Sub-Zero Equal Length Y pipe.

We are now Live! 3rd gen in development!

Www.subzerofabrication.com

Hey guys, so I thought I would get the ball rolling.

Materials to build the final version and the jig will be ordered next week.

What is it?

It is an equal length Y pipe fully constructed of the highest quality 304 stainless available. Fully TIG welded and back purged for a piece that will last the life of your vehicle.

Why equal length?

By being equal length, it is designed in such a way that exhaust gasses are scavenged.


“Scavenging occurs when the rush of exhaust gas leaving the cylinder helps to pull in a fresh air/fuel mixture.

During the exhaust stroke, the exhaust gases escape the cylinder very quickly. This creates a high-speed pulse moving down the header tube. The low pressure behind the exhaust pulse creates a vacuum effect.

During valve overlap (the period when both the intake and exhaust valves are open simultaneously, expressed in degrees of crankshaft rotation), the vacuum pulls out burnt exhaust gases. It also helps to pull in more fresh air on the intake side—the more valve overlap you have, the more critical scavenging becomes.

As rpm increases, the air flows faster and the scavenging effect becomes more powerful.”

“The cylinder is full of exhaust gases at the bottom of the power stroke. During the exhaust stroke, the piston pushes the exhaust out of the engine. Any backpressure or restriction in the exhaust system requires the piston to push harder, which is lost energy. The engine is more efficient when less energy is used to move air in and out of the cylinder. This results in more power and better fuel economy.

Scavenging also has a mini “supercharging” effect. This increase in volumetric efficiency improves cylinder filling, which means more torque and horsepower.”

Since doing this on my naturally aspirated 1GR I have noticed an improvement in throttle response, a slight increase in fuel economy along with the need to downshift for hills drastically reduced. This will deliver even more potent results with a supercharger.

These are going to be built with a 3” outlet merge collector with a 3” V-band. Extensions will be available to adapt your 2.5” exhaust or 3”.

Feel free to ask any questions you may have and I will do my best to help!

 

Interested. Are you able to do a stock connector instead of the v-band?

Currently have a URD Y pipe

 

Collector location is different. So they will all be V band with your choice of adapter to connect a current cat back or exhaust.

By doing V band, it gives the end user the ability to very easily have a whole new system built directly from the V-band. I do intend to get a V-band back to axle dump system rolling as well!

 

FUUUUUUUUUDDDDGE......Thats hot!
Wish I could in Cali.....

 

Watching for possible turd gen things

 

What other changes are required to add this to an otherwise generally stock exhaust?

 

I mean, you definitely can. There’s always a way!

If seconds move well, 3rd will absolutely follow!

Absolutely none! Bolt it up and enjoy!

 

1GR as well, so any reason we can’t strap one to my 4Runner?

 

That’s something I have been exploring the potential of. As of now, I see no reason we couldn’t make it work. What gen?

 

gen 4, 2008

 

Should be no issue! I would just need to find a local that I could pull some measurements from to be sure.

 

I used that portion of gen4 4runner exhaust on my 2nd gen 4wd swap. Should be exactly the same if that helps.

 

That’s my line of thinking as of now as well. Only concern would be any variation at the trans crossmember as things do get a little snug in there

 

well I sub’d either way! Staying tuned

 

Prerunner tacoma exhaust and 4x4 tacoma exhaust are different.

4x4 4runner and 4x2 4runner exhaust exactly the same.

I just rebuilt an 06 2wd 4runner and the exhaust is routed for a transfer case that isn't there.

It's a weird thing I've found. My buddy had a junked 4runner 4x4 that I grafted the exhaust into my downpipe to clear transfer case when I did my 4wd conversion.

So basically if you base it off of a 4x4 it will fit both.

Most of the serious boosted guys interested in a trick exhaust are 2wd anyway. Not to say everyone wouldn't want one, but the guys chasing 400hp from a 1gr aren't getting their tires dirty.

Only platform I have never been under is the Xrunner.

I've seen your work. I would love to be in on the ground floor of this if it's something that you can make happen.

 

There are many weird variations I can’t fully explain between these platforms. But correct. The final revision will be done on an AT 4x4. So it should work for all 1GR applications. Hopefully FJ and 4R as well!

I’m not sure what I picked up for mpg’s as this was my first fill up today. But after 170 miles my gauge definitely isn’t where it would have been before.

On a long road trip today, I started noticing I wasn’t down shifting for hills I always had to. This is a pretty clear sign, it’s definitely doing something.

Anxious to see where this goes. I think most everyone may be able to see some benefit from it!

 

Interested

 

Move over, this may require more popcorn....

 

Please do not PM questions regarding the Y pipe. I would like to keep as much info in this thread as possible for all to see.

No, this is not a copy of the JFR. It is indeed my own design with some slight changes to length etc. This was done to increase velocity.

Yes, extra bungs can be added for wideband sensors. This really should be done at the collector. I’m unsure why it was always done at the flange as this distance is not technically appropriate. But I will put them wherever you request.

3” outlet merge collector will very likely be the only option as 2.5 is going to hurt flow to an extent. However, we will make an adapter that goes from merge v-band to either 2.5” or 3” factory style exhaust connection. Obviously, 2.5” is going to bottle neck a bit.

Pricing will be determined upon completion of final revision.

Please understand. This is not a piece comprised of Chinese materials that lacks back purging etc. This is all top notch from start to finish. Material costs exceed 500$ per. Prices have changed since Roost was doing these, and he wasn’t charging enough to begin with IMO. These are a hand made piece that takes time. I will do everything I can to make these a very fair price for what they are.

 

Put me down as interested. Wasn’t sure if you wanted some of those questions on the thread or not. Sounds good!