Rolling Road Day @ AmD Essex

[S4WON]

I had a call from Audi today, they are putting my query to the head of UK or something - I told them about the figures on Sunday and they seemed pretty interested. Not expecting anything to come of it really but I'd like them to try and explain the advertised 414bhp and why no standard car seems to achieve that.

Seeing as you have their attention, and assuming they do give you the party line on the RR.

use that opportunity to state that on the same day with the same conditions the B8 RS4 and R8 did make the stated figures and ask them to explain that one away..............

[toyneg]

I had a call from Audi today, they are putting my query to the head of UK or something - I told them about the figures on Sunday and they seemed pretty interested. Not expecting anything to come of it really but I'd like them to try and explain the advertised 414bhp and why no standard car seems to achieve that.

Can't remember who but someone done this a few years ago,to no avail..pretty sure audi say there are to many variables on a rolling road...the best way to see if your car is on the money is the 3k to 8k third gear test...other than that it's drive around and try and find a m3 that will have a drag race...

If like to do that in that supercharged one and see their face after haha

[toyneg]

I had a call from Audi today, they are putting my query to the head of UK or something - I told them about the figures on Sunday and they seemed pretty interested. Not expecting anything to come of it really but I'd like them to try and explain the advertised 414bhp and why no standard car seems to achieve that.

Seeing as you have their attention, and assuming they do give you the party line on the RR.

use that opportunity to state that on the same day with the same conditions the B8 RS4 and R8 did make the stated figures and ask them to explain that one away..............

Yes I have given then that info and told them not to fob me off with rolling road variables etc...

[PetrolDave]

@ the figures werent achieved in the first place / its down to variance of the RR
or
@ Its down to degradation of some kind (i.e carbon build up)
or
@ something else? something in the ECU that is limiting power, not playing ball, having a bad hair day


its certainly very strange! interesting though as others have mentioned, the B8 and R8s do make published numbers....

I've recently been experimenting with an iPhone app called DashCommand and a GoPoint Bluetooth OBD diagnostic connection.

What really surprises me is that it doesn't take many minutes driving for the intake temperature to get considerably above ambient (something that I don't see on either of our other cars). Given the known sensitivity of the B7 to ambient air temperature I'm wondering if this is an important factor in determining the greater power loss seen in the B7 compared to the B8 and R8 (which have a completely different - dual - intake system)?

[Graeme4130]

@ the figures werent achieved in the first place / its down to variance of the RR
or
@ Its down to degradation of some kind (i.e carbon build up)
or
@ something else? something in the ECU that is limiting power, not playing ball, having a bad hair day


its certainly very strange! interesting though as others have mentioned, the B8 and R8s do make published numbers....

I've recently been experimenting with an iPhone app called DashCommand and a GoPoint Bluetooth OBD diagnostic connection.

What really surprises me is that it doesn't take many minutes driving for the intake temperature to get considerably above ambient (something that I don't see on either of our other cars). Given the known sensitivity of the B7 to ambient air temperature I'm wondering if this is an important factor in determining the greater power loss seen in the B7 compared to the B8 and R8 (which have a completely different - dual - intake system)?

Tell me more about these apps ? Any good, easy to use ?

[PetrolDave]

Tell me more about these apps ? Any good, easy to use ?

The app can be downloaded from the Apple Store for $9.99 https://itunes.apple.com/app/dashcomman ... 93183?mt=8 I'm working on a universal dashboard for all our cars (RS4, C1 and Fabia).

The GoPoint Bluetooth OBD adapter is more problematic as they won't ship it outside of the US - but since my youngest lives near Boston that was easily solved BTW Amazon incorrectly describes it as an 'auxiliary input adapter' http://www.amazon.com/GoPoint-Technolog ... B0061XSX0O

They make a really useful tool IMHO. Easy to use - yes I think so. Enter basic details about the vehicle (engine size, fuel tank size, tyre size, gear ratios, weight, rpm (max, min and shift point), pair with the GoPoint and connect, download a dashboard, and you're up and running.

[bam_bam]

Tell me more about these apps ? Any good, easy to use ?

The app can be downloaded from the Apple Store for $9.99 https://itunes.apple.com/app/dashcomman ... 93183?mt=8 I'm working on a universal dashboard fro all our cars (RS4, C1 and Fabia).

The GoPoint Bluetooth OBD adapter is more problematic as they won't ship it outside of the US - but since my youngest lives near Boston that was easily solved BTW Amazon incorrectly describes it as an 'auxiliary input adapter' http://www.amazon.com/GoPoint-Technolog ... B0061XSX0O

THIS.
http://www.amazon.com/gp/mpd/permalink/ ... nt_fb_link

HAS TO BE THE WORST PRODUCT VIDEO. EVER.
WHAT IS IT WITH AMERICANS AND FEAR?

[Doug_S2]

Power loss is affected hugely by intake temperature and heatsoak - approx 2ps drop per degrees C rise in temp. I did tests on a car last week with plots that we posted on our fb page. Gruppem intake cars are hard to dyno to get intake temps to realistic temps - and to get realistic airflow into the engine bay when dynoing

a vacuum leak in itself doesnt cause power loss

a vacuum leak will mean though that the flaps (if fitted) in the manifold will not get held open so you restrict the inlet tract by 60%. This is easily seen on your peak maf numbers as well as a vacuum gauge.

Depending on SW versions you might or might not get epc light for the flaps not working

Depending on SW versions the car also goes into limp and will run in low timing mode

You can get 30ps drops in power from heatsoak
You can get 60ps drops from flaps not working
You can get 100ps drops from flaps not working and running in limp mode

[Firestarter]

All interesting stuff. I have fitted my new MAF earlier today. Cleared all DTCs and have just come back from a blast. Car still feels "laboured" from 5.5 to 8k....No MIL on. Im just now going to re check with VCDS to see if any DTCs are present. Will report back in a bit.

One thing that strikes a cord that Doug mentions in his previous post is the loss of power from heat soak. Steve from AmD did say to me after my shocking dyno run that its extremely likely that the cause of my power loss (together with the faulty MAF) is due to the amount of heat soak getting to the exposed revolution induction kit. BUT........if this was a given why aren't all RS4s fitted with this induction kit and tuned in a similar fashion suffering from the same issues? I am starting to loose confidence in the revolution induction kit and if it proves to be the source of "my issues" will be asking for a refund as the kit, even with the dry cone filter isn't fit for purpose.

[toyneg]

This thread is the longest we've ever had

[Timster]

Silas, has you hair started growing back ?

[PetrolDave]

a vacuum leak in itself doesnt cause power loss

a vacuum leak will mean though that the flaps (if fitted) in the manifold will not get held open so you restrict the inlet tract by 60%.
You can get 60ps drops from flaps not working

So piecing those three pieces of information together - a vacuum leak, causing the inlet flaps to not fully open and hence restricting the inlet tract by 60%, can cause a 60ps drop

You can get 30ps drops in power from heatsoak

That's why I was concerned to see the inlet temperatures significantly above ambient even in normal driving - which begs the question of how can we get air at, or close to, ambient temperature into the engine? Gruppem and similar intakes seem to increase intake temperatures, which offsets some (much? most?) of the advantage they could have offered.

[RIV]

Silas, has you hair started growing back ?

hair transplant, glad you noticed
Didn't see you there Tim, you gotta stop taking those pics of kids mate

[PetrolDave]

THIS.
http://www.amazon.com/gp/mpd/permalink/ ... nt_fb_link

HAS TO BE THE WORST PRODUCT VIDEO. EVER.
WHAT IS IT WITH AMERICANS AND FEAR?

Thankfully the product is MUCH better than that terrible video

[MikeFish]

I'm not so sure the drops are entirely related to heatsoak.
A year ago my car spent the whole day in MRCs workshop with the engine on, then after a quick warm up hit 403PS on the dyno, which had been unused. It had gone well past 6pm when it was dyno'd and a cold november evening. Then on Sunday, it took me an hour and a half to get to AmD, then after messing around with the I MAF drove around for ages in an attempt to clear the problem, then changed the MAF a couple of time and had the engine running for ages to make sure the problem had cleared so the engine was pretty hot (ask Gaz, he burnt a knuckle on the engine). Then it went into a hot booth to be dyno'd and it was a fairly warm day and hit the same figure that it did a year ago (OK, maybe 1bhp less). The car had identical configurations both times.
Everything I'm reading here would suggest it should have been lower last weekend (warmer day, warmer dyno, a year after the mods were done etc), but it was pretty muc the same.
Maybe the theory that the coking effects occur quite quickly then lessen as it gets older / higher mileage is the actual problem for the losses here and my car was already coked to the max last year so has lost nothing over the year. The ones who have experienced very quick drops in power are probsably due to vacuum related issues.