C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Tach Filter

Thread Tools
 
Search this Thread
 
Old Apr 5, 2002 | 12:55 PM
  #1  
SprintCarDriver's Avatar
SprintCarDriver
Thread Starter
Racer
 
Joined: Mar 2001
Posts: 327
Likes: 0
From: Southlake, Texas, USA
Default Tach Filter

Is there a Tach filter on the 78 and if so where is it located?
Reply
Old Apr 5, 2002 | 03:21 PM
  #2  
dman535's Avatar
dman535
Burning Brakes
15 Year Member
 
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Default Re: Tach Filter (SprintCarDriver)

Parts book quotes the name part number 75-80. It should be attached to the intake manifold, drivers side rear.

From what I have been told its not required.

Reply
Old Apr 5, 2002 | 05:46 PM
  #3  
Paul Borowski's Avatar
Paul Borowski
Team Owner
Supporting Lifetime Gold
25 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Aug 2000
Posts: 21,457
Likes: 463
From: Massillon,Ohio USA
2020 C3 of the Year Finalist - Unmodified
Cruise-In VI Veteran
St. Jude Donor '08-'09-'10-'11-'12
Default Re: Tach Filter (SprintCarDriver)

Not at all needed, so this owner thought too...
Reply
Old Apr 5, 2002 | 09:21 PM
  #4  
dgruenke's Avatar
dgruenke
Drifting
15 Year Member
 
Joined: Apr 2002
Posts: 1,716
Likes: 4
From: New Baden Illinois
Default Re: Tach Filter (SprintCarDriver)

There should be three wires that plug into the coil on the distributor. The large one is from the battery (gives it juice). There are two smaller ones, side by side, in front of the battery wire. One of those is the tach wire. If you follow that wire, it should have an in-line filter in it. Good Luck.
Reply
Old Apr 6, 2002 | 06:03 AM
  #5  
mrvette's Avatar
mrvette
Team Owner
Active Streak: 120 Days
Liked
Loved
Community Favorite
 
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Default Re: Tach Filter (dman535)

Yes the tach filter or electronic equivalent is required with a stock tach, it smoothes out the pulses from the dist. to the tach doesn't bounce around at various RPM's.....

GENE
Reply
Old Apr 6, 2002 | 11:05 AM
  #6  
dman535's Avatar
dman535
Burning Brakes
15 Year Member
 
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Default Re: Tach Filter (mrvette)

I removed mine from my car and the tach works perfectly. It is impossible that its removal would cause a safety issue. All the filter really is is a capacitor, designed to filter out a range of frequencies on the electromagnetic spectrum.

Here is a schematic of the GM tach filter ( from a Fiero board)

Reply
Old Apr 6, 2002 | 02:25 PM
  #7  
mrvette's Avatar
mrvette
Team Owner
Active Streak: 120 Days
Liked
Loved
Community Favorite
 
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Default Re: Tach Filter (dman535)

The Tach filter is NOT an RFI/EMI thing....it's to integrate out the pulses going into the tach...the HEI or any coil rings quite a bit when points/sending unit opens up the primary circuit....and it's those extra rings that cause sometimes the tach to read rong...this can vary a bit from tach to tach and maybe even the specifics of the HEI....but at any rate the filter cures any problems....

that schematic is not the one I have....I dunno what they did for the 6 cyl engines, but on the vette it's one more pole to the filter, and differant resistor arrangement....

GENE
Reply
Old Apr 7, 2002 | 03:06 AM
  #8  
MIKER's Avatar
MIKER
Melting Slicks
10 Year Member
 
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Default Re: Tach Filter (mrvette)

mrvette,
check out this post from the archives. Is the schematic posted by Smokehouse69 the one that you are talking about?
http://forums.corvetteforum.com/zerothread?id=136220
Reply

Get notified of new replies

To Tach Filter

Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo




All times are GMT -4. The time now is 12:53 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE