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Forced Induction SystemsDetailed discussions regarding cold-air intake systens, superchargers, turbo chargers, and other induction systems for your vehicle.
This is a discussion thread titled "Tundra Exhaust Mod", within the Forced Induction Systems forum, part of the Technical & Vehicle Assistance Forums category.
Well... i put the stock exhaust back on and now it seems like a totally new truck! All the power is back, it's quicker than ever and gives me great gaz mileage. Unfortunately not it doesn't rumble anymore and looks stock. So... if I had my setup reworked with 2.25" pipes I should not loose any gaz mileage and maintain all of the power? Does the size of the piping matter after the mufflers or only before?
Hmmm. My '07 DC 5.7 with 3500 miles has a Flowmaster exhaust installed.
Best average mileage per the computer is 15-16mpg max.
the previous owner installed the FM, which I wouldn't have done, but it makes me wonder if it's affecting mileage.
I've only commuted at freeway speeds and barely gas it at all.
Wonder what's up...?
BTW, I'm using 76 regular...darned if I can find anything in the manula that says anything about using anyhing less than 87 octane (regular)......
Isn't "76" the name of the Gas Station Rapid Dog is refuelling at? as opposed to the octane rating?
Just saying...
Remote Dog, you are equally right in your statement and thanks for the details!
i never thought of that, in michigan we dont really have that chain of gas stations, but i know what your talking about anyway. so that might be the case. sorry for the misunderstanding if that is the case.
Well... i put the stock exhaust back on and now it seems like a totally new truck! All the power is back, it's quicker than ever and gives me great gaz mileage. Unfortunately not it doesn't rumble anymore and looks stock. So... if I had my setup reworked with 2.25" pipes I should not loose any gaz mileage and maintain all of the power? Does the size of the piping matter after the mufflers or only before?
thanks
The piping before the muffler is a bit more critical in terms of size than the exiting diameter out of the muffler. Smaller piping will increase gas velocity and enable the gas to remain hotter further down the exhaust system. Most of the cooling occures in the muffler. Cooler exhaust gas is denser and is therefor harder to push through and will increase backpressure - this is the main reason why larger diameter piping can reduce low end torque output.
In choosing your pipe diameter you have to ask yourself what's more important, low end torque or high rpm power. My findings are that 2 1/4 inch mandrel bent piping is best for overall everyday performance and mileage for the 5.7. If you have a muffler shop bend up a system out of 2 1/2 inch pipe, you will have no better performance potential than 2 1/4 inch pipe due to the pressure bending method they use. Also the catalytic converters in the tundra neck down to at least 2 1/4 inches, so your overall power potential is already reduced negating any worthwhile gains possible with 2 1/2 inch piping.
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2007 Tundra 5.7 4x2 RCSB slate metallic
2005 Corolla - all stock, cause it's the wifes
1986 Mustang GT - the stereo is under the hood
1990 Corolla - cause it was really cheap
Well... i put the stock exhaust back on and now it seems like a totally new truck! All the power is back, it's quicker than ever and gives me great gaz mileage. Unfortunately not it doesn't rumble anymore and looks stock. So... if I had my setup reworked with 2.25" pipes I should not loose any gaz mileage and maintain all of the power? Does the size of the piping matter after the mufflers or only before?
thanks
If you look at the stock exhaust, the front pipes are smaller in size than the tailpipe, even on the TRD Dual, so it would seem best to stick with that pattern I'm guessing. Maybe 2 1/8" front pipes from the the flange back to the muffler for your set-up would work better.
I went with 2.25 in/out and have had no such ill effects. Mileage hasnt changed either.
07Sport,
What did you do exactly, cut your exhaust off right in front of the stock muffler and have the Flowmaster adapted and welded directly on to the two front pipes and then added two 2 1/4" tailpipes?
[quote=Bertsonsracing;766811]By very bad gaz mileage I mean close to 13.5 MPG avg city and HWY. It is not rare for me to get between 9 and 11 mpg when towing my race car on a 19 ft. car hauler.
I see you are in Ontario, are you converting to a Canadian gallon, (4.54 liters) or a USA gallon (3.8 Liters) to get your fuel mileage? Or is this info from the trip computer on the dash?
Re: Tundra Exhaust Mod
magnaflow y pipe with a single 3"i/o cherry bomb or one of the 
flowmaster y pipes with a cherry bomb
Linear Mode
