How to get back low end torque loss due to TRD dual exhaust.

Hello,

I have an 18 Tundra with the TRD dual exhaust. And like many others I have noticed a loss in low in torque. What’s the best way to get that back? Other than putting the OEM exhaust back on. I have seen some people talking about headers others saying put in an X or H pipe.

I don’t want the exhaust to get any louder for sure but I would be ok if it went down a notch on sound. Also I don’t want to do any ECU tuning.

 

This system will solve your problem and is a direct bolt on. We can make it quieter too

http://dirtydeedsindustries.com/product/trd-replacement-system/

 

Yeah, I wish I seen that before I bought the TRD exhaust. I was hoping to find something I could do to the existing TRD exhaust I have. You guys should make bolt on H or X pipe to the TRD exhaust.

 

Supercharger.

 

The system in the link replaces the Trd mufflers with an x pipe. Our mufflers. And helmholtz resonators.

There isn’t enough room in a Trd system for an x pipe due to the length of the Trd mufflers.

Another option is to sell it and get our standard 8” system. It actually gains low end rather than losing it.

 

I've driven 3 different Tundras (all v8's) with and without trd dual exhaust and couldn't really tell the difference in low end torque!
My co-worker has exact same model and year with roughly same mileage and we go for lunch on a regular basis and specifically tested for this "low end torque loss" and neither one of us could tell the diffetence!

V8's have about 401 lb-ft of torque and from what I've read on the internet you may lose a few (4 to 6?) lb-ft of torque at low end and gain a few at higher rpm ...
The torque gain and loss is about %1 of the 401 lb-ft of torque... I

Just curious, what did you compare your car with?

I even asked a Toyota master mechanics and he laughed and said you can't tell the difference and gas, oil and bunch of other stuff have more noticeable impact!!!

I assume the gas pedal sensitivity between different cars and model years would have much more impact than the dual exhaust. We both drove another co-workers 2017 CM with regular exhaust and it felt more sluggish. Not sure if the car weighs more or if it is the gas he had used or what. We both have DC with and without dual trd exhaust and used to compare temperatures and the engine sound (ticking), etc.

 

I could not 'feel' the low end torque either (and I have heavy tires). Did you do anything else to your truck beside the TRD exhaust and intake you listed?

 

I had dual flowmasters, very loud and droaned, they had to go. No X or H pipe.

I tow often and quiet was my priority, so I went back to stock. Found a full takeoff system on Ebay for $200 shipped. The most immediate difference, besides the peace and quiet, was the increase in power under 2500 rpm and an increase of .4mpg average over the course of 1 month. It's real and dirty deeds has the numbers to prove it.

I'm not suggesting you go back to stock, only that what you're feeling is real. You lost low end torque.

There was a member on here that had an H pipe welded into his TRD system. For the same reason you're stating. Bring the truck to a good exhaust shop. Shouldn't cost much.

 

This is what one member did to gain back the low end. I wanna do it.

 

Describe your ‘test’

 

Would you kindly describe your test?

 

Keith, read the man's post; he called his Tundra a "CAR" twice!

 

I dont think other members' "tests" is a dyno test or something factual that you are wanting it to be. Its simply more of a feel when driving the truck, either from roll on the throttle or a stomp the pedal at a green light. It is a driver comparison of having a stock 5.7 V8 with factory exhaust vs adding another aftermarket setup (flowmaster, TRD, Magnaflow, Borla, etc). I myself can attest to this. My 2015 Tundra had dual in/single out flowmaster. Compared to stock it lugged at low end throttle response, therefore giving the "feel" of loss of low end torque. My current 2018 Tundra has xpipe with magnaflow round duals. Comapred to when it was stock, I feel no loss of low end throttle response or have seen a loss in mpg based off of my ecm mpg feedback. Most of us dont have direct access to a dyno, so our conclusions are based on how the truck feels/drives after a new accessory is added aswell as keeping up with mpg.

 

Pretty much what @Heeler13 said!I

No scientific / dino test, just the feel of the car. People say I can "feel" the 4 or 6 lb-ft of torque gain/loss (%1 difference) when driving ...

I believe them but it may just be a placebo effect.

sometimes when I pop the hood and check/add oil and check a few things and wash the car, it feels like it has more power

I've felt more or less power by using different gas... idk, some argue that may have been a psychological effect as well

 

Btw, ask young high school kids when they install a noisy (dual?) muffler and they all say man it's got so much more power ... even though dino may show that they may have lost power! lol

 

So, I understand you also have the 10", which I don't see it on your site, but how much quieter would the 10" be over the 8", when the TRD is already kinda quiet.

 

That’s the answer I was looking for ^

Low end torque loss is felt the most on the highway. Not from a dig. From a dig you’re only in the ‘low end torque’ part of the power curve for a split second.

I notice on my 2013 supercharged BullyDog tuned truck low end torque loss with some dual exhaust systems. Even with stock wheels n tires it will tend to downshift excessively and just bog, with the wrong exhaust on it.

I appreciate your taking the time to respond. Sorry I wasn’t more detailed on my last post. I was getting messages caught up and knew I’d be back to this post so I quickly wanted to see what y’all would say.

 

Exactly!!!

 

Dual exhaust doesn’t show any loss or gain over a good single exhaust, on the dyno. Zero difference assuming the truck has stock mid pipes and cats.

You can’t dyno test a 5.7 below 3900 rpm. And leak power is the same between dual or single exhaust.

 

What is stock mid pipe? Is it the H or X pipe that connects the 2 mufflers?

 

The mid pipe connects the stock manifold, or long tube headers, to the catback.

There is no y pipe, or h pipe, or x pipe in the stock mid pipe. Or in mid pipes for headers.

The stock catback has none of the above either. The muffler ‘is the y pipe’.

We make dual systems with x pipes. Or single systems with y pipes. You want the smoothest, most free flowing path for the exhaust to take as possible.

 

why is that?

not trying to argue... i am just curious

 

I am guessing due to the mega torque the Tundra has, it can spin the dyno into oblivion... Curious to know also.

DD, maybe I should have put a question mark instead of a period after my question.
What can the 10" be compared to in terms of sound? Since I don't want to lose torque I was thinking of single pipe instead of dual. Will this combo make it too quiet? This is a family truck.

Sorry OP on the derail, but maybe with these questions I might just steer you towards a single pipe system. lol

 

The 10” is right in between the 8” and Trd system. With the 8” being a lot more aggressive than Trd when at full throttle. And the 10” is only a little more aggressive.

But either is quieter than Trd on the highway.

 

Because of the trans tuning. If you floor it below 3900 rpm the truck downshifts. And the new gear that it starts off in starts off above 3900 rpm.

 

even in manual mode?

 

So there is no scientific proof/data that proves you actually lose low end torque on the TRD exhaust either then?

If not, it's one person who says they "feel" the loss versus another person who says they do not "feel" the loss. So one vantage point can't actually be proven more right than the other?

 

Yes because even in manual mode it’s not true manual. It’s still acts like a regular automatic transmission it’s just limiting the gear it can up shift to.

 

Nah, it’s more like a blaring light in your face if you know what you’re looking for.

I’ve driven literally hundreds of tundras. Every single one with stock exhaust manifolds and dual exhaust without a crossover won’t hold its gear. Shifts back n forth. And you have to step on the throttle far more, more of the time.

That’s why I always ask what procedure is a guy referring to when they say they lost low end torque. A lot of guys will gun it when the light turns green and don’t notice any low end torque loss.

But they’re looking in the wrong place. When you gun it you’re only using the low end part of the power band for a split second.

Low end torque loss is noticed most during normal daily driving. The truck just doesn’t drive right. Bigger tires has the same effect.