Statistically LOST Power with MSD!

[s13satch]

For my senior thesis in college I tested a 6A MSD ignition on my '91 240SX with the KA24DE. The car has 112,000 miles and 150 psi. compression on each cylinder. The prior mods to the car are as follows:

Accel Thundersport WiresNGK Iridium PlugsMSD Blaster SS CoilASP Crank PulleyHotshot HeaderInjen Intake w. CAE2.25" Exhaust w. Magnaflow MufflerRedline Transmission and Differential Oils

My test consisted of back-to-back dyno pulls (approx. 10 min apart) on a Mustang Chassis dyno. I did a 4th gear pull from 40 mph to 100 mph. Speed was used b/c rpm could not be obtain by the dyno with the MSD installed. As a reference the rpm was roughly 2500 to 6200.

Data points where collected at every .1 sec for the 20 sec the test took. These points where analyzed using a t-test at the .01 significance level (99% accurate). The results where as follows with the MSD ignition installed:

HP / -1.979 Torque / -3.2776

Yes, those are negative numbers. When looking at the entire rpm range these are the average changes that the MSD makes. However, for the first 3.5 sec of the test the car was under 3000 rpm. This is the rpm limit that the MSD switches from multiple spark to single prolonged spark. During this time my HP was mostly 1-2 higher while my torque was mostly 2-4 higher. It was during the prolonged spark period that the numbers fell off with the MSD. Certain points were 5 hp less and 10 lb/ft less.

Another student in my class installed a MSD on his '79 Camaro with a built 383ci that had not cats. His test was a 50/15 emissions test. Again, the MSD failed to deliver as the HC and CO was statistically (big time) worse with the MSD.

As I know all of you where wondering, here are my peak power numbers (which both occurred without the MSD):

100.47 whp 159.97 w lb/ft

The torque was good, but the hp sucked. Not sure what happened there. I guess the dyno could be having conversion problems since all of the cars tested have really low HP compared to torque. As an example, a '03 supercharged Mustang Cobra with an intake, throttle body, and exhaust (may have had other stuff that I did not see) only put down 303 whp. Yet the torque was around 450 and it ran an 11.69 on the dyno'd 1/4 mile test.
Modified by s13satch at 12:02 PM 9/23/2005

[s13satch]

I can't believe no one cares that I have real proof that an MSD is bad for the NA KA24DE motor!

It's not to often you find a well known aftermarket company with a product that causes a car to loose power. However, I am doing some inqury and research about the need to tune the ecu to get a benefit from the MSD. But still, MSD does not advertise that this needs to be done.

[InsanityInc]

Of course MSDs are bad for your engine compared to the stock coil. MSD coils are an ARCHAIC design that hasn't been used for years and years. I mean, the last car I saw with the tube type coil was like an 82 suzuki samurai. Manufacturers didn't switch to different designs for fun.

[s13satch]

The coil was not what I was testing. I had the Blaster SS coil hooked up for both runs. I simply by passed the MSD module on the second run (installed the system prior so that i could dyno back-to-back).

[InsanityInc]

Can't you configure the module differently? I thought that was the point of the module.

[s13satch]

The 6A module has no adjustments. That's why I'm wondering if the ECU itself needs to be reprogramed. Or, it is possible that the car could adjust itself after several drive cycles have been completed. Because I'm not sure about that part, I may re-dyno next week. I only had the module hooked up for 6 miles prior to the run.

[InsanityInc]

I doubt the ECU would have to adjust for anything. I can't think of anything it could adjust that would make any kind of difference. The prolonged spark thing just seems like a bad idea, since that means your peak voltage would have to go down, meaing that the air gap might not ionize properly. I guess you could try reducing the gap on your plugs to see what happens.
Modified by InsanityInc at 5:40 PM 9/23/2005

[AZhitman]

Whoa, there.

Did you re-gap your plugs? Did you advance your base timing? Both of those are possible with the MSD and should increase power.

Remember, a more powerful spark means you have the CAPACITY to make more power. If the ECU has not yet recognized this, and you haven't regapped the plugs and advanced the timing, you're not gaining anything.

Might not get a real good grade on that thesis if your instructor knows anything about cars.

[s13satch]

My professor has an A.A.S degree in Ford ASSET, a M.S. in Vocational Education, a doctorate in Workforce Education, A.S.E certification in advanced engine performance and compressed natural gas, A.S.E. master certification, and has worked as a tech and owned a repair facility.

He seems as stumped by my numbers (as well as the student with the Camaro’s numbers ) as I am. After some brief discussion between him, the other student, and myself we concluded that it is likely that MSD's claims in reducing emissions and increasing power are a stretch of the truth (because I did gained a small amount at low rpm, and the NOx of the Camaro dropped because it appears to be running extremely rich with the MSD.) The tuning of the Camaro's carb and my ECU issues are being looked into. However, the spark plug gap was not something we had considered. I have contacted MSD and JWT about the ECU issue. The other student is going to adjust his carb while hooked to a 4 gas analyzer to see if there is a sweet spot for the emissions.

[s13satch]

Of course. Spark plug gap setting on page 3 of the instruction manual. D'oh.

[s13satch]

As expected, JWT responded to my email, but MSD did not.

Anyway, after doing some research on how much extra gap spark plugs utilizing a performance ignition can safely run I decided to re-gap my plugs to .050". This is .007" beyond the largest factory spec. This is the bottom of the range that MSD recommends, but I did not want to push the ignition and have to re-gap. I am using NGK Iridium IX plugs which come pre-gap b/c they are very fragile. I did not want to risk having to re-gap them again since they cost $12 each.

With the gap opened .007" I gained a small amount of power. I gained on average through the test range .6493 HP and 1.6427 lb/ft.

In the end the MSD did provide more power. However, not nearly enough to justify the $260 of the system. Hopefully I will benefit more from the system once I rebuild my motor w. SOHC piston to raise the compression to 11.1:1.