Will this speedo setup read correctly??

[1988SupraDreams]

Searching didn't yield much information, as I can see no reason why this wouldnt work other than the transmission.

89+ R154 with 4.3 Speedo Gear, 4.3 Rear end, and a Pre 88 Speedo

If this wouldn't work, then what would I need to do to make my car have an accurately reading speedometer with a 4.3 Rear end and 89+ R154?

 

[mkIIIman089]

You won't get a 4.30 gear in an R154 (you might if you disassemble the transmission and swap the drive gears... if thats even possible).

The pre 88 speedo... I don't know what the difference is, I would imagine you would want an NA speedometer. In which case, no that doesn't either.

There is no way to make the stock speedometer read correctly with a 4.30 rear gear that I have found.

 

[BorHor]

I think you are going to need a turbo diff. All speedo's are geared the same so they all read the same.

 

[1988SupraDreams]

Can I recalibrate the Speedometer so that it will read correctly with my Rear end?

 

[mkIIIman089]

There is no way to make the stock speedometer read correctly with a 4.30 rear gear that I have found.

 

[Supraholics]

There is...use a W58 tranny. lol.

 

[1988SupraDreams]

There is no way to make the stock speedometer read correctly with a 4.30 rear gear that I have found.

Well, I guess I'll have to find it then

 

[CRE]

You can indeed calibrate the speedo. However, the tradeoff is that your odometer and trip meter will both still be off by 10% (if your switching from a 3.91 diff).

http://www.supraforums.com/forum/showpost.php?p=2191199&postcount=23

http://www.supraforums.com/forum/showthread.php?t=217310&highlight=calibrate+speedo

 

[mkIIIman089]

Yep, and like I said, it doesn't work. Switching the face and "turning it" all the way down its not even close to enough.

BTW, you could use a W58 like driftking said, LOL, that would work.

 

[1988SupraDreams]

The 89+ R154's had a 3.71 behind them so It'll be off by ~16% And it doesn't really matter to me if the ODO is off, I don't plan on selling it anytime soon, and I can always unplug the speedo to keep the ODO low.

 

[Jeff Lange]

N/A speedo gear ratio is 35:10, the closest I can come to that for the R15x series is 34:10 out of a VZN95 truck.

Drive Gear: 33481-35160
Driven Gear: 33403-39375

I'll take another look on Monday at work to see if I can find something closer to 3.5:1.

Running with a 34:10 speedo ratio, you should be able to easily calibrate the speedo to read correctly, and the odometer should be pretty darn close too.