VT V8 Exhaust question

[feistl]

Problem with going under the gearbox is it will reduce ground clearance. We are working as hard as possible to maximise clearance, don't really want to run an extra pipe underneath.

Our engineer says the engine must meet all requirements of the car it came out in, hence needing charcoal canister etc. We are happy to run cats/o2 sensors etc.

The only real problem is there isnt an easy way to put a balance pipe after the cats/o2 sensor. My only real option is direct from the header/collector, or not to run one. But apparently they reduce overall noise and give a much better note and slightly more torque. I am just worried about upsetting the ECU/tuning.

Is it possible to move the O2 sensors in front of the cat (And have them in the collector?).

Cheers

[Dylan]

If emissions isn't a real problem and off road is it's intended use then I'd forget the O2's if they're being difficult.

[vs ss]

Is it possible to move the O2 sensors in front of the cat (And have them in the collector?).

Cheers

From factory they would have been in front of the cats anyway.
Just stick them in the new bit you welded onto the headers and done.

[delcowizzid]

No cats no O2s here lol just a super Turbo chambered muffler each side before the diff

[delcowizzid]

And 2" balancepipe I'll see if I can find a pic think it went under the gearbox mount

[Charlescrown]

Hey TdracerTD that's an interesting statement you posted. Almost right except for the canister bit. What do you do with a 1976 Ford Escort (ADR27C) that didn't have one. Fit one to it? They vented the fuel tank to the crankcase then purged it off after starting. Not a good idea but that's how they were made. Just thought I would make comment. On the exhaust does it really matter if you don't have a balance tube? Will it really have an effect on power?

[HQ355]

Check your engine number, my VT block was bought direct from local Holden dealer, as it's a replacement spare part to suit 1969-1999 model Holden's it only needs to meet the emission standards of the car it's fitted to, in my case HQ. I'm not running cats or canister and its legal in Vic I'm also running balance pipe but I didn't really notice any difference from before and after

[feistl]

From factory they would have been in front of the cats anyway.
Just stick them in the new bit you welded onto the headers and done.

OMG I feel like such a bloody retard.... You are right, they are in front of the cats...

I must have been thinking of the ls1 which had them further down.

So I should be able to put the sensor at the collector and run a balance pipe right after it??

Omg that solves all my problems. I owe you guys a beer

[TdracerTd]

Check your engine number, my VT block was bought direct from local Holden dealer, as it's a replacement spare part to suit 1969-1999 model Holden's it only needs to meet the emission standards of the car it's fitted to, in my case HQ. I'm not running cats or canister and its legal in Vic I'm also running balance pipe but I didn't really notice any difference from before and after

This was what I thought! The were a heap of people putting VS 5.0L into older commodores for that very reason, They got all the benefits of a modern engine and didn't have to hobble them with all the later model pollution gear. State to state must be different and I guess times have changed too. Logic would have it though that the applicable ADR should be the one that applies to the car.

[feistl]

The pollution stuff doesn't really worry me, its not a performance car so losing a few kw for cats etc isnt a big deal.

Mostly i want the low down torque and exhaust note, plus fuel injection for cold starts etc.

Should be a nice upgrade... Fully rebuilt 195kw 5L V8 with LPG vapour injection and EFI compared to a I6 3.9L with 93kw and a carby.

Ill build the first exhaust with the O2 sensor in the collector and a balance pipe just behind it and see how it goes.

Thanks everyone for your help.

Cheers