Speedometer correction after larger tires and re-gear?

[geeeee89]

Who's the go-to company for this? I drove my truck with 35s and 3.73s for a while and the speedo was off by 5 mph. Just put in 4.88s last week and now it's off by a lot. 95 mph indicated on the speedometer is 70 mph actual speed. So I need to get this corrected or recalibrated.

Blackbear tune? Dealership? Soldering in a dip switch?

I searched on Summit and they didn't have anything for me.

The truck is a 97 K1500 with a vortec 350 and NV4500 trans.

 

[SUBURBAN5]

I want to know too. I thought it was a tune

 

[geeeee89]

I want to know too. I thought it was a tune

I'm not opposed to doing that I just need to know where to go. I plan on calling blackbear when I get off work to see if they do that.

Someone in another thread, maybe @kennythewelder , mentioned using a JET brand tuner but he may have a different year truck and a different transmission

 

[SUBURBAN5]

I'm not opposed to doing that I just need to know where to go. I plan on calling blackbear when I get off work to see if they do that.

Someone in another thread, maybe @kennythewelder , mentioned using a JET brand tuner but he may have a different year truck and a different transmission

I was gonna try that tune for mine (jet)

 

[mtl111]

I changed from 3.42 to 4.56 in my 99' 2 door Tahoe. My speedometer was off about 15mph, i had Black Bear do a tune and correct for the different tire size and gear ratio. All is good now!

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[geeeee89]

I changed from 3.42 to 4.56 in my 99' 2 door Tahoe. My speedometer was off about 15mph, i had Black Bear do a tune and correct for the different tire size and gear ratio. All is good now!

Great news! Thank you. Did you do the regular one where they send you a new PCM or the data logger version?

 

[mtl111]

I sent them an extra computer I had to do a complete tune. I saved my original for a "just in case" scenario! Lol

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[geeeee89]

Sweet I'll give them a call today

 

[kennythewelder]

Yea, it was me with the Jet programmer. I need to reflash mine. I was headed to the car show Sunday. When I broke 105 MPH, the engine shut down, just like it used to at 99. I thought I had it set to max, 228 MPH. I need to fix that. You never know when you may need to brake 120 MPH LOL.

 

[df2x4]

I was gonna try that tune for mine (jet)

IMO for the money you'd be much better off with a tune from Black Bear Performance. They can alter things that a handheld programmer like the JET can't, and will do a custom setup based on your intentions and mods. The handheld programmers just have a few cookie cutter "tunes" you can alternate between.

Great news! Thank you. Did you do the regular one where they send you a new PCM or the data logger version?

Black Bear only offers the scan cable tunes for newer trucks with the 0411 PCM (or newer). For our trucks the standard mail order tune is the only option.