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

[darrenjlobb]

Well times have been a bit busy just recently on the farm with harvest and what not, so progress has been very slow / non existent with the bus just recently, but small things have been going on / some big changes taking place!

I've been having an issue with the manifold / turbos melting the reverse cable, which with a gti'6 box, can lead to some VERY embarrassing situations in the local village of meva with single row streets, and no reverse....your imagination can do the rest...long story short, 2 way traffic jam, oiley haze passing down the street, racket coming from hunting DI motor running plenty of timing, and me looking like a right idiot getting out asking for a push wearing a Deere boiler suit and covered in WMO!

The melted section of cable (plastic inner layer fused with plastic lining on steel cable!):




So after having a good hard think about it, there were two options, A was to bodge it, and have bit of fencing wire thro the bulkhead that you simply yank on to use reverse, simple, effective, and would do the job....but messy / just not going to happen...So came up with something a little more interesting involving a boot popper, some wiring, a relay, and a switch! Basically ended up mounting the solenoid well away from the head, and then with clear line of site, a single solid steel wire back to the tranny, with a oem switch in the right hand trim area which you can activate with your right hand while dropping the tranny into reverse with left hand as normal, works like a charm, and shouldn't suffer from heat issues! Also means I can loose the spasticated gti6 gearlever that feels the need to be half a meter up into the cabin?!


Picture of the solenoid semi in position:




As tuning is now under way, some teething problems have become apparent, and need dealing with....The original plan was to run the two turbos sequentially, and then compound with the supercharger to long term give me some decent pressure / flow to work with... But after being on the road a few weeks with the VNT, its become very apparent that the supercharger is really just not needed anymore, and being one of the most problematic / un reliable components, other than the noise, im more than happy to see it go!

So I made the decision to sack off the charger, and then run the blowers in compound instead, midrange torque / daily driveability is all good fun, but after a couple weeks it soon gets boring, and its never what the cars been about, so chronic top end boost wins for me anyway!

Long term the VNT is really a little small for the compound arrangement I have going on here, but will work for the time being with external gate allowing excess exhaust to bypass the VNT to save cooking it! but upgrading the smaller turbo is certainly on the books for the future.

But anyway for now, it was time to go ahead and plumb it up / remove all the bypass valves (that took ages to make / get working!!) and simplify things a bit, as well as at the same time inverting the gas flow through the intercooler, and relocating the oil cooler to somewhere it didnt look to tragic!

This is the arrangement I've ended up coming up with, again as normal, its a constant fight with making it physically fit under the bonnet, and perform the job in hand without rubbing / fouling anything else!








There are many other things I've no doubt forgot to mension / photograph, but I think that's covered some of it!

The next big thing is really going to be a case of beefing up the head, as the stock head is fitted with valve springs that float at a mere 35psi of boost (hence my serious limitation right now) and also very restrictive exhaust ports...so lots to get busy with!

Thanks for reading

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This project is just epic Darren good work. What sort of hose do I need to get for the custom oil lines? I am looking at getting an oil cooler and want to know how to make up the lines for it using the an connectors. Any advice?

Thanks

If you take a look here:

http://stores.ebay.co.uk/Torques-U-K/AN-...34.c0.m322

The main thing is you need to use the right size hose for the fittings, but provided you do that, you cant go wrong, and can get fittings for just about anything, also worth noting there are other sellers selling the same things cheaper if you spend time searching!

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Any updates on this lately Darren? Have you been able to start tuning it properly yet?

Maybe