Hilux Double cab 1uzfe, Exhaust advise.

[Tiaan]

Hi guys & Girls

I mostly use my Hilux for playing off road which includes a lot of dune charging. It is however also used for Camping roadtrips, but I never drive faster than 140kms (87 miles) per hour.
My original exhaust was 50mm from headers into a 2 in one out muffler then 63mm with small muffler that split into two 63mm pipes out the back. It was a crush bent mild steel system.

When this system needed replacement my friend at the local exhaust shop convinced me to let him built me a dual system. His mild steel, crush bent, Dual system was 2x 50mm from headers that went up to 57mm through a 2 in 2 out muffler and then 63mm through a 2 in 2 out muffler and 63mm out the back.

This system was way too quiet for my liking and which lead to me making my next impulsive mistake. I stopped by our local Powerflow Fitment centre and replaced the fist 2 in 2 out muffler with with 2 seperate 57mm powerflow mufflers. This improved the sound and made me wonder whether I should not change to a Y system with more torque, using the powerflow mufflers.

If I cut up my current system I can easily and quite cheaply build a system with 2x 50mm tubing that Y into a single 63mm tube and then Y into 2x 63mm tubing out the back. But what do I do with my 2 brand new 57mm Powerflow mufflers? Can I put them behind the second Y?

 

[Tiaan]

I stopped by the Powerflow Exhaust shop again to hear their opinion.
The lady who runs the place is concerned that the second Y at the end of the single pipe will constrict the flow as the inside diameter of their Y's are 59mm. She feels that as should keep my current dual system and just ad a balancing pipe after the headers, and also maybe change the rear 2 in 2 out 63mm muffler and piping for two separate 57mm mufflers with 57mm pipes out the back.

All crush bent piping, so I guess 57mm dauls would work well enough?
.

 

[Tiaan]

Maybe something like this in 50mm headers into 57mm pipes. We don't need to have cats in South Africa.

 

[BigSteve]

When I went from a twin system with balance pipe to a Y merge I noticed the power smooth out. Felt like I got some torque back from the balance pipe only system but it was also a bit quieter (butt dyno speaking). I posted a video in the exhaust thread with the 2 diff setups and the sound. I would use Y merge for scavenging and better low down power imo and 2 straight through mufflers up the back.

But I'm no exhaust pro.

 

[ckarl0]

Any update? What exhaust system did you get?

 

[Tiaan]

I should never have changed from my original system!! Dual pipes suck. I have to rev 600 rpm higher to get to the same torque.
So I'm going back to 50mm Y'd into single 63 and the Y'd into 2x 63 mm pipes out the back. What mufflers to use and where is the question now. I think I will end up where I started: My original exhaust was 50mm from headers into a 2 in one out muffler then 63mm with small muffler that split into two 63mm pipes out the back and it sounded smooooth and gooood.