I am thinking of putting white overlays on my 91 110mph cluster.
What makes the needle sweep at the 110 or 140 rate? Is it a difference in the vss or in the cluster? I would assume it is in the cluster. If so, can it be modded to sweep at the 140 rate? Possibly a different resistor or such?

 

what car? bird or maro'? The birds are electric, and you can just swap out the speedo for the 140 unit. I think the camaros were all electric by 91 you you can probably do the same

 

Car is a 91 camaro.It is electronic. I have already swapped the cluster once due to the speedo being glitchy. I was just thinking if I was going to add the whiteface overlays, I could go with the 140 overlay set over a 110 speedo and have the 140 speedo without having to buy a 140 cluster.

 

No, you must replace the speedo in the dash with a 140 MPH one.

 

Think this one through. Did you REALLY think that was going to work?

 

Yes, and I still think it is possible.
All you are doing is changing the rate that the needle sweeps. It is an electronic drive, so a different resistor rate or such should do it.
Only problem, I do not have a full function breakdown of the circuit or enough electronics knowledge to correctly modify it.
It was just an idea that I was wondering if anyone else had tried.

I actually think it could be accomplished other ways. If you change rear gears, your speedo will not read correctly. To correct it, you modify the signal, which really only modifies the speedo sweep rate. Basically the same thing, just a different reason.

Read the tach fix thread, there are people that could do this, I just am not 1 of them.

 

it is possible check out http://www.transmissioncenter.net/sp...0gear%20driven

it has a era (electronic ratio adapter) if you can figure out which gear ratio would slow the needle down enough to be correct than it's simple using the box. so lets say you have the 3.42 than set the box to 2.xx to slow the speed and make the speedo accurate.

try using the calculation page to try to figure it out. hopefully the box can go to a very high ratio to make it up. email the company to make sure, i'm sure it would work.

 

Somthing like that would work. Would have to figure out just how much variance it could handl. I was thinking more along the line of a home cheap job.
I wasn't seriously considering this, as I really have no use for a speedo that reads to 140, but may play around with a few ideas.
What would a pot in the vss line do to the signal? Would it lower the pulse voltage enough to make it read zero no matter what?
I am not set on even going to the white overlays, was just thinking of things I want to do the next time I pull the column and dash apart. I want to change the ignition switch, mabe the steering wheel and replace a cluster backlight bulb.

 

The way you explained it made it sound like you wanted to slap on a 140 white gauge face and hope it magically made it a 140 mph gauge.

 

ummm, no. Even i am not that stupid. I did read back to my reply to the original post and kinda see where you get that from though.
I do know some people that are that stupid, possibly an untapped market?

 

even if you were to change the speedometer gear in the tranmission and it read the correct mph on the 140 overlay's.... the odometer would be incorrect. and i dont think its possible to change the parts off the back of the cluster is it?

since we are on this subject, does anyone know how or can point me to a link of how to rebuild one of the 90-92 clusters?

 

There are places you can send your speedos to get recalibrated. I dont know why you would pay the $$$ or bother to use up your time with something like that, when you can just swap in a 140mph speedo, and put your overlay on that.

I did this in my car, and it works fine, its a 5 minute swap, and very easy to do. Some say that its off by about +/- 2-3 mph, but i guess most cars are.

 

I never even thought about the odo!!!!
It is electronic, so no gears involved, but kinda hard to get around the odo being 30% off.
Guess that is what I get for thinking.

 

what about a mechanically driven speedo, to change from 85mph to 110, or even 145? that direct or need t chang tranny end?

 

Plug and play for any of them. Nothing in the trans requires change unless you've swapped to another rear end ratio.

JamesC