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Propane Injection in a Tdi?


BigSi110

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Not wishing to disrupt the 'supercharging a Tdi' thread, anyone have any pearls of wisdom / advice / experience on propane injection into a Tdi?

Allisport want the thick end of £700 installed for a system and I know Brunel don't do it. Allisport claim around 20bhp extra at the flick of a switch, plus Jerry Thurston's old Disco apparently got better MPG and emissions as a nice byproduct.

I also recall Si at X-Eng playing with it last year with mixed results.

But I just cannot get this out of my head. It's got to be available elsewhere and more affordable yet just as effective than the figure above?

Anyone know whom and / or where?

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Diesel Propane Injection System USD 729.00 (@ 450 GBP) plus shipping. An additional GBP 80 for the on dash controller if you want it.

Bully Dog Propane Injection kit @ GBP 380

Transeco Diesel Magnum Propane Injection kit Site doesn't offer a price for this kit.

These are universal systems. They are designed to fit the standard ubiquitous US propane tank (for barbeques etc.), so you need to make sure that it can be adaptable to a UK tank fitting. The Bully Dog kit with shipping, handling, duty, and even installation by someone else will be less than 700 quid. Just a thought.

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howdy bigsi!! serious3 or flatback90 as i'm known on here!! take a look at this site it shows a homemade set up. i considered tinley and alisport but the cost put me off.

http://www.hammerdownauto.com/blog/2008/09/do-it-yourself-propane-injection.html

and for the solenoid valve check here

http://cgi.ebay.co.uk/1-2-Electric-Solenoid-Valve-12-Volt-Air-Water-B21N_W0QQitemZ300348191409QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ee25b2b1&_trksid=p3286.c0.m14

hth vince

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Hi Vince!! Didn't recognise you with that name.

Thanks chaps. That's looking a little better now.

I'm thinking this is a more reliable setup than going VNT, especially for long trips up Spanish mountains with a full load?

Anyone care to pass comment? An affordable VNT option has also been offered.

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i dont know about more reliable, especially if your using some shonkey DIY kit...

Get the mixture a bit wrong and you'll no doubt put speed holes in your pistons, half way up said spanish mountains.

The VGT otoh is tried and tested, your still using the standard bosch pump for fuelling, and the turbos are used by hundereds of OEM applications,

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...

I'm thinking this is a more reliable setup than going VNT, especially for long trips up Spanish mountains with a full load?

Anyone care to pass comment? An affordable VNT option has also been offered.

To put the last line first, I'm generally negative about propane injection, having been there and done that, allbeit with a different engine.

" ... long trips up Spanish mountains with a full load".

To this full load you are thinking of adding a large and heavy cylinder; even 110s have a finate amount of carrying space and weight capacity.

Check out the availability of LPG as a car fuel in Spain, you may be limited to vapour draw 'barbeque' tanks. UK in-car installations are normally liquid draw tanks.

The only people who make money out of propane injection kits are those people selling them.

Once you take the combined Diesel and LPG fuel costs into account I expect your fuel cost per mile to go up, not down.

Even if you do get suitable LPG cheap enough to get lower fuel costs per mile I don't think you will save enough to counter the installation costs.

Petrol and Diesel have fairly standard quality specifications, the same cannot be said about vehicle LPG. For instance, the stuff in the Netherlands is much better than the stuff in the UK. Ask someone like Gordon Finlay.

Diesel plus LPG should give you increased performance, after all, you are burning more fuel.

A lot depends on the design of the engine AND the state of the diesel fuel injectors. In general, you get better results from improved combustion when the original design of the combustion chamber is poor, and the worse the state of the injectors (emitting drops of different sizes, rather than a uniform very fine spray). Otherwise the performance gain comes from the additional fuel.

It's fair to say that I don't follow the 'industry' closely, but I have yet to see a fuel control system that controls both diesel and LPG, so you cannot increase the cheap fuel while reducing the expensive fuel, while you drive. Neither have I seen altitude compensation for the LPG fuel control system.

Plenty of people have gone to Spain, and returned, with standard vehicles, but if you want more power I suggest the first step is to have your injectors checked, and overhauled as neccessary, and only then look at conventional tuning, to get the engine to burn more diesel.

HTH, even though it reads like a bucket of cold water on your hot idea.

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Thanks. All very helpful. Highly constructive.

Forgot to add I already have a Brunel intercooler and Turner ported head. Injectors are new and maintenance meticulous. According to some, she already goes very nicely indeed. But maybe there's room for improvement?

However, reading about Mo's VNT 90, amongst others, plus the discussion about propane in the supercharging thread got me wondering about taking things a reliable step further.

The Spanish mountain remark only relates to 2 weeks a year, but it's the hardest job my 110 has to do, considering the ambient temps hit 40C last time.

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Diesel is a relatively cool burning fuel, i would think that burning propane as well is going to drive the combustion temperatures up, and if you go too far you risk melting something.

As for davids comment about not backing off the normal fuel, the point being that if the engines developing more power due to the LPG, then for a given amount of power before and after, you need less throttle and hence less diesel to make it when your on LPG.

IF i was to do it, i'd want to ensure it was proper good quality kit.

I would view it in a similar vein to nitrous oxide injection on a petrol motor. If you buy good kit, keep the levels sensible and ensure its setup properly, you're unlikely to melt the engine. Buy a cheapo nasty ebay kit and set it up without a clue, you'll blow it to bits.

I would however say that you should exhaust the normal diesel tuning methodologies before adding more stuff though. Has your fuel pump been tweaked? If it has, can it be tweaked more? I'd get an EGT guage on there, and push the standard diesel fuelling as far as it will safely go, add some more boost if you havent already, etc.

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...

As for davids comment about not backing off the normal fuel, the point being that if the engines developing more power due to the LPG, then for a given amount of power before and after, you need less throttle and hence less diesel to make it when your on LPG.

I agree that's what it looks like, but what is controlling the amount of LPG ingested? If the control is based on the throttle position, or the diesel flow, then backing off the throttle reduces the LPG.

The point I had in mind, but didn't put into words, was about steady state cruising, say motorway work. Here, it seems to me, you only need just enough diesel to light the fire, then ingest lots of the cheaper LPG to provide the bulk of the power required. Of course, a change in timing may be beneficial.

BUT, I don't think any LPG control system gives you the opportunity to ramp up the % of LPG when on a small throttle opening at 3000 rpm, compared to full throttle at 3000 rpm. Also I've never seen offered the facility to change the timing.

Electronic control (did someone say Megasquirt?) offers the opportunity of controlling two fuels, but has any one tried it? Of course, it implies starting with an electronically controlled diesel fuel injection system, while the LPG vapour control could be an adapted EGR system, as some use an electronically controlled valve to govern the amount of exhaust gas being ingested. Obviously in this mode you blank off the exhaust gas input, and use the LPG vapour as the input.

But I think we are gettng away from the original requirement.

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Well, in my limited experience of engine tuning, if you are running the big slab intercooler, ported head etc., you probably have reached the limits of what your engine can put out reliably. If you asking another 20 hp on top of that, you are probably looking at a 150 hp from an engine that originally puts out 110 hp. About +35%. It is possible, but to than expect it to take you to spain and work really hard in very hot conditions, will involve a yellow taxi return one day for sure.

From what I have seen, with that increase in power, you want to start thinking about some funky pistons and that kind of thing.

For sure some people will shoot me down shortly and tell I dont know what I am talking about but there you go, my opinion.

Daan

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Daan, i wouldnt say 150hp is anywhere near the reliability limits of the 300tdi block etc. Its built like a tank, and when you consider something like the VAG 1.9TDi can be hopped up from 130hp to near 200 on stock internals, and even the TD5's regularly are pushed to 170-200hp you'll see that 110 to 150hp really isnt a big deal.

I recon you can get 150hp from a TDi using nothing but the stock engine hardware. Your reaching the limits of the stock injectors at that point anyway so thats were i'd be aiming for if i had a TDi. Big cooler, lots of boost and plenty of fuel and you'll be knocking on the door of 150hp. To get it set up properly though you need an EGT gauge, go too far without a guage and you'll break something.

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Daan, i wouldnt say 150hp is anywhere near the reliability limits of the 300tdi block etc. Its built like a tank, and when you consider something like the VAG 1.9TDi can be hopped up from 130hp to near 200 on stock internals, and even the TD5's regularly are pushed to 170-200hp you'll see that 110 to 150hp really isnt a big deal.

I recon you can get 150hp from a TDi using nothing but the stock engine hardware. Your reaching the limits of the stock injectors at that point anyway so thats were i'd be aiming for if i had a TDi. Big cooler, lots of boost and plenty of fuel and you'll be knocking on the door of 150hp. To get it set up properly though you need an EGT gauge, go too far without a guage and you'll break something.

Yes, i know all that, I think mechanically it will probably stand up to it, but the headgasket will let go at this kind cylinderpressure, and you will start to see more blowby past the pistons. I saw a few TDIs like this and oil leaking out of every seal, due to high crank pressure. Just because you can achieve these qouted power outputs now, doesnot mean it will achieve it, say 100000 miles down the road.

For example, the JCB dieselmax landspeedrecord engines in standard tune deliver 140 hp, in landspeed record tune 750 hp.

It is achieved by changing all the internalls to the highest spec known to man to stay allive, but even so, it lasts only 30 min with this kind of power.

If you are willing to accept less live of an engine, by all means tune it to death, otherwise, know your limits.

Daan

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