modded factory intake

Interesting question...

First of all, my butt dyno may need recalibration Honestly, its the worst way to test any mod. So the truth is, what "feels" like a torque loss down low may not be, and what "feels" faster may be slower.

That said, there are some basic theories about air flow that can be applied here. The least amount of restriction at the highest velocity will net greater air flow. But how much AIR IN is needed without changing AIR OUT or fuel. The extra air in needs more fuel to produce more power in the cylinders, otherwise you're just creating a lean condition and potentially hurting performance. And an extreme lean condition under certain loads could blow up a motor. Lean is bad!! I have no supporting mods to the fuel or exhaust system, and have no idea how much additional fuel the Toyota ECU can add into the system, if any. Most ECU's allow for a small range of fuel control, 10% plus or minus lets say, and so if you add a little more air in, the ecu adjusts the fuel trim to compensate.

I'll finish this later...gotta run Good question vstrom!!!!

 

^^hehe

 

ok I'm back...

Tooter's dyno results showed significant gains across the powerband in both torque and horsepower. However, those gains were the results of much more than just an Injen intake... he also had an LCE header, no power steering, no A/C and lighter tire/wheel combo (which makes a big difference on a Dynojet). Then more recently he added his tooter intake manifold spacer and made even more power. Bottom line, unless he dyno'd the intake alone we can't compare anything.

Also, interestingly, on Injen's website they have a dyno chart (2.4L only - no chart for 2.7) of their intake against stock , and show NO gains below 3,000 rpms and significant torque LOSSES between 2,000 and 2,700 rpms.

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Injen Intake Dyno Chart 2.4L




So I can't say what's really going on with our 2.7s, but I'm going to guess the results would be similar. I would bet most factory intakes produce more torque below 3k rpms based on their design. The smaller factory intake tube along with certain necked down sections help increase velocity at the lower rpms, but become restrictions as the rpms climb and the cylinders need more air.

I drive the snot out of my 2.7....WOT most of the time and take it all the way up the rpm range often. I actually thought my 3" tube performed better than the 2.75" up high - and that seems logical. I'm still working on my design and playing with ideas and options. Like I mentioned in an earlier post............ "I'm still not happy".

Maybe tooter will shed some more light on this. He has lots of design and testing so his comments will be valuable.

Greg

 

**Another interesting thing**

Look at how LEAN both intakes are below 3,000 rpms... "15" WTF ??? That's scary lean at WOT. It doesn't even get into 13's until 3,250 rpm! I don't get this at all...a perfect burn on reg. pump gas is stoich, 14.7 parts air to 1 part fuel. But that's supposed to be ONLY for idle and part throttle conditions.... not WOT!!!!! Only reason I could think of for leaning out the A/F ratio to this level would be just another BS way to lower emissions and up gas mileage ratings. Same reason why they switched from 5w30 to 0w20!!

We need more fuel!!!!!!!!!!!!!!!!!!!
If I pull my plugs and they look lean

 

At WOT and certain rpms, I'm getting a vibration/rattle in the fender since the install of the K&N filter and velocity stack.... need to make some changes

 

I've done alot of research on MAFs....

The sensor must be calibrated to the size of the intake tube.. so size DOES matter! How close it sits to the TB and sound resonance also affect its accuracy.
What a stupid little sensor. Why not just stick with Manifold Absolute Pressure?? worked for decades!

 

^^^Pulled only one plug and it looks ok... but NO WAY I'm running them for 100k+ miles!!!!!!



Factory built velocity stack for the MAF inlet!! nice!







And a sneak peak at my new intake setup... still in progress

From right to left in pic (top of air box to TB):
3.2" box outlet / rubber coupler expanded on one end / 3" AL tube / reducing couple / 2.75" Al Tube / silicone 45* elbow attached to TB

Still working but getting there

 

^^ I'm happy.. it feels good and runs smooth. I had other plans but decided it is worthless unless I upgrade the MAF sensor and tubing size, and upgrade other stuff... header, exhaust, fuel.

Plus my wife got mad at me for having "my entire engine" in the laundry room

 

You're exactly right, Greg.
I believe the Injen intake contributed the least, and that the LCE header added the most. I had good total low end torque gains, but only as the result of a bunch of simple mods all added together. I believe that intake and exhaust mods help each other and help performance more together than each does separately.

It's still too early on the gas mileage results from adding the stock diameter air horn to the Injen...



...but they're quite promising. Last two fillups were 24.9 mpg and 25.8 mpg with regular 87 octane winter blend gasoline.

That's interesting information. Most people just look at the top of the chart and go "Oh wow look at the gains!" I'm exactly the opposite in that I rarely run my engine over 3,000 rpm. So I'm only interested in low end perfromance between 1,000 rpm and 3,000 rpm.

Greg

 

sweet, keep us posted