VT V8 Exhaust question

[feistl]

Hey guys,

I am putting a 5L VT V8 into a landcruiser and am wondering if i can put the exhaust H pipe (balance pipe) BEFORE the cats and o2 sensors?

I will be running the standard holden tune.

Cheers

[vlad01]

better to have it after like factory as the cross pipe will allow each bank fuel trims to effect the other side and vise versa and potentially causing the feedback loop that screws the fueling up.

[feistl]

Problem is i physically cant run it after the cats. My only real option is to run a 1.5" balance pipe which pretty much connects to the header/collectors.

Is there a way it can be tuned without the o2 sensors?

How bad will an exhaust sound without the balance pipe?

Cheers,

[vlad01]

Why not run a dual in/out muffler with internal cross over?

[feistl]

Sorry i should have been clearer from the start...

The Landcruiser im putting it in is a 40 series, so the extractors head out the side and run down the outside of the chassis (under the tub). Think of an AC Cobra style exhaust...

So pretty much my only option for a balance pipe is to go from the collector on the header FORWARDS and under the sump. After the collector the exhaust heads out sideways and never meets again.

Ive been told a balance pipe is very important for a good note, so im not sure what to do....

I am running a 2.5" twin system (mandral bent stainless steel) with a 200cpi cat and a single triflow muffler. There will be no rear resonator.

As the car is pre 83, it can be 96db although i dont want it that loud.

Cheers,

[feistl]

To give you an idea, here is a pic of the system i did in another FJ40 with a Chev 350.





And this is the VT headers (just started...)

[vlad01]

I don't think it effects the note really. They are important for better torque curve and depending on intake side of things can help balance fueling across the 2 cylinder banks. V8s normally are cross plane so each bank of 4 fire unevenly resulting in poor scavaging. The cross over is like a quick fix to help alleviate the problem.

This why Ferrari and alike run 2 seperate exhausts as they are flat plane. Acting like 2 inline 4s.

[Gareth]

Had plenty of twin system B&S rigs in the shop over the years, The ones that have the exhaust outlets next to each other sound fine. When the outlets are on opposite sides of the vehicle sound pox, in my opinion.

As Vlad mentioned there could be tuning draw backs, I don't think that they are that detrimental. Most B&S boys would agree.

[feistl]

,

That's a concern....

Im half way through that chev exhaust system, and ive got a couple of options.

So far its a twin system with a cat and muffler on each side.

1. Leave it as is
2. Add a balance pipe at the very front
3. Add a "dual inlet, dual outlet" mufflers in the rear to join them.

Thoughts?

[Dylan]

Just run two single systems