supercharging a 1.5 diesel???

[lawny]

Alright.... so i love my diesel.... the economy and even the clapping from under the hood has its appeals (i love it when people look at you like something is wrong with it and move away really quickly like its about to blow). But...... power, i want some!!! I want to start my first ever engine conversion/rebuild and I was thinking about looking down the turbo direction but checking out a few other threads, it seems like a lot can go wrong and a bit of a waste of time and money power wise. I then stumbled across a thread where GLDgti mentions something about supercharging a 1.5...... yes i started dancing like a banana. i do have a few question for everyone though.

what is involved??
any ideas on cost to do it??
has anyone seen it done before??

[dubai gti]

hey Mark...interesting one, and I've observed my mate's woe's on his MG K3 over the years, which was originally fitted with a Rootes blower/supercharger. He ended up finding and using a Japanese blower, which like many items from over there, was pretty much identical to English 'over-engineered designs'...anyway, my point is, Japanese blowers are cheap and should be too hard to adapt, the hard part will be which carby to use...how's the condition of your donk, b4 you start thinking about 'charging it ??

[lawny]

my engine has done quite a few k's, still runs really good but i was thinking about buying another engine and rebuilding as well, for learnings sake, never really tinkered with an engine

[Greg Roles]

Well I've done a lot of research into supercharging diesels, and I still can't find a real good reason why it isn't done more often. Given a diesels low rev range, need for low down boost, and excess of torque to turn a blower i would have thought it to be an ideal candidate, but there isn't a whole lot about on the concept.

The upside is you can't make the diesel too lean, as it basically runs from ultra lean down towards 20:1, so if you have too much air it's not going to damage anything. For a carb it's going to take a fair bit of experimentation, and you need to remember that a diesel is WOT all the time and flows a LOT more air than a similar sized gasser, so I'd be looking at a blower from at least a 2L car for a 1.5 oiler. I've seen electrically clutched Merc blowers for their 2.1 kompressor engines show up on US e-bay at about $500 and that would be a good sized unit I would think.

Best blower is a Sprintex "lysholm" style as these are the most efficient, with the common Roots / Eaton and Centrifical blowers coming a respective second and third. Roots style heats the air up more than a lysholm, and the centrifucal ones are more top end like a turbo, so I reckon it would be tricky to get good drivability from in a diesel. Simplest install though!

Plumbing will be tricky, and you'll need an intercooler, but I'm sure if you scour e-bay and pick up some secondhand name brand parts, and even just a cheap chinese 2" inlet kit, you'll have a lot to play with. When I had the idea of supercharging my TDI, the biggest problem apart from handling the crossover from blower to turbo was where to mount it on an east west engine so that it was getting drive and was somwhere near the inlet area. Not straight forward in the modern TDI, but may be different for the 1.5 as I'd assume you have a lot more room.

The merc blower is the "ideal" lysholm too, and with an electronic clutch, you could turn it on and off, with say an OTP electric flap bypass for cruise when you don't need the "weapon". You'd need some way to enrish the fuel though when the blower was on....hmm, we need a carb expert here......????

Real men tinker on engines mate, the rest buy girly bling to look pretty. Get into it!!

[Preen59]

Carbies? Guys we're talking diesels here. No carbies in sight. I know the 1.9 TDI's have a boost reference enrichment built into the injector pump somehow that enriches the fueling when it comes on boost. But the beauty of diesels is that you could probably just use the standard gear and turn up the smoke screw a bit. That's pretty much all my mate did with his old Hilux when he turbocharged it..

You can't actually get a "lean" condition with a diesel as pumping in more air just absorbs more heat on the power stroke and makes more power.. In very simple terms.

Mazda 626 s/c diesels had centrifugal blowers and they were pretty awesome. It really depends on the size and overdrive rather than the type when it comes to them. They had boost from idle and were very nice.

I'd go one of them or a roots blower but it's up to you dude.

Just be wary that apparently the 1.5 bottom end isn't the strongest, they also don't have piston squirters like the 1.6TD units.

The ONLY and i mean ONLY advantage of a turbo over a blower is "free HP", but i'd have a blower any day of the week. You're not after earth shattering numbers after all.

[Jarred]

it wouldn't be cheap I'd imagine. be better off to start with a 1.6 or 1.9 and do it in an M-sdi style. ie use a mechanical pump that has boost enrichment,.

if you were only running say 7 to 10 psi, you could probably get away with a standard pump, with the smoke screw turned up, as preeny mentioned.

it'd pretty much be all custom, and there would be very few people who would be able to tune it PROPERLY!

i like the idea though. was planning on looking into it over summer.

[gldgti]

right.... go look on www.vwdiesel.net and do a search - its all been covered there, and still noone seems to have done it and documented it.

i had thoughts of doing this many times but never got to it - decided that a turbo was the way to go... then i ended up just having turbo engines.

anyway, no reason you cant do it. go for a toyota blower - simple, self contained (have their own oil system) and cheap to find, and really just the right size. you want to run up to about 15psi. there's a 1.4l toyota one (SC14) that would be perfect.

people talk about longevity of these units at high boost, but i dont think its really a concern - mainly because on a 1.5D they will be doing half the rpm compared to a tuned 4AGZE engine.

you dont even need to "tune" it once its on really - all the setup is on the injector pump.

now for the hard part - basically, there is bugger all clearance to run a fat belt from the crank up beside the chassis rail. this is the number 1 problem. i often wondered if a duel V belt would fit. worth a try i reckon, anyway.

[lawny]

this would be the one you were talking about?
http://cgi.ebay.com.au/JDM-SC14-Ford...ht_4432wt_1219

[Greg Roles]

I'd assume that gold pipe is a bypass for higher cruising speeds / low rpm restriction reduction?

[gldgti]

yup, thats the one.

good to get one with all the gear on it too - since then you dont have to bother making up pipes and flanges to bolt up to the supercharger. nice fromt pulley setup too.

if you were really clever, you might be able to incorporate the ribbed belt drive onto a factory mk3 style bracket setup for 16V engines with aircon...

one belt running everyhing, and have the supercharger on a switch too, mad max style.