Another Rover V8 turbo question

[300bhp/ton]

I know this is difficult to answer with any degree of accuracy. But is anyone able to give me an idea how much hp a 3.9 Rover V8 would make with a turbo.

I was thinking setup wise:

- stock tidy 3.9 from a Disco
- new cam and followers (stock)
- running Megasquirt or similar EFI
- tuned to be safe on 99 RON

not sure on turbo setup or type/size yet or boost. Just want a ball park idea. Think the engine in n/a trim should be making 182hp. Would you safely be able to see 300hp with the turbos?

Thanks.

[fatjon]

With moderate boost 300BHP should be easy to achieve but you may need to lower the compression ratio. If you are not going mad with the boost then just a set of low compression off the shelf pistons will do fine.

[stevieturbo]

300bhp would be easy.

[toger13]

i have seen 500bhp @ wheels with my 1.6 saxo so 300 should be quite easy on ab rv8 lump aslong as you keep it cool

my 3.9 disco is quite tempremental with the temp lol

Si

[stevieturbo]

Whilst overly used.....I think LOL is quite appropriate here.

[fatjon]

Quite.

[fatjon]

I use a pair of Garrett GT2860RS units on a 4.5 V8. They are slightly non standard with a 0.86AR. They may be a little large for rover 3.9 as mine is a flat plane and revs quite a bit higher. Maybe a pair of T25s might be better giving a theoretical limit of about 400-450BHP. They will spin up quicker and that will suite a low revver well giving bags of torque low down.

This might be of interest depending on how much space you have at the sides of the engine.

rover v8 turbo manifolds off the shelf!

http://www.chevroletls1.com/rover_v8.html

Otherwise you will need to get busy with the old tig welder and some tubes!

[300bhp/ton]

fatjon said:

I use a pair of Garrett GT2860RS units on a 4.5 V8. They are slightly non standard with a 0.86AR. They may be a little large for rover 3.9 as mine is a flat plane and revs quite a bit higher. Maybe a pair of T25s might be better giving a theoretical limit of about 400-450BHP. They will spin up quicker and that will suite a low revver well giving bags of torque low down.

This might be of interest depending on how much space you have at the sides of the engine.

rover v8 turbo manifolds off the shelf!

http://www.chevroletls1.com/rover_v8.html

Otherwise you will need to get busy with the old tig welder and some tubes!

Thanks. Not looking for silly power just an upgrade on what I've got already.

I've got a 3.5 RV8 TR7 that I had planned to sell, but it has a lot of sentimental value and I'm finding it hard to let go. So want to improve on it's current 220hp. I did think about turboing the 3.5 but with a 4 brl carb
and small displacement I think it would be wasted money for little gains. A head and cam 4.6 sounds nice too but is silly expensive.

While looking about I noticed the 3.9's are still cheap and plentiful. And I kinda reasoned a turbo 3.9 would be cheaper and make more power than a n/a 4.6. Hope my reasoning is sound?

The other option I've been looking at is a Lexus LS400 DOHC V8 as they seem capable of 300hp with just bolt on mods and are very cheap to buy.

If I wanted to go single turbo on a 3.9 Rover what would be a good 2nd hand turbo to look at?

[stevieturbo]

Just hunt about for turbos. Some of the tuners might have some biggish singles lying about for sale from time to time.

Although if 400bhp is all you are after, that shouldnt be difficult to find. As far as turbos go...that isnt overly big. Holset do some new turbos that are fairly cheap brands new.

If doing twins...which will be more comlicated in terms of installation, then there will be dozens of cheap turbo options out there.


But if on a relaly tight budget. Simply turbocharging using a carburettor can work just fine. It may not be very economical comapred to efi....but it will still make power.
My old RV8TT ran a Holley for years before I switched to efi. And TBH...the 3.9 and smaller turbos went about as fast as any engine combo I had for it.

[CraigW]

300bhp, there's a guy on the Classic range Rover forum who has a 1990 3.5 V8 Janspeed turbo, seem to recall talk of 280bhp.

[Boosted LS1]

FJ, I turbocharged my TR7-v8 using a pair of rotomasters blowing into a holley with mechanical secondary'ies. Nowadays you could use t3's or something equally compact. It was a very satisfying experience.

[fatjon]

I think for a single turbo I would go for a gt2871 or GT2876. The single turbo option may well be quite easy using modified TVR manifolds that come round to the front of the engine commoned into a single flange. A point on using carbs with a turbo, remember they have to be pressure sealed and the fuel delivery pressure needs to rise with the boost. Apologies if this is stating the obvious but I don't know if you are a very experienced modifier or this is a first attempt at such a project.

[300bhp/ton]

fatjon said:

I think for a single turbo I would go for a gt2871 or GT2876. The single turbo option may well be quite easy using modified TVR manifolds that come round to the front of the engine commoned into a single flange. A point on using carbs with a turbo, remember they have to be pressure sealed and the fuel delivery pressure needs to rise with the boost. Apologies if this is stating the obvious but I don't know if you are a very experienced modifier or this is a first attempt at such a project.

Thanks. What vehicles would I find those turbos on?

All info is good

I'm not new to modding or using spanners but never done anything like this before and find some of it complex. And as I'm on a budget I don't really want to mess up as it'll only cost me
money.

[fatjon]

I don't think you will find them on any production vehicles so far as I know. Owen Developments is where I get mine from. Circa £900 I think. That's the disadvantage of a single turbo for a big engine, there's not many production cars to take it from.

Re using megasquirt (which I have on a few turbo cars). There is a regular on the MSEFI.com forum who has done MS on rover V8 before. He goes by username jsmcortina, it may be worth looking at some of his posts as fuel injection is the way to go for a turbo motor. Much easier to tune with a laptop and ecu that jets, needles and bob weights.



http://www.jsm-net.demon.co.uk/

[Boosted LS1]

fatjon said:

I think for a single turbo I would go for a gt2871 or GT2876. The single turbo option may well be quite easy using modified TVR manifolds that come round to the front of the engine commoned into a single flange. A point on using carbs with a turbo, remember they have to be pressure sealed and the fuel delivery pressure needs to rise with the boost. Apologies if this is stating the obvious but I don't know if you are a very experienced modifier or this is a first attempt at such a project.

Good thing about the holley is that the float bowl vents would be within the plenum you fabricate to replace the airfilter.

OP, I have a single tvr custom cast 'Y' piece replacment which takes a T3 flanged turbo. I've also got a custom turbo which should flow almost 300 bhp and I've got an aluminium plenum for a holley

[300bhp/ton]

Thanks Boosted really love some of the stuff on your website. Going to have a think about all the setups. I do like the idea of a Lexus V8 a the mo as it'll be a good step up from my current setup on a small budget but still leave plenty if room for more power later on (in the nature of some twin turbos). It'd also give me opportunity to replace the Lt77 too.

[DaveVXR]

Not sure on the packaging but would a rear mounted turbo be easier to install?

A few details here if you've not heard of it - http://www.balancemotorsport.co.uk/products.asp?su...

Not associated in any way, just think it looks like a neat solution if you've got room at the rear.