Hypertech Tunes & MAF sizes

[MattMPS3]

OK, so everyone is starting to play with their Hypertech tuners, while a lot of people are using SRIs & CAIs sourced from the US, there are some local products that arent in the generic listing, so what intake option should I use?, I hear you ask.

Well here is the answer, I emailed Chris from Hypertech earlier today and asked him to give me some of the sizes of the intakes that are on the device, Chris also went on to explain how the intake calculations are made by the ECU etc. Here is the email I received,

Hi Matt,

Thanks for the invitation to come on your forum. I will definitely jump on there in the next day or two and answer any questions.

Below is an explanation of how the air intake tunes work and why we have to do it. I have some of the intake diameters that are listed below. They are in inches, so someone smarter than me would need to convert them to metric.

To understand the need for precise re-tuning for an aftermarket cold air intake system, we must explain what occurs when that system is installed. The engine computer used in the Mazdaspeed MPS uses a Mass Air Flow (MAF) sensor to calculate the amount of air entering the engine. This determines the exact fuel, spark, cam timing, and boost the engine needs under all conditions. The MAF is precisely calibrated to the stock air intake system. The cold air intakes change the air velocity and the volume of air passing over the sensor due to the shape and size of the ducting around the Mass Air Flow sensor and even the type of air filter used. Re-tuning the engine calibration when an aftermarket cold air intake system is installed is absolutely necessary to correct the MAF readings and to take advantage of the increased airflow with the free flowing cold air intakes. With no changes to the tune to account for these errors the EGTs will get hotter, boost will go too high, and AFR will lean out.

In general, the installation of all of the kits Hypertech tested caused the engine to run leaner if the factory tuning was not adjusted. But all performed great once we recalibrated the tuning for the altered MAF sensor readings.

Air Intake Diameters:
Cobb 2.963" - 75.2602 mm
K&N 2.585" - 65.659 mm
Corksport 2.675" - 67.945 mm

Chris

I have also invited Chris to participate in forum discussion where possible, so if you have any questions or concerns, we will try and address them in due course, I will set the next post aside as a Q&A thread where I will merge selected questions and post the respective answers so that people arent pouring through 16 pages of forum to find a simple answer.

p.s anyone running the Cobb SRI, I highly recommend trying the HKS intake profile, Im seeing boost up around the 18 mark, and afr's sitting steadily around 12:1.

[MattMPS3]

Reserved for my Q & A

[steviekfc]

What RPM increase is everyone choosing? What exactly does it do? I have chosen +200

[FatCat]

I ask Tim from MZR and he said his diameter was 68mm so maybe go for cork tune although I'm gen 2

[mazda6mps]

what would be a suitable tune for a mps6, with a k&n panel filter replacement, with the resonator removed??
would assume flow would be higher, even though pipe diameter remains the same.

[rhcp_steve]

I'm getting more popping in the exhaust than before, especially shifting 1st to 2nd under moderate acceleration. Though I even had quite loud pop (not old kingswood backfire loud but definitely louder than normal overrun) just trundling along in 5th @ 60kph!

I don't imagine it's anything to worry about, and in fact I like it!

[AD07]

5th gear at 60k's is NOT GOOD for our cars......

[rhcp_steve]

5th gear at 60k's is NOT GOOD for our cars......

Are you being serious?? How is that bad for them? I've always cruised in 5th or even 6th gear in everyday grandma driving..

[Velocity Red]

Are you being serious?? How is that bad for them? I've always cruised in 5th or even 6th gear in everyday grandma driving..

I agree with what ADO7 said. At 60KPH in 5th gear my 6's engine is doing 1850 RPM. I am happy to use 5th gear when I am doing 70K and above but only if the car is NOT being asked to "pull". (Not sure what the gearing is on a MPS3.)

My own personal rule of thumb is not to allow the revs to fall below 2000 RPM in my MPS6. In fact I dont believe it should be below 2K in ANY 4 cylinder car. Slower revving six and eight cylinder cars are a different story.

Leon

[FatCat]

Any elaboration as to what damage it may cause?