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A few people have recommended higher RON fuels and driving it harder. Why would higher RON fuels burn off the carbon deposits from oil burning or lower quality fuels?

I got the AA code yesterday and am off to the Nurburgring in 5 days. One of the stations there sells 100RON fuel which I've never used but if a tank or two and some hard laps will help then its a good oppertunity.
 

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Unless you are doing this yourself as a hobby or personal challenge, I would just have the DME programmed to ignore low secondary airflow.

Whatever caused your problem to begin with will likely cause it to recur..

A
Any idea where and/or how to get this done?
Still unclear whether or not this problem has any affect on the performance?

I would love to do the right think however, if the performance is not affected by the faulty emissions system I certainly would consider the 'work-around' option which in this case is programming the DME.
 

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Any idea where and/or how to get this done?
Still unclear whether or not this problem has any affect on the performance?

I would love to do the right think however, if the performance is not affected by the faulty emissions system I certainly would consider the 'work-around' option which in this case is programming the DME.
If you'll go and read the FAQ and study the numerous threads on this, you will see that it has no affect on performance whatsoever. It is just an emissions thing.

If it bothers you, or you are failing emissions because of it, look for a DME re-program, ala Powerchips (or similar) that will tell the DME to ignore it.
 

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A few people have recommended higher RON fuels and driving it harder. Why would higher RON fuels burn off the carbon deposits from oil burning or lower quality fuels?

I got the AA code yesterday and am off to the Nurburgring in 5 days. One of the stations there sells 100RON fuel which I've never used but if a tank or two and some hard laps will help then its a good oppertunity.
Higher octane fuels are supposed to clear out carbon deposits. Quality has nothing to do with octane; IE, there are high quality 87 octane fuels (RON+MON/2). We get 93 (R+M)/2 octane here in the states, which is identical to the 98 RON thats sold in europe. If you're already using 98 RON, The 100RON fuel you're using (which is effectively 95 octane (R+M/2) here in the states)... isnt going to make a difference with a 2 point octane boost.
 

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OK. When I get a chance I'm going to take off the aluminium tube that connects the two heads at the front of the engine and check for buildup. I expect to see alot.
 

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Expensive hobby,isn't it?:cheers:
Unless you're a DIYer and like to tackle would-be $$$$ labor projects like rod bearings!

I haven't quite read through the entire CBU FAQ yet, but I believe there should be no noticeable degradation in performance from CBU in the SAS; however, as one member mentioned about the carbon buildup on the valves/pistons/chamber/etc IF in fact the SAS is in any way to blame (doubtful) here are some thoughts. I also noticed a few questions related to the uglyness that Mert discovered and thought I would shed some light... some of this subject to opinion, of course.

Valves - Airflow velocity and pattern in tight places (i.e. ports/runners/head passages) is very sensitive to change in direction and as many of you who have read anything on fluid dynamics/thermodynamics know that air typically follows the outermost 'cavity' edge of a passageway. Sharp directional changes create turbulence which affects flow velocity and creates friction (heat) inherently as the molecules collide. As the air passes by the valve it meets some resistance due to the rough surface, not to mention the amount of air allowed into the chamber is affected due to the buildup on the valve that reduces the space in which it can enter. Most are not aware how tiny a gap the valves create until they see lift specs. The third aspect of carbon buildup on the valves (and pistons) is weight. Add a few grams of CBU to a piece of fairly light piece of metal that changes direction faster than a hummingbird beats its wings and you've compounded transient momentum exponentially towards the redline.

Pistons - A lot of the same principles (weight) as above apply with some additional implications. CBU on a piston dome (and chamber roof) changes the flamefront and increases compression, as one member stated previously. When the surface of a piston is rough the explosion changes significantly and this also creates additional 'hot spots' that can result in detonation that normally would not occur. The S62 is 11:1 - lofty indeed, and you can guarantee that even the thinnest layer of CBU on the dome can and will result in some knock, especially for you Cali guys stuck with 91. I get 93 here in NC and since I put the TMS/Conforti tune on the car I have heard a few pings on hot days and noticed an occasional power reduction because the DME pulled timing after hearing complaints from the knock sensor.

H20/meth injection - What was said about timing advance and H20 injection effectiveness together may very well be true although I have never correlated them as such. It is typically used in forced induction for controlling flame front (knock avoidance) when you run higher boost pressures where air/air or air/liquid intercooling may not be sufficient enough to deter knock. A lot of people use it improperly as a bandaid so they can crank the boost. The result on my previous turbo car w/ H20 injection was amazing though - the byproduct of running such high combustion temperatures was a steam cleaning effect that definitely reduced the amount of CBU in the chamber (I confirmed this by peeking through the plug hole with a flexible pen camera). I can't say that the S62 reaches 1550F EGTs as often as I did with my car, but I would be curious if a fine enough mist (100psi+ w/ a good Aquamist nozzle) would have the same effect on the combustion chamber in our cars. I certainly don't see how it could hurt though. It would be a little difficult to evenly distribute; however, I never worried about this when I sprayed it pre-throttle body... then again, that was under positive manifold pressure. I think if a pair of small (0.7mm) nozzles were placed in each of the two intake tubes near the plenum it would be displaced somewhat evenly across the runners.

Seafoam - I used this religiously on a previous car (98 Eclipse AWD, built 2.4 GT30R ~400awhp) with great results by doing the following, which may be difficult to duplicate with a 'V' motor like the S62. I know some that add it to their gas or oil, but I chose the direct method and went straight to the chamber. I would jack up the front of the car just enough to get the motor level to where the Seafoam would 'puddle' up and cover the entire top of the piston. I would then let it sit for many hours before turning the motor over via the starter (sans plugs/fuel/spark of course) with rags covering the plug covers in order to soak up the resulting spray. Even though I ran this motor somewhat lean I always ended up with flakes of carbon buildup that the Seafoam had broken down into pieces. I then changed the oil (in case any Seafoam had seeped by the rings) and the car always felt noticeably stronger and more responsive.

Has anyone proposed the idea of incorporating the Euro DME info (sans SAS code) into the TMS/Conforti tune that can be flashed via Shark Injector? I would like to remove the air pump altogether but I am unwilling to shell out the cost of the Powerchip for all of the same features I already have in the Conforti tune sans the SES removal from a malfunctioning SAS. The pure garbage they put on cars these days to meet stricter emissions regulations is ridiculous. We all know the M5 is one of the smoggiest cars on the road - who cares - cars are not even close to being one of the major contributors to greenhouse gases anyways.

:cheers:
 

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Please be advised!!

Powerships software does delete the AA code, but it will NOT allow you to pass smog.

The powerchips software causes the "readiness" codes to not be set, so your car WILL NOT PASS SMOG WITH POWERCHIPS UPGRADE.

You need to have stock CPU setting on your car, then drive it enough below 3krpm to set all but 2 of the readiness codes to get it to pass smog.

The previous owners of POWERCHIPS made us believe that POWERCHIPS was the answer for smog test. We were lied to.

Matt is the new owner/manager of Powerchips and is VERY HELPFUL in getting your car smogged, and very honest.
 

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Please be advised!!

Powerships software does delete the AA code, but it will NOT allow you to pass smog.

The powerchips software causes the "readiness" codes to not be set, so your car WILL NOT PASS SMOG WITH POWERCHIPS UPGRADE.

You need to have stock CPU setting on your car, then drive it enough below 3krpm to set all but 2 of the readiness codes to get it to pass smog.

The previous owners of POWERCHIPS made us believe that POWERCHIPS was the answer for smog test. We were lied to.

Matt is the new owner/manager of Powerchips and is VERY HELPFUL in getting your car smogged, and very honest.
so what do you do in states where they only check the readiness checks with the OBDII? clear the code and drive around for a while? how do you know you drove enough for the readiness checks to set ready? and how can you be sure you won't trip the SES again before all the checks are ready?
 

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so what do you do in states where they only check the readiness checks with the OBDII? clear the code and drive around for a while? how do you know you drove enough for the readiness checks to set ready? and how can you be sure you won't trip the SES again before all the checks are ready?

Get inspected in the hottest months of summer. Reset the code, drive a hundred miles or so, and get inspected. The AA should only come on when the sec. air pump is operating, and that should only operate when the motor is very cold.
 

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I'm looking at an 02 with around 80k. How would I know if the owner did the powerchip to get rid of the warning light?
I would think that a code reader will tell you if the "Low Flow" warning on the secondary air system is on. You should be able to get it checked at Autozone. That's what I did.
 

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No not 100 that will cause it more. The higher the octane the more likely to have the wrong carbon make up. In other words higher octane promotes carbon build up.
 

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I ran 102 octane the entire time I was at the Nurburgring, and when I got back my exhaust pipes and valves (had a perv from above) have never looked cleaner. I've noticed she feels smoother since then as well - 1,000 miles of serious hard driving seems to have cheered the old girl up!
 

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Your 102 is not our 100. Your 98 is our 91 IIRC. Different octane scales on each side of the pond. Running the correct octane is fine over kill is not. Oh and you have way cleaner gas where you are it is scrubbed of some of the bad carbon. One of the reason more AA code this side of the pond.
 
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