darrenjlobb's Project M-TDI Twin Turbo Supercharged Derv Bus

[darrenjlobb]

After blowing up 3 XUDS in less than 2 years, I made the decision to move on, despite never running a full power run, I just couldn't justify rebuilding it, just to get some figures, so its something we will never know, but oh well, who cares, its only numbers Ended up cooking the head, really just starting to hit limits of pre cups and other bits, all of which with more time and money, could have been ported out / modified etc, and quite probably made more power, but with engines running coming up for 3x stock power, problems are always around the next bend, quite literally...So decided it was time to move on....

To a petrol......























Ok, That was a lie, but you most likely already knew that

Decided I wanted to start playing with DI, the XUD is IDI, and as much as I love it, its inefficiancys were really starting to catch me out, mainly heat...from the head....So figured DI was the way forwards, or at least, until Ive tried it, ill never know, which means ive gotta try it, or else ill always be pissed off not knowing.

Spent a good month debating weather to bite the bullet and risk putting an ECU in my car, or sack it off, and try to convert a hdi to mech injection....Well after the first week, I had a HDI ecu on the bench, and a map on the computer, and although could see the potential, very quickly realised, that you need to have ALOT of time on your hands (alot of respect to the guys like TB that have spent the time testing outputs / features etc) to be able to tune these past "stage 1" levels, as so many things come into the equation, and I could relie on someone else to be in charge of such a critical (fuelling) part of the car....so as quickly as the ecu arrived, it departed, in the bin.



So that was that decision made, wanted to build an M-TDI dw10.....

Idea is initially, to be fueled by a VE (so much simpler to keep this legal / smoke free and driveable etcetc) with custom home brew mech injectors and to retain the old compound supercharger setup, due to its positive effect with keeping big turbos right in there efficiency, and the ability to build chronic boost levels, which lets face it, is obviously important...

The biggest problem Ive always had with the VE however, is retaining 100% fuelling up in the RPMS, infact, anything over 4krpm, seems to have a serious effect on fuel output, meaning you can give it all the air you want, and its useless because you cant fuel it... Or when you do, the pump lasts about 5 minutes, and snaps a plunger / looses tolerance and becomes useless (like fcs)....So the plan is to be running a second VNT turbo, sequentially with the big one, to be "on boost" much earlier, and then switch over to the big turbo once its spooled up, which in theory will be much earlier due to much more exhaust heat / flow from much bigger combustion....So basically a sequential turbo set-up sat in front of a supercharger to compound its output...if that makes sence :S

Anyway, enough of the blarb, onto things that are going on at the moment...

Got the car dragged into the workshop after being sat outside for months, first thing was to get the turbos "jigged" into a position they would fit / be routeable before removing the engine, as once its out, you really have no idea where it will fit etc, so started by welding up a simple bracket that bolts to the head, and then to each of the turbos, and supports them in position) which would mean once engine was built and ready, the manifold can be made up out of the car without "preying" its gunna fit....or at least, reducing the risk somewhat!

Few pictures of that job in process:





So next job was to pull the old motor out:

(Sorry car, last polish, FCS , yup, oops!)







Note the most important tools are to the right and at the bottom of the shot here:




Stripped it to bare block:




Then to pull the sump to remove the conrods, (little scared at this point, preying to find them all straight and good!)

Anyway pull the sump, to be presented by an oil pickup full of crumbled ally / steel....Not good....On closer investigation, quickly noticed that a oil squirter had been knocked clean off...would appear I didnt allow enough clearance on the last build....all I can say is thank god the head let go, or id never have known, and most likely locked a little end up and bust a rod out the block, which would have been expensive!



Anyway, proceeded to pull the rods and pistons, and then spend 15 minutes with a clean rag (A very hard find around here) to clean them up, and thankfully find them in perfect condition, so that was a relief!

Almost look like new!



Thats pretty much it for now, have been working on injectors, having to use parts from several different injectors to make up the final correct length body / coupler / nozzle angle etc...



And the new HDI bottom end, havent really done much more other than strip it to bare bottom end so far, next step will be strip the block bare.



And a pile of random crap that was stripped out the way to get at the motor before removal!



Will try to video as much of the rebuild as I can,

Thanks for reading,