RS6 C5: About to upgrade stock IC's to Wagners, what to log

[PatrickRS6]

I've bought a set of Wagners, including the carbon air ducts and fog-light grills, also bought the reinforced hoses and clamps.
I suspect my OEM IC's to be leaking, so i wanted to log before and after with Vagcom.

Logged the RPM, Intake air temp, Mass Air Flow G70 (Bank 1), Mass Air Flow G246 (Bank 2) & Mass Air Flow (G70 + G246)
Did a run on the freeway, 0-240km/h...
Will post the log, and footage from my VisionDrive.

Do i need to log more to be usefull?

[PatrickRS6]

DOH! How could i forget to log the boost, will do that tonight, to much traffic now

[bakustax]

I'd be surprised if you see much of a difference...from my understanding the main reason for the upgrade is to save the turbos rather than any performance gain

[PatrickRS6]

Here's the video of the run, LOGs wil be posted later on...
http://www.youtube.com/watch?v=-ar2XDGeUO4

[Shoppinit]

Cool. Is that near Osnabruck? Drive there quite a bit myself.

[PatrickRS6]

It's in Holland, near the German border A1 (Oldenzaal)... heading towards Germany (just a few kms)

[Shoppinit]

Cool. Driven that route many times. Used to have a good friend in Nijmegen and I'd go that way on my way to Osna. These days I mostly use the E34.

[Nobby]

I'd be surprised if you see much of a difference...from my understanding the main reason for the upgrade is to save the turbos rather than any performance gain

You might not see any performance benefits, but I cannot underestimate how important it is that if your intercoolers are leaking then your car is not running properly.

Air goes in, past the filter, through the MAF(s), ECU reads airflow and adjusts fuel trim/ignition accordingly. If subsequent air is leaked out past the turbos (or some gets in) then your ECU DOES NOT KNOW.

[PatrickRS6]

One of the rare highways in Holland where you aren't stuck in traffic, unless its May 1st, like today, a few kms ahead the limit is 70 today due to the restriction for trucks on sundays in Germany. They were all parked on the emergency lane.

Don't know for sure, but i think we will pass Osnabruck on June 17th, the route is a well-kept secret, but the StreetGasm challenge will be passing Germany then, with a RS3, RS4 and a RS6 (the R8 V10 is still on the competitors list, but from what i've heard, it won't attend).

@Nobby: I know, that's why i also orderd new hoses and clamps, May 13th we'll drive 1100km to Reifnitz Wörthersee Tour 2012

[bakustax]

I'd be surprised if you see much of a difference...from my understanding the main reason for the upgrade is to save the turbos rather than any performance gain

You might not see any performance benefits, but I cannot underestimate how important it is that if your intercoolers are leaking then your car is not running properly.

Air goes in, past the filter, through the MAF(s), ECU reads airflow and adjusts fuel trim/ignition accordingly. If subsequent air is leaked out past the turbos (or some gets in) then your ECU DOES NOT KNOW.

Fair point...noted...would this show it's self in decreased MPG?...or would it be minimal with un-noticed damage being done

[Shoppinit]

In closed loop mode then the lambda will detect the overrich mixture and compensate. Under WOT and in open loop then the ECU uses a guestimate for the mixture correction.

The real problem is that the turbos will not have enough resistance and risk exceeding their safe RPM leading to excessive wear. $$$

[JCviggen]

The real problem is that the turbos will not have enough resistance and risk exceeding their safe RPM leading to excessive wear. $$$

Not correcting you, but I'm bored so i'll dwell a bit more on the mechanics of turbo's over-spinning: what happens when part of the charge air gets lost is simply that more air needs to go pass through the turbo to reach the same boost level. The wastegates stay closed(ish) until target boost is reached so the turbo itself basically has no choice but to spin faster than normal. Resistance aside, the reason they can over-spin is that the wastegate actuators are controlled by boost pressure. Vicious circle.
Over-spinning only occurs when you have a leak that is sigificant, but not so large that you're not making much boost anymore. A large leak that does not allow much boost will not spin turbos as high because there will be less (and less hot) exhaust gas available.
So it's the nasty little hard-to-notice leaks that will do them in after an extended period of time (MIL is likely however certainly on stock mapping)

[bakustax]

The real problem is that the turbos will not have enough resistance and risk exceeding their safe RPM leading to excessive wear. $$$

Not correcting you, but I'm bored so i'll dwell a bit more on the mechanics of turbo's over-spinning: what happens when part of the charge air gets lost is simply that more air needs to go pass through the turbo to reach the same boost level. The wastegates stay closed(ish) until target boost is reached so the turbo itself basically has no choice but to spin faster than normal. Resistance aside, the reason they can over-spin is that the wastegate actuators are controlled by boost pressure. Vicious circle.
Over-spinning only occurs when you have a leak that is sigificant, but not so large that you're not making much boost anymore. A large leak that does not allow much boost will not spin turbos as high because there will be less (and less hot) exhaust gas available.
So it's the nasty little hard-to-notice leaks that will do them in after an extended period of time.

Man this is exactly what we all miss...tricky stuff explained for the average Joe...great to have you back posting JC

[PatrickRS6]

slightly offtopic, but bad mpg... haha been there.
Old TC: 4 km per liter
New TC: 6,5 km per liter

[bakustax]

slightly offtopic, but bad mpg... haha been there.
Old TC: 4 km per liter
New TC: 6,5 km per liter

Yup It's my guess too...It's not banging about but the MPG ain't great...15 in town and 25 on a run...it's inevitable.