Dual pipes with X pipe muffler

[b454rat]

Also got thinking about it, I have an 08 Tundra with the 5.7, makes 370 horse and 381 torque, with dual 2" i think to a single out muffler, maybe 2.5". That thing pulls like a freight train, even lifted with 35s.

I think I'm gonna use Summit's headers again, with the Jegs offroad down pipes that are 2 1/4", with 2 into merge pipe then 3" single out the back. Found a muffler on the highway, that's half the price lol...

 

[White96k2500]

Also got thinking about it, I have an 08 Tundra with the 5.7, makes 370 horse and 381 torque, with dual 2" i think to a single out muffler, maybe 2.5". That thing pulls like a freight train, even lifted with 35s.

I think I'm gonna use Summit's headers again, with the Jegs offroad down pipes that are 2 1/4", with 2 into merge pipe then 3" single out the back. Found a muffler on the highway, that's half the price lol...

My dad had a tundra and i swear that thing was a train. Lmao

 

[CalebAdams]

Just an FYI, dual 2-1/4" and single 3" flow about the same which is plenty good for anything up to 400 HP.

Ok, so really I just need to have a new y pipe made and get a new 3” cat? I heard the stock y and cat were pretty restrictive by design to help it pass emissions. I don’t plan on rebuilding it for a long time since I’m in college now, and even then it’ll probably just be around 250-275hp, most likely under 300hp.

 

[PlayingWithTBI]

Here's what I have on mine, JBA Y pipe and a high flow cat bolts right up to Summit Racing shorty headers or stock manifold. The Y pipe is a little spendy but they're stainless, mandrel bent, and have a good flow through the collector.

You must be registered for see images attach

https://www.summitracing.com/parts/jba-2831sy

https://www.amazon.com/Thunderbolt-...1161&sprefix=Thunderbolt+3+cat,aps,806&sr=8-3

 

[b454rat]

I just put a Jegs offroad down pipe on my 98 Tahoe. They have true duals to the muffler. The stock down pipe is not even 2". Thats the only thing i did to it, and noticed right off the bat it had more power. It was pretty sluggish accelerating, now it will **** n git. I noticed when I put it on, the rest of the exhaust needs to be upgraded, someone put a patch in and now it's choked on one side. i really wanted to put long tubes on it, but not gonna happen. So gonna put Summit shorty's on, eventually get a cat back, should really wake it up.

 

[CalebAdams]

Here's what I have on mine, JBA Y pipe and a high flow cat bolts right up to Summit Racing shorty headers or stock manifold. The Y pipe is a little spendy but they're stainless, mandrel bent, and have a good flow through the collector.

You must be registered for see images attach

https://www.summitracing.com/parts/jba-2831sy

https://www.amazon.com/Thunderbolt-Universal-Catalytic-Converter-High-Flow/dp/B079Y1N1RB/ref=sr_1_3?crid=3NTUET6S05554&dchild=1&keywords=thunderbolt+3+catalytic+converter&qid=1601311161&sprefix=Thunderbolt+3+cat,aps,806&sr=8-3

Awesome, I had already looked at the JBA cat4ward headers and liked how they looked. I think that would work perfect for mine. For the time being I could hook onto my old 3” pipe that goes to the muffler as well. One question: I have deals bolted into each manifold that suspiciously look like O2 sensors, and I could not see the O2 sensor where everyone says they are, right after the y pipe. Are the 2 things bolted into my manifolds O2 sensors, and if so how would I go about using them with the JBA headers? I’ll try to take a pic of my manifolds this weekend

 

[PlayingWithTBI]

Are the 2 things bolted into my manifolds O2 sensors, and if so how would I go about using them with the JBA headers?

In your original post you mentioned you have a 90 truck right? Then you should only have one O2 sensor on the driver's side manifold. The Summit Racing shorties have a bung at the collector for that. The JBAs should too but, you need to check that out. I have a 3 wire Heated Narrow Band O2 sensor in my shorty headers and a Wide Band O2 in the bung at the Y pipe collector. Right now I'm running with it. Later down the road, I'll switch back to the Heated O2. When running headers and low restriction exhaust, it's a good idea to use a Heated O2 so you can go into Closed Loop sooner and stay in CL when idling.

 

[CalebAdams]

In your original post you mentioned you have a 90 truck right? Then you should only have one O2 sensor on the driver's side manifold. The Summit Racing shorties have a bung at the collector for that. The JBAs should too but, you need to check that out. I have a 3 wire Heated Narrow Band O2 sensor in my shorty headers and a Wide Band O2 in the bung at the Y pipe collector. Right now I'm running with it. Later down the road, I'll switch back to the Heated O2. When running headers and low restriction exhaust, it's a good idea to use a Heated O2 so you can go into Closed Loop sooner and stay in CL when idling.

Yes it’s a ‘90. I probably just overlooked it, and seen something else. So what would I have to do about changing my O2 sensor(s) over to the 3 wire? Also, why the need for the one in the header when you have one in the y pipe?

 

[Erik the Awful]

To swap in a 3-wire you would have to tap switched power to the positive wire on the heater and ground the other wire. I went to the treasure yard and nipped both sides of a fuel pump connector under the brake booster. Back at home I made it Y to a short harness with the appropriate O2 sensor plug, which I also nipped at the yard. That extra connector in the pic below plugs into the original O2 sensor plug (mine had been snipped). It got a ring terminal on the end.
View media item 32127Edited because I forgot that extra pigtail isn't a ground wire, it's the O2 wire. Meh, it's been a few months.

 

[PlayingWithTBI]

why the need for the one in the header when you have one in the y pipe?

The further you get the O2 sensor the more the response is delayed. Then you may get stumbling unless you go in the .bin and add some more delay to the "Duration Offset vs Airflow" based on Gms/Sec calculated in the calibration. In other words, the ECM will correct AFR based on O2 feedback but it'll be late since it takes longer to receive it.

To swap in a 3-wire you would have to tap switched power to the positive wire on the heater and ground the other wire. I went to the treasure yard and nipped both sides of a fuel pump connector under the brake booster

Or you can get this adapter.

https://www.amazon.com/Michigan-Mot...higan+motorsports+22300&qid=1601559804&sr=8-1

And an AC Delco AFS74 heated O2 sensor