Thread: Headers/extractors for Range Rover

Walker

I'm no expert on the topic but when my mate changed his engine he brought 3.9 extractors and had to change the gearbox cross member to a later model to get them to fit.

adrian

Walker

No expert either but extractors on my 4.6 RRC a couple of years back did nothing for it at all bar some sound improvement.

No performance gain, quite the opposite and cost a bomb, I went Mandrel bends of course and than stainless pipes, what a waste.
Looked good though.

Best of luck.

Yes, I wasnt expecting massive improvement, but it must make a difference. The exhaust manifold on the 3.5 and 3.9 is very very restrictive. But the biigest improvement is definately in the noise, much much better sound.

Adrian, yes it was the crossmember that had me worried. I know the 3.5 headers are made to go under the frossmember, not sure what the later ones do. If they go over the top then it might be worth sourcing a later crossmember. From memory the later crossmembers were round, is this correct?

Yeh i'm pretty sure they are round.Disco ones are round.I would just go the 3.9 headers.

I'm sure i read somewhere that the original 3.5/3.9 efi headers with 2 into 1 pipes were about as good as you'll get without going to a full tuned length system, i dont know of anyone he spent the $$$ and got an improvement they were happy about - seems like a waste of money to me unless you get them cheap or free. On my old 3.5 rangie the biggest improvement was made with some mild match porting of the inlet manifold/heads and slight opening up of the exhaust ports along with a single 2 1/2 " pipe with free flow centre muffler and hotdog on the rear using stock exhaust manifolds.

Agree with loanrangie.

To do properly, do the cam, haltech or similar injection, some proting and polishing and than the exhaust.
Ditch original, go mandrel bent where you can and try and get tuned for best flow and make sure there is sufficient back pressure.

If too loud it can become annoying but the sound can be music to your ears also.

Too much power can put extra strain on drive-train etc, so be careful cause the 4.6L is pretty good as it is.


After mine was finished the 4wd dyno joint on south rd in SA tuned mtor for 107kw at the wheels.

Car was awesome.

I sold it because of never ending electrical gremlins that kept shorting stuff out.
3 Times at auto electrician in one week.

Moral of the story, Exhaust is only 1/4 of the story. Unless you just want to hear the howl of the pipe.

Go for it.

Ok thanks all. I will go with the 3.5 headers then I dont have to worry about changing the crossmember. I already have a 2.5" exhaust with single free flow muffler.

The Rangie is just a dedicated off-roader, so noise is not a problem. Only problem will be getting it passed with the engineer. It will be running on straight gas and I did do some porting and polished up the inlet manifold already. Cam is a towing cam cause I want low torque rather than high hp. Not sure what the headers and new Y pipe will cost but I am guessing maybe $500. I just want to get them on before I put the body back on the chassis.

Adam,
Try Exhaust Fix in Croydon - heard really good things from mates with some pretty wild street cars.

Cheers
Dave.