Thread: supercharging a diesel

I was talking with a bloke about turboing my Isuzu and he mentioned supercharging may be better, so i'm reading this thread with interest.
He reckoned using the aircon condensor for a water/air intercooler would be the go.

Originally Posted by isuzutoo-eh

I was talking with a bloke about turboing my Isuzu and he mentioned supercharging may be better, so i'm reading this thread with interest.
He reckoned using the aircon condensor for a water/air intercooler would be the go.

If supercharging worked well on diesels, you'd be able to buy factory supercharged diesels. This thread is worth following, but for your Isuzu a turbo is the answer.

Thanks Dougal,
I knew there'd be a good reason supercharging isn't popular, I think my mate just wanted to tinker-he recently supercharged a daihatsu charade that he found at the rubbish tip

Don't go there, Supecharging a 4BD1 will produce quite a few other issues like torsional vibration destroying the blower, excessive intake noise, overdriving the unit due to 3200Rpm max available engine speed, thereby requiring all sorts of 'blow off valving ' etc etc etc.

As Dougal says, utilising the waste heat energy from a diesel with high speed expanding exhaust gasses to drive a turbine is wayyy more useful than driving a supercharger from the crank....

This goes for most diesels In my opinion.

Using a supercharger to provide instant boost etc prior to turbocharging would be worthwhile if you so desired, but personally a simple efficient turbo charger and intercooler works wonders for any compression ignition engine.

JC

well, driving this in its erly stages puts a vnt to shame, yes i no top end it will loose out abit but its a 4wd, so low down pull is what were after,

plus god dose it sound goodi wana put one on my td5 just put it inplace of the idler pully, perfict size,

Originally Posted by stig0000

well, driving this in its erly stages puts a vnt to shame, yes i no top end it will loose out abit but its a 4wd, so low down pull is what were after,

plus god dose it sound goodi wana put one on my td5 just put it inplace of the idler pully, perfict size,

The Td42 will rev harder than a 4BD1, the engine is very smooth and therefore will be easy on the blower, but fuelling is paramount. You may require a lot more than you think, so watch the EGT's.

I was looking at a 1HZ with a Sprintex on it some years back, went quite well but had all sorts of overheating issues, had to run a very free flowing exhaust and back off the fuelling to reduce it. This in turn started to reduce the reasons it was fitted in the first place. IIRC the owner ended up fitting a turbo and intercooler (A Safari system I think) and never looked back.

Not saying it can't work, far from it but IMHO turbocharging a diesel makes more thermal/ engineering sense.

JC

Originally Posted by stig0000

well, driving this in its erly stages puts a vnt to shame, yes i no top end it will loose out abit but its a 4wd, so low down pull is what were after,

plus god dose it sound goodi wana put one on my td5 just put it inplace of the idler pully, perfict size,

Well, if you can persuade BAS to engineer a fuelling solution then why not run a supercharger AND the factory turbo???

But then you'll just break every bit of the drivetrain....


JC

I wonder why GM were so successful with their supercharged diesel engines? Turbochargers were added to GMs but had to have different fuel pumps and porting to be successful.