Un-turboing a diesel

[ob1]

Strange request I know.

I am getting a S2A 88 It is a project vehicle. It will hardly ever go on the open road, just some town driving. If we go into the bush I will likely hitch it to the Subaru on an A-frame.

My long term goal would be to get it as close as possible to original. Not concourse condition, but at least with a Land Rover diesel. I prefer diesel over petrol any way.

Problem is that the original 2.25 is very scarce in South Africa. If you find them they are in concourse vehicles, or rusted away in the seller's yard long ago. We also never really got the 2.5 NA diesel.

Lots of guys removing 200 and 300 Tdi's in favor of cheap imported Lexus (yuck) VVTI V8's. These motors come in from Japan, and can be had for a song. It is so popular that a couple of engineering firms now have an off the shelf adapter plate to the R380

I am weary what the Tdi will do to the running gear of a standard Series. It is the original 4sp gearbox (was it LT75?) There is a Salisbury at the back so that helps, but still. Plus the physical room in the engine bay. I don't want to bring the grille forward and loose the series nose.

So what about sourcing a tired 200 Tdi, redo everything inside. Then set it up to run without turbo.

1. Is it possible?
2. What would it entail?
3. What would be needed? I suppose new intake and exhaust manifold?
4. New diesel pump or restrict the flow somehow to add less diesel to less air in combustion?
5. Would direct injection work without a turbo?

Thanks

[greenstream]

Have a look here www.glencoyne.co.uk

[Tanuki]

You can de-turbo a 200/300TDi relatively simply: just remove the turbo/pipework, and blank off the connection on the "boost compensator" part of the injection-pump.

This will give workable fuelling - basically the boost-compensator senses when there is boost from the turbo (if it's there..) and adds extra fuel to give more power. If there's no boost the boost-compensator won't add extra fuel so you don't have to worry about overfuelling.

You shouldn't have any problems with the standard Series transmission behind a de-turboed 200/300: people fit Rover V8s to standard Series transmissions without them exploding - though it has to be said, a good-enough idiot can always break anything if they try hard enough! Sympathetic and understanding driving-style counts for a lot.

Personally, if I was re-engining a "series" I'd probably go for the 2-litre-turbo *petrol* engine from a Discovery MPi (did you get those over in .za?) - Light, powerful, and just *loves* to rev!

[Chicken Drumstick]

200Tdi with the turbo, sans intercooler. All fits in a Series, no need to move the front panel.

Standard Series gearbox and transfer box.

[Ex Member]

Get a 2.5NA exhaust manifold and a 2.25D intake manifold. This makes the intake plumbing to the stock series location simple and easy.

Personally I would leave the turbo on... It is super easy to reduce the on boost fueling to limit torque if you are worried about the drivetrain strength.

[FridgeFreezer]

This has been covered many times in the Series forum.

[Yostumpy]

OR leave the boost fuelling blanked off . but also leave the turbo. You'll get xtra air in , and it'll create a lean burn engine. No smoke. I ran my 110 300 tdi like it for a while to check its effect on mpg, but it made no difference. runs well tho' much better than I thought it would.

[ob1]

Thanks all.

Good news

Need to spend more time in the series forum

[Ex Member]

OR leave the boost fuelling blanked off . but also leave the turbo. You'll get xtra air in , and it'll create a lean burn engine. No smoke. I ran my 110 300 tdi like it for a while to check its effect on mpg, but it made no difference. runs well tho' much better than I thought it would.

That won't work. Without extra fueling, the turbo cannot produce boost. The boost fueling rate is easily adjustable with the fueling pin and can be adjusted to limit boost levels to whatever you wish.

[Yostumpy]

That won't work. Without extra fueling, the turbo cannot produce boost. The boost fueling rate is easily adjustable with the fueling pin and can be adjusted to limit boost levels to whatever you wish.

but if the engine is turning, then the turbo is spinning, thus giving some boost, at lower rev range anyway. Its quite peppy of the mark, but obviously not as powerful, will cruise at 70mph, but will slow down on hills as your fuelling is limited. Quite fun to drive actually, its a bit like.......a non turbo tdi in a series, especially around country lanes, because with a good tdi , you get a bit lazy, because of the power, but without the extra fuelling, its fun as you have to be up the rev range a bit, and it feels a bit nippier, even tho' it probably isn't. I did think about interrupting the fuel boost pipe and diverting it into the cab, and plumbing in an on/off gas tap. Absolutely NO smoke at all. In fact I'm going to fill up tomorrow and blank it off again, and try another tank for mpg comparison.

[Ex Member]

The mass flow from the exhaust needs to be higher than the intake to produce boost. You do not get energy for free. You need fueling to make boost.

Regardless of any setup, there is never boost at low rev range. These turbos do not produce boost below 1800 rpm.

[ejparrott]

I've been running 200TDi for many years. I point blank refuse to move front panels and yes there is room to work in the engine bar. My 88 has no intercooler, and is still on the original Series transmission.

TDi's don't kill Series gearboxes, lead boots do!