Thread: supercharging a diesel

Good luck with it

You may need to do the maths first I'd say.
The blower and pulley size must meet the CFM required at given revs.
That by pass valve on the M90 is not a wastegate. It is only designed to take the load of the blower wile on cruise to reduce drive effort hence better fuel economy. Also a very good way of super heating the intake air

Cant wait till Brian comes across this thread. He'll remind you how frustrating it can be setting these things up.

I wouldn't be running over 8psi with no intercooler on a pootrol

yer well this is the kit that was made up,, i thort the same as its ment to be on 3.6l petrol motors???

iv seen alot of mates turbo them b4 but never supercharge, and were told the safe limit is the 14 mark, id love to get as much on this as wel can, iv looked at the coolers that sit under the blower, but its going to raise it 55mm, and we have allready had a hammer to the bonnet as the pully was touching,

If you want big boost an intercooler is a must. The roots style blower are a pain for heating the intake air. Just leave the bypass valve closed as wont have any effect on max power.
You may have to remote mount the M90 then run a front mount Air/Air intercooler. You would be lucky to get 14psi out of it on the 4.2... The M112 may do better there.

A 4.2 diesel flows a lot more air than a 3.6 petrol at the same revs. 8-9 psi on a 4.2D vs 12psi on a 3.6P with the same pulley sounds about right.

Subscribing.

yer,, well wev put a wastegate off a turbo on there so its closed, wev put a 2 core aloy rad in as well with 3 12' thermos as the last rad fell apart when we pulled it out,

now that its staying cool time to play fuel pumps,

after a few rd tests and tinkering the aultenator has now packed it in gota high output winch one coming tomoz, glad im not paying

just playing with pootrols i just with landrover would look at how things should of been done

I think you need to find out at what RPM the blower achieves the 12psi at, you might find the td42 want rev hard enough to be able to produce 12 psi so would require a different pulley.

Originally Posted by Rangier Rover

Good luck with it

You may need to do the maths first I'd say.
The blower and pulley size must meet the CFM required at given revs.
That by pass valve on the M90 is not a wastegate. It is only designed to take the load of the blower wile on cruise to reduce drive effort hence better fuel economy. Also a very good way of super heating the intake air

Cant wait till Brian comes across this thread. He'll remind you how frustrating it can be setting these things up.

I wouldn't be running over 8psi with no intercooler on a pootrol

Well, I have never had a look under the bonnet of a 4.2 Patrol. What sort of engine is it?

I know it is an in-line six, naturally aspirated.

These questions are relevant.

What sort of fuel system? Mechanical injection or electronic common rail?

How many ports in the head?

Big or small ports and valves?

Inlet manifold. Will it give even distribution of charge air? Most won't.

Exhaust manifold. Restrictive or free flowing?

Exhaust system. Restrictive or free flowing?

Does the fuel delivery system have the capacity to provide double the fuel supply to the cylinders? If you are proposing 14 psi boost then you will need this. Twice the air needs twice the fuel.

You don't just bung on the blower you found down the back of a shed and hope for the best.

Many people new to pressurised engines assume that charging an engine provides 100% volumetric efficiency. Wrong. Restriction is restriction whether under vacuum or under pressure. You need to do the same to valves, ports, manifolds with supercharging as you do when modifying an NA engine for high performance.

I don't think that blower mentioned is big enough. That is the first problem. Get one big enough then work your way through the list above. At least with a diesel you will not encounter the massive ignition and mixture problems encountered with a spark ignition engine when modifying to high manifold pressures.