MSD ingition mod question
#1
MSD ingition mod question
So I looked at this mod here: http://www.mazspeed.com/msd.htm. Question: Is there any reason I can't use 2 6a's and 4 coils? one box and two coils for leading and one box and two coils for trailing...
#3
Old Fart Young at Heart
iTrader: (6)
You can get away with 1 box for the leading because both the front and rear trigger and fire at the same time. The trailings don't. They are triggered at different times so they need separate boxes to fire at different times. It's more cost effective to simply drop the trailing. Their main purpose is for emission clean up, not performance. Disable the current trailing setup and see if you even notice a performance difference. Bet you can't tell.
#4
79 w 13B4port
iTrader: (5)
The easiest thing to for the trailing is nothing leave it stock, It works fine that way, unless you need/want over rev protection and then you don't have to answer endless questions from well meaning people pointing out that your spark plug wires are off. Plus there is no lingering question in the back of your mind: Am I really smarter than some Japanese engineer??????????
#5
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,603 Likes
on
1,847 Posts
So I looked at this mod here: http://www.mazspeed.com/msd.htm. Question: Is there any reason I can't use 2 6a's and 4 coils? one box and two coils for leading and one box and two coils for trailing...
or you can just run 1 MSD, and run both leading and trailing coils off of it.
#6
the torquinator
iTrader: (1)
I think the only way to run one msd box per trailing plug would be to use a standalone computer. But, as mentioned above, it would probably not give you the performance boost you are hoping for.
I think, for the most part, na race cars and turbocharged street and race cars benefit from 2 msd boxes for the leading plugs (one for each leading plug). It's harder to spark as compression goes up, so the turbo guys get big benefits from the mega sparks.
If you have a streetcar, one msd on the leading with stock trailing, in my opinion will be fine.
I have never run 2 boxes on the leading, maybe someone who has can tell us if a mild streetcar will benefit from it...
I think, for the most part, na race cars and turbocharged street and race cars benefit from 2 msd boxes for the leading plugs (one for each leading plug). It's harder to spark as compression goes up, so the turbo guys get big benefits from the mega sparks.
If you have a streetcar, one msd on the leading with stock trailing, in my opinion will be fine.
I have never run 2 boxes on the leading, maybe someone who has can tell us if a mild streetcar will benefit from it...
#7
Senior Member
iTrader: (6)
Join Date: Jul 2005
Location: Orlando, FL
Posts: 565
Likes: 0
Received 0 Likes
on
0 Posts
I run Mallory boxes - similar to MSD, but its a Capacitive Discharge system not Multiple Spark. I have one box/coil for leading and one box/coil for trailing and run them all through the stock distributer.
Fuel economy improved noticably, idle improved, and top end power is considerable, especially after a street port. This mod, although pricey, was money very well spent.
I am tempted to put both boxes and coils on the leading and leave the trailing stock with the stock coil, but never found the time to research how to do it. My current setup does have a full rev-limiter which is nice insurance, but since I'm not spraying NOS anymore, I'm not heartbroken if I lose it.
Fuel economy improved noticably, idle improved, and top end power is considerable, especially after a street port. This mod, although pricey, was money very well spent.
I am tempted to put both boxes and coils on the leading and leave the trailing stock with the stock coil, but never found the time to research how to do it. My current setup does have a full rev-limiter which is nice insurance, but since I'm not spraying NOS anymore, I'm not heartbroken if I lose it.
Trending Topics
#8
Senior Member
iTrader: (6)
Join Date: Jul 2005
Location: Orlando, FL
Posts: 565
Likes: 0
Received 0 Likes
on
0 Posts
Think of it as one box per coil on a stock setup.
#9
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,603 Likes
on
1,847 Posts
this gives you zero timing split though.
if you need timing split then you need one MSD on the leading and one on the trailing. and if you do that you might as well run 2 leading coils.
#12
Senior Member
iTrader: (6)
Join Date: Jul 2005
Location: Orlando, FL
Posts: 565
Likes: 0
Received 0 Likes
on
0 Posts
Aside from the sheer age of the coil, the stock ones are fine. High boost, etc, I would go with a hotter one.
#13
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,603 Likes
on
1,847 Posts
lol, ive run no split and a turbo... but yeah i'm running NA, where mazda actually WANTS zero split
#14
Senior Member
iTrader: (6)
Join Date: Jul 2005
Location: Orlando, FL
Posts: 565
Likes: 0
Received 0 Likes
on
0 Posts
People have had good luck with no-split, but they are the ones that know what they are doing and are squeezing every bit of HP from a motor (most likely with a standalone). I'm not saying it can't be done, but that for someone who isn't experienced - I'd say stay away from it. As far as Mazda intending it.....I'd like to see some evidence of that. If thats the way they wanted it, why don't our cars come that way? Not pointing fingers, just asking since I haven't heard that before.
#15
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,603 Likes
on
1,847 Posts
People have had good luck with no-split, but they are the ones that know what they are doing and are squeezing every bit of HP from a motor (most likely with a standalone). I'm not saying it can't be done, but that for someone who isn't experienced - I'd say stay away from it. As far as Mazda intending it.....I'd like to see some evidence of that. If thats the way they wanted it, why don't our cars come that way? Not pointing fingers, just asking since I haven't heard that before.
"5. lgnitiontiming. The timing is set with the drive pulleynotchandthe indicatorpin on the fronl cover; the notches aredenotedas shownin the illus- trationbelow:
The trailing and leading plugs shouldboth be set to fire al 20" BTDC."
why? couple of reasons.
on a high output engine, crossfiring of the spark plugs is very very bad, but if there is no timing split, this basically eliminates the problem, as you can't fire the plug at the wrong time if they fire at the same time anyways.
the second is probably emissions, but even the stock distributor runs split near zero under some conditions, the trailing vacuum advance unit advances more than the leading one does.
not saying zero split is the best way at all, but it can be done
#16
35r 13b first gen
iTrader: (3)
Join Date: Apr 2002
Location: Richland Center WI
Posts: 1,290
Likes: 0
Received 0 Likes
on
0 Posts
So is there any potential problems with just one box for leading and one for trailing? locked dizzy where it normally rests. one box runs off one igniter and the second box off the other igniter.
#18
Waffles - hmmm good
iTrader: (1)
If your leading spark is hot enough you really won't need trailing. I did an
HEI ignition using 2 TFI coils (one for each leading plug). I was too cheap to
buy MSD boxes
Anyway, I dropped the trailing ignition because it just wasn't needed anymore
and I could not tell when it was there or not. Also simplified the wiring and got rid
of one HEI and the use of the dizzy cap. I just use the dizzy to get a signal
for the leading HEIs now.
HEI ignition using 2 TFI coils (one for each leading plug). I was too cheap to
buy MSD boxes
Anyway, I dropped the trailing ignition because it just wasn't needed anymore
and I could not tell when it was there or not. Also simplified the wiring and got rid
of one HEI and the use of the dizzy cap. I just use the dizzy to get a signal
for the leading HEIs now.
#19
Full Member
Join Date: Oct 2008
Location: huntsville AL
Posts: 98
Likes: 0
Received 0 Likes
on
0 Posts
two boxes?
So I looked at this mod here: http://www.mazspeed.com/msd.htm. Question: Is there any reason I can't use 2 6a's and 4 coils? one box and two coils for leading and one box and two coils for trailing...
nah... all you need is one box w/two coils wired in parrallel and then just run the trailing off the cap and a seperate coil. that is what i did, and i actually ran it without even having a trailing for a while and honestly i could tell no difference with or without. the msd made a difference on easier starting and smoother idle but thats about it. seems like a lot to pay for two 6als and 4 coils for only small benefits....but i mean it would look a lot cooler (more expensive)
#21
35r 13b first gen
iTrader: (3)
Join Date: Apr 2002
Location: Richland Center WI
Posts: 1,290
Likes: 0
Received 0 Likes
on
0 Posts
nah... all you need is one box w/two coils wired in parrallel and then just run the trailing off the cap and a seperate coil. that is what i did, and i actually ran it without even having a trailing for a while and honestly i could tell no difference with or without. the msd made a difference on easier starting and smoother idle but thats about it. seems like a lot to pay for two 6als and 4 coils for only small benefits....but i mean it would look a lot cooler (more expensive)
#22
Rotary Enthusiast
iTrader: (12)
Join Date: Oct 2007
Location: Fort St John B.C. Canada
Posts: 871
Likes: 0
Received 0 Likes
on
0 Posts
I tried every configuration with two 6al boxes and I found the best to be 1 box per coil for leading and just run trailing stock through the dizzy or delete it all together. This was for supercharged which i found it ran better under boost with 1 box per coil than 1 box for two coils.
I rev limited the leading and left the trialing stock and it worked fine, the major loss of power was more than enough to let you know to shift.. and your not loading your exhaust with a load of raw gas.
I rev limited the leading and left the trialing stock and it worked fine, the major loss of power was more than enough to let you know to shift.. and your not loading your exhaust with a load of raw gas.
#23
35r 13b first gen
iTrader: (3)
Join Date: Apr 2002
Location: Richland Center WI
Posts: 1,290
Likes: 0
Received 0 Likes
on
0 Posts
I tried every configuration with two 6al boxes and I found the best to be 1 box per coil for leading and just run trailing stock through the dizzy or delete it all together. This was for supercharged which i found it ran better under boost with 1 box per coil than 1 box for two coils.
I rev limited the leading and left the trialing stock and it worked fine, the major loss of power was more than enough to let you know to shift.. and your not loading your exhaust with a load of raw gas.
I rev limited the leading and left the trialing stock and it worked fine, the major loss of power was more than enough to let you know to shift.. and your not loading your exhaust with a load of raw gas.
Thread
Thread Starter
Forum
Replies
Last Post
msilvia
3rd Generation Specific (1993-2002)
28
04-14-16 12:58 PM