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

Tach Filter

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: 21,427
Likes: 456
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

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-1

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-2

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-3

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-4

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-5

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-6

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-7

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-8

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-9

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski


Thread Tools
Search this Thread

All times are GMT -4. The time now is 01:38 PM.

story-0
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-1
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-2
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-3
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-4
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-5
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-6
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-7
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-8
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-9
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE