allroad V6 TDI slow build

[gldgti]

Yeah man! Weekend turbo swap coming up!

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[gldgti]

Split a boost hose coming home on the weekend. I used an old hose from my mk3 when I put the car all back together a couple of weeks ago. Turns out that wasn't a great idea.
Replaced tonight with silicon and stainless for win

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[gldgti]

...and its in!

I have been just driving the car basically stock since I rebuilt the heads, as after i sent the injectors for cleaning, they came back with the number 3 injector (which has a needle lift sensor to tell the ecu about the timing) that didnt work anymore.

Yesterday I finally got around to fitting a working second hand replacement courtesy eBay Italy, and while I had half the engine apart, decided to swap in the BV50 K04 in place of the GT2056

So yeah - turbo swap is done!

Its faster than stock for sure. I have the vane adjustment pretty conservative at the moment, but it spool about the same as the stock turbo. However, the midrange response is much faster, and it pulls much harder at higher revs. I guess that's down to a whole newer generation VNT going in there - its larger, flows more, but spools better.

I had a pantsmessing moment after the first drive, which I stupidly executed without a boost measurement device. It didn't run quite right, and I realise now thats because it must have been boosting way too hard.... but not as hard as I thought when I saw the actuator position at idle, (which is fully closed, maximum boost setting) which for about half an hour convinced me that it was all backwards or something, and that I'd majorly stuffed it. in the end, I have learned that the ECU asks for fully closed vanes at idle, so that boost builds as quickly as possible off idle - its also much quieter that way, as with vanes fully open, there is a way more direct path through the turbine and it makes a lot more noise.

Anyway, after that first drive, I adjusted the mechanism back a lot, so that it literally feels (when you have the car idling with the N75 connected to the actuator, and you pull on the actuator arm with your hand) like the stock one. The way I had it first was probably a bit "light" i.e. when the ecu asked for more open, i dont think it would open quickly, or far enough. This resulted in too much boooooost. Lucky it was a short and tentative drive I went on.

after adjustment, I have it in a spot where it doesnt close all the way to the stop - so in theory I could see some extra response with careful adjustment. Max boost is about 20psi, which is basically pretty much as before, so the ecu is coping with the actuator mechanism OK. I havent seen anything much in the way of spikes.

Regardless, 20psi is getting close to 2.5 Bar absolute, so it might be time to go a larger range MAP sensor.

Cant wait for this to be tuned. Its going to be good!

[Greg Roles]

Nice to see you still messing around too. Reminds me of the time I messed with my first turbo, and just turned the wastegate arm " a few turns". Sure boosted amazingly well about three times, then I learnt all about the turbo rebuild industry.

Glad your turbo survived !

[gldgti]

Yes indeed.

Progress on previous post - I've since wound in the actuator arm 2 full turns (1.6mm) and its made a huge difference. Its now a lot more like I thought it should be - much more responsive and quieter too. Boost comes on much much faster than stock.

Basically I have just wound it in 1 turn each day before I leave work, then drive home and keep an eye on the boost. I'm still in the realm of actuator function where the boost isn't running away at high rpm - i.e. the ecu is capable of keeping boost in check under high load - so there might even be another turn in it yet. We'll see.

I'm just chuffed that its working so well. I've got more power, better response, and all with a hardware only change .

The best description I could probably give is that the car has gone from feeling pretty "old school" diesel, with noise and whine and lag, to rather new school, with quick response and less noise.

I can definitely see why this size turbo is the daddy for the 4 cylinder diesels.

Also considering doing the boostvalve type mod, so that it wont be possible to have boost spikes or overboost. I'm thinking that will let me tune it right to the limit so I get maximum spool without the obvious dangers.

[anthony--t]

Sounds like I have to come visit you soon for a drive!

[Greg Roles]

Yes indeed.

Progress on previous post - I've since wound in the actuator arm 2 full turns (1.6mm) and its made a huge difference. Its now a lot more like I thought it should be - much more responsive and quieter too. Boost comes on much much faster than stock.

Basically I have just wound it in 1 turn each day before I leave work, then drive home and keep an eye on the boost. I'm still in the realm of actuator function where the boost isn't running away at high rpm - i.e. the ecu is capable of keeping boost in check under high load - so there might even be another turn in it yet. We'll see.

I'm just chuffed that its working so well. I've got more power, better response, and all with a hardware only change .

The best description I could probably give is that the car has gone from feeling pretty "old school" diesel, with noise and whine and lag, to rather new school, with quick response and less noise.

I can definitely see why this size turbo is the daddy for the 4 cylinder diesels.

Also considering doing the boostvalve type mod, so that it wont be possible to have boost spikes or overboost. I'm thinking that will let me tune it right to the limit so I get maximum spool without the obvious dangers.

I agree a BOV is the key, would let you tune it a "bit beyond" and let the valve sort the excess. Plus it would then sound fooly sick bro.

[gldgti]

Plus it would then sound fooly sick bro.

not that kind! the kind where when the boost goes above the set limit, it vents into the actuator line opening the vanes fully Like I did on the Octavia back in the day.

[Ryeman]

Interesting U.S. test
Volvo V60 Vs. Audi Allroad: Compare Cars

[gldgti]

not a real allroad..... real allroads are a6 platform cars with air suspension. A4 allroads are fake

[gldgti]

So, its been a LONG time between updates here....doesnt mean i've been idle though!

I decided after a fair bit of research that paying for an aftermarket tune, anything more than stage 1 would be a big investment - and since I've swapped the turbo for a bigger one already, it would mean stage 1 would be like the minimum I would be happy with. Most tuners offer a stage 1 for this engine of about +35hp and 50Nm. But because of my new turbo, it would be a lot if iterations in tuning etc....

So I've decided to tune it myself.

How? What? Well theres a lot of places you can start, but basically the word around the net is 'dont bother self tuning unless you are prepared to do a lot of work, learing, etc, and it probably wont be cheaper blah blah blah.

So yeah, thats where I'm up to.

So far, I have tooled up with a cheap cable from ebay ($22) and MPPS software to read and write via the OBDII port. I have successfully done this on several occasions already.

I have been using winOLS demo version to analyse my ECU dump and I have been following the numerous winols and various chip tuning forums/guides in order to learn how to identify and interpret maps within the ECU dump.

I have been using a free bit of software called vagsuite EDC15P (developed specifically for tuning EDC-15 pump Duse diesels) to actually modify the maps I have identified in winols and verify the checksums before writing the modified file back to my ECU (vagsuite doesnt correctly automatically identify my particular ECU's maps as my engine is not PD).

So far, I have only modified the N75 control map, which is used to provide transient control setpoints for the N75 valve. I have started here for a couple of reasons - first, because before I start trying to make more power, I want to ensure my boost control is as good as it can be. Second, because in the particular case of my engine/ECU (the 2.5 V6 TDI), modifying beyond a moderate fuelling increase is a bit tricky and I havent figured out how to do it yet!

I have been doing lots and lots and lots of logging using VCDS, basically just of group 11 (specified and actual boost, and N75 duty cycle) and making both mechanical and software adjustments to try and improve the spool and minimise boost overshoot. I think I'm getting to a point where I'll be happy to start increasing fuellign and boost soon, and all of the other required modding that goes along with that (torque limiters, gear dependant limiters, etc etc etc.

The fuelling increase problem particualr to my ECU / engine is an interesting one, and it will be interesting to see what happens, whether I am amble to get where I want to be or not. As far as I have been able to research so far - all over the internet there is this idea that the VP44 (thats my injector pump) controlled 2.5 TDI is limited in injection quantity by the pump software - however, when you dig a little deeper, it seems that this may not actually be the case, and infact it may be that there are 'single value' injection quantity limiters in the ECU file which are just difficult to identify.

If the former is true, it means tuning beyond 'stage 1' means getting a bit more creative with hardware mods etc. But if the latter is true, its theoretically a matter of my time and patience in analysing the data to find these limiters, and testing the results.

Anyway, we shall see what happens!

[Greg Roles]

Hey ol mate, good for you. Funnily enough winOLS is what my overseas provider uses to do their tunes, and they are WAY better than the old ones I used to get, which were just % increases in boost, fuel and timing etc. They worked pretty well, but the power of open source is astonishing. A lot of companies still tune via the % increase method, winOLS is the way forward. That said I know RDT here have a LOT of additional software they had to buy, to do specific things, but it is amazing what you can get out of doing an indepth of a set parameter. I had no idea even just the throttle map, which is usually tweaked "a bit" in most tunes, when done in depth with specific software just for that, well the difference is amazing in just that alone.

So good for you for giving it a go, and I have no doubt you will end up a guru going that indepth. Also if you take the time you can write an amazing tune, thing is it's generally not worthwhile spending that long on each and every car from a commercial tuners perspective. I've had several different tunes on my car now, and when the programmers really spend the time, my god they can get insane results.

So shall you no doubt!!

Hey and don't worry about lengthy updates, I've been back on here a handful of times this year and noticed the diesel section quite dead outside dieselgate, but I too have been busy, just not on here as much to post. Have decided to change that, and have stopped doing business work on weekends and have made sure I get back to tinkering, which is the whole point anyway!

[TDIfan]

Good to see this is still going
Waiting to see some great results

I'm also looking to tune my PD100 Polo myself in the future (if I have the time to study how that works)
The tune I got from my current tuner still need a few tweaks and he just decided to not to respond

[gldgti]

your in luck with your polo mate, if I guess correctly you should have an EDC15P and you should be able to use vagsuite to tune it. Its a really user friendly program and made just for early PD cars, thats it! You can even enable launch control

Thanks for your comments Greg. I am pretty happy with the decision over all, as I said I've already learned a lot and I haven't even really tried anything much yet.

I am pretty happy with where my boost control is at at the moment. I've been doing 'back to back' logs on the way home from work this week and I have today's and yesterdays here for your interest:



I've tried to align the axes so that you can compare the 3rd gear pull towards the end of each graph. So each one is a log of rpm, boost spec, boost actual and n75 duty cycle (multiplied by 10 so its easier to see against the other numbers.)

The lower graph is yesterdays, which is where the actuator rod was set up then. Last night after looking over that graph I decided I could go another turn shorter, theoretically improving spool some more.

What you can kind of see from the graph, and what you can see in the data, is that yesterday, it took about 4.1 seconds to get from 1310mbar to the specified boost 2301mbar, and today it took about 3.5 seconds to get from 1222mbar to 2301mbar. Both pulls were on the same road, with the same conditions, time of day etc, even ambient temp is within a few degrees.

It also kind of looks like the big slope of the rpm plot is a little steeper from today, so perhaps the engine is making a bit more power with this setting (i.e. accelerating faster with the same load).

I'm also glad to see that the N75 is able to regulate boost properly all the way to redline.

I have been having some pretty bad boost control issues, which I have basically managed to figure were due to me using too small a lever arm on the vane control, which made it too sensitive for the control system to actuate properly. I have 2 ball sockets I can clip my actuator onto on the little lever arm on the turbo, 1 I welded on and 1 which was stock. The 1 I welded on I thought I needed because I cant quite get the full range of motion from my actuator and the outer lever, however when I have tried using the inner one, which gives me the full range of motion, its too powerful and I get big spikes on the plot, and the car is actually slower - I fear because it closes the vanes too much when you try and accelerate hard, and it builds up heaps of EMP, then it spikes over the requested boost, opens the vanes, the car surges forward as all the EMP rushes out, and boost drops back below specified, and it all happens over and over again. Terrible!

With it how it is now, you can see the N75 and actuator are able to do a reasonable job of regulating the boost. Certainly it drives better, I'm not getting lots of nasty surging going on which is probably a good thing for my engine and turbo.

[anthony--t]

My eyes glaze over a little when we talk about this and most of it goes straight over my head but keen to see results / lend a hand where I can and attempt to learn something!