Thread: Turbo upgrades

IMHO the best value would be to have the turbo high flowed (and refurbished at same time). Increase boost setting of wastegate to approx 18 psi, adjust fueling of injection pump (egt gauge required), clean any buildup from inside the intercooler and fit silicone hoses. If you then need a little more power and response, upgrade the exhaust system to lower back pressure.

If you don't think that will be good enough, then you should look into a kit with a variable nozzle/VGT turbo.

One obstacle when you want to upgrade the 300Tdi turbo is that the turbine housing is integral with the manifold - when you remove the stock turbo, you don't have a manifold to mount another turbo on. This increases the cost significantly.

So if you are not in a hurry, search for a 200Tdi manifold at a reasonable price, then you can look for a better turbo - if not a VNT, then a good ball bearing turbo.

But you will need to increase the fueling or you have wasted your time and money. A VNT turbo will give more boost at lower revs but for an improvement at the higher end, you need to burn more fuel - the turbo upgrade will provide more air to burn the increased fuel cleanly.

I bought a 300 Tdi 130 from another member on here who had just fitted an Alisport VNT kit with upgraded intercooler and radiator and fueled up. I am quite impressed with the performance. It goes much better than the Td5 Defender that I just sold.

Cheers, Murray

Thanks guys for that, I looked at the ALLI Sport one and emailed them a few questions, it looks good but was not sure of cost to bring in the country. How did you get on?
Also a higher flow intercooler would help???

Originally Posted by philco

Thanks guys for that, I looked at the ALLI Sport one and emailed them a few questions, it looks good but was not sure of cost to bring in the country. How did you get on?
Also a higher flow intercooler would help???

The previous owner imported the kit, so I'm not sure what the total cost was to get it here.

A bigger intercooler will deffinately help if you plan to turn up your fueling, and fitting an EGT gauge is highly recommended to keep temperatures at a safe level.

Cheers, Murray

Originally Posted by philco

Thanks guys for that, I looked at the ALLI Sport one and emailed them a few questions, it looks good but was not sure of cost to bring in the country. How did you get on?
Also a higher flow intercooler would help???

Yes, a larger intercooler will help. I am just in the process of sorting out something to upgrade the power of my 300tdi... exhaust would be a good start, as would a larger cooler. Fueling is also critical. But, you are going to need fuel to match the boost.... whilst it is good for diesels to run lean, (that's the deal with diesels) to lean and they run hot. So you would need more fuel THROUGHOUT the rev range! Not just up top. I have not had a look at my mechanical injection pump, but I would assume that there is built in boost compensation. To a point. Hence the need to "wind in" more fuel to get the stoic mix right.

Originally Posted by klappers

... Fueling is also critical. But, you are going to need fuel to match the boost.... whilst it is good for diesels to run lean, (that's the deal with diesels) to lean and they run hot. So you would need more fuel THROUGHOUT the rev range! Not just up top. I have not had a look at my mechanical injection pump, but I would assume that there is built in boost compensation. To a point. Hence the need to "wind in" more fuel to get the stoic mix right.

Nope!

A higher air to fuel ratio will help a diesel run cooler, and will lower EGT.

Diesels run considerably higher air fuel ratios than stoic... usually about 22:1 at full load (will be much, much higher at light load). Smoke ratio is about 18:1 and stoic... is about 14:1.

The 300Tdi has a boost compensator - it is there to reduce fuel as boost pressure (hence air) drops, and so reduce smoke for pollution reasons.

With an upgrade turbo, more fuel will usually be needed to spin a larger turbo up to obtain higher boost pressure (because it is driven by the energy in the exhaust gas), as well as to make more power. However upgrading to a VNT turbo of similar size could see some improvement without more fuel, but will still perform better with sensible increase in fuel.

You won't make more power just by adding more air to a diesel engine (adding air to a petrol engine will increase power because the carbie/F.I. system will correct the air fuel ratio).

So a 200Tdi manifold will be better to add a new turbo, as the waste gate is attached to the turbo instead of the manifold? so doesn't matter on turbo type? I was looking at a Garrett T28 or T30 to fit with a 3 inch mandrel bent exhaust and no mufflers

The 200Tdi Disco manifold is better as it uses a T25 type bolt on flange, and scuttlebutt used to be that it flows better than the 300Tdi manifold anyway.

There's a thread here from a while back where I posted some phone pics of a 200Tdi manifold on a 300Tdi which is a Bruce Davis upgrade.