URD Y Pipe Dyno Result

For those interested the truck was strapped to the dynojet today with OV Tune 2.0. Truck is manual so no problem starting runs in 4th gear at 2000 RPM.

URD Y pipe gains 5 peak WHP. This sounds meager but more importantly it gains 9 WTQ between 2200-3300 RPM. As we all know, this is the problem area for this 3.5L and because the torque increase happens the moment you hit the throttle, (the dyno just happens to start at 2k RPM), YES you can actually feel this as a tangible difference in throttle response. Something the 3.5L desperately needs in my opinion.

Of note, this Y pipe is almost brand new. It was sprayed with VHT and installed today on the dyno for testing purposes only. It is for sale. Any Washington trucks interested send me a PM.

 

Love to see before and after dyno results. Question, was this bolted to an aftermarket exhaust or the stock exhaust/muffler?

 

Surprised that taking the cats out and reducing back pressure also resulted in a torque boost.

 

"back pressure" helping torque is some dumb thing that was made up to explain what someone didn't understand. Exhaust velocity and pressure wave tuning is all that matters to improve torque as far as exhaust scavenging goes.

 

Agree. Nice to see before and after dyno results posted. I think there’s some misconceptions about back pressure and how these motors respond. In this case i think it has more to do with the crushed segment of the OEM Y pipe. The truck has a TRD exhaust.

The stock Y pipe is actually very restrictive so I’m not surprised. If you look under your truck at the pipe as it crosses from driver side to passenger side you will see a significant crushed segment. This design carries over from prior generations and I’m not entirely sure why.

 

^^- This ?? Would like to know.

 

The flattened section of pipe isn't a restriction. It's the same cross section area, just a different shape. Volumetric flow is unchanged.

 

Can you explain those dips at 3300 rpms? Shifting?

 

I was wondering the same. I thought the OV2.0 had smoothed those out considerably.

 

It’s not shifting, that’s probably either the tune (and or) cam changing / moving between FI and DI.
(FI used in the original sense, Fuel Injection not forced induction)

 

I thought the same until I cut it in half! If you cut the Y pipe at that crushed segment you will be surprised to find a pipe within a pipe with significantly smaller diameter than that on the passenger side. Again, not sure why they did it.

I assumed the same. However, according to @tonered it was never completely tuned out. The amount of torque the OV Tune 2.0 provides over stock down low is significant. It’s just unfortunate the dip wasn’t entirely removed.

I was under the same impression.

 

I am surprised at the size of the dip. It didn't feel that way driving it.

I have ideas to tune it out, but it is up to you. Lemme know.

 

Yup, I tucked the stock crossover up higher, and there is indeed a smaller pipe inside what you can see. Super strange and dumb in my opinion

 

So...is replacing the stock Y-pipe with an aftermarket one worth the money (don't knowhow much $) and any gains in MPG?

 

When does AICS kick in?

 

It kicks in 2600-2700. I have seen it to kick in at 2300.

 

Thanks for posting this. It's great to see what the gains are on fixing the factory y pipe mess.

 

Not my truck in this clip, but the URD Y does sound pretty good with the TRD cat-back, drop in filter and intake flow accelerator:

https://www.youtube.com/watch?v=Z6RecMgVOto

 

Posted for sale:

https://www.tacomaworld.com/threads/fs-3rd-gen-urd-y-pipe-450-picked-up-bellevue-wa.742824/