I really should not comment given embracing the more sensitive person I am striving to be, but..............

BAM!

So! What's the point?

- tirwin -

"I knew precisely what the dwell was prior to and after switching to the MSD. If I knew of a local shop that actually had a CO meter, I would've had the CO checked, but I don't know of one."

So tell us how much the dwell changed, right? Or if you're going to make a major
claim, then support it with actual data from a gas analyzer! Based on your old
thread about your 'understanding' of dwell (or lack of), one has to wonder how
you really measured the change in the dwell you claim.

Bottom line: Why 'feed' the OP with 'hearsay' when he's going to possibly waste
money for the MSD and NEW plug wires (not cheap), but also for wasting his time
re-wiring his ignition system? As a result, the value of the Pelican Forum becomes
minimized when hyperbole is presented.

Hi All,

Definately opened a can of worms with this one then!

I have agreed to buy the MSD, and will look into Clewitts vs Magnecor as I am running Beru now.
Probably shouldn't ask which wires are best or is the Blaster II coil the dogs Boll*cks.
I will also look into the points delete as well.
I will probably never dyno this car but a bit more grunt lower down and better gas mileage appeals.

My main motivation was to see if moving into this century might improve my car over the old Bosch technology plus I'm getting a decent deal on the main component.

I will carry on reading and collecting parts but please do continue the discussion on my original post and I would also be interested in comments on the different combinations people have tried of wires coil and electronic triggers for the distributer to complement the MSD 6AL.

Cheers
Bill

So, "Dave" let's not beat around the bush here.

The OP shows up and asks for help. Instead of providing help, you decide to get into a sideshow debate on the merits of switching from a Bosch CDI. Something that has been done... what... maybe hundreds or thousands of times given that Wayne lists this as a project in his own book? Why do you want to turn this into a crazy A/C thread where instead of actually addressing the OP's questions, you want to take it off into the hinterlands? Do you perhaps have some motive behind your actions? Why are you so passionate about the Bosch CDI? Do you have some involvement with them? It would only be fair to disclose such personal bias.

I know my car. I know how it drove before and after switching CDIs. You do not. I'm pretty sure I know enough to know the difference. At no time did I make any claims as to the scientific accuracy of my statements. I'm sitting on a beach waiting on the rain to stop right now so I can enjoy my vacation, so you'll have to excuse me for not having my lab notebook handy. (That last part was sarcasm in case you couldn't tell. Had I known I was going to be called into court I would've taken better care in my documentation.) The mixture went more lean using my meter. There was a noticeable difference in the exhaust smell in that it smelled less rich than before. I did have fouled plugs at the time I switched CDIs. I just pulled the new ones after putting maybe 200 miles on them and they looked great. I even had a witness to that from a fellow Pelican, Your Honor.

I don't know what I did to warrant the attack (other than apparently having the audacity to use something other than a Bosch CDI -- who knew?). And I really don't understand why this seems to be such a hot button topic. I've appreciated the vast majority of your posts and knowledge you've shared... up until now.

So now that we have that out of the way, why don't you try to do something constructive to help the OP?

Steve's reply
 

Steve - Do you think there is an advantage to the MSD over a properly working stock Bosch box? If so, do you think it is the multiple sparks (which are at rel. low rpms only)?

Randy:

There are clear differences in performance and drivabilty with MSD's. The advantages are huge with any engine that tends to run richer or leaner in certain RPM ranges where the OEM Bosch systems cannot cleanly fire off an imperfect A/F.

These were a godsend with cars like our 3.5 litre slide-valve RSR's, 935's and even the old 917/10 that we used to run for a client. The Bosch igntions could never prevent plug fouling with any idling and adding a pair of MSD's made them run like CIS engines,...

One thing too,......MSD's permit the wide plug gaps that not only improve idle qualities, but make more HP on the dyno.

Ya can't do that with any Porsche OEM ignitions and the dyno doesn't lie,...

Its the combination of low speed multi-sparking that fires rich mixtures efficiently and the much higher voltage & current that does the job.
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
503.244.0990

For Performance Parts and Upgrades, Machine Shop Services, & Technical Information, visit us on the Internet at:
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Steve Weiner-Rennsport Systems is offline

Pulled this from the rennsport forum,
chris

Bill,

Who knew, right? :D

I only switched to the MSD because my PermaTune died. At 20% of the cost of sourcing a reman Bosch it seemed like the way to go. All I can tell you is what my experience has been so far. I was neither the first nor the last.

There is debate on coils. Actually it's not so much the coil. The MSD Blaster II is a drop-in replacement for the original coil. It is one of the few coils that can be mounted upside down like the factory Bosch coils. Some people suggest using an E-type transformer coil and that is probably a good option too, but you may find it takes some more work to mount it. If you have a rear decklid A/C condenser then fitment is something to think about as some of the E-type coils are taller. So if you went that route you might have to look at relocating it someplace like the left side of the engine bay and lengthening the coil wire.

I think debating Magnecor vs Clewett is probably splitting hairs.

Good luck!

Chrismorse,
Thanks for the quote from Steve Weiner,

I was looking for reasons they were considered to be better to help me justify the effort and money to upgrade.

Now if I can only decide on the peripherals.

Cheers
Bill

I believe "Dave" is in the business of repairing Bosch CDI units.

I have had an excellent experience with Daytona-Sensors CD-1 CDI and coil. You, tirwin, and many others have seen the benefit of MSD.

Our "BUTT DYNOS" tell us there is an improvement as do other indicators. I have my Bosch CDI polished up and on my shelf. I did not butcher my 73 intalling the "strange aftermarket CDI". I am enjoying the extra performance.

What is wrong with that? Are we not supposed to enjoy, love, and care for our 911s?

I put the standard red Clewitt wires in. Love them. However, lots of folks use the Magnecors.

I am pretty sure each make chubbier wires. I don't know if that allows you to open the plugs further.

First
 

Recommend just generally staying away from MSD boxes and such unless you know what you are doing on any type of twin plug setup! I am sure someone will want to start a thread now about that, now that I mentioned this caution for Twin plug engine builders!

Now that I am done saying that above, with an MSD you should be indexing your plugs and side gapping them along with lengthening the gap in my opinion! By side gapping them and widening the gap, you are uncovering more spark to ignite the fuel air mixture. When doing stuff like this, make sure you are precise on cutting back and widening the tip! In indexing the plugs initially, the Heads are off because I in my Porsche engine builds concentrate on plug penetration depth into the combustion chamber also! But if heads are on, just draw a black marker line in relationship to the spark plug tip to index! Also I have taken many a wire set and re-terminated the wire ends myself giving better quality than a bunch of hacks in a factory doing such for 8 hour shifts!

PS when all done, I always recommend putting the car with engine lid open into a very dark garage, and fire it up to check your work on your wiring and such! If you see too many fireworks, then you may want to rethink your skill level!

Oh, boy.

Funny!
 

I gave my reply to the topic, all that I felt should be added! :D;)

PS maybe on topics, we should create a checklist, to make sure everyone has weighed in! I still see a lot of guys missing, and others will probably want to say more than they have said already!:rolleyes:

OH BOY, sidegapping, indexing, grind the eletrode....."220....221..whatever it takes"

I thought
 

I was done:D:D:D

Not grind the electrode, but to shape it! To control the spark jump is a beautiful thing! :);) To harness fire!!!!!

Done! :D

Whatever it takes..............................

Hi All,

The MSD6AL model I have been offered is a 6420 plus a MSD Blaster III coil. Just want to check these are correct for my car? Was this superseded by the 6425 and is there a lot of difference?

Cheers

Bill

I quickly looked at the MSD website and couldn't find the reference I was looking for but I remember that the Blaster II (not the III you have been offered) coil is the only one MSD makes that can be used upside down. I'll keep looking to see if I can find the reference.

Not sure on the differences in 6AL versions but I think one is just a newer version of the same thing.

Edit: Here is the reference in the coil documentation.

"It is recommended to mount the PN 8202 and 8223 coils in an upright position. The High Vibration Coil, PN 8222, can be mounted in any position due to its epoxy potting compound."

http://www.msdignition.com/WorkArea/DownloadAsset.aspx?id=15032386218

Hi Tirwin,
I am now realising there are different combinations of Ignition controllers and coils requiring different physical installation requirements. I was sent a PM from a Pelican about his streetfire install with hidden coil which woke me up to the point that it is possible to have a neat and stealthy install. Naively, I had thought the controller would fit where the Bosch CDI does now and the coil would be in the tradionalmposition. I am now thinking about the size of the 6AL and the fact the coil I have been offered cannot be mounted upside down like the bosch. I need to research installs others have done (hopefully with pics)to see what the different packaging options are. I realise there is more to consider with this upgrade than I had thought. Will start using the search function but any pics of installs and part numbers would be appreciated.

Cheers
Bill

Bill,

Exactly. I used the MSD StreetFire and it can be installed where the Bosch goes but it does not use the existing mounting holes. All you need to do is screw it through the sheet metal and the hardware is included for that. It is smaller than the 6AL. I've seen people fit the 6AL in the same space though.

The 6ALs require a little more work because they require a vibration isolating mount whereas the StreetFire does not.

The orientation of the boxes is something to think about when choosing a mounting location. I installed mine with the wiring towards the nose of the car -- this is the orientation where the lettering can be read normally. I talked to MSD support and I seem to remember that the preferred mounting is horizontal or with the wiring pointed to the ground. This is not ideal if you want to change the settings in a 911 but it is what they recommended.

Some people have kept the Bosch CDI to have an authentic "look" and hidden the MSD someplace like under a seat.

I used the Blaster II High Vibration coil. Some people have pointed out that the E-type transformer coils are best for this application and that is probably true. You just have to consider the specific model and where it can be mounted. If you choose one that has to be vertically mounted then you could look at mounting it on the side of the engine bay next to the fuse box. You would need a longer coil wire in that case. You might want to look at picking the CDI/coil first and figuring out where you want to mount them and then see if you can get a custom made plug wire or do them yourself. I think Clewett would do something like that for you. Might be worth checking into.

If everything is working fine, it might be best to leave well enough alone. On the other hand if you want to do a hidden install then it's probably better to do it on your own terms instead of throwing something together because it failed and you want to get back on the road (which is what I did).

Now that my setup works I might go back and put the E-type coil in and keep the Blaster II coil in my "go bag" as a spare. But I have a bunch of other work to do in the meantime before I get back to that.

Analog vs digital. You need RPM (limiter) pills to stick in the side of the 6420. Mine is a 6420. May need a tach adapter. I bought one but not convinced I need it.

6420

http://www.summitracing.com/parts/msd-6420/overview/

6425

http://www.summitracing.com/parts/msd-6425