Let the tinkering get serious!!....

[Greg Roles]

It's not something that is either easy, or recommended you do. It raises the EGT's and done wrong, that can melt your turbo. It's why i have spent years increasing the cooling capacity of the system, and added water meth, plus I'm prepared to rebuild my grenaded engine should it do so. It also seriously messes with the DPF, and done wrong, again will quickly destroy a $4k part.

If you read back through the thread I go into it all, but basically EGR is recycled exhaust that is there to lower the available O2, lower the combustion temps, and thus NOX emissions. Thing is this both drops power, and paradoxically raises soot production. The EGR valve body is also a major restriction in the intake, and the factory flapper actually causes a restriction to assist exhaust to be drawn into the inlet.

I now just have a much larger manually controlled flap purely for run away situations, and the bonus has been I can use it to run successful regens like I did today.

[Buller_Scott]

that's mad.

so, in the event of run away, when you close the flap the intake mani will only be accepting EGR, is that correct?

if so, when the flap's fully closed, i presume it's a very tight seal, unlike the stock setup in the polo (whereby it's only around 80% shut, by the looks of things)?

keep it up man!

[Greg Roles]

There's no more EGR mate. My inlet is now 100% oil blowby and EGR free. Next step is to remove the entire EGR plumbing and bolt a plate to the manifold, should aid spool a bit, as the log manifold volume is a LOT bigger with the entire EGR circuit bolted on.

[Greg Roles]

Well I'm driving around rather quietly, as I'm not 100% finished with the last 45 degree copuler into the QTP flap, and the hose that turned up from ebay is rubbish, so it'll be a little bit yet till I can let rip.

What is interesting is how much smoother and responsive the car is at part throttle, and on transitions. Before the stock TDI was a bit jerky down low, espcially when driving slow and transitioning from on-off light throttle applications. Anyone with a stock ECU manual TDI will know what I mean, especially the GT, it isnlt the smoothest car. It would seem to me that the stock flap is doing all sorts of things in the inlet at part throttle, and the jerkiness has simply vanished from my car, even first feels good now! The car seems quite willing to respond to small, part throttle applications, and the turbo response is quite instantaneous and apparent. Amazing drive quality difference, even still pushing through a stock DPF and exhaust. It's not massive, but the car feels quite perkier.

[Greg Roles]

Yeehah!

[benough]

Sweet!

What does it mean? haha

[Greg Roles]

Sorry, that's a Snow water meth controller injecting. Finally!

[gldgti]

Greg, glad to see you finally injecting some meth.....anol

No surprise that your getting a smoother throttle response.

When you refer to run-away - are you just referring to the turbo leaking oil into the inlet if it decides to go belly up? Only reason I ask is that since you now have no crankcase breather gasses going in pre turbo.... theres nothing in the air to burn anymore.. (well, apart from methanol).

[Greg Roles]

I can't help but wonder what would happen if you blew a turbo seal, all that lovely hot oil to run to redline on.

I really wanted to have it for shutdown "anti shudder", but the shutdown without any flap is hardly any worse, and the drive home I had in start stop peak hour traffic was just wonderful. Even creeping along on off in first is just SO dramatically smooth now, feels like a NA petrol car off boost down low, and the boost pickup is a lot more rapid. That stock EGR/Flap is causing ALL the hesitation, pauses and rough running, and I'm loving my car all over again.

I have to come clean and admit I'm only injecting distilled H2O for now, as I want to set the system up right, check for leaks, and I'm waiting till pay week next week for a decent volume of Methanol. I did check my inlet on getting home tonight, and the QTP flap and black manifold were warm at best, MUCH better without the hot EGR entering, and with the water spray happening, it's a lot cooler in there.

Does feel good to be finally making some serious progress after three years of a lot of pondering and minor mods. Having no warranty anymore is a liberating thing too. Scary, but refreshing.

[Preen59]

Nice work, Greg. Lovin' it!

[Greg Roles]

It's been interesting driving the car for 2 weeks now.

1. It's dramatically smoother, more eager, and feels like it's had a new lease of life.
2. It has as yet to do another regen! In theory taking the EGR out shoukd raise EGT's and in return drop soot production, plus help the DPF run hotter, so it should passivley regen better. I'd have to say that in it's current odd state of quite frequent regens after the pressure sensor replacement, it;s odd to have gone this long without a regen. I'm putting in on Vag Com for the drive home just to check soot levels.
3. I've got a tiny leak through one side of the QTP flap, so will have to sort that out before I go methanol.
4. Injecting just water my manifold on the engine is cool to the touch after running the car. Amazing.

Heavily into the exhaust pipe now.....

[Greg Roles]

Final stages coming together.....3" resonated mid pipe from 42DD today....to add to a 2.5" cat back "just lying around"... : )

Also fitted an electronic QTP flap controller, so have much better control of the intake flap for regens, and emergency shutdown.

Hope to never use that!

[GoLfMan]

looks like a nice System Greg! Really interested to see the results

[Greg Roles]

Just to let everyone know, it's impossible to complete a standard DPF regen without the EGR mechanism hooked up to the loom, albeit hanging in the breeze. Anyone considering an Allards EGR delete, if you have a DPF, it's going to cripple the regen cycle, and while I had mine unhooked the DPF load got up to a all time high of 60% and I had to hook the EGR mechanism back up ( only to the loom ) to complete a regen with my QTP flap. The DPF light came up at this level of loading ( first time for that one ) and the engine light is on due to the low EGR flow error.



The electronic controller has been impossible to calibrate, so I have had to go back to a simple switch, but it works fine for regens. Hope to get the QTP controller to work so I can close it a bit more accurately than just counting 2 seconds and hoping it;s about half way ( takes 5 seconds to fully close ).

[poyta]

They don't make it easy do they? Best to just rid of the damn DPF then.