Dual exhaust

[scdanny]

New guy here, I just bought my first Tundra. Can anyone tell me about thier experiences on installing dual exhaust. I'd rather not purchase a Borla, Gibson etc. but would like to install 2 flowmasters and have the exhaust exit from the rear. Has anyone went this route? And the results.

[v8Toilet]

I went with the TRD dual exhaust, which takes the 2.25" pipe and splits it into two 2.25" pipes. The first thing I noticed when I installed it was that I lost a very noticeable amount of low-end torque. Than I noticed that I couldn't spin the tires even in a turn. I eventually went back to the stock exhaust and now I have a Spintech muffler in place of the stock muffler. With the Spintech muffler I could feel a slight increase in power even in the low-end. I verified this when I put my truck on a dyno with a 12-ft. lb. increase in peak torque and an increase across the entire RPM band.

[scdanny]

That's what I want to avoid.... losing low end torque. I'll do some more research and get some more opinions. Thanks guys!

[KLS]

Danny,

There are only two advantages for true duals--
1) That great V8 sound
2) Smaller mufflers for cars with ground clearance problems.

Duals with an H-crossover pipe have more power than true duals. Duals with a X-crossover have more power than the H. http://www.drgas.com/art-sync.html And, a properly sized single muffler has just as much power.


Ken

[Mudog715]

Originally posted by scdanny
That's what I want to avoid.... losing low end torque. I'll do some more research and get some more opinions. Thanks guys!

If you go the "true dual" route, stick with 2" pipes and mufflers all the way through. The pipes from the cats are only 2" so going 2.25" or 2.5" after them will gain next to nothing in HP, but will substantially cut into low-end torque (from the reduced air velocity). Also, as KLS mentioned an X pipe or H pipe connecting the two halves together will make more torque than if you kept the two pipes separated the whole way and will have no loss at high RPM. The people that have gone this route (duals, 2" pipes and X pipe before the muffler) generally note the greatest power gain with no loss of low-end.

Also, if you're more interested in power than sound, then Flowmasters are not your best choice. Tests have shown them not to flow as well as some other mufflers on the market (that also tend to be quieter).

[scdanny]

Sounds like the duel mufflers with 2" pipes & "X" connection is the way I'll go. I chave 40 series Flowmasters on my old muscle car and "H" connector, they are loud but appropriate for that car. I'll go with quiter mufflers on the Tundra.

[v8Toilet]

Originally posted by scdanny
Sounds like the duel mufflers with 2" pipes & "X" connection is the way I'll go. I chave 40 series Flowmasters on my old muscle car and "H" connector, they are loud but appropriate for that car. I'll go with quiter mufflers on the Tundra.

Why would you go with a dual exhaust when a single exhaust with a higher flowing muffler will make as much or more power and cost less?

[scdanny]

I guess I just have a thing about true duals that exit from the rear of my truck.

[v8Toilet]

Believe me I would love to have those two pipes coming out the back but it has to be a modification that will net me more power/ torque over just looks and sound. If it cost me power than it's even worse!

I researched the dual exhaust subject to death and everywhere I looked (most people I talked to) I found that true dual and cat back dual exhaust systems costs you low-end torque. I even tried the TRD dual cat back and was disappointed. A true dual exhaust doesn't offer any advantages over a properly sized single exhaust system in terms of power. If you keep the pipes no larger than the two pipes after the cats and use an X-pipe than you might be OK but it isn't any better than a single exhaust and I think the sound of a performance muffler on a single exhaust sounds awesome.

[Dude Boy]

Why would you go with a dual exhaust when a single exhaust with a higher flowing muffler will make as much or more power and cost less?

So who's Tundra with single exhaust is making more power on the dyno than duals? I haven't seen any dyno results yet where this has been true. Is anbody with single exhaust getting 220-230 RWHP or better? I've seen those results for duals and headers.

[v8Toilet]

Originally posted by Dude Boy
So who's Tundra with single exhaust is making more power on the dyno than duals? I haven't seen any dyno results yet where this has been true. Is anbody with single exhaust getting 220-230 RWHP or better? I've seen those results for duals and headers.

The only way to accurately compare the two setups is on the same day on the same dynamometer. If it makes any difference I put down 285-ft. lbs. of torque and 208 horsepower with nothing different but a Spintech muffler in place of the factory muffler and a TRD air filter. Another Tundra at that same dyno on the same day with TRD headers and dual exhaust put down 273-ft. lbs. of torque and 202 horsepower (catch is with larger tires though). At about 4650 rpm I'm putting down 232-ft. lbs. of torque he is putting down 214-ft. lbs of torque and 205 horsepower and 190 horsepower. The larger tires hurt his power some what but how much I don’t know. He did have a much better breathing exhaust system than I did and it sounded awesome. Bigger is not always better.

The low-end torque is what true duals hurt the most. In a pickup truck you don’t want that to happen.

[Dude Boy]

Yeah, I was just trying to get a rise out of you! I saw that you used the term "power" in your post, but I knew what you meant. Sorry about pickin' on ya Did you see that dyno in the Off Road magazine that bolted right to the rear hubs? That was kind of cool!

[scdanny]

After researching all my options and flip flopping a few times, I have ordered the Borla stainless exhaust system. Single muffler w/ dual rear exit tips. A bit pricey but I like what I have heard regarding the product. I'll let ya know the outcome once I get it installed.

[dbflyguru]

scdanny, let me know how you like it after you install it. I'm thinking of purchasing the same exhaust for my 2000 IS tundra. Where did you purchase it from. I found a site that has it for $630.00 shipped. Seems like a good price.

[scdanny]

guru, $630.00 including shipping is a very good price. I ordered mine from "Big Exhaust" and the cost was $660.00. System has not arrived yet, should be here this week and installed next weekend.