Valves- carboning up

[Mahyar]

Had a little problem. The Audi Swiss solution was to clean and then change the whole thing.

[Mahyar]

It started with EPC light that came on. Went out and came on again so booked it in with the result that there was carbon and one of the, what ever they are on each side of the engine, had failed. Changed that, cleaned the engine and put on a new top part. This is not really a good description but am sure you guys will all understand.

[HYFR]

im on 73k, still fast as feck!!!!

i'll try and do the 3 - 8k rpm for you Arthur this week

Arthur! I did it!

3rd gear 2.5k rpm.....footdown, hit the OBC timer at 3krpm...nailed it....the boost at 5krpm was massively noticeable....hit 8k rpm, hit the OBC to stop the timer

Time: 8.0!! Dead! I was suprised!
Saloon
73k mikes
Less than 1/4 of tank, just me
Straight road, no incline

I'll try again some more times when i can and see if it was fluke

But to reiterate, the boost at 5krpm was VERY noticable and made the difference in times

Food for thought....

[ArthurPE]

let's put this into perspective, first I'm assuming you took great care in timing, and it's accurate, why wouldn't you?

second: the average of numerous magazine tests (4 or 5) for the same speed range (36 to 96 mph) using ALL gears is 8 flat...these were new cars, that Audi made sure were running perfect (they knew they were for magazine tests) on a track, under ideal conditions...

your car using 3rd gear only is as fast! with 73k miles to boot
think about it...does that sound down on HP to you? to anyone?

Arthur! I did it!

3rd gear 2.5k rpm.....footdown, hit the OBC timer at 3krpm...nailed it....the boost at 5krpm was massively noticeable....hit 8k rpm, hit the OBC to stop the timer

Time: 8.0!! Dead! I was suprised!
Saloon
73k mikes
Less than 1/4 of tank, just me
Straight road, no incline

I'll try again some more times when i can and see if it was fluke

But to reiterate, the boost at 5krpm was VERY noticable and made the difference in times

Food for thought....

[HYFR]

Ok, I did this again this morning, on the same road albeit on the opposite carraigeway...this time less petrol (25miles range in tank)

same procedure.....

time = 7.9sec!

Am I using the OBC timer correctly? I press the '+' button twice to start a new lap (at 3krpm) and nail it to 8krpm and at 8k press the '-' to stop the clock ? thats right no?

This is absolutely genuine & if I can figure out a way to film it I will...

The road I do it on has 40mph SPECS....so when im coming up to the last camera, I put it into 3rd, slow to 2.5/2.7krpm, once passed the last camera, nail it up to 8krpm (its a motorway so as long as its clear in front its pretty simple)

I'll try it again on the way home tonight if I get a clearway in front at the last camera

[crispy]

Just out of interest (why not) I tried the 3rd gear test this morning.

I did 4 runs:-

8.2
8.3
7.9
7.7

For true checking I will need to test again going the other way to compensate for any potentially un-noticed subtle inclines.
I am confident that my operation of the start / stop button was consistant.
I would also add that the additional shove from approx 5K was particualrly noticeable during the runs.

For the record my car is an 07 Avant with 36K on the clock, with a full tank of Shell Optimax, assorted junk in the boot including a very large bag of dog, and 100Kgs of me.
The oil Temp changed between 85 and 90 as the tests progressed.
The outside temp was shown on the display as 8.5'C and it was dry and sunny. All stability aids were active.
The car is currently on 255/35/R19 Winter Tyres

I have owned the car from new, only had it serviced as per the AVS display and it is totally standard.

My commute to work takes me over some fantastic roads, and my car is often worked quite hard, and 8K on the rev counter is a fairly regular occurance.

[matthew.lewis2]

I have come back from doing 7 runs:-

8.5
9.0
8.4
8.6
8.6
8.7
9.0

well, i tell a lie, i did 8 test, the first one was around 16.5 secs, but, i didnt record that, i realised after the test i was in 4th!!

I am confident that my operation of the start / stop button was as consistant as I could muster.

For the record my car is an 08 Saloon, with 41,561 miles on the clock, with a shade under a half tank of 98ron Dubai fuel (rumour has it its not as good as optimax), driver only and no junk of any sort in the car

The oil Temp was 112c half way through the tests.

The outside temp was shown on the display as 42.0 C and (not surprisingly) it was dry and sunny. All stability aids were de-active and in sports mode.

The car is currently on 275/30/R19 Goodyear F1's.

I have owned the car from 6,000 miles, serviced every 15,000 kilometers (as per Audi UAE schedule). Modifications are de-cat and MRC panel filter.

Due to minor compression loss Audi replaced the 'short' engine at 27,000 miles. 'short engine' being the bottom end including pistons etc, intake manifold, valves etc are original, and uncleaned.

I forgot to mention, I am happy with the performance of my vehicle. bearing in mind the tmperatures here, and poorer quality fuel, a few fractions of a second 8-8.3 to 8.5-9 to me are acceptable (and un-noticable).

Hope this data helps.

[oscawhite]

[P_G]

It may be boring to you Oscawhite but it helps.

Average is 8.68 which given the temperature is phenomenal. Given I can have a difference of 0.3 second average between 0 degree C and 13 degrees C I can't imagine how much the engine is retarded with 42 degree C temperatures.

[ArthurPE]

It may be boring to you Oscawhite but it helps.

Average is 8.68 which given the temperature is phenomenal. Given I can have a difference of 0.3 second average between 0 degree C and 13 degrees C I can't imagine how much the engine is retarded with 42 degree C temperatures.

I agree, when first looking at it, it seems high
but when you factor the temp in, it actually looks good...108f!!!

[ArthurPE]

from 70f to 108f is a 6% difference in HP, probably more when timing is factored in..>25 HP
using basic estimates that equates to a 0.3 sec difference...puting his times at <8.4...right where they should be...

[P_G]

The car is decatted though Arthur.

[PetrolDave]

The car is decatted though Arthur.

Usually decatting results in a loss of power due to the loss of back pressure upsetting the fueling, unless the ECUs have been recalibrated.

[P_G]

Sorry, I didn't mean it in a way that it had increased power; just as you say it should be down unless there is a remap along with that MRC filter but there is no mention of that?

[2manytoys]

I don't get this, it's got to be full of errors, but anyway, if not:

aka dk is doing it in 8 secs (7.9 in one run)
Matthew Lewis is doing it in a average of 8.7 (just under actually)

Arthur, if you say 25hp is 0.3 seconds, that's more than a 50hp difference between these two guys. Interestingly 'aka dk' is saying he has that boost at 5k.

Now I've seen cars running at 8.6 (I don't have a huge database like you) but surely the difference is showing that someone, even in your tests, can have a 50hp difference, and in each case you're saying the car is good. If I paid for 420hp and only got 370 I wouldn't be happy (assuming the difference isn't CARBON BUILDUP, mmmhahaha)

I'd put money on the difference is at the upper end of the rev range too.

Can someone time 3000-6000 and then 6000-8000?