Putting "Engine Carbon Clean" to the Test

[FaisalJ]

So manifold off, and here are the pics.

They've advised a quick (basic) carbon clean, and replacement of the cyclone breather pipe as apparently there is oil/grit everywhere.

Manifold has already been deflapped which is good (Kev said it was, but MRC didn't have a record of it being done by them so weren't sure.)

Once that's done, they're going to tweak the map to suit my intake and exhaust and we'll see where we are.

The pics reinforce the view I've had since having the clean done. That is, that the hydrogen clean does nothing for carbon buildup in the manifold, but registers improvement (which I can't ignore completely) by virtue of the italian tune effect and possibly cleaning inside the combustion chamber on back.

[Robnic]

Without wanting to piss on the hydrogen carbon clean fire - to anyone who has scraped this stuff out there is no way on this earth passing a gas over a running engine is going to remove the carbon build up, sorry but that is just fact. Even if it did you wouldn't want that dropping in your cylinders!

We use a BG product two stage chemical for cleaning the carbon with the inlet off, it softens but doesn't help that much and still needs scraping to loosen the chunky bits then we use a walnut shell blaster to finish the clean.

The hydrogen gimmick is right up there with the oil additive that replaces worn metal on your piston rings and the magnets on your fuel lines that give 20% mpg increase over

[audi_do_dat_den]

I had a 'hydrogen carbon clean' done a long while back..... the difference wasnt very noticeable and while its chemistry sounds impressive, theres no way it will remove solids.
During the cleaning process, the operator does around 10 red line revs and holding them for about 5 secs each time..... made me cringe.... but i suspect that does an effective job of blowing the cells through in the CAT...... and thats about it. An 'itallian tune' effectively.

Ive recently had the full manifold off carbon clean and porting done..... and the difference was intense!

So, i wont be bothering with the voodoo of hydrogen cleaning again.

[FaisalJ]

So the (proper) clean has been done! +44hp --> 427 PS

Pics of the cleaned parts, and before/after dyno

The guys at MRC noted that my intake really didn't help dyno figures. Even with fans on and bonnet open (which they do for all runs), intake temps were 15 deg higher than they would expect with a stock airbox. Hopefully different on the road!

I'm undecided now whether to a) keep the intake for the great noise and not worry about dyno numbers, b) go back to a stock airbox and decent filter, or c) double down and get a cold air feed next!

Something else interesting. They watched my hydrogen clean vid and they noted the dyno runs were done with bonnet closed and fans not best placed. They think those are the main reasons the power registered lower.

Seems these cars are really really sensitive to intake temp!

Draw your own conclusions about the hydrogen clean....

[MikeFish]

Faisal if you ae happy with how it drives now then keep the filter. It looks and sounds incredible too. But a cold air feed will help. I noticed a big change when I changed the cold air feed pipe from the standard mrc size of 89mm to 102mm. I think the trumpet on the standard airbox is 89mm so that is the size MRC normally fit but if you have an open intake like the Revolution then it makes sense to use a bigger pipe.

[FaisalJ]

I think you're right Mike.

Apparently one of my aux rads is on its way out anyway. Once it gets critical, good excuse to do the cold air feed. Trust me to pick the most expensive option! agh!!

Looking forward to picking the car up tonight, not driven it yet!!


EDIT: Just to add - I've sent over details of all of this to EngineCarbonClean, just stating the facts and attaching pics/dyno etc, and have asked for their thoughts.

[FaisalJ]

Just drove it home...holy crap!!! That made the world of difference! I actually enjoyed slow drivers pulling out into the outside lane of the motorway, so I could floor it when they pulled out of the way! Every time I looked at the speedo though I was doing 10-20mph faster than I thought I was...

Anyway.

I had a good chat with Doug when I picked the car up. Some useful words of wisdom from the man himself.

On the revolution intake; he thinks it costs 10-15hp on the dyno, but might not be so bad in the real world. Reason for that is they can't get enough airflow to keep the intake temps down with the intake on the car. Optimal setup (for dyno at least) is standard air box with cold air feed, intake temp might be within a degree or 2 of ambient. He also reiterated that the MAF misreads once you have the intake, so he applies a correction factor on the map to compensate.

On the hydrogen clean; he thinks it might well clear out some gunk post-combustion, but he also thinks it might have actually spewed some crap in the manifold! There was oily gunk everywhere, including on the throttle body and breather pipe which he said was odd.

I'm pretty convinced now and feel I have enough info to confirm that I don't want another hydrogen carbon clean! I can see it having some benefit for some cars, but it does nada for carbon in our manifolds.

Sorry for boring you all with repeated posts on this topic, but I think I'm done now. Off to enjoy my MRC restored 427 PS!

[Robnic]

'Sorry for boring you all with repeated posts on this topic, but I think I'm done now'

Don't think many will think that on here (well mebs some!) informative and well put together post imo, thanks for taking the time to do it

[Pistolpete2543]

I agree, this thread has been far from boring and I've followed it all the way through. Its great that you were able to close the loop with the physical strip-down and proper carbon cleaning to confirm internal condition. Rather than being bored, I would say many thanks for your help.

[FaisalJ]

'Sorry for boring you all with repeated posts on this topic, but I think I'm done now'

Don't think many will think that on here (well mebs some!) informative and well put together post imo, thanks for taking the time to do it

I agree, this thread has been far from boring and I've followed it all the way through. Its great that you were able to close the loop with the physical strip-down and proper carbon cleaning to confirm internal condition. Rather than being bored, I would say many thanks for your help.

Thanks gents! I must have forgotten I'm surrounded by other Audi nerds!



EDIT: Some more wisdom from MRC on email this morning:

"To keep the carbon build up to a minimum it needs a diet of good fuel (Tesco 99 or Shell V power) and it’s nice for it to see the redline at least once on every journey. This way air speeds are high in the intake which doesn’t give the carbon a chance to stick."

[toyneg]

Doug said the same to me but it isn't easy when you use it daily to hit the redline, well in rush hour it isnt ha

[MikeFish]

Especially this time of year when it takes so long to get some heat into the engine.

[Audi Pardner]

Another Audi nerd here saying thanks Faisal for the thread and the amount of detail you've gone into. I've just sold an old car/unfinished project so have a few bob burning a hole in my pocket, and I'll be off down to see Doug in the Spring with the breadvan for a good check over, CC and map. Can't wait

[Briggy]

'Sorry for boring you all with repeated posts on this topic, but I think I'm done now'

Don't think many will think that on here (well mebs some!) informative and well put together post imo, thanks for taking the time to do it

+1. This is exactly what this forum is for - sharing useful information. You've given lots of us the evidence and confidence that we can tackle a rewarding and productive job ourselves.

Cheers,
Bryan

[FaisalJ]

As I mentioned, I sent over the details, including video, pics inside the manifold, and before/after dyno by MRC. Response from EngineCarbonClean:


Faisal

Thank you for your email and for forwarding the video.

We agree with your assessment that more information is required, regarding the testing day on the rolling road, which may well lead to more testing.

It would be useful to know a little bit of history along with the manufactures hp for the Golf GTi and Jaguar XJS in order to assess the 3% improvements on these engines. Although improvement was marginal, context is always useful.

The RS4 improvement of 13hp we are broadly happy with, especially as our experience is that the engines improve further with use in the week following a clean.

The fact that the RS4 engine was still well short of the manufacturers standard hp, may indicate a secondary issue with the engine and we would be interested to have a sample of the discoloured oil apparently found when the manifold was removed, to establish whether removal of oil rather than carbon from the engine was the key to the final 427 hp achieved.

We would be delighted to attend a retest in the future, where amongst other objectives we would be keen to disassociate the revving of the engine during the cleaning the process, with reference to an “Italian Tune” by adding a control measure before and after revving but prior to the Engine Carbon Cleaning.

So please do send us a sample of the oil found in the engine along with your own assessment of how it came to be there and the likely effect on the engine.

Regards
Den