BlairB
New member
Well I decided that although I already had a TRD exhaust, I would like to have something that was even a little more free flowing (TRD is chambered) and sounded a little more aggressive, so I talked with Keith at BAMufflers.com/dirtydeedsindustries.com, who worked with me and made a muffler for the 4th gen 4.0 V6, and I love the final product.
It is definitely more free flowing and I feel that there is better throttle response higher up in the RPM's than there was before. Also, it does not sound too raspy, which you sometimes get with a V6. I have already put 2hrs of freeway driving and there is no drone at all, which was another thing I was afraid of. When you punch the throttle, this exhaust is mean sounding.
Here is a quick writeup of what he did from another forum, followed by some videos after we got in installed. Let me know if you have any questions!
Some Video
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It is definitely more free flowing and I feel that there is better throttle response higher up in the RPM's than there was before. Also, it does not sound too raspy, which you sometimes get with a V6. I have already put 2hrs of freeway driving and there is no drone at all, which was another thing I was afraid of. When you punch the throttle, this exhaust is mean sounding.
Here is a quick writeup of what he did from another forum, followed by some videos after we got in installed. Let me know if you have any questions!
Just like the title says, pictures and video will come as this build progresses. Here is the vehicle description:2008 Sport Edition 4WD V6 with 255/80/17 BFG MT KM2, and TRD Exhaust. With I'm pretty sure stock gears.
I was at my local dealership today to look at the stock exhaust, and TRD exhaust. They're both very well made! 409 stainless with all mandrel bends stock, and mild aluminized steel for the TRD. I've seen pics of the TRD exhaust in stainless as well so I think there may be an option or they just made runs of exhaust based on what they had on hand. Either way the exhaust looks properly sized for the displacement and expected power output. As I've said in the past, Toyota exhaust is very high quality. Unfortunately their hands are tied. They are required by federal mandates to meet noise levels. Not only that but the average consumer doesn't want to hear their exhaust. The 2 most restrictive parts of the system are the exhaust manifolds and the muffler.
Without changing the exhaust manifolds for long tube headers, it's pointless to get larger exhaust tubing. Some manufacturers actually make a cat back for a 4Runner in 3 inch tubing! What a loss of power we're looking at! When you open up the system that much you effectively "put on the brakes" since the velocity slows down so much through that massive tubing.
Moral of the story, if you stick with stock manifolds, keep the stock tubing size. Get rid of the wheezy stock muffler for one that can actually flow at high rpm's and provide the backpressure the engine is expecting at low rpm's.
A properly sized flow through style muffler is the best way to make power in a high performance exhaust system. At low rpm's the exhaust travels through the tubing in high pressure pulses. When those pulses enter the muffler they expand into the canister. That expansion slows down the flow effectively 'putting on the brakes' which causes backpressure. When the rpm's increase the exhaust is a steady flow, not pulses. This steady flow causes the muffler canister to have increased pressure. When the pressure in the muffler matches the pressure in the exhaust tubing, it is a flow through muffler and maximum scavenging is achieved!
For this build we will be using a BAMufflers.com 2.5" muffler. The inner core is stainless steel perforated tubing with 40% open area. This duplicates your expensive brand name mufflers to the 't'. That's the main similarity. Everything else if entirely different. My core is tightly wrapped with stainless steel wool. That stainless steel wool is held tightly to the core with stainless steel welding wire. Then it is tightly wrapped with ceramic wool which is temporarily held in place with blue painters tape. After that it is tightly wrapped with fiberglass which is also temporarily held in place with blue painters tape. Once the core is 'squeezed' into the canister an end cap is tacked on. Then the other side is packed even tighter and more packing material is added as necessary. An end cap is welded on and now it's time for a coating.
With the end caps being up to 3/16" the muffler doesn't necessarily need a coating. It would take years for material that thick to rust through. The body is made of 5" aluminized tubing and also doesn't need to be coated, the coating is for looks only. See below for the basic build pictures of this muffler. The install is tomorrow afternoon. I will post pics of the install as well as drive by and in car video. Please enjoy this thread.
Some Video
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