Speedo

[Kiwidoc]

Hi everyone

My 81 corvette speedo only goes to 85mph. We are heading to a race track for a fun day and I want to put the foot down. I presume the car will exceed 85 and wonder what happens to the speedo when this occurs

Dean :confused

 

[damoroso]

It'll go alittle past 85 and stop moving. It won't hurt it at all....trust me. I'm in the process of changing it to a 145mph speedo this week though. First an 85mph speedo in a vette just doesn't seem right, second, as alot of folks routinely drive speeds near that on the highways so it makes sense to have some "head room" on it!!

 

[LordVader]

It'll go alittle past 85 and stop moving. It won't hurt it at all....trust me. I'm in the process of changing it to a 145mph speedo this week though. First an 85mph speedo in a vette just doesn't seem right, second, as alot of folks routinely drive speeds near that on the highways so it makes sense to have some "head room" on it!!

Are you just using a speedo from earlier vette? or did you order it from somewhere? I would love to change out my speedo on my 80

Mike.

 

[bill81vette]

I believe the 145 mph speedo's can be had at the corvette vendors...

 

[damoroso]

Are you just using a speedo from earlier vette? or did you order it from somewhere? I would love to change out my speedo on my 80

Mike.

I sent mine to Red Line Gauges Home. John has a great reputation, and does not only speedo's but other gauges as well. I sent him my actual speeds (in 10 mph incriments) and what my speedometer was reading so he can calibrate it. He'll then put the 140 face on it. I'd opt for the 165, but John says those aren't accurate throughout the scale.

 

[JohnZ]

I sent him my actual speeds (in 10 mph incriments) and what my speedometer was reading so he can calibrate it.

All GM speedometer heads calibrate exactly the same way (1000 rpm cable input = 60 mph on the gauge); actual vs. indicated corrections are a function of the speedo gears, not speedo head calibration.

 

[damoroso]

All GM speedometer heads calibrate exactly the same way (1000 rpm cable input = 60 mph on the gauge); actual vs. indicated corrections are a function of the speedo gears, not speedo head calibration.

I believe you, but when I talked to John, he said to clock the car and send him the info, he could calibrate at the head... Which is good, cause it's a pain to play with the driven gear in the 2004r I have in the car, and I'd have to change both the drive and driven gears!! I'll verify it next week when I get the speedo back though.

 

[spikebot 81]

I also sent my speedo to Redline last year for the 140mph swap. Great work at Redline and aprox 10 day turn around. I think it was $125 + shipping