Baja Burley

Hi Guys, Im new to the LS scene and have done alot of searching to decide on these engines. I have a landcruiser in australia that I tow my trail rig with as well as daily drive.

The truck currently has a tricked out 4.2 turbo diesel. So I love the torque from driving on boost. It runs 20psi from about 1900rpm.

My question for you guys is what turbos should I use for a brutally torquey twin boosted LS truck motor??

Im not really phased by big HP numbers just really good streetable power for towing. I want to go twin turbo just because I can! And it brings the turbos down to a size thats really common here is Australia.

My initial thoughts were a pair of GT2860's, big fuel pump, bigger injectors and a tune. Ive fabbed manifolds and such before so thats not an issue. Even If I can have it making max 300whp REALLY early. Id be happy with that.

But as I said Im new to LS's so let me know what you think!
Luke

gametech

iTrader: (1)

You are both overthinking and underestimating this. A tiny little 67mm garret behind an LQ9 will easily rip the tailshaft out of any 4l60 trans you can build for it, and still not choke out until twice the rpm's diesels have accustomed you to. The idea of twins is really only window dressing at this stage.

stevieturbo

So are you looking to use second hand turbos, or new ?

TBH given how cheap BW's are, I see little reason to restrict your options, but a pair of 2860's would probably be a decent starting point.

Or a pair of VF34's or something from a Subaru.

But absolutely no reason why a well sized single turbo wouldnt get the job done, a bog standard single BW S366 might not be far off and they're very cheap, or something like this even better

http://www.agpturbo.com/borg-warner-...3-13009097047/

FourG63 97GST

iTrader: (1)

agreed, my 6.0 with 67mm made 400ftlb by 2500rpm, over 500ftlbs by 3000-redline. on the 7psi wastegate spring. keep it simple, boost fixes things

Baja Burley

I agree these things do make good torque. But I want more! my Diesel makes 500ftlb at maybe 2000rpm. Just nowhere near the horsepower.. I do believe that id be able to package twins nicer in my cruiser engine bay as its very wide, thats my main reason for it. I absolutely agree that a single would do the same job.

Id be looking at brand new 2860's or maybe good condition second handers. My goal is to move the power down the rev range as much as possible without choking the big motor with little snails hanging off of it. Ive never really dealt with turbos smaller than t28's. Could I go smaller?

stevieturbo

There's no doubt you could go smaller.....but how much smaller before they physically choke the exhaust is another matter

Interestingly this popped up on UK forum recently before they got booted off for advertising. I doubt they are genuine Garrett turbos although they are using their naming schemes

http://www.goatperformance.com.au/

Not really too much different than the APS or GenTT stuff ? Or maybe AVO ?

Maybe if they had some graphs of their GT2871's it might help ?

Tuskyz28

A 4 inch stroker crank with a small turbo for MAX torque down low..... a 4 inch crank will alone will make the motor a torque monster..

stevieturbo

A stroker would definitely improve things...although requires a total engine strip down.

Baja Burley

Yeah Im not real keen on pulling the motor down. Because then I'll think "while im here" and end up spending 10k on the motor before I even buy turbos.. I think I'll start looking for 2860's then and we'll start from there. Thanks for the advice guys.

stevieturbo

I dont think they're quite 2860, but a lot of the Nissan 200's use a very similar turbo. Could maybe pick some of them up cheap ?
Or other small options are a lot of the 1.8t VW stuff, they're bound to be plentiful down there too ?

Baja Burley

Looking further into the 2860's all are internal waste gate.

Will the 1 internal gate on each turbo be enough for this thing to stop creeping boost?
I'll run all the appropriate gauges as Im used to driving by the gauges on my diesel, but ideally i'd want a no fuss tune on this build..

It would make plumbing a lot easier and neater too.

stevieturbo

Really the only way to find out, is to try. They should be fine in most cases....but there is no rule of thumb

depending on the shape etc, often most castings can be ported/smoothed a little which can dramatically help prevent any creep. Just depends how badly flowing the current wastegate path is at present. Some are ok, some are terrible.

roastin240

iTrader: (13)

Could always keep it cheap and go with a couple Buick Grand National turbos. they are 0.63 A/R turbine housing (T3) standard wheel...can do about 300-350whp each and would spool real fast. Wouldnt be a bad choice for a 4.8 or a 5.3 but if I was going 6.0 I would run 2 Holset HY35's....they would spool good and be capable of 700-800whp, and have a T3 flange as well, but larger compressor housing/wheel (somewhere around 58mm-60mm comp. inducer I think)

gtfoxy

I ran the late-GN turbos on a 302. With TFS heads & stock 86 cam it made about 600CHP 10.65-10.70's @ 125-128mph @3K lb's consistently) on not quite 14psi. Came on pretty decent, about 3,300rpm I was at full boogy. Response on a 5.3 should be better.

Big issue with that turbo is if you use the gated elbo & the gay 2-bolt inlet horn. I hacked mine up & used a 3" pipe & retained the flapper. You could plate it & run an external. The horn just makes them a little harder to package.

TBH, I would use a different turbo for the reasons mentioned above. As an aside I ditched that system @ built a twin TO4B system with .69 A/R P-trims & it spooled the same & made more power. Ran the same ET on 10psi as the GN's did on 14. Pump gas vs race gas also

roastin240

iTrader: (13)

Ya they are very old technology and has the strange 3 bolt turbine inlet setup. I want to say we tried swapping a different .63 A/R off a Ford 2.3 or a 84-86 300zx turbo because they "should" be the same turbine wheel ansd turbine housing should work but I think we found out they were very slightly different wheel designs...As far as I know, those are the only T3/T4 Garret branded hybrid turbos that came in a factory gasoline spark ignition OEM factory vehicle.

Baja Burley

OK, so keep the 'dump pipe' flowing nicely and it should be able to waste enough exhaust.. Otherwise I can package in a little 35mm either side later on to save it..

Could be a silly question, Blow off valves.. Are they needed with this kind of setup? Im only looking to run 9psi. I hate the sound of them, but if its gonna save my motor, Im sure i can muffle it somehow.

gtfoxy

Plumb the BOV back into the turbo inlet & you won't here it as much as vented to atmosphere.

stevieturbo

At such low boost there would be minimal sound from a BOV. You could easily opt to run without them though

Or do as foxy and OEM do, just re-circ back into the inlet tract pre-turbo, post filter and it should be almost silent.

SethU

As with any engine build, well matched components pays dividends.

Part of what makes Diesels torque monsters is the short duration cam timing, which maximizes VE at a low rpm. (hoping to avoid a really long discussion within that statement. It's a way deeper subject than this generalization)

The smallest aftermarket cams available for an LS may not be small enough to really target your goal area. However, any smaller than what's available would really like a smaller intake port... and now we're talking money.

However, I would absolutely put a small aftermarket cam in. Many have shown strong (20+ lb/ft) improvements in bottom end torque over the stocker (N/A).

The correct diff gear ratio will likely help make up for any shortcomings in off idle torque.

Keep us posted on results. I'm curious myself.

Baja Burley

Interesting point Seth..

I'll be running a built 4L60E through a 1:1 transfer case and into a 4.11 rear end. Keep in mind this is a 7000lb truck on 36" tires. Currently the 100km/h revs are about 2500rpm (through factory 5sp manual). Ideally I'd like to see this drop with some overdrive. So maybe stepping up the rear end to a 4.33 will get me that initial torque, but the poor thing will be singing at 110+km/h..

I've just ordered a pair of GT2871's to go on!! So we'll find out soon enough