UrS4 2.2T Avant project

[andy10v]

Amazing! That should be great to drive once you have the pulley size and map dialled in.

Sounds like an angry beehive.

[Tille]

Amazing.

If you want you can post a vemslog file and we will take a look.

Greetings

[prj]

That does look pretty cool.

[NakSu]

That's sick ! Great work too.

Dahlbäck intake manifold coming to you from aRtiS I guess ?

[Thuppu]

Uploaded a few logs(remove the .txt from the end of the file). First one is with the cutout(fuel pumps stops, need to turn off and on the ignition). I start to belive it's some malfunction elsewhere that causes it, because I could take few logs without issues. At least I couldn't find anything in VEMS that could cause it, no safety setup...

Second file is with 3rd gear up to 5000rpm. Third file up to 7000+rpm.

Somehow the car feels lame in the upper end. But it can be just the feel because there is no boost spike whatsoever. I get 1 bar at 2000rpm, and 2 bar at 4000rpm. I have no clue when the turbo is taking over, it will propably spool a lot faster than before, but can't feel any step or spike in the power curve.


NakSu, no I havn't bought the dalbäck IM.



Edit. Somehow my MAT temp is showing just 23-24 degrees. Should VEMS read the stock MAT sensor? So I havn't a clue about the air temps...

[Tille]

Are you sure its a real fuel cut aktion from your ECU? A friend of mine has same problems. But in his case the VEMS ECU crashes on high boost, but only if the laptop is connected. Without Laptop connected everything is fine. So take a try without laptop

But first you should do a small remap, low rpm and part throttle is to thin.

Greetings.

[diesel des]

Thomas I have many questions. Are you using the stock width aux belt just longer to drive this? Any slipping? What front crank setup have you? You will he pulling maybe 50 hp from the front of the crank now so is the keyway strong enough?

Is the supercharger on a electronic clutch? This would reduce drag once the turbo is spooled.

Really cool. ..

[Thuppu]

First I tried the AAN belt for aircon, but it was not long enough. This belt is 1740mm, normal stock width. Havn't noticed any slip. Stock crank pulley, that one which cracks easily. I did assembled this engine of scrap you know... Have to keep in mind that when the turbo spools up, the supercharger pressure side starts to go to vacuum, so actually the supercharger won't have to work against pressure anymore(on high rpm). That means that a roots supercharger won't steal much power and won't generate heat. I wan't to keep it simpple, so no electric clutch. Only control setup is the one-way valve and the 50mm dump valve(which stays open always when the throttle flap is closed.

[Thuppu]

Qestion about the MAT/IAT sensor and VEMS... Do I need to use a 1.8T sensor and some patch?

http://www.s2forum.com/forum/showthread.php?t=66564

http://www.s2forum.com/forum/showthread.php?t=48814

Edit. Anyone have the part number for right sensor?

[diesel des]

I'm using stock aan sensors on my vems with the aan patches.

So I'm trying to understand your setup. Supercharger takes air in from red air filter. Supercharger outlet feeds inlet of turbo with y pipe with check valve on the y part with blue air filter. Outlet of turbo feeds intercooler then intake manifold.

So the control strategy is as engine speed increases at wot the turbo will start to suck the supercharger dry of boost. At that point the check valve opens feeding the turbo inlet air from the blue filter.

But the supercharger has no clutch so is still spinning and drawing air and dumping it out the check valve? So it's not building boost but still will have lots of "pumping losses "?

Have i that setup right? If so I think a clutch will really help. I wonder if connecting one air filter to the turbo as normal then outlet of turbo to intake of supercharger then intercooler then intake might be easier. You would need some sort of supercharger bypass valve once the turbo was spooled though.

It's the control strategy that's the secrete here...

[Thuppu]

The Holset is sucking all air the supercharger feeds, plus it sucking an extra amount of air thru the one-way valve. The turbo uses a lot of more air than the supercharger. When you release throttle the dump valve dumps all compressed air and the one-way valve closes. Nothing goes out thru the one-way valve.

A roots supercharger is nice because it does not compress air internally, like a Lysholm. It just moves air from one side to the other. If there isn't a restriction(engine) and pressure, it will just spin freely and move 1,5 liter(M90) of air from the intake to the output, no compression, no heat, no power loss. As when the Holset sucking a huge amount of air, the pressure side of the supercharger is under vacum, so the supercharger spins freely.

[quattro-nick]

about iat patch,sie link,check point 5!

http://www.efiexpress.com/catalog/ar...?articles_id=6

[quattro84]

Good effort, excellent crafts.
I would suggest looking into a kind of diverter valve as one-way-flap replacement to have less restriction and even better spool-up And, because of wear/failure it makes your precious Holset eating it.
Good thing you use the HX40, because of it's massive thrust bearing it is very capable of resisting this minor compounding effect of the M90.
Perhaps add an extra pressure sensor pre turbo? Gives some insight in when it starts spooling.

[Thuppu]

Nick, thanks. So seems that you have to choose the patch when downloading the firmware, so it's build in..? No wonder why my MAT doesn't work. Whats with the coolant patch?


In fact, VAG has a big one-way valve in the Audi 3.0 TDI. I may try it out some day.

[diesel des]

The Eton supercharger can pull air through a turbo, but a turbo can't pull air through a roots blower as it's fixed displacement. I think for optimal results you need to have the turbo feeding the supercharger with a bypass on the supercharger.

Have a read of this.

http://www.eng-tips.com/viewthread.cfm?qid=198474

When your turbo spools up at the moment you open the check valve due to the vacume. The supercharger is still spinning and heating air due to its inefficiency even with no pressure across it. Your turbo then is mixing cool air from the check valve and hot air from the supercharger.

With the turbo and supercharger reversed and with a supercharger bypass, when the turbo spools no hot air from the supercharger would reduce turbo efficiency.