getting more air into CIS?
04-12-2009, 03:08 PM
#16
Nordschleife Master
The MSD ign system is nothing more than a fancy trigger, and CDI.
I have tried running larger gaps on multiple cars and it wears out the cap and rotor really quickly.
I prefer the MS with EDIS or COP units as then there is no loss and you can run a MUCH larger gap.
I have tried running larger gaps on multiple cars and it wears out the cap and rotor really quickly.
I prefer the MS with EDIS or COP units as then there is no loss and you can run a MUCH larger gap.
04-12-2009, 04:55 PM
#17
Burning Brakes
Thread Starter
So...can I just get the MSD Blaster 2 coil and replace my existing coil with it to hold me over until I have enough saved up for a full MSD (the Blaster 2 coil is $35, the 560 coil is $90)?
The reason I want to eventually go to a full MSD setup isn't just for the hotter spark but so I can map the timing. I'd just hate to spend $90 on a 560 coil now to replace it later with a $35 Blaster 2 when I do an MSD conversion.
And yeah, we still have control pressure to spare with the UTCIS-PT, and you can see from the dyno chart (those lines have none of the software smoothing done to them btw) that I've got the mixture in the 12.5:1 to 13:1 A/F range, which gave me max power on the dyno.
The reason I want to eventually go to a full MSD setup isn't just for the hotter spark but so I can map the timing. I'd just hate to spend $90 on a 560 coil now to replace it later with a $35 Blaster 2 when I do an MSD conversion.
And yeah, we still have control pressure to spare with the UTCIS-PT, and you can see from the dyno chart (those lines have none of the software smoothing done to them btw) that I've got the mixture in the 12.5:1 to 13:1 A/F range, which gave me max power on the dyno.
04-12-2009, 07:34 PM
#19
Three Wheelin'
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Go to Unwiredtools.com
It's a WUR replacement that allows you to program control pressure over RPM and Vacuum. MOre than just warm up and WOT enrichment.
It's a WUR replacement that allows you to program control pressure over RPM and Vacuum. MOre than just warm up and WOT enrichment.
04-12-2009, 08:02 PM
#20
Burning Brakes
Thread Starter
It's damn useful too. I don't think any of my rpms have the same control pressures.
Last edited by marlinspike; 04-12-2009 at 09:33 PM.
04-13-2009, 01:33 AM
#22
Burning Brakes
Thread Starter
Could you possibly grab the part number off it for me? The MSD I was planning to use is wound 100:1 and the Benz ones are apparently 185:1, so I figure the MSD won't be an improvement. However, there are two bosch coils being sold is if they're for the 560, so I wonder which you're using.
04-13-2009, 08:06 AM
#23
Racer
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The part number of the coil i'm using is 0001586403, which looks like its the same for a 420 too. It looks completely different to the original 380/500 version, but it bolts up to the original holes and wiring. There is a heat shield available to go over the coil too, don't forget that - I can imagine the heat from the exhaust manifilds would cook an unprotected coil.
I haven't noticed any problems with arcing inside the distributor cap though.
I haven't noticed any problems with arcing inside the distributor cap though.
04-13-2009, 05:36 PM
#24
Burning Brakes
Thread Starter
Just to check before I spend my money, did you check your old coil to make sure it simply wasn't bad? I ask because I just checked out my coil and the primary resistance is at the bottom end of the acceptable range (which is good) so I'd hate to change it out for no reason.
04-13-2009, 08:08 PM
#26
Three Wheelin'
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FYI. The blaster II coil is not a step up from the stock Bosche coil.
Choosing a coil is always a compromise. Finding a coil system that is well designed for the shark or your Merc, even more of a compromise. A coil with one form of winding might make the engine easy to start, but at the top end (high rpm range), the coil won't function properly. Another coil-winding ratio might be best suited for use at high engine rpm, but it won't work well to fire the spark when starting the engine. Because of this, most coils are a design of compromise. Going with a "Bigger' coil does not automatically mean you get higher RPM performance.
Higher voltage allows for a larger gap, yet higher amperage leads to a better ignition and burn. You can't have both. It's funny that most manufactures advertise secondary voltage which in realty only leads to what size gap you can use, not it's ability to ignite the fuel at high RPM. Typically higher voltage coils have fewer windings, leading to a less powerful spark with a shorter duration. That's why the MSD ignition helps at low RPMs with it's multi firing. It allows you to run a high RPM coil that will still work well at low RPM. Less of a compromise than a traditional Coil / CDI set up.
Choosing a coil is always a compromise. Finding a coil system that is well designed for the shark or your Merc, even more of a compromise. A coil with one form of winding might make the engine easy to start, but at the top end (high rpm range), the coil won't function properly. Another coil-winding ratio might be best suited for use at high engine rpm, but it won't work well to fire the spark when starting the engine. Because of this, most coils are a design of compromise. Going with a "Bigger' coil does not automatically mean you get higher RPM performance.
Higher voltage allows for a larger gap, yet higher amperage leads to a better ignition and burn. You can't have both. It's funny that most manufactures advertise secondary voltage which in realty only leads to what size gap you can use, not it's ability to ignite the fuel at high RPM. Typically higher voltage coils have fewer windings, leading to a less powerful spark with a shorter duration. That's why the MSD ignition helps at low RPMs with it's multi firing. It allows you to run a high RPM coil that will still work well at low RPM. Less of a compromise than a traditional Coil / CDI set up.
04-13-2009, 08:27 PM
#27
Burning Brakes
Thread Starter
Yeah, I sort of figured that out when I looked at the stock coil specs and saw it had about half the primary resistance of the MSD and a 185:1 coil winding ratio. I thought I posted it here but it looks like I only posted that on another forum I asked this question on. That's why now I'm considering of following Ben and going to the coil Mercedes used in these cars after 1986.
04-14-2009, 06:17 AM
#28
Racer
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Hi,
Well, the car performed fine on the old coil and old engine... after I installed the 5.6 engine I was having issues with the tuning.
I did research into the coil, and how the workshop manual states that I must only use the correct coil for the car or I risk blowing up the ignition module. I thought what the hell and put in the 560's coil and all is well.
Yes, I guess the old coil may have been weak. Fine for the old engine, but not good enough for the new one, but I never tested it... It was easier to just swap it out because I had the whole 'spare' 560SEC for parts.
I remember that the spark was yellow before, but after swapping the coil it was a nice bright blue. All other ignition components were new or less than a couple of years old.
Well, the car performed fine on the old coil and old engine... after I installed the 5.6 engine I was having issues with the tuning.
I did research into the coil, and how the workshop manual states that I must only use the correct coil for the car or I risk blowing up the ignition module. I thought what the hell and put in the 560's coil and all is well.
Yes, I guess the old coil may have been weak. Fine for the old engine, but not good enough for the new one, but I never tested it... It was easier to just swap it out because I had the whole 'spare' 560SEC for parts.
I remember that the spark was yellow before, but after swapping the coil it was a nice bright blue. All other ignition components were new or less than a couple of years old.
04-14-2009, 10:18 PM
#30
Burning Brakes
Thread Starter