More power from the Rover V8?

[Deicist]

Hi all,

Bit of an open ended questions this, and not specifically related to TVR but....

I have a 2001 Range rover, with the 4.6 'thor' Rover V8 and I'm looking to get a bit more grunt out of it. Now, realistically I know my 2.5 ton beast is never going to pick up its heels like a sports car, but I'm sure there's more power there with a bit of a cash injection.

First off, I'm thinking a new cam shaft? The original one has done 156,000 miles now so even putting a new stock one in it would probably help, but I've been eyeing up the Piper 'Torquemax' camshaft kit, which includes new timing chain etc.

Then maybe ported heads? Do the stage one heads actually make much difference over the stock ones?

Turbo / Supercharging might be an option as well, I don't think there was ever an off the shelf kit for the Thor engine, but maybe you TVR Types know of something that could be made to work?

[FunkyGibbon]

Try these folks for some ideas ..

http://www.tornadosystems.com

They support the 'thor' system as well.

Mark's disco was surprisingly rapid.

[phazed]

I have had several 4.0 discos in the past, they're not fast! They are smooth though.

What does a good 4.6 Thor put out, 180bhp?

I always wondered how my 400 horse RV8 would fare in a disco/RR. Pretty good I would imagine but to get there you would have to spend 12K or maybe more.

Surely your best bet would be to go turbo, cheap and easy.

Rebuild engine first, soft cam etc. Would the Thor self learn turbo speak, I have no idea!

[blitzracing]

All id say is dont believe all that's written on some sites about the piper cams- you wont find Pipers the cam of choice of many V8 tuners- I fitted a 270 to a 3.9 expecting a quoted extra 20 BHP, and apart from a very limp extra 1000 rpm above 5000 rpm, I simply lost a wad of mid range torque. I wish Id fitted an MC1 as they pull like a train as the RPM rises. Maybe not so suitable on a 2 tonne car however. Go and speak to V8 developments.

[MisterT]

phazed said:

What does a good 4.6 Thor put out, 180bhp?

I seem to remember my 2001 4.6 Thor RR had about 220bhp (standard engine, according to LR specs), can't recall what the torque output was.

[phazed]

Just had a quick gander on the web and yes they quote 221 BHP for the 4.6 but they also laughably quote 20 mpg average!

Mixed motoring on my 4 L disco, it always returned 12 mpg , 10 when I converted it to gas.

[phazed]

Just had a quick gander on the web and yes they quote 221 BHP for the 4.6 but they also laughably quote 20 mpg average!

Mixed motoring on my 4 L disco, it always returned 12 mpg , 10 when I converted it to gas.

[900T-R]

In a car as heavy as a Disco/RR I'd be sorely tempted to supercharge the lump.

The preferred route to seriously up the power of a N/A 4.6 would be to take it apart, put 4.0 pistons in for a higher static compression ratio and do some serious work on the heads including intermediate large valves, topped off by a cam of your choice, induction and engine management work (the GEMS and Thor hardware will be fine with the exception of the std injectors, no need for a wholesale replacement).

[Boosted LS1]

You'll find RR turbo headers on a well known auction site. They work really well.

[QBee]

My TVR has a standard 4.6 RR engine in it, RR cam and RR heads, but the top end looks standard GEMS, not the later Thor.
I stuck a turbo on it, a GT35 kit I believe.
It gives 395 bhp at 7.5 psi (which is pretty low), and 525 torques.
Nuff said?

[Byker28i]

Find a tvr engine and drop it straight in?

[Deicist]

If I wanted to stick a turbo or a supercharger on my current engine, what's required? From reading around, 6 or 7psi gives a nice 'boost' to performance without wrecking the engine so.....

Can I stick with the stock (Thor) ECU or will I need an aftermarket one?

Do I need to switch to a carb, or can I keep fuel injection?

I presume the turbo manifolds just bolt on and a turbo just bolts onto that?

Can I stick a smaller turbo on each side to reduce turbo lag?

[Boosted LS1]

Deicist said:

If I wanted to stick a turbo or a supercharger on my current engine, what's required? From reading around, 6 or 7psi gives a nice 'boost' to performance without wrecking the engine so.....

Can I stick with the stock (Thor) ECU or will I need an aftermarket one?

Do I need to switch to a carb, or can I keep fuel injection?

I presume the turbo manifolds just bolt on and a turbo just bolts onto that?

Can I stick a smaller turbo on each side to reduce turbo lag?

Mark Adams can offer a mapped chip.

Turbo manifolds bolt straight on. You can use twin or single turbo configuration.

Rovers don't suffer from lag as they have plenty of exhaust gas to power suitably sized turbo's. T25's, t3's etc for a twin conversion or a slightly larger single.

Usually you'd start with a HP target and then pick the turbo/s that meets airflow requirements. 350/400 hp would be a good target imo.

[QBee]

I can confirm no turbo lag - it's not a 1980s rally Audi running 30 psi boost!!

[ChimpOnGas]

QBee said:

My TVR has a standard 4.6 RR engine in it, RR cam and RR heads, but the top end looks standard GEMS, not the later Thor.
I stuck a turbo on it, a GT35 kit I believe.
It gives 395 bhp at 7.5 psi (which is pretty low), and 525 torques.
Nuff said?

^^ This has to be the smartest approach by some considerable margin ^^

[Boosted LS1]

I have just sent this to an RR owner in Portugal. He wanted a single turbo conversion and has used a twin scroll turbo, hence the divider in the manifold.

[Deicist]

Okay, since my engine is a Bosch / motronics 'thor' is it possible to just stick the blower on the cool air side of the MAF and retain the stock inlet manifold, injectors etc rather than faff around with a new manifold?

[Dominic TVRetto]

That would be an exhaust manifold...

[Deicist]

Ah! Durr, I'm an idiot. Okay, so that exhaust manifold goes on the bottom of the engine, the turbo mounts to that and some pipework goes from the cool air inlet to the turbo and then back to the MAF sensor bit of the air inlet yes?

[Steve_D]

Deicist said:

Ah! Durr, I'm an idiot. Okay, so that exhaust manifold goes on the bottom of the engine, the turbo mounts to that and some pipework goes from the cool air inlet to the turbo and then back to the MAF sensor bit of the air inlet yes?

The whole lot will likely be on a new aftermarket ECU which will probably do away with a MAF. In which case the connection will be to the throttle body or perhaps a plenum.

Steve