ZD30 Turbos any good for TD42

[oondy]

just noticing that there are often Factory Turbos from ZD30 Patrols on ebay, and they go relatively cheap.

Are these turbos just too small for a TD42 or would they be ok? I wouldn't be after record breaking horsepower but for an average gain would they be suitable?

cheers

OONDY

[manzzook]

I think youd find being made for only a 3 litre they would be more of a hindrance than a help. Itd probably make boost on idle (well not wuite) but the tiny exhaut housing would restrice flow in higher revs a fair bit. Also compressor wheel would run out of flow very early.

[Shadow]

They are a garret T3 i believe (T03?).

What does a 3litre engine rev too? and what does the 4.2 rev too. The amount of flow is proportional to redline and engine capacity.

A 1 litre engine that revs to 20,000RPM needs the same flow as a 10 litre engine that revs to 2000RPM.

[ISUZUROVER]

They are a garret T3 i believe (T03?).

What does a 3litre engine rev too? and what does the 4.2 rev too. The amount of flow is proportional to redline and engine capacity.

A 1 litre engine that revs to 20,000RPM needs the same flow as a 10 litre engine that revs to 2000RPM.

Agree. If the redline of the 3L is 30-40% higher than the 4L then a 3L turbo should be fine (in terms of size and flow). If it is indeed a T3 then it should be fine for a 4L diesel.

EDIT - looks like they both rev to 3600-4000rpm, so sounds like the ZD30 turbo may be a bit small.

[awill4x4]

just noticing that there are often Factory Turbos from ZD30 Patrols on ebay, and they go relatively cheap.
Are these turbos just too small for a TD42 or would they be ok? I wouldn't be after record breaking horsepower but for an average gain would they be suitable?
cheers
OONDY

The reason they are going cheap is unless you have the nouse to wire up a 3 litre Patrol computer to run with your TD42 then they won't work at all.
The reason is they don't have a wastegate they have a variable nozzle exhaust housing which essentially constantly changes the exhaust housing size so one minute the turbo thinks it's a little one then next it thinks it's a big one. This is how they get good response down low and up high but they are also prone to failure if the variable vane sticks and you end up with a massively boosted diesel. (perhaps one of the causes of people reporting ZD30's with 25 + psi boost pressures).
Note these variable vane turbo's are on the Patrol's not on the Navara's which run a standard wastegate type turbo.
So if you see these advertised on Ebay be aware unless you have a ZD30 they are of little use to you and some people are advertising them to suit TD42's. They are easy to distinguish if there's a photo of the exhaust out the turbo as there's no wastegate. Alternatively, have a close look at the variable vane actuater it is very different to a standard wastegate actuator.
Regards Andrew.

[Patroler]

They are a garret T3 i believe (T03?).

What does a 3litre engine rev too? and what does the 4.2 rev too. The amount of flow is proportional to redline and engine capacity.

A 1 litre engine that revs to 20,000RPM needs the same flow as a 10 litre engine that revs to 2000RPM.

Agree. If the redline of the 3L is 30-40% higher than the 4L then a 3L turbo should be fine (in terms of size and flow). If it is indeed a T3 then it should be fine for a 4L diesel.

EDIT - looks like they both rev to 3600-4000rpm, so sounds like the ZD30 turbo may be a bit small.

Not only would it be about revs, but engine efficiency, the ZD30 would be a fair bit more efficient (volumetric) than the td42, a more useful way to look at it would be to look at the power output of a ZD30, 118kw from memory in the latest one, therefore the turbo should be able to support 118kw...

But aside from that i'd agree with awill4x4, not worth the hassle to set up.

[Shadow]

They are a garret T3 i believe (T03?).

What does a 3litre engine rev too? and what does the 4.2 rev too. The amount of flow is proportional to redline and engine capacity.

A 1 litre engine that revs to 20,000RPM needs the same flow as a 10 litre engine that revs to 2000RPM.

Agree. If the redline of the 3L is 30-40% higher than the 4L then a 3L turbo should be fine (in terms of size and flow). If it is indeed a T3 then it should be fine for a 4L diesel.

EDIT - looks like they both rev to 3600-4000rpm, so sounds like the ZD30 turbo may be a bit small.

Not only would it be about revs, but engine efficiency, the ZD30 would be a fair bit more efficient (volumetric) than the td42, a more useful way to look at it would be to look at the power output of a ZD30, 118kw from memory in the latest one, therefore the turbo should be able to support 118kw...

But aside from that i'd agree with awill4x4, not worth the hassle to set up.

youve lost me, Volumetric efficiency?

As i understand it, a 3L engine and a 30L engine running the same compression ratio. If the 3L revs to 10,000RPM and the 30L engine revs to 1000RPM, they will both use the same amount of air.

[tweak'e]

its depends on what boost pressure you want to get out of it. a 3L@ 15lb would be ~ similar to 4.2@ 10lb (the numbers are not accurate but you get the idea)

[Patroler]

They are a garret T3 i believe (T03?).

What does a 3litre engine rev too? and what does the 4.2 rev too. The amount of flow is proportional to redline and engine capacity.

A 1 litre engine that revs to 20,000RPM needs the same flow as a 10 litre engine that revs to 2000RPM.

Agree. If the redline of the 3L is 30-40% higher than the 4L then a 3L turbo should be fine (in terms of size and flow). If it is indeed a T3 then it should be fine for a 4L diesel.

EDIT - looks like they both rev to 3600-4000rpm, so sounds like the ZD30 turbo may be a bit small.

Not only would it be about revs, but engine efficiency, the ZD30 would be a fair bit more efficient (volumetric) than the td42, a more useful way to look at it would be to look at the power output of a ZD30, 118kw from memory in the latest one, therefore the turbo should be able to support 118kw...

But aside from that i'd agree with awill4x4, not worth the hassle to set up.

youve lost me, Volumetric efficiency?

As i understand it, a 3L engine and a 30L engine running the same compression ratio. If the 3L revs to 10,000RPM and the 30L engine revs to 1000RPM, they will both use the same amount of air.

Yea you're on the right track, but volumetric efficiency is the actual amount of air an engine ingests as a percentage compared to its theoretical maximum.

Therefore a 4.2 litre engine has a swept volume of 4.2 litres, but it may only require 80% of that in one cycle - two revolutions.

Newer engines such a zd30 which has twin overhead cams and 4 valves a cylinder are considered in general to have a higher volumetric efficiency than sohc 2 valve and pushrod 2 valve engines such as TD42 - all other things being equal. This is why some engines have more power than others being the same capacity at the same revs, boost etc, they can get more air into their cylinders.

I realise also that we are talking turbocharged engines and that they can fill an engine well over its swept volume, but efficiency diffences still apply, otherwise manufacturers would stay with pushrods for turbo engines and nobody would make good flowing tubular exhaust manifolds

Compression ratio also wouldn't really change the swept volume of the engine as long as the bore and stroke remain unchanged, it'd just alter how much the air got squished at TDC

Also as Tweak'e mentioned boost pressure is another factor to consider.

[Shadow]

Ok, so your saying the 3 litre has a better volumetric efficiency.

Wouldnt that make the turbo more suitable for use on the 4.2? since the 4.2 wont be as volumetrically(that a word?) efficient it wont use as much air as its more modern 3litre brother, per litre of swept volume.

But it sounds like the turbo is unsuitable for other reasons so its not really worth dwelling on the finer details