo and had the factory tyres.
 
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I use the GPS as well. Do any of the items listed above help with the accuracy of the odometer, or just the speedo? It would be nice to know how many miles are accually on the cruiser without doing some sort of crazy MIT math.

edit: after thinking about that for a while, I suppose changing the speedo will also change the odo by default...sorry
 
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For those with automatic transmissions, the transmission ECU uses the speed signal for determining shift points. So that's one advantage of using the speed calibrators over a GPS or scangauge.
 
For those with automatic transmissions, the transmission ECU uses the speed signal for determining shift points. So that's one advantage of using the speed calibrators over a GPS or scangauge.


So my shift points are off too? does it short shift or shift late?
 
I don't know the answer. My speedometer is spot on w/o correction. But I am guessing it would affect downshifting as well. Maybe somebody that owns the Truspeed or Marks 4wd box can experiment with it since they can toggle between corrected and non-corrected.
 
to be honest, i dont remember noticing a difference in shift points when I installed it but ya, ill make the settings really drastic and see if it changes anything. Dont expect me to get it done anytime soon though, I'm lazy. No really like, LAZY. :D
 
OK, this may be a non-techie question, but what does the dealer do, when asked to calibrate the speedo?
 
tell you that your tire size is incorrect and try to sell you the most expensive 275/70/16s(assuming you have a 98-02) on the market.
 
loud was spot on. they actually told me my tires were to large and normal driving on pavement will destroy the drivetrain before the tires wore out. also, when i pulled in i asked them about the speedo correction and they said they didnt make anything for GM trucks. I told them it was a landcruiser and they all started talking like they know 100's.

They tried to sell me 275's half off and take my BFG's for 75$. I laughed and said they should learn their product and not be such dumbasses.
 
Incredible...
 
For those with automatic transmissions, the transmission ECU uses the speed signal for determining shift points. So that's one advantage of using the speed calibrators over a GPS or scangauge.

to correct the shift points, you would have to intercept the signal INTO the ECU from the drivetrain and offset it accordingly. the slee (and other) device is simply used to correct the OUTPUT from the ECU to the Speedometer (visual indicator for the driver). the ECU is still tricked into thinking the truck is moving slower than it actually is by the input signal from the speed sensor(s).
 
to correct the shift points, you would have to intercept the signal INTO the ECU from the drivetrain and offset it accordingly. the slee (and other) device is simply used to correct the OUTPUT from the ECU to the Speedometer (visual indicator for the driver). the ECU is still tricked into thinking the truck is moving slower than it actually is by the input signal from the speed sensor(s).

Wiring diagram shows 2 VSS.
 
Thanks. I wasn't sure if there were VSS, or if it just used the ABS sensors and averaged them for speed. Since there's two, you would have to intercept both signals and offset them accordingly to get a TRUE speed to the ECU for controlling shift points and speedo display.
 
I'll stick to my ScanGuage, seems like an ton of work and money for a speedo corection. SG was a good buy. Ill just watch that. Unless its a DOT regulation, I'll use my gps and SG
 
to correct the shift points, you would have to intercept the signal INTO the ECU from the drivetrain and offset it accordingly. the slee (and other) device is simply used to correct the OUTPUT from the ECU to the Speedometer (visual indicator for the driver). the ECU is still tricked into thinking the truck is moving slower than it actually is by the input signal from the speed sensor(s).

The device takes the signal from the pickup in the transfercase and changes it prior to ECU. So the speed fed to the ECU is correct, and everyone after that is normal.
 
The device takes the signal from the pickup in the transfercase and changes it prior to ECU. So the speed fed to the ECU is correct, and everyone after that is normal.

NICE. Glad to know it's done the RIGHT way.
 

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