Commard ECU!

[Kregar]

Commrad ECU*

So according to DSPORT's intake test article the reason we see such low gains from our after market parts is the tyrannical factory ECU. I know a tune is recommended after you begin bolt ons, but I guess the ECU sees it as "1+1=1". Which could explain the low gain numbers after doing exhaust and intake upgrades, which even without a tune should make bigger numbers. Feel free to share your thoughts on this or any other opinions.

Hugs and Kisses

[2forme]

There are two main parts to how the ecu reacts to an intake; flow (including charge temp) and readings.

The stock intake isn't very restrictive and the factory ecu is tuned to read the intake charge with a stock design. When you introduce a different intake, on the stock tune, you are now throwing off how much air the motor gets, as well as how much it reads. Because of the efficiency of the stock system, a lot of manufacturers will try to lean out the mixture to gain power.

My dyno testing has shown that you don't start seeing consistent gains on an aftermarket intake until around the 185-190whp+ range. The motor just doesn't breathe enough air to warrant the intake until that level of power. You will see people throwing up dynos showing their intake made x power and such and such, but a lot of times it's cherry picking, test environment (open hood) or AFR manipulation. I did all my comparisons after tuning the car on the dyno for a FLAT AFR. That negates any "lean power".

So to answer your question, the factory ECU itself isn't the limitation, the factory tune is.

[Kregar]

Originally Posted by 2forme

There are two main parts to how the ecu reacts to an intake; flow (including charge temp) and readings.

The stock intake isn't very restrictive and the factory ecu is tuned to read the intake charge with a stock design. When you introduce a different intake, on the stock tune, you are now throwing off how much air the motor gets, as well as how much it reads. Because of the efficiency of the stock system, a lot of manufacturers will try to lean out the mixture to gain power.

My dyno testing has shown that you don't start seeing consistent gains on an aftermarket intake until around the 185-190whp+ range. The motor just doesn't breathe enough air to warrant the intake until that level of power. You will see people throwing up dynos showing their intake made x power and such and such, but a lot of times it's cherry picking, test environment (open hood) or AFR manipulation. I did all my comparisons after tuning the car on the dyno for a FLAT AFR. That negates any "lean power".

So to answer your question, the factory ECU itself isn't the limitation, the factory tune is.

Yes, I guess I should have been more clear that the tune is very restrictive. I just assumed referring to the ECU the tune was included in that.

[feldy]

This is a repost.

[Kregar]

Originally Posted by feldy

This is a repost.

My Apologies

[2forme]

Originally Posted by Kregar

Yes, I guess I should have been more clear that the tune is very restrictive. I just assumed referring to the ECU the tune was included in that.

Yea, but you can use the stock ecu and have it tuned better for your mods.

[avg]

AFAIK this has always been the case with Subaru's ECU. It's a big no no to mod a wrx without tuning it, there are very few things you can do without a tune and you won't see much improvement until you get it tuned.