S3 AMK Stage 1 Remap Logs - Possible Boost Leak ?

[sideways steve]

I am now fairy happy that we have the map sorted however I think I have worked out why the airflow readings are still so low.

I have also done a log with the N75 disconnected and its pointing to a weak actuator from what I can see.

Have a look at these logs and see what you all think !

First Log,
Boost and CF's:

Second Log
Boost & Fuel:

Third Log
Actuator Test:

 

[beachbuggy]

Did you run the car stock map and log to see how it went?

How was the xdf?

 

[sideways steve]

Hey Dan,

Yeh I did and boost was also down as was the power. Bill had suggested trying a run with the N75 unplugged and said you should see 6 psi climbing to 8 psi but in doing that you can clearly see mine is around 3 psi climbing to 5 psi so tomorrow I will adjust the actuator preload a bit and see what happens.

I done a couple of runs with the MAF disconnected too and it made no difference so I reckon the MAF is ok on that basis.

 

[sideways steve]

Ok further testing over the weekend has left me stumped !

With the remap on the car it runs brilliantly, pulls hard in all gears and seems very very quick as you would expect. however no matter what I do the Airflow readings never seem to move above 180 g/s which equates to around 220bhp. Additionally the boost readings are always below the requested even though I have now adjusted the prelod on the actuator a litte.

I also found a leaking hose meaning it was sucking in unmetered air from the inlet side however despite fixing that I still get low airflow readings and boost not meeting the demand.

I tried logging the stock map and again same issues, low airflows and boost running below the demand level.

What I have noticed though is that with the remap on the car I am able to log a considerable increase in torque across the rev range and the levels I am seeing do tie up with a stage 1 mapped car (approx 270lbft), but despite that the bhp figures are still low (both when calculating from the airflow or from the torque figure).

Anyone able to shed any light on why this would be happening ? I am almost certain I dont have a boost leak as like I say the car runs very well and if you unplug the N75 it will build and hold boost all the way to the redline which indicates there is definately not a leak.

Could my problems be linked to the N75 itself ? I am tempted to fit a MBC in place of the N75 to see if that makes any difference.

Thoughts ?

 

[aragorn]

Tired MAF can give low readings like you describe...

Also your boost request looks to peak very early, Its wanting 22psi by about 2k, which simply isnt going to happen...

 

[sideways steve]

The thing is even with the MAF disconnected if you log block 120 and do a BHP conversion based on the torque it still doesnt ever see more than about 221bhp.

Is it possible that the stock airbox and stock filter is strangling the engine and physically it cannot suck any more air in ? I wouldnt have thought so but it really does seem like that.

I can certainly adjust the boost request to come in more gradually, do you think the way it spikes early is preventing the N75 from properly controlling the actuator due to it building the boost to quickly low down ? I guess the N75 is having to go from closed to fully open to bring the boost back down and prevent massive overshoot ?

 

[<tuffty/>]

The thing is even with the MAF disconnected if you log block 120 and do a BHP conversion based on the torque it still doesnt ever see more than about 221bhp.

Is it possible that the stock airbox and stock filter is strangling the engine and physically it cannot suck any more air in ? I wouldnt have thought so but it really does seem like that.

I can certainly adjust the boost request to come in more gradually, do you think the way it spikes early is preventing the N75 from properly controlling the actuator due to it building the boost to quickly low down ? I guess the N75 is having to go from closed to fully open to bring the boost back down and prevent massive overshoot ?

Nope... I ran 350hp on a stock airbox (green cotton filter) so I don't think thats the issue... you done anything with the timing advance? the high CF's top end of the rev range won't be helping

You need to get it on a dyno really...

<tuffty/>

 

[Alais DJA]

This is the thorn in the side with any map

I wish i had done my on a dyno when i was with the guys setting up my map. I am extremely cautious of loading the car heavily what with all the bad reviews and concerns that i had from chipped uk. Im going to contact bill at B5 next month to quote me "all in" for the work for the Audi.

It's just so much better if you've got her running on a rolling road at the same time.


Marcus

 

[sideways steve]

Nope... I ran 350hp on a stock airbox (green cotton filter) so I don't think thats the issue... you done anything with the timing advance? the high CF's top end of the rev range won't be helping

You need to get it on a dyno really...

<tuffty/>

Yeh I have managed to get the Cf's back down, I dont actually know why they were so high initially but there all very low now on subsequent runs. Either way though this wouldnt explain my odd boost and airflow readings especially since this also happens on the stock map file.

Dan would be best placed to answer the timing question as he altered that for me as I didnt have an XDF file for the AMK at the time.

I agree that getting it on a rolling road is the best option all round but to be honest I dont trust anyone up here and it will be quite some time before I could make a journey down south to someone I would trust.

Its also worth mentioning that this map was run on a 225 TT without any issues and I believe it made around 260bhp. It was then adapted for my AMK engine by copying over the relevant tables and their values.


As said above however, this issue is still present even on the stock map so I am confident that its not a mapping issue unless Audi's stock map was faulty.

 

[beachbuggy]

Steve.

I did send the xdf to you but it's now up on nef if you haven't got it. The timing maps are stock I think as the cf's where high it was was worth running stock to eliminate other issues first, ie boost leaks dodgy maf etc. I'm on holiday this week so can't help until I get back.

 

[sideways steve]

Hey dan, cheers for the reply, yeh I got the xdf so I have been trying to get my head around the different tables and their functions (the ones that are defined) I have been concentrating more on trying to determine the cause of my inconsistent boost so hence flashed the stock map back on to run a few tests

I thought it would be worth posting up the issues to see what peoples thoughts are

 

[R-Tech-Nick]

Tired MAF can give low readings like you describe...

Also your boost request looks to peak very early, Its wanting 22psi by about 2k, which simply isnt going to happen...

Tuning by bringing the boost request in early is the best way to turn the K04 and K03s turbos imo, It can be used to gain better boost control and stop nasty boost occilations, the me7.5 PID controllers work better that way.

Running the boost request low at lower rpm on a taper ramping up the rpm range can cause issues in differing gears. Same with running the boost request over what the turbo can do at the top end the post-N75 control (KFLDRL) can be used to maintain the boost to a safe level which is smooth and has no intervention from other settings.

 

[sideways steve]

Tuning by bringing the boost request in early is the best way to turn the K04 and K03s turbos imo, It can be used to gain better boost control and stop nasty boost occilations, the me7.5 PID controllers work better that way.

Running the boost request low at lower rpm on a taper ramping up the rpm range can cause issues in differing gears. Same with running the boost request over what the turbo can do at the top end the post-N75 control (KFLDRL) can be used to maintain the boost to a safe level which is smooth and has no intervention from other settings.

Thanks for that Nick, I found another small leak so sorted that out and have managed to log 233 bhp which is the highest I have seen, boost is still all over the place though but I will look at KFLDRL and see if I can do anything from there to help it.

 

[oldcar]

Steve, i had the same car as your with revo stage 1, first hit 22psi and boost drops as gears went up till 16psi. AND I finally found the problem was caused by springs in the diverter valve-I used 30psi spring but in this case it is still too soft. So I use the one that has double lengths to 30psi spring(I reckon this 30psi spring is actually 15psi). When installed the new spring I went for a test drive to make sure the diverter valve is actually release pressure to the intake once throttle i lifted- to reconize this you must have a good hearing and driving in a quite street to hear :shhh" and it did. And I WOT, it went up to 22psi and same thru all gears. Even on the top 6th, I press the throttle wot-it will reach 22psi. So I have fixed the leak= from the aftermarket DVoo7 copied forge diverter valve. I hope this is the same issue as yours and worked for you...

 

[<tuffty/>]

Steve, i had the same car as your with revo stage 1, first hit 22psi and boost drops as gears went up till 16psi. AND I finally found the problem was caused by springs in the diverter valve-I used 30psi spring but in this case it is still too soft. So I use the one that has double lengths to 30psi spring(I reckon this 30psi spring is actually 15psi). When installed the new spring I went for a test drive to make sure the diverter valve is actually release pressure to the intake once throttle i lifted- to reconize this you must have a good hearing and driving in a quite street to hear :shhh" and it did. And I WOT, it went up to 22psi and same thru all gears. Even on the top 6th, I press the throttle wot-it will reach 22psi. So I have fixed the leak= from the aftermarket DVoo7 copied forge diverter valve. I hope this is the same issue as yours and worked for you...

You don't typically need anything more than a std green spring on an aftermarket DV like the Forge 007p as long as it doesn't leak... early Forge piston design leaked and they have now addressed this using an o-ring seal... the spring is just a return sprin as the pressure is equalised under boost both sides if the piston so it won't open under boost under normal conditions... fitting the DV the wrong way around (a popular internet myth) where boost is acting on the pistons face (the end thats normally in the TIP) then it can force the piston open due to the increased surface area it has available to press on..

Fitting stiffer springs require more vacuum to lift the piston... at part throttle this leads to a choo choo choo noise which is compressor stall due to the DV not venting the pressure properly as vacuum on 1.8t's is not the best

Stick to as softer spring as you can or just use a brand new OE valve as they hold 30psi

<tuffty/>