- First Name
- Quez
- Joined
- Sep 25, 2024
- Threads
- 14
- Messages
- 126
- Reaction score
- 215
- Location
- Nashville
- Website
- www.bigdawgstoyotatuning.com
- Vehicle(s)
- 2025 TRD Pro, 2025 TRD Pro 4Runner
- Thread starter
- #1
When I posted this initially, I was just getting done with a 2 hour v-band clamp fight.
Hindsight, I realize I didn't give any context about the purpose of this upgrade - or really any info about it. I wanted to come here and give a quick rundown for those who may be unfamiliar.
On the 2024+ Tacoma, the downpipe (DP) is the section in the engine bay that links the turbo to the rest of the exhaust system. From the factory, it’s one of the more restrictive pieces because it houses the catalytic converter (what people mean when they say “cats,” “catted,” or “catless”).
The main reason people swap the DP for something like Overland Tailor Tuning’s (OTT) version - it flows much better than the OEM unit.
Less restriction = better airflow = more power.
Like most manufacturers, Toyota builds the stock downpipe with a focus on keeping things quiet and emissions-compliant. A high-flow catted DP uses larger piping and a more efficient core. In simple terms, that reduces exhaust backpressure and allows gases to move out more quickly.
With less backpressure, the turbo can spool faster, which means reduced turbo lag and improved pedal responsiveness in a wider RPM range.
Pair that with the OTT Stage 1 calibration from Big Dawgs Toyota Tuning, and you’ll notice a solid bump in usable horsepower and torque.
Just to note, a downpipe is more of a supporting mod when you’re power hunting. it’s one part of a larger picture. It can provide gains, but I've yet to dyno test my truck to give exact numbers for this specific dp.
Another big reason people go with a DP is the sound. Everyone wants their truck to have a more aggressive tone. I’ve always joked that overlanders are the modern version of JDM bois, and that still holds true imo. A high-flow catted DP will give you a louder, deeper exhaust note. I’m running a stock TRD Pro exhaust, and it’s noticeable but not over the top.
A high flow catted dp won’t be as loud or obnoxious as going catless, but you’ll definitely hear the difference. I’ll have to get some sound clips together at some point.
You probably noticed I’ve said “high-flow catted” a few times. That part matters for most people (probably 95% or more). A high flow catted DP keeps your emissions system fully in place, which helps cut down on exhaust smell and avoids triggering check engine lights (CEL). So you’re not dealing with strong fumes at stoplights, on the trail, or at your local Cars & Coffee. And of course, it’s the better choice environmentally as well.
Here's a couple quick pics of the OEM downpipe and OTT High Flow Catted Downpipe (@JustDSM) next to each other.
Hindsight, I realize I didn't give any context about the purpose of this upgrade - or really any info about it. I wanted to come here and give a quick rundown for those who may be unfamiliar.
On the 2024+ Tacoma, the downpipe (DP) is the section in the engine bay that links the turbo to the rest of the exhaust system. From the factory, it’s one of the more restrictive pieces because it houses the catalytic converter (what people mean when they say “cats,” “catted,” or “catless”).
The main reason people swap the DP for something like Overland Tailor Tuning’s (OTT) version - it flows much better than the OEM unit.
Less restriction = better airflow = more power.
Like most manufacturers, Toyota builds the stock downpipe with a focus on keeping things quiet and emissions-compliant. A high-flow catted DP uses larger piping and a more efficient core. In simple terms, that reduces exhaust backpressure and allows gases to move out more quickly.
With less backpressure, the turbo can spool faster, which means reduced turbo lag and improved pedal responsiveness in a wider RPM range.
Pair that with the OTT Stage 1 calibration from Big Dawgs Toyota Tuning, and you’ll notice a solid bump in usable horsepower and torque.
Just to note, a downpipe is more of a supporting mod when you’re power hunting. it’s one part of a larger picture. It can provide gains, but I've yet to dyno test my truck to give exact numbers for this specific dp.
Another big reason people go with a DP is the sound. Everyone wants their truck to have a more aggressive tone. I’ve always joked that overlanders are the modern version of JDM bois, and that still holds true imo. A high-flow catted DP will give you a louder, deeper exhaust note. I’m running a stock TRD Pro exhaust, and it’s noticeable but not over the top.
A high flow catted dp won’t be as loud or obnoxious as going catless, but you’ll definitely hear the difference. I’ll have to get some sound clips together at some point.
You probably noticed I’ve said “high-flow catted” a few times. That part matters for most people (probably 95% or more). A high flow catted DP keeps your emissions system fully in place, which helps cut down on exhaust smell and avoids triggering check engine lights (CEL). So you’re not dealing with strong fumes at stoplights, on the trail, or at your local Cars & Coffee. And of course, it’s the better choice environmentally as well.
Here's a couple quick pics of the OEM downpipe and OTT High Flow Catted Downpipe (@JustDSM) next to each other.
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