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Discussion Starter · #1 ·
OK so I have one or two questions...

Now I read the bumf on the site and I thought what it said was basically that instead of having the N75 to control when the DV opens and closes you put this Dawes Device thing in there instead. I assumed this would take the DV control away from the ECU and make it purely mechanical ( which sounds good to me ).

But someone else said that it just goes inline with the N75 and so all it does is increase boost, or more accuratley increases the boost that gets held.

Can anyone tell me how this thing should work??? :confused:

Pete
 

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It doesnt go inline with your original N75, it actually replaces the N75,

BUT, you have to leave the original N75 connected electrically (tape over the hose connections to stop dirt getting in though) otherwise you will get possible ecu faults logged if it cant get any feedback from its input
 

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Discussion Starter · #3 ·
I thought so... so rather than replacing the N75, I might be better off with one of these?

Am I right in thinking that the N75 is the bit that allows the ECU to control the DV opening? If so then surely a Dawes jobbie would get rid of my surging problem... :D :D

Pete
 

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Sort of!, N75 actually controls the opening of the wastegate,it doesnt have any control of the DV at all, thats the job of N249
 

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The N75 lets a proportion of the boost pressure back to the wastegate...

eg if it has a 50% duty cycle signal fed to it and the wastegate opens at 5psi only 50% of the boost pressure is fed to the valve therefore the boost pressure required to open the valve is 10psi.

Thats the way I understand it works! ITs probably cack though... lol
 

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Originally posted by Steve
Go i hate it when you electronic boy's get hold of car's!:flame:

You lot confuse me!:swear:
You're going to be totally shafted by the new generation Audis then... My friend who also works for an Audi dealership was telling me about the latest gizmos and stuff coming through.

Training course after training course.

The W8 sounds like a monster.... You will need a PhD soon to work on them! Amazing but scarey. Who on earth could ever maintain them... Yikes...
Shape of things to come maybe?

Bill
 
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Originally posted by badger5


You're going to be totally shafted by the new generation Audis then... My friend who also works for an Audi dealership was telling me about the latest gizmos and stuff coming through.

Training course after training course.

The W8 sounds like a monster.... You will need a PhD soon to work on them! Amazing but scarey. Who on earth could ever maintain them... Yikes...
Shape of things to come maybe?

Bill
That be me!

The new A8 that come out next year is going to be mad! You have to be put forward by your francise and accredided by Audi to touch them!

At my place we have two people going to germany to train for 5 weeks and im one of them!:eek:

Not sure if thats good or bad!(Good for training, bad for hassle!)

There are some mad gizmo's on it, black ice detector's and such and a W12 engine! thats going to be mad to works on if it ever breaks!

Iam rebuilding a S4 engine at the mo, two turbo's, 6 pistons and thirty valves were damaged by a cambelt failure!

Bout £7000 in parts!
 

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Originally posted by Steve


That be me!

The new A8 that come out next year is going to be mad! You have to be put forward by your francise and accredided by Audi to touch them!

At my place we have two people going to germany to train for 5 weeks and im one of them!:eek:

Not sure if thats good or bad!(Good for training, bad for hassle!)

There are some mad gizmo's on it, black ice detector's and such and a W12 engine! thats going to be mad to works on if it ever breaks!

Iam rebuilding a S4 engine at the mo, two turbo's, 6 pistons and thirty valves were damaged by a cambelt failure!

Bout £7000 in parts!
S4 rebuild... Owch!
My mate said he had a 4.2 A8 in for a replacement engine (1st time ever in his experience) Put it all back together and drove it out for test drive and it would'nt engage drive... Pushed back in, only to find the oil pump drive had snapped on the g'box. All out again... Customer ended up with all new engine and gearbox. (EAK!) - Warranty tho... and they had them on the shelf!!! would you believe.

W12 sounded like a nightmare. 4 cats, 8 lambdas, only 2 of them accessable without having to remove the engine !!!

He mentioned something about the latest models (high end top of the range I guess) having telemetry back to Audi HQ, where you have to log into ECU into Service mode before touching anything otherwise it would call out for help via its phone as its being tampered with !! Big Brother...

Good luck with your training. Well worth it if you become sought after in the dealer network when fully trained. sort of like the Ur Quattro techies were after they were factory trained back in the Fatherland.

All the best
regards
Bill
 
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Originally posted by badger5


He mentioned something about the latest models (high end top of the range I guess) having telemetry back to Audi HQ, where you have to log into ECU into Service mode before touching anything otherwise it would call out for help via its phone as its being tampered with !! Big Brother...

All the best
regards
Bill
Ive heard of that as well, we already have the loggin section for it on 5051.

We can Remap ECU's now as well! Nothing performace related but more for fault rectification, ie updating software and such. We just burnit of a Audi CD! (Already doing it as part of the multitronic gearbox recall)
 

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Discussion Starter · #14 ·
Back to the original thread.... :p

Steve that's why I was thinking it would be good to be able to replace the N75 with a dawes jobbie. Take the ECU and all the gubbins out of the equation and leave us with something purely mechanical...

I might be a software engineer, but when a mechanical method is better.... ;)

Pete
 

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Why does the ECU need to be able to adjust the boost pressure then steve????

Wont the ECU get a bit ****** when its expected boost level dont match its acutal boost level? Those were two items I mapped with mossers VAGCOM.... They tracked wreasonably well too...
 

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N75 is under ECU control so that they can be adjusted according to the altitude, temperature and a few other variables i cant remember

The ecu doesnt always run the boost pressure at the most it can, if you fit a dawes device the boost is optimised to give the maximum possible every time (according to how you set it that is!)
 
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Originally posted by matt1e
Why does the ECU need to be able to adjust the boost pressure then steve????

Wont the ECU get a bit ****** when its expected boost level dont match its acutal boost level? Those were two items I mapped with mossers VAGCOM.... They tracked wreasonably well too...
I haven't actually seen how these dawes device's work, but yes your right, the ecu has a requested boost level and a actual boost value that should match or faults will be logged.

The ECU needs to CONTROL boost pressure. For obvious reasons really, ie if the wastegate doesn't get told to open it won't until it damages something etc etc

The ecu basically looks for a torque figure. you plant ya foot and the ECU adjust boost, timing, fueling etc to give you the best torque possible, boost is the easyest thing to change so thats normally the case,

Does your car surge Matt? I thought it was only chipped ones?

Mine does, you can watch the boost gauge going from say 16psi to 5 then back to 16 again over and over even though your foot is on the floor!

Wouldn't mind going for a race n75 instead, rather than a Dawes device.
 

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I didnt know you had surging Steve?, are you running an 'f' or 'c' version fo the N75 ?,

I'm using an 'f' version and didnt get any surging with my previous 'c' version but now cant get hold of a swapout from my dealer :(
 
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Originally posted by Pete
Back to the original thread.... :p

Steve that's why I was thinking it would be good to be able to replace the N75 with a dawes jobbie. Take the ECU and all the gubbins out of the equation and leave us with something purely mechanical...

I might be a software engineer, but when a mechanical method is better.... ;)

Pete
Worth a go mate,

Is this more of a quest for a dumpvalve tho Pete?
:rolleyes:

Get a boost gauge, then you can see what happens when ya car is surging, and see if its the same as mine.
 
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Originally posted by mosser
I didnt know you had surging Steve?, are you running an 'f' or 'c' version fo the N75 ?,

I'm using an 'f' version and didnt get any surging with my previous 'c' version but now cant get hold of a swapout from my dealer :(
Every so often i do mate,

I haven't checked what N75 i have, will probley just put a 225 tt/S3 one on there, haven't heard of any faults on those ones.
 
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