Cold Air Intakes?

Well that just about settles that. LCE > DT

 

Yeah, it's pretty decent evidence of the old school theory that a long tubes make more low end torque than short tubes. And that's the value of recorded dyno runs. It just saved us from needing to do more.

Greg

 

true... I still foresee a dyno day in the future though.

 

I'll be doing another dyno sometime next week to test a two inch thick intake manifold spacer that I developed for the Toyota Yaris 1NZ FE 1.5 engine. This is the prototype. I just installed it a couple of days ago so the car needs to be driven for a while for the ECU to relearn the new operating parameters.








With the engine cover on, you can't even tell it's there.





Greg

 

Ya, I moved the decimal when I was doing the mental math. I wasn't being all that mental And the 10% isn't going after any 1 specific person, just kind of a gathering ball park number from over the years.

Back to back runs on the same car can make pretty significant changes in output with no hardware changes. Figuring the 1996 2.7 was rated at 150hp, not sure but I'm assuming that's engine only and not through the drivetrain. Take 85% of that to account for normal losses and you *should* be seeing numbers around 127hp bone stock and probably a bit lower with an auto. Elevation etc changes things.

After that I always say to look at the output for where you drive most often. Just cruising around yesterday I see I spend most of my time around 2500rpm. Looking at Tooter's dyno post, that puts the truck right around 56hp stock, 62hp modified. So about 10%. That's intentionally ignoring the peak sense the engine only sees that for a second or so before I shift if I'm on it hard but doesn't come close to it if I'm just cruising.

For me personally, adding 5hp to a 5hp motor makes a huge difference. Adding 5hp to a 150hp, not so much. But I still throw money at things without an expectation of noticeable improvements. My toys, I do with them what I will

Kind of a long way of saying to always look at the whole, not just the pretty part.

However, lowering the rpm for max torque even at identical numbers... for any vehicle that's a good improvement. For off road, it's a big plus.

 

Correct. Toyota publishes horsepower and torque at the engine's output shaft and not at the wheels. I'm sure this is because it looks better on paper.


The 2TR FE 2.7 specs out at:


159 hp @ 5,200 rpm

180 ftlb @3,800 rpm

Just as an aside, those Toyota specs highlight another point. Notice that the DT header actually raised the torque peak above the stock peak by 200 rpm to 4,000 rpm. This is further evidence that short tube headers enhance top end performance. While the LCE long tube header lowered the torque peak 650 rpms below stock. (longer intake manifold runners further lowered the torque peak another 250 rpms below stock.)


So as far as I know just from my own experience, lengthening the tubes on either side of the head will both increase torque, and make the engine reach it's torque peak sooner.

That's true on paper. So far the real world dyno consensus is closer to around 120hp (119-121) for bone stock which is pretty close to the theoretical value.

Every mod I did on my engine was only to enhance low end torque and not horsepower. So taking a look at the dyno charts' torque values at 2,500 rpm puts things into their proper context.


Bone Stock 2.7:


114 ftlbs @ 2,500


My 2.7:


140 ftlbs @ 2,500

That's a difference of 26 ftlbs at 2,500 rpms which is an increase of 23% more torque over the stock engine.

When you look at a dyno chart, torque is almost always the dominant force at low rpms while horsepower is usually weaker. At 5,250 rpms, the two values always cross each other because of the mathematics of how they are each derived. And then horsepower dominates in the higher rpms at the top end while the torque drops off.

You have no idea how useful the increased torque is when you're crawling at low rpms in first gear. It's like driving a freaking tractor.


Greg

 

Tooter, you better start making more spacers!

 

I need to dyno test the tooter I.V first.




Greg

 

Check your PM's, Mark.
They're in the works.




Greg

 

ok ok

 

My samurai was riding 31's, geared for 35's in the diffs, and then 5:1 tcase. In low i could start from a dead stop uphill in 4th gear without touching the throttle. I loved that thing off road, crawling makes a world of difference. On road... The engine was so tired it would top around 55mph, if i had several miles of flat ground to get there





And im actually still on trail in the stream pic before it riles folks. My buddy with the camera is on dry ground, trail crosses over and starts back on dry ground around the bend.

 

That's the magic of gearing. The power of mechanical advantage is amazing. In contrast, I wanted to make my work truck pull really good at very low rpms even with high 3:31 road gears, where even at 60 mph on the freeway, the engine is just loping along at only 2,000 rpms.




Greg

 

Since this is intake thread I'll throw it back on topic............K&N intake tube, Volant box with homemade clear lid & aFe dry flow filter. Had the scoop but didn't like the dirt and moisture that had straight path to filter box and it made no difference in performance, so I sold it. Just has the fender air into box. And as countless others have mentioned, this is aesthetic underhood appearance item and a sound maker. MPGwise and HPwise, it is simply placebo.

 

That's a clean neat setup. The black intake looks good along with with the black valve cover.
I'm also pretty sure my intake doesn't make any power. I just think the sound is really neato.

 

Ingen says they get a bit of an increase in both Hp and Tq.
http://www.injen.ca/contents/en-us/p939.html


Not to get too far off topic.. but Tooter have you done any mileage keeping before and after you installed your intake? Having a 'warm' air intake you should get abit better mileage but abit less power so I'm curious if you have any conclusive data..

 

Unfortunately no, because I put the intake and the header on when I got the truck.

The current average gas mileage for the last thousand miles is 23.5 mpg. Most of that is on Winter blend gas. This is not too bad considering the driving conditions. I work in a canyon where a lot of driving is crawling around fully loaded in first gear on steep narrow winding roads. My "normal" driving hardly gets out of third gear. And there are almost no freeway miles in that average. One time I took a 150 mile mostly high speed freeway drive (70+ mph) and got 29.0 mpg. That was on summer blend gas.

I also believe that a warm air intake helps to get better gas mileage, but that's just one ingredient. The others (besides the high torque long tube header and intake manifold spacer) are lightweight alloy wheels and high mileage low rolling resistance passenger car road tires, no power steering, and no air conditioning.


Greg

 

Maybe somebody can explain, but this goes against everything I know about engines...

 

As I understand it, warm air is less dense and has less oxygen in it so the ECU monitoring the exhaust, meters less gas so as not to run rich. Warm air also warms up the engine faster. And warmer air assists in producing higher combustion temperatures.

 

Warm air also makes less power, so why wouldn't that offset any leaning of the mixture that might give better mileage? Why do most all vehicle makers go to the trouble to make cold air intakes, if warm air is better?

There won't be much warm air until the engine actually warms up anyway. The difference in combustion temps due to the difference in intake air temps would be negligible.

I just can't accept this theory, until somebody proves it under scientific test conditions. I know what turning the intake heat on does to an aircraft engine.

As Mack Truck said of their chassis mounted direct air inter cooler, "the cooler we run, the hotter we burn"...