Thread: Hypothetical 300 TDI Rebuild

<span style="color:blue">modify the pump first then go from there.....
it controls what the engine does......


no good building a big V8 then putting the standard carby back on.....</span>

Garrycol,
I have no experience with a turbo diesel but have owned and modified several turbo petrol cars.
Effective mods I have found to be
1 Free exhaust system reduces the back pressure on the turbo and aids spool up.
2 fabricated exhaust manifold to Turbo, brings in higher boost at lower revs.
3 Given that its probably not feasible to put in bigger pistons or valves , some port work on the inlet and exhaust ports would release more power, especially bringing the turbo onto boost earlier.
Like a petrol the diesel is a pump and anything that improves pumping efficiency must be good.
4 In a petrol , unless you increase the wastegate opening pressure , the outright power is not affected much and I think a diesel will be similar, but the above mods I bet will transform the performance by filling in the bottom of the power curve. IMHO from what I see most mods on diesels simply add more fuel and give black smoke KOFF KOFF.
5 In a diesel the exhaust temperature is the limiting factor, so any mods you make would have to consider this. All of things I have suggested should improve performance without increasing exhaust temperature greatly.. (er I hope). anyway , they will be better than stuffing many extra PSI into the engine unless you put on a big intercooler, then what happens in sand on a hot day EGT up.
regards Philip A

Not completely on topic, but what about one of the LPG fumigation things?

Cost a bit, but you don't have to take any bits out.

Cheers
Simon

Originally posted by PhilipA

5 In a diesel the exhaust temperature is the limiting factor

Yep but could also add initial compression pressure. On a petrol it can be lowered or raised or left alone. Unfortunately with diesel it's an unmodifiable (such a word ? :? ) attribute of their workings.

Hi Gazz, I can tell you all about the external mods; better intercooler and pump adjustments etc as I have done to mine and get perhaps 25% more grunt. I've fitted an egt guage and can provide info on the temps etc as well. I improved boost by more than 2 pounds at the inlet manifold just with a better intercooler!

But back to the internals I believe Turners Engineering in the UK have improved heads. Not quite sure what they do to them but they are only a bit dearer than a normal replacement head. As the heads go "soft" a new one is often on the rebuild list and as such an improved one might be the ticket. I imported a new standard head and it was only $12-1300 landed here. I found them helpful so they may be able to give info on other possible mods.

http://www.turner-engineering.co.uk/

I'm in Canberra if you want to catch up to discuss sometime.

Cheers

Jim

$$$$$ is all about $$$$ how much do you want to spend..up to 10k or over that go one of those 2.8 Brazilian jobs..then once you've sorted that out you think jesus another 4k and I can get a TD5 in an updated vehicle ...where does it all stop..$$$$

Originally posted by DirtyDawg
$$$$$ is all about $$$$ how much do you want to spend..up to 10k or over that go one of those 2.8 Brazilian jobs..then once you've sorted that out you think jesus another 4k and I can get a TD5 in an updated vehicle ...where does it all stop..$$$$

A valid point - but the original question was to do with internal mods when an engine was pulled down during a rebuild - any engine is relatively cheap to rebuild if you are doing it yourself and the question relates to that - yes there are heaps of external performance mods and they are expensive.

It is just that I can get my hands on a worn out TDI 300 engine and it might come in handy for a future series project I have in mind. I would be rebuilding the engine and was after mods that could be done at that stage to improve lower end performance. Yes big $$$ if you send to an engine rebuilder - relatively less $$ if you do yourself. I have rebuilt a number of engines in the past from 500cc 4 valve bike engines to a v12 Jag. It is not so hard as long as you sub-contract out the specialist bits.

Gazzz

Originally posted by garrycol+--><div class='quotetop'>QUOTE(garrycol)</div><div class='quotemain'><!--QuoteBegin-DirtyDawg
$$$$$ is all about $$$$ how much do you want to spend..up to 10k or over that go one of those 2.8 Brazilian jobs..then once you've sorted that out you think jesus another 4k and I can get a TD5 in an updated vehicle ...where does it all stop..$$$$

A valid point - but the original question was to do with internal mods when an engine was pulled down during a rebuild - any engine is relatively cheap to rebuild if you are doing it yourself and the question relates to that - yes there are heaps of external performance mods and they are expensive.

It is just that I can get my hands on a worn out TDI 300 engine and it might come in handy for a future series project I have in mind. I would be rebuilding the engine and was after mods that could be done at that stage to improve lower end performance. Yes big $$$ if you send to an engine rebuilder - relatively less $$ if you do yourself. I have rebuilt a number of engines in the past from 500cc 4 valve bike engines to a v12 Jag. It is not so hard as long as you sub-contract out the specialist bits.

Gazzz[/b][/quote]

I'm a follower of the old mindset too, older motors can be "worked" into better performers than their new counterparts.

Ahhh a TDI300 project motor! Money no object ? Get the internals up to high quality then make it a supercharged turbo diesel. Be a very toey and wound up on the wick motor but would certainly give you what you seem to desire of a motor and certainly be frowned upon by those of authority unless (large) cash donations are made. Sure would perform though, not necessarily be able to wind the needle off the clock but definately a great tow vehicle providing you could keep water temp below boiling.

EGT shouldn't go up much if the supercharger and turbo efficiency range were matched and set up to work as staged. I'm to believe a factor in increasing EGT under load is the turbo working outside it's range as a result of someone's "fiddling" to find cheap horsepower. DD managed to do super-turbo successfully in the 70's on their diesels, granted only 2 stroke but principal of forced induction remains for four stroke.

What it would cost ? Jap 6cyl supercharger, plumbing, tuning.... dunno... was just a thought I had the today whilst spraying the orchard.