Product Summary

Capacitive Discharge Ignition Box Output, Red, Red

  • Engineered to accept Hall-effect, points and mag pickup triggers
  • Adjustments can be made via four rotary dials in 100 RPM increments
  • Has an upgraded digital spark output versus the standard 6AL series
  • Includes high end overrev protection plus clutch or transbrake launch limiters
  • The multiple sparks over 20° of crankshaft rotation ensures complete combustion
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Key Specs

D-722-2
MFG. Part #6421
BrandMSD
Ignition Box OutputCapacitive Discharge
CircuitryDigital
CARB EO#
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Need To Know

Quick and Easy Returns

Return Policy

MSD 6421 Details

MSD is excited to announce the next generation of 6-Series ignition controls - the 6AL-2! The ignition control combines a new housing, new digital controls, and more power in a sleek package. Inside the new cast aluminum housing, you'll find an advanced micro-controller that manages the built-in two-step rev-limiter. The spark output of the new box has been turned up to 535 volts of primary voltage with spark energy reaching up to 135 millijoules! The multiple sparks of the 6AL-2 burn in the cylinder for 20 degrees of crankshaft rotation to ensure complete combustion.

Two more great features are the rev limits! There are two rev limiters; one for high-end overrev protection and another you can activate off a clutch or trans-brake to set a launch limit. This feature will help your car blast off the starting line! Adjustments are made via four rotary dials for 100 rpm increment control!

The all-new capacitive discharge ignition will easily connect to nearly any 12-volt negative ground distributor system.

Features:

  • All new housing, same reliable digital circuitry and performance
  • Built-in 2-Step rev control adjustable with rotary dials
  • Higher output with up to 135mJ of spark energy
  • Accepts Hall-effect, points and mag pickup triggers
  • Managed by an efficient digital processor

Learn more about determining the proper MSD ignition control box for your application by reading our tech article. MSD Ignition Box: Ignition Controller Buyer's Guide

Warranty Information

For warranty information, visit http://www.msdhelp.com/

MSD 6421 Specifications

D-722-2
KEY SPECS
MFG. Part #6421
BrandMSD
Ignition Box OutputCapacitive Discharge
CircuitryDigital
CARB EO#
GENERAL
Rev Limiter IncludedYes
Data AcquisitionNo
RPM Range12,500 RPM with 14.4 Volts
Timing RetardNone
Coil IncludedNo
Primary Voltage535 Volts output to coil
Secondary Voltage45,000 Volts
Spark Output135 MJ
Voltage Required10-18 Volts, Negative Ground
Ignition Box ColorRed
GTIN Code085132064212
Overall Length7.00"
Overall Width4.00"
Overall Height2.00"
ColorRed
NotesVibration mounts included.
Wiring Harness IncludedYes

Ratings & Reviews

5

3 Reviews

Overall Assessment

Customers value the product for its versatility, fitting well for both street and strip cars. It successfully solved clearance issues when paired with a distributor, highlighting its practicality. The programming features ensure future adaptability, enhancing user convenience. Through the addition of the product to their AC Cobra 408 Stroker, customers demonstrated its potential in automotive projects. A note on its user-friendly installation process has also contributed to its strong reputation. The majority of users recommend the product enthusiastically, confirming it as a superior and reliable choice compared to its competitors.

5

3 reviews

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Great product

5.0

6 years ago

69oldsfan

Lakeville,MN

Verified

Great for a street/strip car.

Would Recommend

I would buy again

5.0

7 years ago

bigfish_oh

Ohio

Verified

paired with distributor that was needed for clearance issue. programming features leave the future open for options.

Would Recommend

Will buy again for the next project

5.0

8 years ago

Steve G

Central NY

Verified

Great addition to my AC Cobra 408 Stroker. Watching a YouTube video helped clarify the install directions a lot, I would recommend this to any first time installers.

Would Recommend

Showing 3 of 3 reviews

Questions & Answers

1 Question • 1 Answer

What good is it after 3000 rpm?

by Nancy

• 10 years ago

1 answer

1 of 1 questions shown

Customer Impersonation Script