RBlover69

iTrader: (2)

however peak hp wise, the 1/2 spacer and the mrev 2 on revups provide the most peak gains . Its under the curve that the 5/16 and mrev 2 that provided the best under the curve gains. In the peak over HP world for lets say a top end highway type individual, the 1/2 md spacer and the mrev2 still looks to be the king for the buck.

Ziggyrama

iTrader: (15)

When was your baseline done without the spacer?

norapat01

iTrader: (18)

About a week before I installed the spacer and I just did my oil change before the baseline dyno. At that time the weather was in the mid 70's, so it shouldn't make that much of a different. I didn't do the dyno right after the installation and I drove the car for about 2 weeks so that the ecu could adjusted to the change. But I was expecting to gain about 3-5hp and same for the torque since most people here gain about 7-10 in hp & torque.

Hydrazine

iTrader: (53)

The spacer always makes the gains every time, but there are several big variables that can affect the outcome of the dyno results if the pre and post testing is not done back to back. The ECU is the number one driver of variability.

And its not so much about the ECU learning the spacer, its about the ECU learning to go into what I call "lazy mode" where it retards spark timing.

There are three basic levels to the ECU performance map:

1) Performance mode
2) Lazy or Granny mode
and
3) Safe mode

Sometimes just normal everyday driving will cause it to go back and forth between performance and lazy mode.

Assuming there is nothing causing it to go into safe mode and it is already in Lazy mode, a ECU reset can put it back into performance mode.
Hence the optional nature of a ECU reset as described in the installation manual.

You could go back to the same dyno again next week and it could gain another 10HP for doing nothing but driving. The ECU learns driving habits but it's not always consistent in what it sees as driving habits. So ECU performance table settings can vary quite significantly from week to week.

Even day to day variability is possible. I've dynod my Z on the same dyno with everything being exactly the same... same mods, same tank of gas, same atmospheric temperatures, etc. And the next day it can lose or gain 10HP. And for apparently no reason. But its the ECU changing its setting on the fly.

Atmospheric temperature makes a very significant difference too.
All of these dyno pulls were done within an hour of total time. The only variable in the dyno plots below is air intake temperature.



The ECU adjusts spark timing based on air inlet temperature. The higher the air inlet temperature, the more it pulls back timing to prevent ping... but that reduces power.

The same can happen with a bad tank of gasoline. If the gasoline has a higher tendency for ping, the ECU will hear the ping through the knock sensors and pull back timing accordingly. And that can easily take out 10 HP.

So there are a lot of variable to be careful of when doing a critical comparison.

The best way to do it is back to back dyno comparisons. Same car, same day, same dyno, same atmospheric temperatures, same oil temperature, same coolant temperature, same tank of gasoline, same gasoline temperature, same tire pressure, same everything.... Its a lot to keep track of.

For development testing, I've practically made a science out of eliminating dyno variables. I even went as far as installing an FCON on my NA engine. While the FCON certainly helped, I still cant nail down the variables 100%.

Dyno variability can be controlled to an extent but it can never be fully eliminated.

Hydrazine

iTrader: (53)

Also note in the plot above.

That is a very good reason to be careful about the cold air intake you put on your car. There are many intakes out there that have no heat shield at all and the filter is just hanging inside the engine compartment behind the radiator.

If you put a ECU scanner on the car to see what your air intake temperatures are, you can see inlet temperatures as high 150'F... or higher with some of these intakes.

Some intakes have the potential to reduce power tremendously because they draw in so much hot air.

Just a FYI.

norapat01

iTrader: (18)

Thanks for you input. I know that many intakes out there are actually reducing hp and torque while the car is running because they sucking in hot air from the engine bay. So, I my intake is OEM with upgrade Blitz filter that way I could keep out the hot air while increasing air flow.

As far as the dyno goes, I think everything is almost the same except for the day. I use same tank of gas (shell V-Power), same mod, same dyno facility, and atmosphere temp (+5/-5). I believe even my engine temp is about the same because I would drive 15 min to the facility, pop up the hood and wait 30 min until I start the dyno.

I don't drive aggressive at all, so could this be the reason that put ECU into "lazy mode"? If I drives more aggressive, would the ECU goes into "Performace mode"?

Thanks for your input.

Hydrazine

iTrader: (53)

Yes and yes.

Or you could do a ECU reset and it would go back into performance mode instantly.

SponGer

iTrader: (1)

Good info. Thanks.

Miketsi

iTrader: (5)

It really seems like MD just spends ALOT of time researching. All of the products they release (somewhat small product line) have been proven to be great performing.

norapat01

iTrader: (18)

I see, I have no idea our ECU could do that. Sounds like I need to give MD another try - gonna order a new set of MD spacer tomorrow