V8 y piece exhaust

[CraigE]

Just a quick one and not interested in negative legal requirement comments at this stage, as just looking to play a bit and see any gains. Are the D1 v8 and D2 V8 header to muffler y pieces the same fittings and dimension on a D1 & D2? I know the D1 does not have Cats. Looking at a better flowing exhaust and maybe 1Cat in place of the big main muffler. If a D1 y piece fits I am sure I could get one fairly cheap from a wreck to play with. I know some of the D2s have O2 sensors, but you can weld these in right? Or would I need to get a custom made Y piece?
The centre muffler is going to come out anyway, so thought I may play a bit.
My understanding of the ADRs is you only actually need 1 Cat in the system anyway, correct me if I am wrong.
Cheers
Craig

[steve_a]

Nope, the D1 is annoyingly different. I had the y piece sheer at the flange on one side and bought one for exactly this reason.
From memory the D2 is slightly wider and I think the meeting point is in just the wrong spot. So there is a bit of cutting and welding to be needed.
I never got far enough to figure out if the flanges and pipe sizes were compatible.
You can probably get a shop to make one (though my offer was off the books...) or get a wrecked on and do the welding yourself.
Problem is that with 2 cats a second hand section isn't cheap, the cats are probably $40 each scrap...

[FisherX]

The DI and D2 Ys are a little different but if your handy with a welder and grinder you can adapt the D1 Y piece to fit. I bought a set of D1 headers and fitted them to my D2 last year and welded in the 02 adaptors.


BUT DON"T BOTHER!!! It make absolutly NO power difference all. I was just noisy and not the good noisy either. The thin wall headers let alot of noise into the cabin that was kind of annoying. I tested the before and after on my "Dynolicous" app. This is the Disco's last run with the 4.6.



https://www.aulro.com/afvb/images/imported/2016/10/493.jpg

So they didn't stay in the car for long. But I do have a set of D1 headers modified for a D2 out the back if you are interested :)

[Roverlord off road spares]

I had a D2 y pipe that I de cated only until i could source a new y pipe with cats.

Without the cats the noise drove me insane. when you pulled up at thr lights hoons in WRXs would try to drag me off thinking I was also a hoon.

The drone, was too loud to bury by turning the radio volume up.

Apart from being illegal I wouldn't do it. A normal standard V8 burble is good, but the noise like marbles running down a rain on acceleration is not nice.

Re the O2 sensor holes, you can plug them with an appropriate size bolt. The exhausts might have bolts blocking off the rear cat holes anyway if not NAS spec.

I think you will find you need 2 cats as it defeats the purpose emissions if having pollutants going down one bank


Cheers, Mario

[BigJon]

I think you will find you need 2 cats as it defeats the purpose emissions if having pollutants going down one bank


Cheers, Mario

Not if you have a single cat after the Y piece joins together.

[CraigE]

Not if you have a single cat after the Y piece joins together.
Yeah what I was getting at, maybe putting a cat where the muffler is.

[Slunnie]

I don't think the D2 header/Y piece are very well designed. Infact they are very budget. If it will clear, I think you'd be better off trying to fit the D1 manifold and Y piece and removing the D2 lot.

The Disco2 setup doesn't look like it will flow well.

https://www.aulro.com/afvb/images/imported/2016/10/500.jpg

https://www.aulro.com/afvb/images/imported/2016/10/501.jpg

https://www.aulro.com/afvb/images/imported/2016/10/502.jpg

https://www.aulro.com/afvb/images/imported/2016/10/503.jpg


Compare this to the Disco1 y-piece below and it looks like it will flow a lot better. Note, the D1 and D2 manifold outlets look similar, but I cant recall if they were compatible

https://www.aulro.com/afvb/images/imported/2016/10/504.jpg

https://www.aulro.com/afvb/images/imported/2016/10/505.jpg

https://www.aulro.com/afvb/images/imported/2016/10/506.jpg

[bee utey]

. Note, the D1 and D2 manifold outlets look similar, but I cant recall if they were compatible
I've fitted D2 manifolds to a 3.9 RRC, same as D1, they are identical.

[Battler]

My D2 exhaust system came off my Classic Range Rover. The only modification I needed to do was to bend the shield near the Y pipe a bit.

[CraigE]

My D2 exhaust system came off my Classic Range Rover. The only modification I needed to do was to bend the shield near the Y pipe a bit.

Interesting we have a RRC down at the BILs farm, may pull the exhaust off it and see.

[Battler]

I should add I have headers with no cats (hi flow cats going in very soon) so you might have to use the RRC manifolds as well.

[Pedro_The_Swift]

Yeah what I was getting at, maybe putting a cat where the muffler is.

Having had a standard exhaust, and one with the rear removed and one with the centre removed,,

remove the rear.

the internal noise/drone is just rediculous with the centre removed