Single Turbo RX-7's Questions about all aspects of single turbo setups.

msd ?

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Old 10-18-03 | 12:09 PM
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msd ?

If I get a msd 6a can I have two crane lx91 for my coils?
Old 10-18-03 | 04:45 PM
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Sure.
Measure the primary resistance on the coils - how much is it?
I think the MSD is safe down to about 0.05ohms.


-Ted
Old 10-18-03 | 06:52 PM
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the spark will not be as good. you should run one box per coil but yes it should work
Old 10-18-03 | 08:18 PM
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Whats the proper way to setup a complete ignition? 1 MSD 6AL on each leading and 1 for both trailing with 1 coil per plug?

Or 1 MSD DIS2 for both leading and 1 DIS2 for both trailing with 1 coil per plug?
Old 10-18-03 | 08:25 PM
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You need 2 6AL boxes for the trailing and 1 for the leading or 2 for trailing and 2 for leading

Jim
Old 10-18-03 | 09:24 PM
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O.K. thanks
Old 10-19-03 | 06:14 AM
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If you're looking at MSD products, it's a Digital 6 for leading (on twin tower coil) and a DIS-2 for trailing.

OR

Split the leading into two boxes, so you can run a pair of Digital 6's into two single tower coils (split signal before the Digital 6's), and the DIS-2 into the trailing. This allows you to run all aftermarket coils.

This would be the most costly (and arguably the best) system.


-Ted
Old 10-19-03 | 12:54 PM
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If I do the msd and two crane coils will it be better than my current setup? I have one crane amp and the stock coils. Which coils are better msd or crane? Thanks
Old 10-19-03 | 03:23 PM
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I wouldn't mix and match components. Stick with 1 brand.

Thanks Ted.
Old 10-19-03 | 03:37 PM
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why couldn't you just use 2 6a boxs on the leading with two upgraded coils and be done with it? The reason im asking is becuase thats how I set mine up. I was told that 1 msd box wasn't enough for 2 coils, so thats why I went with 2. anyone?
Old 10-19-03 | 07:05 PM
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It will probably work fine...just not as good as the complete setup with digital boxes and all that other fancy ****
Old 10-19-03 | 09:17 PM
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I wanted to stay as low of cost as I could. Two msd's and two coils are going to cost $500. I know it is worth it but dam I'm tired of putting money into this beast.
Old 10-19-03 | 09:19 PM
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Originally posted by ULTIMATERX7
I wanted to stay as low of cost as I could. Two msd's and two coils are going to cost $500. I know it is worth it but dam I'm tired of putting money into this beast.
quit playing be money chiropractor
Old 10-19-03 | 09:36 PM
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you could just use a 6a on turbo2 leading coil. I here that the t2 coil is enough.
Old 10-19-03 | 10:20 PM
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I use a 6a on the leading with a twin post MSD motorcyle coil. The trailing I have a Dis 2 with Blaster 2 coils. The spark from the twin post is much stonger then the Blaster coils. If You do it this way You save buying 2 6a for the leading.
Old 10-19-03 | 11:06 PM
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I've been doing some reading up on this subject as I just pulled out my crane Hi-6 and went back to stock for now. My concern was that I had heard that we should run a digital unit and not analog. This will make the timing signal more accurate and this is important when running a small igntion split. The digital boxes supposedly put out a square wave form which is very sharp and consistent.

I am not sure if the crane Hi-6 that I have is digital or not. Their website states that the Hi-6 uses all surface mount digital components. Does this make it a digital unit like the MSD Digital 6? Their website also has a sport/compact section which lists a Hi-6 digital multispark cd ignition box which boasts the same specs. My unit is about 3 years old.

The regular MSD 6 series is analog. Do not confuse digital and analog with inductive and CD (capacitive discharge). These are two diffent things. MSD 5 series is inductive and analog. MSD 6 is CD and anaolg. MSD Digital 6 is CD and Digital. I am not sure about the Crane offerings. DIS units offer digital and CD and are designed to work with factory coils. This where I get a little confused.

Our factory ignition is inductive, therefor the coils are designed as storage type units. The ignitor pulse is designed so that it causes the coil to charge up and then discharge for a longer period than a CD style system. This is why inductive units have good low end response, a long spark pulse. The problem is up top. The cycle time is too fast and and the coil doesn't acheive full power. The inductive downfall. The Cd ignition is just the opposite. Great spark up top, to quick down low. This is why they have multiple spark. To get back the low end. If you can't have one long spark then how about a bunch of short ones to make up for it. But as stated earlier, the design for a CD coil is the opposite of that of an inductive coil. Therefor while the factory coil is very good, it would seem that it is not of the type needed by a CD setup. So why do the DIS setups which are still CD style systems say to use the Factory coils, and the other setups say not to. They are all Capacitve discharge.

The Hks system is both inductive and Capactive. This is why it does not need to be multiple spark. The only thing is that I can find no actual specs on the output. It should work well with our factory coils down low but what about up top.

It seems that the best setup from a purely technical point of view would be to start with a digital cd unit that powers its own cd style coil. This means 2 Digital CD units and 2 CD coils for leading, one for each plug. Then use a dis2 for the rears once again with new coils for each plug. This adds up to a lot of money.

Another option is a twin post CD style coil for the leading. The problem with this is that I do not know if spark voltage would be less because of having to fire two plugs from one coil and one amp. Has anybody checked to see if the twin post units fire with the same power when the batch fire as a single post unit. If so then we can just use one digital unit with one two post coil for leading. This cuts the cost in half with no loss of power.

The other idea is to use one box that fires two channels at full power to two coils. I do not like the idea of parralleling two coils on one channel. Do any of the DIS units have this ability. If so then you could just use one of these and set it up to fire both channels from the one leading input. I would imagine that the units would have to have larger power supplies or independent ones for each channel to develop full power if they fire at the same time.


Anyway this is my incomplete uderstanding of ignition setups. I hope this helps some and I hop others can fill in the holes. I have searched alot and there always seems to be conflicting data out there.

sorry for the long post

mike
Old 10-20-03 | 01:23 AM
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Gordon Monson was one of the first People on this forum using the MSD set up. I think You can go as crazy as Your wallet can afford but when there will be minimum gains I think with using a bunch of fancy, very expensive boxes. Your post is interesting and You might be correct but a 6a worked well with BGEV 11 plugs and 18 PSI on pump(92) gas for Me. I am sure the digi boxes work better but are way more money. I would spend the extra cash on a good wideband to get correct AFR`s which will ultimately get the best performance out of the car.


http://www.factorydirectperformance.com/mccoil.htm

Here is the MSD twin post
Old 10-20-03 | 08:31 AM
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cool thanks
Old 10-20-03 | 01:01 PM
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i have a msd6a with a blaster coil. i bought it used. the blaster coil in new in the box. does someone want it. i don't know how to install it so i will sell it. kevin
Old 10-20-03 | 01:07 PM
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$10
Old 10-20-03 | 03:25 PM
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Originally posted by 93 R1
$10
how about i give you fifty to take it off my hand.
Old 10-20-03 | 04:00 PM
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ok come down to the meet this sunday
Old 10-20-03 | 04:28 PM
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what meet? what kind of single turbo do you have. maybe i can skip out on my atlantic city vacation and come down and check out cars. kevin
Old 10-20-03 | 06:58 PM
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The Crane Cams HI-6 is a digital box - this is what I recommend to everyone who asks.

If you're worried about a single CDI box into two coils, how about you scope the outputs? This is irrefutable proof that it works or not - I have never heard of the single box split into two coils being inferior.


-Ted
Old 10-20-03 | 07:45 PM
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Thanks for the info on the Crane. I called their tech support today and they confirmed that it is digital also. If there is no problem running two coils on one box, then which model coils would you recommend for use with my hi-6; LX1's or LX2's. also, what about some of the msd twin pole coils, any info on these.

one last question. When I installed my unit along time ago, the diagram that everyone was using for the hi-6 said not to connect the blue wire. I have now seen comments to the opposite. What is the propper method for connecting the blue wire? If I put this back in, I want to make sure that everything is the way it should be.

mike



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