Outer Limits 4x4 Board

Looking at upgrading the turbo on a GU 4.2 TD6 but not sure of the best option. Have heard the roller bearing units are the the best. After some ideas of which way to go.

Has anyone upgraded a factory turbo GU and what kind of results has this acheived.

A mate bought his GU and the factory turbo had alredy been high flowed and it hauls ass.

LudaCris

I was told by a diesel specialist that you tend to loose bottom end power when hi flowed. I want to improve this.

Unfortunately the more you ask these guys the more confusing it becomes.

i'm actually now thinking about high flowing my turbo as i have seen a few done and i think it might be worth while. should expect to get about 120kw at rear wheels with about 12psi of boost.

ron moon did this recently and it was in 4x4 australia

however if your thinking of getting another turbo altogether you'll probably need new manifold as well then it just comes down how much money you want to spend. you most likely wont get much change from a few thousand thrown at it.

roller bering will spool up quicker, they are a more efficient turbo.
you have to match the turbo flow characteristics to your engine

this may meed different housings...

start from here http://www.turbofast.com.au/TFmatch.html

looks like a GT25 would be a good start.

you can never have to much information

cheers,
Jes

Was it a reasonable increase with RM vehicle, did the torqure curve improve in the rev range or just an overall increase.

If I was to go with a different turbo I was hoping there would be a exhaust housing with the same mount as the Nissan. As with most car manufactures this is probably not the case for its most likely to be a special.

How much power do you want to get and how much money do you want to spend. I've fitted a 3in dump pipe and custom exhaust $700 and a boost controller to the factory turbo for 12psi boost $110 and then dyno'd the truck to get 110kw or 150hp at the rear wheels with 33in tyres $165. Total cost of $975. I'm only going to a bigger turbo with a bigger waste gate to accomodate the propane injection and flowed head.

Toughnut, do you know what sort of boost can you run on the stock diesel internals without doing harm/increasing wear etc? how safe is 12psi?

what was the stock boost at if you increased it to 12psi? do you know how many kw before the mods/what the increase in power was?

would you say it was worth it because im looking at quite the similar setup.

did it change fuel economy at all?

The factory turbo runs at about 7psi, you can safely run the boost upto 15psi as long as the exhaust temp is OK with the extra fuel you need to utilise the extra boost. The first run I did was 84kw. Factory apart from exhaust and the water/air intercooler (tapped into the heater hoses though). After playing with the intake piping and winding the fuel and boost up I ended up with 110kw / 150hp. Didn't get a torque figger though. I'm upgrading my turbo to get the bigger waste gate which is needed get the most out of the propane injection. You don't need the bigger waste gate but its like pumping up the boost and fuel without upgrading the exhaust, you'll get some benefit but not as much as doing it properly. I won't be running more than 16psi on the new turbo anyway as I want a reliable engine rather than chasing the extra little bit of hp or torque. I'm going to get the head ported and flowed. Since I'm taking the head off I might as well upgrade the conrods and pistons while I'm at it. Providing I have enough cash and only if the engine needs it. In the end it should be good for around 160kw or 220hp at the wheels. Thats just an estimate on information that I've been given. I almost forgot about the fuel economy. When I drove down for Outback Challenge, my navi drove his GU cab chassis down as well which is bog stock. I had better fuel economy than he did. Around town though it isn't as good if you drive like I do. It's fun to drag commodores from the lights and see how pissed they get when they can't shake you.

You have a couple of choices as said above. If you hiflo it, you get to keep all factory fittings and can then fit a bolt up mandrel system with dump pipe. If yours is intercooled you can go as high as 100 - 125 rwkw safaly. If you want more, then a garret gt25 would be the ideal suit. But a manifold an or adapter may be require along with some sligfhty different plumbing.

All depends on how deep your pockets are and much power you want.

have u guys done the pump up with the anneroid thingy? when fitting dts turbo to td42 westend guarenteed 60% increase over standard with hi flow, aneroid and 3 inch dump and exhaust..
the turbo kit which includes 3 inch dump is good for 35%, the high flow and aneroid do the rest.. this is backed up by the christie boys who have probably the most leathal td42 in the country..

viperguy wrote:this is backed up by the christie boys who have probably the most leathal td42 in the country..

thats a big call

alot of trucks down south that have over 170kw at the rear wheels i'd be surprised with a standard manifold and non major pumps and only a high flowed turbo where you could get that amount of power.

sorry morkz.. they got head work and stuff done too.. they never been near a dyno but there truck absolutely smacks ass.. they run a gq auto behind it from a tb and u gotta see this thing fry its 38 swampers on bitumen..

i know its a big call and guys probly got more power but it still is a leathel deisel

I am selling a T28 roller bearing turbo....

Check for sale section.

Mk

damn i wish my diesel was lethal..

not that i really need it to be... but still.

(i just realised you were all talking about 4.2? i have a diesel so figures would be different no doubt..)

I was talking about my TD42T. Matt Bolger and Cam Blackmore have 300hp at the rear wheels but have spent the better part of $20 000 on the engine and turbo. The other benefit of a slightly larger turbo is that it produces the same boost easier, which means that the air temps after the turbo are lower. The down side is it takes a bit longer to spool up in most cases.

i screwed up again!

there was supposed to be 3.0 between "a" and "diesel" in my last post..

All of these mods still apply to a 3.0L but you also need to upgrade the computer. The principles are the same though.

i did a hi-flow turbo{GU] upgrade and the low end grunt is still SHIT.my crusier hzj 75[boost comp,big injectors,denco turbo] eats it [but only low down] and my injected v8 chev GQ smashes it!!!

viperguy wrote:sorry morkz.. they got head work and stuff done too.. they never been near a dyno but there truck absolutely smacks ass.. they run a gq auto behind it from a tb and u gotta see this thing fry its 38 swampers on bitumen..

i know its a big call and guys probly got more power but it still is a leathel deisel

nah its cool

i remember the 4wd monthly add about nick mannels GU extra cab talking about how such an awesome job west end did to it i.e. power and torque but it just doesnt compare to what everyone else has done..

And yeah i forget the queenslander like kym bolten and matt bolgers GU and there a few other that have over 160kw @ the wheels with 35/36" tyres.

I have already fitted a dump, 3" system and had it tuned. Boost was running around 9psi and the aneroid was adjusted. The torque comes in a lot earlier and is much better to drive, but you can always have that bit more.

Was even considering changing the exhaust housing to boost it up earlier. Full boost a 2000/2200 rpm is to late in my opinion, it would be far better at 1500.

Gawd you all make me envious my gu only has a motson stage three.

Care to expand more on that. What does stage 3 mean, got any dyno graphs to show?

Went from 95hp to 120hp at back wheels after stage 2 of motsons powerup. See Overlander add.
Sorry my previous message should have read stage 2.
This is on a 4.2td GU 2000 model Y61 wagon.
Torque from 550lbs to 700lbs
Do not know what the conversion figures are.

Went from 95hp to 120hp at back wheels after stage 2 of motsons powerup. See Overlander add.
Sorry my previous message should have read stage 2.
This is on a 4.2td GU 2000 model Y61 wagon.
Torque from 550lbs to 700lbs
Do not know what the conversion figures are.