Let the tinkering begin...

[gregozedobe]

Having spent a lot of years both in and around the motor industry, I'm hardly worried at this point. Compard to an ECU mod, this is minor, minor stuff. Still, I can tell you for sure as next Thu they have their 1500km checkover.

Sorry Cogdoc, I don't believe you will be able to give a truly definitive answer on VWA's attitude towards your mods unless you have to make a really expensive engine-related claim (eg cooked engine, a new turbo). Remember it is VWA who make the decision and actually pay out the $$$$, not your dealer (they only make a claim to VWA).

Based on my recent experiences with problems with the TDI motor in my VW Transporter, VWA currently don't have a particularly generous attitude to warranty work (and my motor is absolutely bog-standard stock, no mods whatsoever). My van has been back to the dealer for fixes related to a particular fault 4 times (and is booked in for a fifth), and it appears VWA will only pay for the first visit. As best as I can tell the underlying repeating fault is related to the VWA mandated repair procedure being inadequate, so I believe VWA should pay for the lot (currently it looks like the dealer is picking up the tab, and they are distinctly unhappy about it).

However, I hope your car never has any problems, so you never need to get any warranty work done.

[Greg Roles]

Hey Gregoz,

Dude I totally understand. The bottom line is a manufacturer can wrangle their way out of warranty work if they really want to, and yeah I'm taking a certain risk. It's calculated.

Everything I plan to do is aimed at reducing thermal and other stresses on the vehicle, so I'm quietly confident I'm actually increasing my chances at a long serving turbo vehicle.

If it goes bang, well it's an excuse to get serious, and I will go that way in the end. Imagine a 13 second oiler

[gregozedobe]

If it goes bang, well it's an excuse to get serious, and I will go that way in the end. Imagine a 13 second oiler

OMG ! That would be a hoot at traffic lights, especially if you had a big badge/sticker on the back that said something like "Diesel Power" or "Congratulations, you have just been smoked by a diesel ! "

I'm guessing you have been/will have having a bit of a look here to get some ideas
http://forums.tdiclub.com/forumdisplay.php?f=13

You would have to spend some serious $$$$ to get to those sort of times (although I suppose 13.99 is feasible), and not just on engine mods , either.

The problem with getting really good times out of a diesel is the limited rev range of the engine (c.f with similar power from a petrol engine). You spend too much time changing gears and not enough accelarating (that's one reason why people like the DSG/TDI combo)

If you seriously want to go that fast have you considered starting off with a much lighter car (eg Golf Mk 1) ? Weight is the enemy of quick accelaration, and Golf Mk 5s are not exactly svelte. With a heavy car you will quickly enter the realm of diminishing returns (increasingly large expenditure for increasingly small gains in performance).

Sounds like fun, anyway

[Greg Roles]

OK, I spent the arvo pulling the inlet and front grill off, and had a poke around the intercooler plumbing. My plan to pull the intercooler out has been postponed, probably indefinately, as the radiator would be a major piece of work to remove. A lot of AC and induction hoses in the way.

The only downside to the intercooler is that the AC radiator is in front of it, which is great for cool cabins, but would pass the heat into the intercooler behind it. It sure is a decent size though, feels about 2cm thick.





Mikinoz has claimed the glory for the weekend with his great aftermarket pod fitment, but I too pulled out all the stock inlet, and boy it sure frees up a lot of space. I notice I have a cheapy battery cover compared the Mik's nice battery box...









One thing I did find is there is a LOT of space behind the passenger foglight shroud, and this is where I believe the MK4 TDI intercooler is. This space opens up right below the factory airbox, so if you wanted to run a secondary inlet to the filter box, it would be dead easy.









The photo dosen't do it justice, but there's a ton of free room in there, right back to the front wheel. The drivers side has a bit of room, but the bulk is taken up with the windscreen washer tank.







The next shot gives you an idea of the space below the inlet and MAF sensor etc, as this is a front on shot along the space showing my obviously crooked Provent 200 mounting... but plenty of space to run bigger inlet plumbing to the intercooler. The silver alloy turbo to intercooler pipe in the lower left area is not a uniform cylinder and has a lot of diameter changes and funny bends along it's length. I'm keen to ammend that....

[Greg Roles]

From underneath, the return pipe from the intercooler is rather soft rubber in 2.5 inchdiameter. The plastic and metal sections run approx 2 2/10 inch to 2 3/10 inch. Sorry I only have a vernier in tenths of an inch. One glaring thing is the lower radiator hose being clamped directly to the cool side of the intercooler pipe. This protects it from the electric radiator fan, but I'll be separating these guys! The pipe to the left is the radiator...






This is the lower end of the oil filter, being the tricky little water cooled oil cooler. I think an auxillary radiator just prior to this would help lower the engine temp water used to cool this, and be the easiest way to increase it's efficiency without setting up a standalone radiator and pump system. I'm going to do some coolant temp measurements here, as oil cooling is all the turbo has...




The inlet from the intercooler into the EGR / throttle flap mechanism. The radiator hose mentioned above that is clipped to the cool side of the intercooler tube also wraps around this top part of the same inlet tube. This is definately adding heat to the cool side of the intercooler ( as if the EGR addition isn't bad enough! ) Jamyz you can easily tap a temp probe halfway up this pipe where there looks to be a connection. I think I'll end up tapping into the blanked off hole in the top of the silver doobie and make it permanent temp reading place just prior to the inlet. EDIT: This isn't "blank" but the other side of the throttle flap, so don't go drilling here OK kids?




The turbo itself has a nice heat shroud from factory, that covers it somewhat like a beanie cover you see on some cars. The second pic is the top of the particle filter, and there are two fittings I would assume are for the nasty catalyst addition I've recently read about, and there is definately a probe before and after the particle filter. I've read this is how the car works out if the filter is clogged and it overheats the exhaust to burn it off by adding extra fuel etc. EDIT: No catalyst added to the VW DPF like some other cars, these are just probes for temp and pressure, the DPF is self contained and self regenerating, and will eventually clog over a long period according to VW.







So here's the tinkering I did this arvo, I covered the stock inlet in the areas I had been watching for heat transfer over the last several days. I think Mik has the best answer, but for now, this is what I'm running with.





You need to look at the small radiator pipe shown here, as it touches the airbox in stock form, so I trimmed it down a little, so now it clears the box and the scoop.





So here's the finished article for today!

[Jaymz]

Excellent write up, thanks for sharing.

There's definately a few places for improvement. I think i will be looking at the intake temps next and try to make some improvements there. Might use some of that nice shiny tape you used also. Want to get that temp probe in there first to see some before and afters.

Interestingly i went down to Murwillumbah for a drive on Saturday and was checking the air box temps on the way down and back up. I went the back way through Canungra to get there and there is some good twisty hilly roads to explore temps. Oh yes you have to love the open speed limit through there also
The average ambient temp was 25deg and the average airbox temp was 35deg. The highest airbox temp i saw was 38 and the lowest 32. So not that high really, i was expecting it to climb higher than that. I came back along the highway and the average airbox temp was slightly lower at 33.

So with that said there is good airflow through the front of the car at speed.
Where it suffers is city driving, where i have seen the airbox temps up to 69 and averaging 45-50 or so. Alot of the plastics suffer from heat soak from the engine/turbo and it seems they fail to transfer the heat once hot. This is proved by driving around town to get the airbox temps up to 50deg and then seeing how long it takes to bring them back down. Lets just say along time and alot of road! (read: big waste of fuel)

I have also noticed that when the airbox temp is up to roughly 40-45deg and then i shut the car down for 3+ hrs the airbox temp has climbed and is averaging 50+ deg.

All this hot air just makes the IC's job harder. I am seeing the real value in a waterspray system on the IC for a MKV.

I would also be interested to know what temps your airbox is seeing Greg and for that matter if mikinoz's is any better as this will determine my next course of action with the inlet.

Cheers,
Jamie

[mikinoz]

What is the scientific method (ie. your methods) for getting an intake airbox temperature? I have in the past used a cheap probe type (read $5 ACME brand) but it is not what I refer to as degree perfect in accuracy...

[Greg Roles]

No probs Jaymz, I'll run a temp monitor in the airbox this week and report on what I notice.

Where arre you putting the probe exactly? Above, below, behind the filter?
I need to put mine in a similar place if it is to be somewhat comparable.
My digital thermo is a dual display one, and will give me room temp as well, so I can compare simultaneously.

Mik, my method is to poke it in, get some averages, do some mods, get some averages, and compare my readings directly with my readings on the same unit. Even if we all have units a few degrees out it doesn't really matter, for your inlet is basically either 70, 60, 50 degrees etc.

I'm not going to get that scientific, for I'm more interested in spending my time sanding, filing and generally di<king with the car!

[Greg Roles]

Oh yeah, from what I've seen so far, I reckon the biggest problematic heat additions are happening post intercooler and at the EGR / throttle flap. The turbo / particle filter won't be helping heatsoak is city traffic either.....

The bits I've heat proofed thus far won't have had much overall impact as yet I'd imagine. The thermometer will be interesting.

My next efforts will be in the intercooling pipes...but i have some major plans there

[Greg Roles]

Sounds like fun, anyway

You hit the nail on the proverbial head my man!