Dyno Log..opinions welcomed

B6/7 S4/RS4
#1

Took the car today to a MAHA LPS 3000 Dyno to see the output after finally soritng out tyhe clutch issue.

Some say ignorance is a bliss…you will see why.

The car has the following mods/works recently done:

  1. Revolution Pipercross intake
  2. Cold Air Feed
  3. Gutted pre-cats
  4. Forge Oil Cooler
  5. JHM spacers
  6. Manifold separators removed
  7. Carbon cleaned about 2k kms ago
  8. New spark plugs
  9. New Oil and gas filters
  10. New diff oil
  11. LOBA Sachs Stage 2 clutch kit

The gutted pre-cats were done about 400kms ago.

Well it did 363hp and 359Nm/6365rpm :thumbsdown:

Attahced you can see the graph (apologies for the terrible quality as their printer had run out of ink).

In addition you can see the log with VCDS.

Obvious remarks are very low timing (BTDC) of max 28 and really low RPM/Sec. Despite not pulling too mich timing on high IAT of ca 55-58 degrees Celcius. The Mass Air flow look ok i gues at ca 332gr/sec.

So the question is why so low timing and so low torque? What was holding the car back?

To be quite honest with the mods in place I expected soemthing in the range of 380-390hp and a far better torque.
The guy at the dyno suggested that MAHA dyno’s are quite strict on the 4WD Audis due to Torsen and I should adjust upwards the output by some 10%, ie 363x1.10= 393.

I have no idea whether this is true or just something to make me feel better… :?

Any ideas please as to what might be the cause of this restriction? You can obviously feel that the car is not puling as hard as it could…

#2

Can’t seem to be able to upload the xls file…
Although it is 17KB it says the upload folder is full…

Help pls?

#3

no idea how Maha dynos work, and to be honest not many people on this site put too much stock in a dyno at all. Let’s focus on the car and how it a tall accelerates before we worry too much.

1 Can you explain what revolution intake is? Is that the carbon fibre one from Britain? It will likely make you slower so that’s a start.

The stock airbox does very well on these cars. It’s a huge filter, and the aibox is closed which is important in the hot engine Bay. An open intake just flat doesn’t work that we’ll on the 4.2

2 If you are proficient at logging etc take your car to a flat straight highway and run from 2000 rpm full throttle to 8200 rpm while logging group 003 and 020 in the ‘engine’ module with turbo mode engaged.

Make note of your elevation and the temperature outside as well as the weight of the car (any cargo?) and the fuel octane and level in the tank. Once done you can upload the log file to audilogs.com , or google docs

That will tell us how your car is doing.

3 once we can see these things we can help look for any potential hindrance to performance… But as of now we don’t k of how your car is performing so that may prove to be a waste of time.

PS 28 degrees of timing is what your car is requesting? Or what your car is seeing net of timing being pulled? If its cool out and you’re running good fuel, you can see the rs4 request 31 degrees on stock tune. Otherwise 28 might not be bad if you live somewhere that is midsummer right now.

Where are you located?

#4

Hi and thanks for jumping in…

I have the log but I cannot seem to be able to upload it…anyways, I will describe you the figures.

  1. Yes it is the British carbon intake which I have installed after developing a heatshield. (rs246 forums)

  2. The car is asking for 28 degrees at a time when cyl 1,2,3,4 are pulling -6, -2.3, -3, -1.5 at 6920rpms (which is about the max figues)

  3. The IAT ranged 55-58 Celcius

  4. Lamda correction % ranged minus 6%-7%.

  5. RMP/Sec where really low at around 300-350

  6. MAF read 330gr/sec on max value

Can you tell me how to upload the file please?

#5

Log attached on imgur

[img]http://imgur.com/BVoTNYt.png[ /img]

#6

Not logs from your dyno run.

We want you to go out and take acceleration logs on a roadway.

#7

Gotcha…

I will do so tonight and post them.

Thanks guys for this.

#8

Yeah dyno is kinda hard to compare to the road.

Also what was ambient temp and octane of fuel?

#9

Ambient temp was around 30-32 Celcius and it ran on 91 Octane ( 95 EURO equivalent)

#10

are you in Greece? Heat sure doesn’t help.

Running 91 in the heat is a pretty big limitation for the RS4. Any chance you can access 93 (north american AKI; 98-99 Euro RON equivalent)?

I found about a 20hp gap between running 91 in the summer vs. 94 in the summer. Simply based on ignition timing and retardation.

Looking forward to your 003 and 020 logs

Audilogs.com was created by MISTRO and allows you to load logs up and then graph the parameters. GIve it a shot. It’s pretty awesome.

#11

20hp gap for just running higher octane?

Difficult to believe…

Yes I am in Greece and i know ambient conditions are a hindrance.

I am now at half tank so i will run some logs tonight with lower ambient temp at night, fill it up with 93 octane tomorrow and redo the logs. I will post the results.

Thanks for letting me know about the log site. Will do it.

#12

Btw do you know if the JHM tune that i just ordered takes care of any CEL faults due to the gutted pre-cats?

#13

Yes it will. It will take care of the catalyst efficiency threshold and the catalyst heating threshold faults/CELs

Yes, 20hp. That’s what I found when testing my car (about 2 tenths at the dragstrip from 91 octane in the heat vs. 94 octane)

#14

That is impressive.

Anyways as some folks at another thread suggested, perhaps the gutted precats without the appropriate tune to take care of the additional flow have something to do with it.

As the workshop has not installed any spacers could be that the ECU is trying to compensate the rich mixture by corrected with the lamda values hence the retardation on top of the heat.

I have just ordered the JHM tune and from what i read this should take care of that.

#15

no, my car has race cats, no precats, and stock tune and it would whip the shit out of any stock RS4

#16

Carbon cleaning??

#17

[quote]The car has the following mods/works recently done:

  1. Revolution Pipercross intake
  2. Cold Air Feed
  3. Gutted pre-cats
  4. Forge Oil Cooler
  5. JHM spacers
  6. Manifold separators removed
    7. Carbon cleaned about 2k kms ago8. New spark plugs
  7. New Oil and gas filters
  8. New diff oil
  9. LOBA Sachs Stage 2 clutch kit
    [/quote]
#18

Chances are the issue is the intake. Intake intake intake…the guys in Europe love to change them but it’s more harm then help. The stock air box on the RS4 is very exilent. You will see guys like saki going high to mid 12s with the stock air box. Then jhm tuned guys are going low low 12s all stock air box. This same issue came up with the b6 S4 guys. Turns out lots of performance was lost when you went away from the stock air box. The stock air box on the S4 and RS4 is actually a high pressure zone.

Maybe post a picture of your intake set up. From everything we have seen aftermarket intakes on the 4.2 are performance losers

#19

I agree with you partially.

Aftermarket intakes do cause performance issues due to the heat soak.
That is why the car has the JHM spacers and a heatshield below the intake.

In that contenxt, and given the ambient conditions here, I would agree that the intake during summer months is a cause of underperfomance. In colder days however I am sure that the CAF with the intake will be supportive to performance.

#20

here it is Justin. It looks great, but basically it’s a nice piece of CF and an open element filter underneath.

http://www.revolution247.com/cachedimageservice.axd?ImageID=69fd5d71-187a-41fb-accf-f5834bca73f7

http://www.revolution247.com/cachedimageservice.axd?ImageID=92084594-24f9-4388-b6c9-befe94e9f4e6

http://www.revolution247.com/cachedimageservice.axd?ImageID=45baa090-7115-4b6d-b634-b6af9f4c9d56

http://www.revolution247.com/cachedimageservice.axd?ImageID=bbfa16c0-3e36-491e-82b7-986f8f81efaf