Increasing boost on the 4x4

[1hotbusa]

Hi there,

I was thinking of posting in the turbo section but decided to post here as the subject is not a bike.

I have a turbo diesel 4x4. The turbo is an internally waste gated model. I am looking at pushing up the boost a bit to improve the holding ability when I'm hauling up a hill on the freeway.

I have been told but think that the person may be wrong, that the boost can be wound up on an internal waste gate turbo by turning the shaft on the actuator shaft, which adjusts the spring. The other way to go is to fit the cheap flow restrictor boost controller from Turbosmart and start winding up the boost.

The motor is a direct injection diesel motor, and is intercooled. I'm talking a few pounds of boost here, not enough to require the fuel output of the injector pump to be adjusted. I know that a diesel will compensate to a degree for excess air applications, which is why they can run without intake air temperature measurement.

Can anybody tell me if I am on the right path?????

[Maj]

Graham sometimes those threads are spotwelded and it will break the shaft before moving, but if yours will move then you can preload the wastagate a little more for another couple of pounds pressure.

I put a switch ,bleedvalve and solenoid on my Patrol and stepped the boost up from 7 to 15 psi , had to turn up the injector pump a bit to get it fueled to suit, only trouble i had was never used low boost again....

[highwaybruiser]

An alternative [but it will cost a few $$$] is to get LPG injection put on it. Gives about 20% more grunt. See here: http://www.dieselgas.com.au/home.htm

[highwaybruiser]

Shit, I can't believe that's my first post since the site moved!

[NEMESIS]

Ahahaha maj!

[spamanglenn]

you can put a bleed valve in the line from the intake to the wategate.What you could also do is take the boost pressure after the intercooler which is the boost the motor actually sees and is a lower number.Hence the turbo boosts harder to bring this pressure up to wastegate level.What i have also done is run a longer line with a 500-600ml canister teed off this boost line.This canister has to fill up to pressure DELAYING the wastegates response to the engine boost.This effectively keeps the wastegate totally shut until you have exceeded the set psi spooling up faster and mildly overboosting on initial throttle then dropping back to your desired level.This gives a heavy vehicle more instant torque.The balance with this is to not overboost too much as the wastegate bounces a little before settling.You can,t kill a diesel with more boost a no extra fuel,it,ll just run leaner(cooler) and go slower.The limiting factor is intake temp and engine life once you,ve added more fuel to suit.Don,t most turbo diesels have a fuel pressure regulator that adds fuel according to boost?Maybe not.Turbo diesels rock i love them.Go for a run in bruces one day and you,ll see what i mean.

[mechanx]

I have seen many diesel engine shit themself because of to much boost , it does not take much either. Adding a bigger exhaust system will increase boost by about 2lb, cheap hp .

[1hotbusa]

Spapool

A question, by delaying the response of the wastegate by makng it raise pressure on a reservoir is just putting in a bloody big boost peak into the motor is it not??? And not enough fuel can kill a diesel turbo application just as fast as a petrol turbo application.

I want to give it a few more psi, that's it. I don't want to go to the point where I adjust the fuel delivery. Agree on the bigger pipe, know that one works. This 4x4 is to keep me happy until I can afford a Landcruiser so simple is better IMHO.

Thanks for the help guys

[spamanglenn]

i only spike about 2psi before it settles.The leaner a diesel runs the cooler it runs,the opposite of a petrol car which can hole a piston.diesels kill pistons,bearings,cranks and rods when you go apeshit with boost and matching fuel.The richer they are the hotter they run.my rodeo has a safari intercooler kit fitted along with a 2.5" mandrel bent exhaust.I also upped the boost from 10-13-14psi at about 75000k,s.It now has 230,000k,s and still uses less than 10L/100km around sydney at about 22-2300kg.I just don,t overrev it 3600-3800 tops with regular 5000km oil changes and the magical militec every 25-50000km.A little suggestion though is ideally a catch can to capture blowby before it returns to your intake will stop the intercooler slowly being oiled up.safari 4x4 never did a chip for the jackaroo,a shame really,it was the first decent efi turbo diesel.