Thread: Good engine mods for the 4.0 V8???

I suggest a cam for towing but best is to get a 4.6 with high compression motor and good computer like Haltech or similar.

Huge improvement, I realise its only 600ccm but it just rocks.

Pull yours out and sell seperately if it still runs well and or do exchange or similar.
Have a look at trs website.

Cam
Head clean up and unshroud valves
Port match heads to manifold and Exhaust
Haltech
& 4.6 bottom end....

back pressure?

anyway,, before you spend ANY money on it,, think about liners.

any decent improvement would be more than a D2 V8 is worth,,
not that that should stop you--
or me
but to get any decent torque figures you'll need 4.6 or 5L.

tophat it and stroke it to 4.9.
bullet proof and will go forever.

Originally Posted by Pedro_The_Swift

back pressure?

I guess the back pressure???? hasnt been noted before?

Small exhausts will have plenty of back pressure / restriction so when you put it in a lower gear (no accelerator) and back off, it is more likely to hold its revs - or put you through the windscreen. Eg going through the Burnley tunnel in Melbourne, or down a hill.

With a bigger more flowing exhausts in the same car, when you drop it into a lower gear the revs a more likely to build and will gradually speed up.

I'm no mechanic but have changed a few exhausts on my Falcons over the years, and I wouldn't want to modify it andt bugger up what I guess would be an important thing on decents - without having to use the 'hill descent' button which seems painfully slow....

Would love to have the spare cash around to throw some more 'Cubes' at it, but really looking for any cheaper mods that may free up a few ponies that are already lurking in there!

Sawing a muffler off SOUNDS like you have more power but it's an illusion on a standard V8. The best way to increase your power/engine braking is to drive everywhere in 3rd gear instead of 4th. Multiply your flat torque curve by 30% extra revs and you get more power.
Seriously, save your pennies and get a 4.6 or 5.0 conversion.

I guess the back pressure???? hasnt been noted before?

Small exhausts will have plenty of back pressure / restriction so when you put it in a lower gear (no accelerator) and back off, it is more likely to hold its revs - or put you through the windscreen. Eg going through the Burnley tunnel in Melbourne, or down a hill.

Seeing the injectors switch off on overrun over 1500RPM , it is hard to see how back pressure has any effect as there is no/little hot gas exhausting.
Regards Philip A

Not sure about the D2 but it made a noticeable difference to my D1 when I fitted 2.5 inch free flow system using a Supercat straight through muffler. More torque and revs out freer. I retained the standard exhaust manifolds, which are quite good.

The Rover V8 usually responds to exhaust tuning. The works racing 3.5 SD1s picked up 30 bhp when they ran open exhausts.