TRD Exhaust actually add HP and Torque?

At first I thought the TRD Exhaust did not add HP or Torque then I saw this article. Curious if anyone noticed a HP and Torque increase?

https://motoiq.com/project-toyota-tundra-part-5-testing-trds-warranty-friendly-exhaust-system/4/

 

Interesting ... at least the system was dyno'd to prove some gains. Plus the dual side exit looks sick AF

 

Not surprising, the oem muffler blows

 

I would add an H pipe to the TRD exhaust, and I would only consider adding an X pipe only if I was running higher RPMs more often than not.

 

I've heard you lose some low end torque because of the loss of back pressure.

 

You absolutely lose low end torque with the TRD exhaust. So much that you can feel it. I did the “upgrade” a couple years ago and immediately regretted it. The only plus was the sound.
I recently changed it out for a Dirty Deeds system. They 100% live up to the hype.

 

Dirty Deeds is the best.

 

Love it or hate it there is nothing with as deep and bassy of a tone as the TRD duals. I’ve tried other things but always come back to it. Removing a set of the rear cats takes the great sound and makes it louder and more aggressive. I tried the DD TRD rep system with the x pipe and noticed a loss of low end torque. I went back to the TRD with true duals. I could see trying an H pipe on it in the future, but I think the true divorced duals are what gives it the unique sound.

 

I've heard this on the forum but the dyno numbers don't really show a loss of low end torque. So not too sure if it's made up or I'm the one who doesn't understand. Either way I just thought it was interesting you actually gain torque and HP, I always thought it was just for sound and no gains.

 

I do love that deep sound it's like no other.

 

I read when toyota developed it , they had 30 iterations, settled on this one. I've heard most manufacturers do a few iterations and a choose one.

Shows toyota tests and tests stuff to get it as close to right.

I have a trd exhaust, haven't installed it. Expecting a little less torque off idle and then a little bit more power at revs.

If you tow a lot, it could be annoying to lose a little torque.

I think the loss of torque is under 2k rpm. And then it settles to feel fine.

Variable valve timing works with load and back pressure. Taking some back pressure away, doesn't let the motor make max torque at low revs.

 

The low end torque happens at the rpm you drive your truck in. Not at the measurable rpm you run a Dyno at.

an x pipe helps with this loss of low end torque. But nothing is better than a single exhaust with a flow thru muffler and 2 3/4” tailpipe. I’ve also Dyno tested both a TRD system and one upgraded with our x pipe. TRD systems do indeed make more horsepower than stock. And our system with x pipe has better low end torque. But neither is as good as our single exhaust at low end torque.

 

I can confirm this statement as fact.

Keith, do you offer a single exhaust with a flow thru muffler and 2 x/x” tailpipe for 4.7L 1st generation Tundra with a 128.3" wheelbase?

 

If i remember correctly the 4.7 used a 2 and 3/8th pipe?

 

Just added Keith’s 20” muffler. Paired with the OTT tune I definitely notice a difference in hp/torque and it sounds great. Next move is to re-gear

 

Thanks for clarifying. Good info.

 

I undoubtedly lost low end torque with the X pipe system. Back to back from TRD duals, to X pipe, back to TRD it was like flicking a light switch on and off. It wouldn’t hold gears as well at cruise, and it took more RPMs before shifting to the next gear.

What I read is true duals have better low end scavenging, and the X pipe has better scavenging at mid to high range.

 

Good info! Just curious what do you mean by scavenging?

 

Nerd explanation courtesy of AI. Essentially it promotes better cylinder filling of fresh air and fuel to maximize efficiency and power.

 

The level of control on modern engines (VVt, adjustable intake runners, etc) has greatly “muted” the effects of exhaust systems. Hence why you can cut off a gigantic boat anchor stock muffler, put a performance straight-through muffler on and net only 3-5hp. That being said, no modern engine wants back pressure period. What yields the best performance is using the smallest diameter tubing possible that will flow the target cfm for your horsepower range. That helps keep as much heat in the exhaust as possible, allowing the velocity of the exhaust pulses to maintain a higher speed longer, which aids in scavenging. It all comes down to a balancing act, a 2” ID tube system will probably be perfect from 500-3500rpm but then become a restriction above that so manufactures increase the tube size and sacrifice some low end torque for a system that has a wider operational range. To me, a dual 2.25” system with a h-pipe is a great all around setup for these trucks, the h-pipe gets rid of the “chop” the trd system suffers from at low speeds and then essentially acts invisible at higher rpm.

 

Single or dual ?

 

I changed my TRD duals to the DD single 10”.

 

my recommendation:

to mitigate any potential HP loss, that would come from exhaust related issues, is to install a different intake.

one of these gadgets renders all those minute exhaust related HP gains mute.

YMMV



and the TRD exhaust is fabulous with this setup.(I added it when I purchased the truck new)

If I ever decided to change, I would definitely only consider @dirtydeeds

 

A 1.2G launch off idle should be sufficient low end torque.