Tachometer - ZR-1 Net Registry Forums

Intruder · 09-05-2015

My tachometer reads approximately 48% high based upon the AC display verification.

WVZR-1 · 09-05-2015

Quote:

Originally Posted by Intruder

My tachometer reads approximately 48% high based upon the AC display verification.

Likely a '90 and it's not unusual and will likely continue to get worse. There's DIY repairs for recalibration and I'm sure someone will provide some links and maybe personal experiences. I understand the requirements but have never personally done a fix.

I discovered mine when actually trying to confirm a rear axle ratio that would have explained my tach variance but this was on a car that wasn't thought to be modified. I checked mine vs. a Tech1 scanner rather than the C68 display. Mine is repaired and correct but NOT by me.

FU · 09-05-2015

Easy way ? Take the lens off then gently pull the sweep off . Then read set it and push the sweep back on.

Intruder · 09-05-2015

Not sure what you mean by pulling the sweep.

Intruder · 09-05-2015

OK, I am guessing by "sweep" you are referring to the tach needle?

LGAFF · 09-05-2015

http://www.zr1.net/forum/showthread....highlight=tach

FU · 09-05-2015

Sweep = Tach needle.

Paul Workman · 09-06-2015

Quote:

Originally Posted by FU

Easy way ? Take the lens off then gently pull the sweep off . Then read set it and push the sweep back on.

He's kidding

!!

The error is a % (of rpm) error. In short, re-positioning the needle to read accurately only works at one rpm value. the same % error will result above or below that "set" rpm.

secondchance · 09-07-2015

Quote:

Originally Posted by Paul Workman

He's kidding

!!

OR...if one were to pluck the needle and reset it to read correctly at idle, it would still read ~ 7000 x 1.48 minus 480 or 9380 rpm when actually at 7000 rpm!
!!

One way to get higher revving LT5!

Intruder · 09-07-2015

Yea. Who knew these LT5's would get up to 8,000 RPMs without hitting the rev limiter.

09-05-2015	#1
Intruder Join Date: Sep 2015 Location: Mt Airy, MD Posts: 17	Tachometer My tachometer reads approximately 48% high based upon the AC display verification.

09-05-2015	#3
FU Join Date: Mar 2004 Location: Found Member Posts: 4,346	Re: Tachometer Easy way ? Take the lens off then gently pull the sweep off . Then read set it and push the sweep back on. __________________ Frank Urbo. NCM Lifetime member # 982 Registry Founding # 237

09-05-2015	#4
Intruder Join Date: Sep 2015 Location: Mt Airy, MD Posts: 17	Re: Tachometer Not sure what you mean by pulling the sweep.

09-05-2015	#5
Intruder Join Date: Sep 2015 Location: Mt Airy, MD Posts: 17	Re: Tachometer OK, I am guessing by "sweep" you are referring to the tach needle?

09-05-2015	#6
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,186	Re: Tachometer http://www.zr1.net/forum/showthread....highlight=tach __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

09-05-2015	#7
FU Join Date: Mar 2004 Location: Found Member Posts: 4,346	Re: Tachometer Sweep = Tach needle. __________________ Frank Urbo. NCM Lifetime member # 982 Registry Founding # 237

09-07-2015	#10
Intruder Join Date: Sep 2015 Location: Mt Airy, MD Posts: 17	Re: Tachometer Yea. Who knew these LT5's would get up to 8,000 RPMs without hitting the rev limiter.