TWIN SPARK
Rennlist Member
Joined: Sep 2002
Posts: 1,749
Likes: 54
From: Palm Beaches Fl /Southern VT
Technical Guru
Rennlist Member
Rennlist Member
Joined: May 2002
Posts: 8,138
Likes: 122
From: USVI
I thought I read somewhere that for their street engines the trade off was that the additional surface area and mass for cooling the head was more important than any additional timing they could run? Porsche motorsports did twin-plug the M64/82 used in the MY98-99 993 GT2 EVO but they also had to use Secan intercoolers to reduce the intake temperature.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
Three Wheelin'
Joined: Jul 2005
Posts: 1,635
Likes: 20
From: Estonia
With twin plugs you actually need to run less timing, meaning MBT moves closer to TDC. That is because mixture burns faster (having ignited simultaneosly from both sides of the combustion chamber).
Race Car
Joined: May 2003
Posts: 4,222
Likes: 102
From: SoCal
Cupcar:
I would have to question what you call "folklore". If I understand the reason the twin spark was used it was to allow a higher compression ratio with the car, hence more horsepower. The twin spark doesn't create the extra horse power...I suppose you could say it makes it possible though. Without the twin spark the car will suffer from pre-detonation.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> Bill Wagner
I would have to question what you call "folklore". If I understand the reason the twin spark was used it was to allow a higher compression ratio with the car, hence more horsepower. The twin spark doesn't create the extra horse power...I suppose you could say it makes it possible though. Without the twin spark the car will suffer from pre-detonation.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> Bill Wagner
Read under "Detonation" here: http://www.systemsc.com/problems.htm
Last edited by Lorenfb; Dec 16, 2017 at 01:25 PM.
