glhs422

iTrader: (4)

http://www.lsxtv.com/news/shocking-p...s-cts-v-coupe/

I've always heard that there are no gains to be had from swapping to after market (MSD) coil packs.

Does anyone have experience with these?

Excerpt:

"When we saw the dyno graphs after the pull we couldn’t believe how much of a gain these SOS coils gave our CTS-V – a gain of 26.4 horsepower and 24.1 pound-feet at the wheels! That brings the CTS-V’s power output up to 539 horsepower and 545.8 pound-feet to the ground!"

thunderstruck507

iTrader: (18)

Forced induction changes things. Both in how more spark can benefit the engine and what dyno numbers are obtained in general (think heat soak) if the tests are not done in a very scientific manner.

MSD brand coils are very expensive and have (or at least used to have) a very high failure rate. Couple that with the fact you are not likely to gain anything on a naturally aspirated car and you can see why they are not recommended.

The truck coils with the heat sinks (see sticky at the top of this section) are higher output than stock ls1 coils.

MikeWS6

Sounds on par with K&N hp claims lmao

.boB

iTrader: (1)

A coil is like an alternator. It's only going to produce as much power as it needs to get the job done. If a stock coil produces a nice bright spark across the gap, then adding an aftermarket or higher output coil will do nothing.

OTOH, as said above, some conditions will make it more difficult to make a good spark - like higher cylinder pressures and nitrous. In that case, a good aftermarket coil - or a truck coil - can gain power by burning more of the fuel.

The dyno doesn't lie, it's simply a piece of test equipment. But dyno operators can tell all kinds of lies if they want to.

ULTIMATEORANGESS

iTrader: (4)

JUST get some granatelli wires for another 20 hp lol.

IS SOS THE SAME AS msd?

2nd Gen Fl 'bird

iTrader: (13)

but-but-but you can do the test at the auto parts store! lmao

Paul Bell

iTrader: (9)

From the article:

"The first step of the installation is to disconnect the negative battery cable."

This negates the results of the test. When changing coils, there's no reason to disconnect the battery. After disconnecting the battery, the PCM needs to start a new learn procedure-which can take a while, and miles driven.

What they should've done was to have the second set of coils on brackets ready to go and only one bolt through the bracket to the valve cover. This would've made the swap a five minute job.

Assuming a stout spark to begin with, increases from spark energy result from the ability to have more dwell-and control it better. The heat-sinked GM truck coils have more dwell ability but to take advantage of better dwell, it needs to be programmed into the PCM.

Paul Huizenga

Think what you just said through for a minute...

We tested the CTS-V without shutting off power to the PCM to get our baseline.

We disconnected the battery, changed the coils, reconnected the battery, then ran the car again. Never unstrapped it from the dyno, never gave the PCM a chance to "relearn" anything. And we got the horsepower increase shown in the article.

If that's true, you're saying that erasing the PCM's short term memory actually improves performance? That's one hell of a speed tip - disconnect the battery every night so your car has more horsepower again in the morning...

Paul Bell

iTrader: (9)

Perhaps. The PCM is primarily designed to tune for best economy and emissions. During the learn process, it normally runs rich as it discovers the needed settings.

By disconnecting the battery and erasing the settings the first test was done which made the second test invalid. You completely changed how the PCM was tuned for the second test.

When you do a back to back dyno test to see if a component change results in a performance change, you cannot change anything other than that one component.

You surely must have realized something was wrong when you achieved a whopping 26 HP gain (which relates to about 30 crank HP).

Paul Bell

iTrader: (9)

Don't get me wrong Paul, I'd be the first in line to applaud you if these numbers were accurate. But until you show the numbers are on the money with a proper back to back dyno test result, I'll maintain my opinion that the results are inaccurate.

LS1-450

iTrader: (33)

Why even discuss this? NA, coil swaps only improve power if the previous coils were not up to the task. Forced induction power improvements could be caused by any number of variables. This is pretty much a repeat of what thunderstruck said, but, the whole topic is redundant to begin with. Heat sink truck coils have shown to provide the needed spark @ high RPM where the LS1 stock coils were shown to struggle. Beyond that, it's a pointless discussion; pretty much no more than an advertisement for an over priced product.

Paul Bell

iTrader: (9)

Here's some serious hyperbole: They say in their video interview from SEMA 2013 that as each coil is 7,000 volts more than stock, the entire ignition system has 56,000 more volts than stock.