bigger turbo

[damo667]

Hey
I've got a 1990 2.8l D Bighorn and I'm pretty happy with it the only thing that lets it down is it doesn't quite have enough top end to overtake the millions of campervans around these parts who all sit at 90k's 10k's below the speed limit.
The bighorn sits nicely at 100 but getting there from 90 takes a while so overtaking is difficult.
I've heard that the later 3.1 turbo fits straight on.. so my question is.. Is this true and is it just a case of unbolting one and bolting back on the other?
Also will this make any difference to my power and get me just enough to overtake with confidence?

Cheers
Damo..

[jellis]

have you fitted a bigger exhaust and upped the fuel and boos and added an intercooler?
without doing that i cant see a bigger turbo benifiting you at all.
possibly it would make it worse

[mudslinger]

i would not put a 3.1 turbo on, they are not serviceable nor rebuildable. and they arent too reliable. as just being said exhaust and boost and fuel been wound up? intercooler is a good idea i find i get 2 to 3 more psi at highway speeds.
if you decided to put a bigger turbo on you sacrifice full boost at low rpm

[4x4SWANNY]

The guy who bought my old 2.8 was mucking about with the fuel screw once and got the thing to do 170kph...
said it drank half a tank of diesel from waimate to timaru and back .. thats a hundred k round trip..
A little tweak will give you more go for sure Damo.

[damo667]

cheers guys.. It has the standard intercooler it came with..
by the sounds of it a bigger exhaust and a bit more boost is the way to go.. I dont want much more power just enough to overtake.. does anyone know if cranking a bit more fuel and turning up the boost a little will affect the torque? I live up a 'steep hill'..

[geeves]

More fuel=more power=more torque as long as there is enough air to burn it all.
the 4jb1 does not produce its torque low down and upping the fuel might not help if this is your problem. Use a lower gear but then Ive seen your local streets and starting on them could be interesting. You can select low4 without locking the hubs to get you going. Its not recommended but you can shift back into high range at lowish speed once you are on the flat.
Best way to get low end power out of the 4jb1 is 2.5 inch exhaust. Low restriction filter like a K&N or Finner filter and snorkel. The snorkel works because you get rid of the restrictive pipe behind the radiator

[damo667]

Thanks Geeves I was talking to someone the other day and they said that a snorkel helped get a load more air in and upped the power thanks for confirming that.
It is something I was thinking of installing anyway
Probably wait for the exhaust to need replacing to swap for a 2.5 inch and air filter I can do tomorrow.

[damo667]

Thanks Geeves I was talking to someone the other day and they said that a snorkel helped get a load more air in and upped the power thanks for confirming that.
It is something I was thinking of installing anyway
Probably wait for the exhaust to need replacing to swap for a 2.5 inch and air filter I can do tomorrow.

[geeves]

The amazing thing is that most of the extra power comes low down. Have usefull power from 1700 rpm or so rather than the 2300 before. It also goes hard all the way to the red line once the 2.5 exhaust is added

[damo667]

Cheers
That is where I need the power at the moment to get up the steep hills around here without having to slip into first..
I would like a bit more top end too.

Can I just run this by you to confirm..
I am going to upgrade the exhaust to 2.5,
Fit a snorkel and finer filter,
Turn up the fuel screw a lttle on the pump,
And turn up the boost.

Most of this is simple enough, just a couple of questions..
Do I have to fit a boost controller.. seems simple enough to do.. but if I can achieve the same without I will.
How far back do I need to go with the exhaust? just the muffler or all the way back to the manifold.
Also can you or anyone recommend a snorkel?..

Thanks again
Damo

[geeves]

Most boost controlers work by bleeding pressure away from the wastegate so it doesnt get the true pressure. It is a cheap simple way to increase boost but with diesels its fit and forget as there is no point lowering boost later. In my opinion its better to permanantly adjust the wastegate although this can be a mission

[damo667]

ok.. this is my first vehicle with a turbo so its all a learning curve to me.. do you think its simple enough or should I get a desiel mechanic to do the work?
I've just bought a K&N air filter (america via ebay as my local Repco hadn't heard of it )
So thats done.. Just looking into the best snorkel option theres one on trademe that looks ok.. I've heard the fun bit is inside the hood but should be able to handle that ok..
I've found the fuel screw on the pump and as I belive turning it clockwise will give more fuel.. I was goint to try 1/8 of a turn a time and see how she goes..
The muffler is on the way out so when its 'kaput' I'll look into the bigger exhaust..
So the boost is the only thing I've got no idea on..
willing to give it a go if its simple enough..

Cheers for all your help