TRD Cold Air Intake Problem?

Yup. So with a drop in high flow filter (TRD, K&N, etc.) The only airflow restriction would from the air box to the intake manifold.

 

I think removing restrictor on any model Taco would help. I installed the TRD cold air intake

 

If I'm not mistaken, that tube connects the airbox to the velocity stack which draws cold air from the fender. By removing it, you may be drawing in hot air from the engine bay.

 

for some reason I don't see that "restrictor" having any restricting going on. Seems to me like it's helping velocity of incoming air, maybe to better distribute where the air is hitting the filter.

 

Your engine is going to blow up now.

 

Nah, I gotta sticker that prevents that.

 

This will happen then.

 

No. Air is still drawn 100% from the fender.

 

As long as it's still sealed to the fender.
Did you install any other parts at the same time that you removed that length of tube?

 

Yes, it is sealed in to the fender and the rain guard was reinstalled. I was installing the trd intake system when i found that piece. I am considering checking dyno time prices around town. If i can get a dollar from every TW user that has told me it doesn't make a difference, it would cover the cost of the dyno and some bank left over. Take it in stock and install it in 3 different phases and dyno each phase.

 

Folks with experience messing with older Miatas will recall a device in the airstream called a Helmholtz resonator. It was mostly for sound control.

Removal did change performance. There is a dyno measured power/torque dip in the mid band RPM range that had a negative effect on streetability or worse for those of us who auto-xd.

However, noise did rise and some replacement bits looked better.

I don't know that something like this is what you've removed. What I do know is that OEs don't add parts (expense) that reduce performance that have no other benefit (emissions, NVH improvement, etc.)

I also know that outside of the former S/C, TRD bits on these trucks aren't anything more than dream bling. Nice if you like that kind of thing.

I understand the joy of the butt dyno as well. But until real dyno numbers show up pre and post part removal.............

 

Just for the record we did not get the first 2GR engines. the 2gr with D4s injection has been around since 2005 in Lexus vehicles and was one of Wards top 10 engines for several of those years.

 

More than one variable changed then, so it's difficult to solely attribute the effects to removal of that tube.
If someone wanted to install in stages and dyno, I'd be interested to see the results.

 

When you say "curved rain shield", are you talking about the elbow that goes in the fender? That part was supposed to be replaced with the air accelerator piece that's made of rubber and seals the intake to the fender. It's one of the benefits to the TRD CAI. Are you saying you used both the air accelerator and the elbow somehow?

 

That's interesting. Does any have those air flow digital simulator thingys?

In the 80s, people would shave the fins in side the airbox to "provide" better air flow? Basically making the air box as smooth as possible. But I think that tube would help distribute the air more evenly through the flat panel air filter. The more air you can spread across the filter, the more air can pass through.

Just my thoughts.

 

Not sure about the TRD airbox for the taco, but I can tell you why they don't include it on the 4runner...It's LOUD!

As mentioned, it removes the resonator. The airbox itself along with the inlet and outlet are both larger than stock. Someone on T4R dyno'd their 4R and gained around 9hp and almost 20 ftlbs of torque. I can hear it under nearly all throttle conditions and under WOT and upper RPMs, it wails. Not bad, but it doesn't sound like a stock, quiet vehicle which is what most buyers would be looking for.

 

From the pictures of others who installed a TRD airbox on their trucks seems to have something similar to a resonator. Certainly it does sound louder and different. See image below :

 

I'm not super familiar with Atkinson cycle engines but if you're looking at pulses of pressure waves coming back through the intake system as a result of delayed closing of intake valves on the compression stroke, the more baffle areas where pressures can smooth out probably helps MAP and MAF sensors with accuracy in addition to noise reduction. Not for sure, but just a hunch.

 

Could a no baffle scenario create more input air intake @Scooby24 ? Not a mechanic, but to me less volume in the tubing results in better intake pressure if other parameters remain the same.

 

You did not remove a restrictor, you removed a Venturi. Look at the profile of that tube (parabolic). Your performance may be worse now, but placebo effect gives 10Hp every time.

"Venturi tubes are used in processes where permanent pressure loss is not tolerable":

https://en.m.wikipedia.org/wiki/Venturi_effect#Venturi_tubes