Correcting electronic speedo??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

79Silv4x4 · 03-02-2005, 01:17 PM

I just put new tires on my '91 Burb (about 3 inches taller). Is there anyway to calibrate/correct the speed sensor since it is the electronic one? I have seen fixes for later model year vehicles but can't seem to find anything for this year.
Thanks
Rob

TrainD5115 · 03-12-2005, 08:26 PM

Don't they make a programmer for that? I thought I just read something on this that you hook up to the ECM to recalibrate for larger (or smaller) diameter tires.

gchemist · 03-12-2005, 10:56 PM

All you need to do is change is the gears. You can find a calculator and gears at www.tciauto.com. Look under their technical section then speedo gears.
Read this page. http://www.geocities.com/crosley_az/700spd.htm

79Silv4x4 · 03-13-2005, 12:16 AM

Quote:

Originally Posted by gchemist

All you need to do is change is the gears. You can find a calculator and gears at www.tciauto.com. Look under their technical section then speedo gears.
Read this page. http://www.geocities.com/crosley_az/700spd.htm

Thanks G but, correct me if I am wrong, this applies to taking a tranny that has electronic speedo provisions and converting it to cable drive to mate to a cable driven speedo? ASs I understand it, my speedo is electronic and has no provisions for a cable so converting the tranny to cable drive would not help. . .

However, as best IU can tell, I need to modify (or have modified) the DRAC in order to adjust for changes in gear or tire diameter.

Train--it works that way for the majority of vehicles but not for this one. I used a Hypertech programmer to adjust the speedo in my '96 & 97--easy as can be with those. . . too bad I can't do that here. . .

**special-K** · 03-28-2005, 09:59 PM

Do you have a 4L80E?This application(`91 Sub)seems passed-over by the aftermarket.I put 35s on mine and called Jet,Superlift,and anyone else I thought would make a VSS-Buffer.No luck,mine`s a 6.2 diesel and the trans uses a stand-alone computer.I gave up.My next move was to try to see what street rodders use when running a 4L80E.I know mine`s 10%off.I have 4.10s and if I went to 4.56s with the 35s,I`d have 4.09s.But,power`s good,so I`m leaving it alone.

u2slow · 03-29-2005, 03:27 AM

Read up on the DRAC module.

http://614streets.com/drac.html

03-02-2005, 01:17 PM	#1
79Silv4x4 Workaholic Join Date: Oct 2002 Location: Katy, TX Posts: 1,589	Correcting electronic speedo??? I just put new tires on my '91 Burb (about 3 inches taller). Is there anyway to calibrate/correct the speed sensor since it is the electronic one? I have seen fixes for later model year vehicles but can't seem to find anything for this year. Thanks Rob

03-12-2005, 08:26 PM	#2
TrainD5115 North Coast, baby! Join Date: Jun 2004 Location: Toledo, OH Posts: 437	Don't they make a programmer for that? I thought I just read something on this that you hook up to the ECM to recalibrate for larger (or smaller) diameter tires. __________________ Brad 79 Scottsdale C20 350/350 3.73's Still running full CA smog gear!

03-12-2005, 10:56 PM	#3
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	All you need to do is change is the gears. You can find a calculator and gears at www.tciauto.com. Look under their technical section then speedo gears. Read this page. http://www.geocities.com/crosley_az/700spd.htm __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

03-28-2005, 09:59 PM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Do you have a 4L80E?This application(`91 Sub)seems passed-over by the aftermarket.I put 35s on mine and called Jet,Superlift,and anyone else I thought would make a VSS-Buffer.No luck,mine`s a 6.2 diesel and the trans uses a stand-alone computer.I gave up.My next move was to try to see what street rodders use when running a 4L80E.I know mine`s 10%off.I have 4.10s and if I went to 4.56s with the 35s,I`d have 4.09s.But,power`s good,so I`m leaving it alone. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-29-2005, 03:27 AM	#6
u2slow Web Wheeler Join Date: Jan 2000 Location: BC, Canada, eh? Posts: 388	Read up on the DRAC module. http://614streets.com/drac.html __________________ '66 C10 longstep - Clifford equiped '84 C20 Suburban 6.2L - awaiting 4x4 conversion '91 V3500 Crewcab - awaiting diesel swap



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