FYI - I plan to call this company tomorrow and find out the charge for a dyno run, that way I'll know what the R2C and "Y" pipe actually make HP/TQ wise.

http://www.xactdyno.com/

Hopefully I'll have this done shortly.

 

Well, I'm anxiously awaiting the results. So I take it that everything with the install went well and sounds great. If you can, please post up a soundbite so we can hear it.

Thanks in advance

 

No I'm doing this first with a stock setup, then I'll do it again after the modifications No more "butt" dyno observations I want real before and after numbers.

 

I wasn't looking for the numbers yet, just the sound of the intake. Can you please provide that if you have the capability?

Thanks

 

I would love to see:

1) stock numbers
2) with intake, without exhaust
3) with exhaust, without intake
4) with intake and exhaust

Just want to see if the better "breathing" of the combined intake/exhaust has any effect on the numbers without having to do a custom tune to account for it.

 

Check other Nissan/Infiniti message boards. Apparently the stock computer will only allow about 12-15 hp gain from intake OR exhaust. The computer rebels if the power produced is out of range and you get less with both mods than with either single mod. Just sharing what seems to be a consensus of modders..personally I have no knowledge. This theory is fairly widespread as it has appeared on more than one message board. One may be on the 6th gen board..can't recall.

 

great idea, but are you gonna get accurate readings from a dyno because of the cvts?

 

"We put our project car on a dynamometer with the K&N Typhoon intake and the Magnaflow exhaust (the numbers mentioned earlier were achieved with each performance piece installed solo on the WRX). With both installed, horsepower was up by 11 over stock and torque was up 20 pound-feet—increases that are less than those produced by the modified intake alone. The extra airflow on both ends was apparently too much for the factory ECU to cope with, and it compensated by cutting power right when the turbo reached maximum boost. Either the intake or exhaust works fine alone, but ECU modifications are required to get them to work in tandem."

This was on a Subaru done by Car and Driver.

On the M45 board, the poster Ken in Az has this to say.

Our ECU's have what's called a "calculated load value" as far as what it looks for. What does that mean? It's a nifty way of saying how much load is on the engine, or in other words - how much torque is being developed. Nissan/Infiniti has built in parameters for their Calculated Load, if it see's that the engine is making too much power, then it will pull fuel and timing and or in extreme cases throw a code or even a MIL light.
How is Calculated Load measured? A combination of things really, but mainly in our situation in adding airflow through the engine, it'll be looking at the Mass Air Flow sensor, O2 sensors, Injector Duty Cycle.

The MAF tells the ecu how much air is entering the engine, thus based on this parameter the ecu then tells the Injectors how long to open and this is called duty cycle. Finally the ecu will also read the O2 sensor to determine if the mixture is in a rich or lean condition and adjust the injector duty cycle to increase or decrease the amount of fuel entering the engine. This operation is called "Closed Loop" where the ecu controls the engine completely to maintain the air fuel ratio.

In cars of yester-year this closed loop operation only happened at Idle, Cruise, and Part throttle conditions, but once the ECU recognized that the engine was under Wide Open Throttle, it would kick into "Open Loop" operation. Open Loop is a preset established parameters that were hard programmed into the ecu and regardless of the actual air fuel ratio, it would still use the exact parameters to control the engine. Often times we would add an intake and exhaust to these cars and they would run great because they were programmed on the safe limits of the Rich side of the air fuel mixture. Sometimes they would run poor because we had then taken them outside of the factory limits of the air fuel mixture to the lean side causing them to loose power because of poor air fuel mixtures.

Our car, the M45, and many newer automobile models are now actually running in Closed Loop Operation at "ALL" times. Meaning the engines should automatically adjust to the mods. These engines/ecu's actually do adjust pretty well to some mods, but get outside the realm of what the factory wanted they will pull power to limit and maintain the factory preset limits.

That's where Calculated Load Value comes into play. This is where the ecu see's too much airflow and will pull timing to control the torque output of the engine. If it see's that it has to increase the duty cycle too much to maintain the air fuel mixture, it will pull timing to maintain factory limits. If it see's that the Turbine speed in the trans is to high as compared to the output chaft of the transmission indicating the transmission is slipping, the ecu will pull timing to control the torque output to factory limits.

What are those limits? Well for our engine, the limits are safe until we close in on the 8%-10% over what the factory limits are. Any higher than that and you are making the ecu work overtime. From my undestanding the ecu can adjust up to 25% but not using optimum parameters and ultimately loosing power or not gaining any more.

And that example posted is using a car with a turbocharger - apples to oranges comparrison to our car, but has the same jist as to what is going on. Turbo ECU's can raise the boost pressures easily making more power. I - myself - made 50more hp by adjusting the base timing on my old Z from 15btdc to 20btdc - at the same boost level. so there is definitely more helping that subie in that example.

 

As I stated I want a baseline and then the difference when I add the mods. I will run in 3rd gear as that ratio is 1.11, typically you want 1.1 but 1.11 will suffice.

 

Anything new on the dyno run?

 

I'm waiting to see if the R2C Intake is going to be released...