Toyspeed.org.nz Message Board

Click here to see "My Black Hole" · by **Stealer Of Souls** » Fri Jul 20, 2007 10:30 am

Hi.

Okay. So changing the ratio in my diff, which will change the speedo reading. The question is... My dash is from an AE85, and i have a K50 in it. So all gear that was meant to have a 3.9:1 behind it. I'm now fitting to my diff the 4.3:1 ratio (factory for most?all? AE86s).
What parts would I need to make the speedo read correct. Is it the dash? Or the box? Or some other part that I can utilise.

by **Adoom** » Fri Jul 20, 2007 12:37 pm

You know where the speedo cable goes into the gearbox? If you undo the bolt next to that the speedo drive gear comes out. I believe to fix the ratio you are supposed to get different sized drive gears.
Or just get a marker pen and change the numbers on the speedo

Oh and forget about the ODO reading.
In my race car its out 20%. Starlet speedo, nissan gearbox, 3.9 celica diff. the wheels/tires are the same diameter as starlet ones still(way wider though) 50kph = 60 on the speedo 100kph = 120 and so on. You get in trouble when you get used to that and then drive a different car

Click here to see "My Black Hole" · by **Stealer Of Souls** » Fri Jul 20, 2007 4:14 pm

Yeah. My mechanic friend said it's almost invariably on the gearbox too. My speedo currently reads 10% out... and I have adjusted to that... I'm not sure another 10% will be so easy for my poor brain.. And I don't think my mechanics are going to like felt marker for a speedo... I could be wrong... They do understand my plight after all.

In my case, if I use a T50 (I do have one I could use) this will hopefully therefore fix this issue...

by **Zak** » Fri Jul 20, 2007 11:22 pm

You might need the speedo drive for the t50 as well.

I'm not sure what they did to my car to get the speedo correct, but there is a place that can recalirbrate your speedo. I can't remember their name off the top of my head though.

Click here to see "My Black Hole" · by **Stealer Of Souls** » Mon Jul 23, 2007 9:54 am

Zak wrote:You might need the speedo drive for the t50 as well.

What do you mean by speedo drive exactly?

I've raised with myself another interesting question.
Is a felt marker speedo legal? The VIRM doesn't have any specific requirements. It just says that the speedo must indicate the speed when travelling forward. A felt marker speedo would do this... But surely it isn't "operating as intended".
Vehicle Inspection Requirements Manual

by **ollieboy** » Mon Jul 23, 2007 11:35 am

If you get really stuck you can buy a cheap GPS and use it as a speedo. My Boss does that and passes warrants all the time.

by **nz_climber** » Mon Jul 23, 2007 5:46 pm

Most speedo's can be calibrated, talk to the guys at Robinson Instruments (09-377 1565, 19 Sale St Central Auckland) they have a rolling road etc and good to deal with, i had them make a speedo cable for my chevron w50 gearbox to triumph speedo, they had it ready the next day)

by **Zak** » Mon Jul 23, 2007 10:08 pm

Thats the guys I was thinking about.

SOS, the speedo drive is just the part that plugs into the gear box with the gear on the end that spins the cable.

Click here to see "My Black Hole" · by **Stealer Of Souls** » Tue Jul 24, 2007 9:47 am

I know about robinsons. I remember calling them once and they told me something along the lines of...
If the speedo varies in it's accuracy (10% at 50kph and say 15% at 100) then it can be recalibrated. If it's constant inaccuracy (10% the whole time, usually because of ratio changes) then you would need a ratio box.
Is this still the case? Or was I originally misinformed?

Zak wrote:SOS, the speedo drive is just the part that plugs into the gear box with the gear on the end that spins the cable.

Little right angled thingame? If so... bugger... don't have one of those.

by **nz_climber** » Tue Jul 24, 2007 6:24 pm

Don't know, i just know they pretty helpful when i have been dealing with them, i am sure a ratio box in the speedo cable would be easy (not sure about price thou)

by **Zak** » Tue Jul 24, 2007 9:24 pm

Stealer Of Souls wrote:Little right angled thingame? If so... bugger... don't have one of those.

I think I have one some where you can have, If I can find it I'll PM you.

Click here to see "My Black Hole" · by **Stealer Of Souls** » Thu Jul 26, 2007 9:46 am

Zak wrote:
Stealer Of Souls wrote:Little right angled thingame? If so... bugger... don't have one of those.

I think I have one some where you can have, If I can find it I'll PM you.

Wicked. Thanks. I'm hoping you have one. I'll have to sort you out with something.

nz_climber wrote:Don't know, i just know they pretty helpful when i have been dealing with them, i am sure a ratio box in the speedo cable would be easy (not sure about price thou).

Yeah. I remember the guy being really helpful on the phone too. Exlained it to me quite well (so long ago though). I remember the price on a ratio box being something rather ridiculous though.

by **MikeMan** » Thu Jul 26, 2007 3:55 pm

Stealer Of Souls wrote:Yeah. I remember the guy being really helpful on the phone too. Exlained it to me quite well (so long ago though). I remember the price on a ratio box being something rather ridiculous though.

Umm when you consider the price of a gear cutting machine and the know how of how to use it, the cost of the dyno to check it and then the time to make it I am not so sure the price is ridiculous.

There is a lot of gear and knowledge required to do the job right.

by **frost** » Thu Jul 26, 2007 4:04 pm

just buy off the shelf stuff like TRD,

Click here to see "My Black Hole" · by **Stealer Of Souls** » Fri Jul 27, 2007 11:27 am

MikeMan wrote:
Stealer Of Souls wrote:Yeah. I remember the guy being really helpful on the phone too. Exlained it to me quite well (so long ago though). I remember the price on a ratio box being something rather ridiculous though.

Umm when you consider the price of a gear cutting machine and the know how of how to use it, the cost of the dyno to check it and then the time to make it I am not so sure the price is ridiculous.

There is a lot of gear and knowledge required to do the job right.

It's probably the right price for the right job... but it's extravagant to spend the $450ish asking price to fix the speedo when, to be honest, I don't need it fixed unless the WOF man tells me so.

frost wrote:just buy off the shelf stuff like TRD,

I'm not sure how this comment helps at all.
I put a 4.1 TE71 diff into my AE85m and the speedo was out by around 5-10%.
I'm now replacing the 4.1 with a 4.3 (standard ae86 ratio), and it'll be out by 10-12%.
Funnily enough all parts from toyota...

by **frost** » Fri Jul 27, 2007 3:22 pm

oh oops sorry, when i read gear cutting i was thinking gearbox gear cutting, my bad,

Click here to see "My Black Hole" · by **Stealer Of Souls** » Mon Jul 30, 2007 10:55 am

frost wrote:oh oops sorry, when i read gear cutting i was thinking gearbox gear cutting, my bad,

Lol. Fair enough then. Make sense now.

by **JamesM** » Fri Aug 24, 2007 12:22 am

old post i know.. but i got pulled up for the speedo being out of calibration.. he said go to auckland speedos and they will just change the gears in the dash

Click here to see "My Black Hole" · by **Stealer Of Souls** » Fri Aug 24, 2007 10:13 am

Any info is good info.

Theres a possibility you can change the drives at the box end too. I'm gonna try and get motivated this weekend to check it out.

by **JamesM** » Fri Aug 24, 2007 12:54 pm

yea he said you can also get a box that goes inline with your cable (intercepts it)

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