Dual Exhaust vs Single exhaust

I keep seeing it on this site people saying that dual exhaust leads to lower end torque and if you want to keep/possibly gain low end torque then one needs to keep a single exit exhaust. Is there any truth to this? If so why? Is this to say the Toyota TRD exhaust decreases low end torque? I thought it did the opposite. Please shed some light on this issue.

 

It's not like your truck will be a slug if you do... Well depending on your exhaust set up. But you can feel the difference. Your truck won't lose power, it just changes the powerband. The guy that wrote this in the link below is who I had make my dual exhaust. He does say track tested dual exhaust that he makes will get you gains, but normal driving or towing, not floored, you the tq is less on the low end. There are more things that he has written and I'll try and find them. But this is a good place to start. I love my system and I decided on duals just in case I ever get headers or my flex fuel could ever be safely supercharged.

The reason I didn't go with the trd exhaust is that it doesn't have an xpipe and I've read people do experience a significant low end loss.

http://www.tundratalk.net/forums/tu...ons/135562-5-7l-tundra-true-dual-exhaust.html

 

His full exhaust replacement has a HUGE tq and hp gain though. It's when deciding on a cat-back system that it's best to have a single out.

 

I would like to know the correct answer. I have dual exhust but one muffler. Both sides leading into one muffler and it has two outlets. What does this do?????????

 

The older TRD exhaust was like that (07-08). I don't think that's considered a true dual exhaust. Newer TRD exhaust (09 and newer) is a true dual exhaust.

My truck did not come with the TRD exhaust. I had it installed some time after I bought my truck so I have a fair point of comparison. I have not experienced ANY power loss after the installation. Because of some rumors of lower end power loss, I did pay special attention to the low end.

I did not dyno the truck. But if I cannot tell the difference, I certainly would not call that a "significant" loss. If this claims of significant low end loss is correct, that would mean Toyota is selling their best selling trim (TRD Pro) by severely handicapping them (which doesn't make sense to me).

 

I realize this thread is old but I just bought 2020 crew max and would like to add trd dual exhaust but not is the truck doesn't work well with the set up. Seems odd Toyota would make the exhaust that diminishes their 5.7 liter. Thanks guys.

 

2 words.....Dirty Deeds!

 

Get in in the group buy right now... The dirty deeds exhaust can’t be beat

 

If you really want dual tailpipes, buy the trd replacement system from dirty deeds and order the trd tailpipe section

 

Well to be honest I just want a decent sounding exhaust that doesn't hurt tundra performance. I thought the trd exhaust sound was just right. Does dirty deed ship to Canada?

 

Im sure he would, call him he’s awesone

 

Has anyone heard anything about the stainless works exhaust?

 

I’d stick with dyno proven results from @dirtydeeds and tailored toward the Tundra Powerplant

 

I don't race my truck, but I tow loads regularly with it. Single exhaust for me as I wont trade any low range torque loss for upper range HP gains. That, and while the "sound" of healthy duals was cool when I was young it gets old on long road trips now

 

I installed the standard stainless 8" single from dirty deeds. I was orginally set on the trd replacement, but after having talked to Keith, he assured me that the single was the best option unless I planned on also added long tube headers with the dual exhaust or if I planned on supercharging (which I'm not). The great thing about @dirtydeeds is that in the future, if you want to upgrade your system, you can essentially trade in your current exhaust you bought from him and use that towards a different system. I installed the standard 8" in my driveway in about 45 mins, have had it on for a couple months now and it honestly sounds great! Highly recommend, plus Keith really knows his shit and can explain and answer every question you have. Doesn't hurt to help out an American small business either in my book. If they are having a group buy going on now, I would jump on that because they are easily the best deals. I got mine in the black Friday sale, so it was even harder to pass up.

 

BAMuffler cat-back with a single tail pipe works for me.

 

I've been considering redoing my exhaust system on my SC'ed Tundra recently. Currently it has the stock front half, Dirty Deeds 8", and custom tail-pipes.

The key reason I want to change is because I am considering building a torque-arm style traction (anti-wrap) bar, but there is no room for it with the dual exhaust setup.


One of the things I keep reading is the regurgitated misconception of back-pressure as a requirement. Back-pressure is bad for performance, period. The problem with over-sized exhaust in any part of the exhaust system is a loss of velocity for the application...which incidentally can have results like adding back-pressure to the system.

A better way to compare different setups is to compare potential velocities for different pipe diameters (16 Gauge):

2-1/4" = 408cfm
2-1/2" = 509cfm
2-3/4" = 622cfm
3" = 747cfm
3-1/2" = 1029cfm
4" = 1352cfm

By breaking it down in this manner, it is easy to see that a dual 2-1/4" system @ 816cfm or a dual 2-1/2" system @ 1018cfm will both outflow a single 3" @ 747cfm.

So the common statement that a single 3" is HUGE is just flat out wrong.


Now, going back to my supercharged application, I am considering building 2-1/2" into a single 3.5" or a custom 2-3/4" into a single 4" to make room for the anti-wrap bar.

Keep in mind that it is considered somewhat acceptable to install a dual 3" on an SC'ed Tundra, and we are then talking about 1,494 cfm of potential flow...nearly 150cfm more than a single 4".

Also keep in mind that a supercharged application has higher flow requirements than naturally aspirated.

I'm currently leaning towards the 2-3/4" into 4" behind long-tube headers; the headers obviously throw an entirely different wrench into the performance equation.


Now this has nothing to do with the subjective issue of sound quality. I imagine a 3-1/2" or 4" single would have a deeper tone, but most likely will be considerably louder. I really like the sound of the Dirty Deeds 8" system, and will likely end up with a very different acoustic result, but...trade-offs.

Has anybody here with a SC'ed Tundra gone this route yet?

 

https://www.tundras.com/threads/supercharger-and-stock-exhaust.62608/#post-1638827

 

Keith at dirty deeds can explain everything you need to know about exhaust for your tundra. He is very knowledgeable and can fit your truck for what you want it to do and sound like.

 

No offense, but I find it very hard to believe that there is not power to be had with exhaust upgrades; I understand there may very well be tuning involved to do it right.

I've seen very similar engines (of different makes) make very, very impressive gains with full exhaust, pulley and tune.

Some people also over obsess about peak gains versus gains throughout the powerband; while others can be deceiving about their gains by advertising a gain somewhere in the curve versus properly stating peak gains.

While I'm sure I won't see as much gain over Dirty Deed's setup as I would stock, there still has to be room for improvement with the rest of the setup, and in my experience power-adder setups tend to make more impressive gains with such improvements. I'm failing to understand how the Toyota engine could be so different from anything else.

 

4 words

^ Yeah, what he said! ^