enough spark?

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Feb 23, 2005 | 07:10 AM

devilfish

Thread Starter

Melting Slicks

Joined: Oct 2000

Posts: 3,010

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From: Sweden/Stockholm

enough spark?

What is the sign of a to weak ignition system? Missfire at high rpm? Fould plugs? Down on power? How can you tell when its time to get a "better" ignition system?

Last edited by devilfish; Feb 23, 2005 at 07:13 AM.

Feb 23, 2005 | 11:01 AM

rick lambert

Le Mans Master

Joined: Oct 2003

Posts: 6,130

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From: seattle WA

Can't get specific about what signs you'll see when the ignition needs new components-but I can say this, the stock ignition system in our C4s are going to provide all the spark you'll need.

Feb 23, 2005 | 01:57 PM

Lone Ranger

Le Mans Master

Joined: Feb 2002

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Best way to make sure the stock ignition system is delivering the best spark it can, is to install new spark plugs and a new set of spiral core spark plug wires. Don't use the stock carbon core wires-- too much resistance. Use the spiral core type of wires designed for EMI supression. MSD, Taylor, Moroso, Accel, Bosch all make this type of wire as custom-fit for Vettes.

The Bosch mag core (spiral core) wires are a pretty good choice if the other brands aren't available where you live.

Feb 23, 2005 | 11:02 PM

devilfish

Thread Starter

Melting Slicks

Joined: Oct 2000

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From: Sweden/Stockholm

thanks!

Feb 23, 2005 | 11:34 PM

65Z01

Team Owner

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From: SE NY

Cruise-In II Veteran

Our stock HEI is good to mid 4k RPM range and begins to fall off by 5k RPM.

That is why I installed HyperTech coil/cap/rotor, TPIS wires and cut back spark AC Delco plugs. I have no problems pulling to 5,800rpm.

Feb 24, 2005 | 04:45 AM

devilfish

Thread Starter

Melting Slicks

Joined: Oct 2000

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From: Sweden/Stockholm

Quote:

Originally Posted by 65Z01

I need good spark to 6000rpm. And right now I use a GM HEI with external coil, due to my LT1 intake conversion. Just need to know if I have to change it to a "better" one.

Feb 24, 2005 | 07:15 AM

M Nordin

7th Gear

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I read a book written by D Vizzard about HEI ignition and his opinion - then - was that a high output module and MSD or Accel coil would do the trick way over 6000 rpm. Stock ign would start missing at 4500 rpm.

BR

MN

PS Anders, vad säger dynokillarna - de borde veta? DS

Feb 24, 2005 | 09:37 AM

parafrog

Racer

Joined: Jan 2005

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From: Tucson, AZ. L98-85 AUTO COUPE: 120k MILES: daily driver. SOUND OFF IF YOU'VE BEEN THERE. Ex-Jumpin' Junky-82nd Airborne-2/505 PIR: 1st ID-1/16th Inf: Recon Marine Retread. GOD BLESS GRUNTS.

Quote:

Originally Posted by M Nordin

i don't think he was referring to the corvette though. i found a dealer maintanence bulletin, and it referred to a problem in the high output coil.

Service Bulletin Number: 85-93
Bulletin Sequence Number: 107
Date of Bulletin: 8506
NHTSA Item Number: 79274
Make: CHEVROLET
Model: CORVETTE
Year: 1985
Component: ELECTRICAL SYSTEM:IGNITION:COIL
Summary: HIGH OUTPUT IGNITION COIL REPLACEMENTS- HIGH OUTPUT COILS EXHIBIT DRIVEABILITY P ROBLEMS RANGING FROM HESITATIONS, SAGS, AND STUMBLES TO COMPLETE IGNITION CUT-OU T. CAUSED BY A SHORT IN SECONDARY WINDINGS OF HIGH OUTPUT COIL CAUSED BY EXTENDE D EXPOSURE TO HIGH TEMPERATURES. SERVICE TO REPLACE COIL AND DISTRIBUTOR MODULE WITH STANDARD OUTPUT COIL AND MODULE. 1985 L69 CAMARO AND MONTE CARLO, 1985 LB 9 CAMARO AND L98 CORVETTE.

this seems to suggest the corvette already has a high rpm module. at least i would hope so. but what chevy considered as high output for its coil and relay in 85 is the real question, and how high could this relay rev.

frog.