Olcha911

No improvement. It ran well before. Theoretically, things like ignition parts on a DME car only improve when things were wrong in the first place, etc. I did all the ignition items, especially the wires (and a few other items that are hard to reach like the fuel regulator) when I had the engine on the stand in my garage for its rebuild.

-Keith

Alex Sol

yes i agree that it would show an improvement over faulty, dead or dying wires, rotors, caps. A new set would just work as it should.

Fuel regulator: would this be the problem that half my engine has no fuel??? cylinders 1,2,3 are not getting fuel, car runs on 4,5,6 but rough, mis fires, lacking in full power, feels like it's on limp mode...

Will do some research here...

does it require an engine drop?

ja78911sc

Interesting article from a 944 tuner which compares the OE black/silver coil to the MSD blaster coil.

http://www.roguetuning.com/944951_ignition

Alex Sol

wow, good read.... so the result?

at lower rpms the bosch makes more joules than the msd blaster 2 but...

at higher rpms the msd blaster coil makes almost 50% more pop than the stock Bosch unit

Lorenfb

"at higher rpms the msd blaster coil makes almost 50% more pop than the stock Bosch unit"

Not really! If one reads the specs below, the 8826 (4.2mh) and original
Bosch (3.6mh) are basically equivalent and as such produce the same
energy. It's only when you use the MSD data (8mh) do the results
change AND with the 8mh spec provided by MSD the high RPMs are
a problem just like with the Bosch blue coil. Read the post again, in all
assumptions, the 8mh spec is worst than either the Bosch or MSD at about 4mh.

Bosch TCI (black/silver) - R(primary) = .70 ohms, R(secondary) = 6200 ohms, N = 90,
L(primary) = 3.6 mH, L(secondary) = 30 H, ~ 60 mjoules @ 6K RPM - 6 cylinders TCI
Bosch Blue Coil - R(primary) = 3.5 ohms, R(secondary) = 8800 ohms, N = 65,
L(primary) = 12 mH, L(secondary) = 50 H, ~ 30 mjoules @ 6K RPM - 6 cylinders TCI
Bosch CDI (small black) - R(primary) = .30 ohms, R(secondary) = 700 ohms, N = 78,
L(primary) = .20 mH, L(secondary) = 1.2 H
Bosch CDI (small silver) - R(primary) = .70 ohms, R(secondary) = 720 ohms, N = 63,
L(primary) = .40 mH, L(secondary) = 1.6 H
Bosch TCI (Porsche 993) - R(primary) = .70 ohms, R(secondary) = 8200 ohms, N = 90,
L(primary) = 3.1 mH, L(secondary) = 25.3 H
MSD Blaster (8222) - R(primary) = 1.1 ohms, R(secondary) = 4700 ohms, N = 95,
L(primary) = 4.2 mH, L(secondary) = 38 H
Perma-Tune - R(primary) = .90 ohms, R(secondary) = 10000 ohms, N = 125,
L(primary) = 4.7 mH, L(secondary) = 74 H

"The Bosch Silvers at 70% efficiency is 106 mj"

It's not 70% efficiency. It relates to the time to store the energy (dwell time)
for the next cylinder's spark.

"Interesting article from a 944 tuner which compares the OE black/silver coil to the MSD blaster coil.
http://www.roguetuning.com/944951_ignition"

A joke, typical hyperbole to sell what is NOT needed! Like Porsche/Bosch didn't know how to design an ignition
system, right? The presented equations don't lie like marketing 'snake oil'.

Alex Sol

oh, but they sound very scientific. thanks for clearing up the claims. and the efficiency vs time

TurboTommy

Lorenfb;
Well, you're presenting equations based on specs from the manufacturer; fair enough
But roguetuning has the equipment and actually tested the coils and came up with the findings.
The mH spec that's in MSD's literature is deceiving; so says a MSD tech when I called (because I was curious myself)

Bob Rouleau

Loren - you are always quick to criticize tuner improvements. The Bosch coils were built to a price spec. If you have hard evidence that Rogue's tests are wrong, then post them else you are giving an opinion which is at best unfounded. The article you linked to shows "typical values" as opposed to what Rogue actually tested. It seems that you are arguing against hard evidence with nothing but conjecture and scorn.

refresh951

To sell what is NOT needed? Marketing "snake oil"? Rogue does not sell any MSD products. His sharing of this coil info was purely informational and for end user benefit.

Ken D

nm

JasonAndreas

His bedside manner might be lacking but his technical critiques are almost never wrong! In this case, there is no benefit to 964 owners and depending on the specific MSD coil that is being pushed as an upgrade, you are actually potentially creating a problem where none exists without additional changes!


Actually he shared the coil info to point out the benefit of using his tuner software which has the functionality to adjust the dwell mappings to prevent you from shortening the life of your other ignition components when using MSD coils... Definitely a worthwhile feature that most tuners/shops are completely oblivious to and something he should be commended for but don't confuse this for altruism!

refresh951

He did it because he could and several of us were looking for a solution. I was the first (besides Rogue) to run an HVC II coil. I know him quite well the guy is just a true enthusiast. More than anything he was doing a favor for some of us on the 944 Turbo board.

Rogue_Ant

He is absolutely wrong. Multiple logically fallacies, hasty generalization, genetic, ad hominem, etc. I've tried to have a well-reasoned debate with Loren in the past. I am not going to waste my time with that anymore. However, I will not stand-by for his blatant attacking me or my business - especially considering he then is promoting his own business out the back door.

To explicitly go over his failure:

First, he is taking multiple liberties with his equations, over-simplifying.
For example, ignition current is the single most important part of the energy equation. Loren uses this equation for finding current:

I = time * Voltage / Inductance

This equation omits several very important things. First, he is omitting all resistance in the system (coil, wiring, etc). He is also ignoring the ignition driver (BJT) VCE drop, which reduces the actual voltage across the coil.
If I use his equation to derive current, with the values I used on my test-bench setup (Voltage = 13.8V, Inductance = 5.85mH, time = 6.46mS):

I = 6.46mS * 13.8V / 5.85mH

I = 15.24 amps


On my test-bench, I have the entire 944 ignition circuit setup, and the equipment to watch coil current in real-time. The current value I measured is plainly visible on my website; the current reached 9.0 amps.
So, for the single most important part of the equation, Loren is off by roughly 70%. A 70% error is the same as traveling 127mph in a 75mph zone...
An error of that size, and I shouldn't need to go on with my point. But I will, because it is important to see how much of an effect this error has on the end-result.

If we continue Loren's hasty calculations, and derive final coil energy, using the standard coil energy equation: 1/2 * Inductance * Current^2

Energy = 1/2 * 5.85mH * 15.24^2
Energy = 679.35 mJ

Holy cow! Nearly 680 mJ of energy! That is nearly three-times what my actual measurement values concluded. Loren's contradiction becomes even more obvious, as he mentioned that 30 mJ is what is necessary for ignition (another over-simplification). So, why would Bosch make a coil with twenty-times the necessary coil energy?
Obviously they did not, nor does that coil have 680mJ of energy (the coil would saturate before ever reaching 15 amps). This is what happens if your ignition current value is not accurate. Because of the current^2 (current squared) part of the calculation, a small change in current results in a large change in final energy. This is why I not only modeled the circuit properly, but also setup the test-bench, because as a pedantic engineer I am never really happy until I see the real-world results.



Absolutely disagree. While the benefit might not be a large power increase, there is a benefit from improving the ignition system, be it combustion reliability, emissions, or power.

Agreed that using the wrong coil, without the appropriate changes to the DME/software can cause issue. This is exactly why I released the ignition coil info. Perhaps not as prevalent in the 964-world, but with the 944/951 many are running non-stock coils and ignitions. The 944 Turbo ignition must overcome much higher cylinder pressures than its non-turbo equivalent, including the non-turbo 964. Rather than see more and more DMEs possibly being harmed from use of non-stock coils, I wanted to show the differences.

Regarding Altruism, I definitely do not claim to be George Price... But I have tested many coils for people not running my software, and others running full stand-alone who will never run my software. Furthermore, configuring the software for different coils generally is more work for me (especially since I support previous customers wanting to change coils), and I doubt the bit of coil info I have put up has steered much business my way.
No, I try to be as forthcoming with information about tuning, the software, and results as possible. This has been my mantra since starting Rogue Tuning, a fact that I hope is fairly clear from my postings on Rennlist, and my website.

FeralComprehension

Thanks for stopping by, Rogue Ant. What's your take- is the MSD a direct drop-in for the 964 or are we putting other components at risk?

Rogue_Ant

When I get some time, I'll setup my test-bench for testing the 964 ignition module and share what I find.

Until then, if you want to run the MSD drop-in coil, I suggest running the MSD ballast resistor (MSD part number 8214), to help limit the maximum current through the coil and ignition module.