so i’m having my carbon cleaning done in two weeks and have seen mention of cylinder port spacers in other posts and when doing a carbon cleaning they should not be reinstalled afterwards - is this the general consensus? what do they do and what are any effects (if any) of not having them installed? thanks…
I didn’t reinstall mine because I added the intake spacers from JHM.
From what I see I believe they are for cold starts and give a bit more tumble into the port to make the starting easier.
From my experience after the JHM Tune and the addition of the spacers and the removal of the port splitters my cold starts have been rough (under -15C or close to 0F) or colder.
But once the car is warmed up there is no difference noticed.
they are carbon magnets as I’m sure you’ve seen.
interesting…yes i did notice from another post that they are carbon magnets. i am installing the phenolic spacers, but being in CT where we obviously do get in the 0-F range of temperatures occasionally, maybe i should consider leaving them in? if the only downside to keeping them is they accumulate carbon deposits, is it worth the rough cold starts to not have them? since i’m guessing they’re removed during a clean, they’re probably not too hard to clean, unlike the valves
Can I get an exact look at which parts we’re talking about? I have yet to do a carbon clean, but it would be helpful to have an idea as to what this cylinder port spacer looks like.
I would not put them back in. Overall they end up being a restriction and a carbon magnet as you mentioned.
With the JHM spacers that helps add performance and keep carbon at bay but the low temps that cause harsh starts are going to also effect the car even if you have the spacers in.
Obviously doing the injector service and all of the other maintenance work will help the cars in below freezing temps.
I live in central Canada, so winter temps average lower than 0F and 20+ days at -20F or colder.
Basically with the JHM Tune and the the spacers, I need to let the car warm up for a few minutes longer than previously. Usually 5-6 mins, then I turn the car off and restart it and it is fine. On days where it’s sat a few days the warm up takes a bit longer. i’m going to add an oil pan heater for next winter, I know that will aid in the cold starts.
I’m not sure that they would actually help that much in a cold start. well worth taking them out.
there are pictures of them in the carbon cleaning thread.
If any other noob has the same question, some research yielded my answer per another AR thread.
http://audirevolution.net/addons/albums/images/678661216.jpg
As mentioned before, they are to aid in tumble which is necessary in a DI engine for a proper homogeneous mixture.
Especially important on a cold start. I dont know what the ignition and injection duration and events are stock vs JHM but perhaps the injection is not advanced for cold starts with the JHM tune.
Letting these cars warm up for 5 mins IMO is not a bad thing, yes emissions are higher but I do think it is key for longevity for tight high revving engines. This is especially crucial on the m5 v10s which has microscopic rod bearing clearances while using a 60w oil.
That being said, if you are not concerned with letting the car warm up for longer and higher emissions on cold start, no issue removing them. I did put mine back in though, and I do have a gutted intake manifold. My warmups are decent here in MI with no misfires.
I know most of y’all are in the northeast, so cold starts in freezing temperatures would be something to be mindful about. However, are these really necessary in warmer climates like Texas?
You will certainly have an easier time and wont need quite the length us northerners need. You will feel what the car does/does not like
Out of curiosity, what’s the general consensus on the cold starts? I’ve seen different sides; some saying to wait when first starting their S6 and others saying to drive and let the S6 warm up that way.
According to Audi you don’t want to let your car sit and warm up. This is per your owners manual. For the best results they say start and drive the car within 3 to 5 seconds of starting the car.
I fully agree with this. As the internal combustion motors run the least efficient when sitting at idle. And sitting idle is when the PCV system is working in a fashion that is more conducive to carbon build up.
For me I say start the car. Let a few seconds go for the oil pressure to settle and pump pressures to come up but only a few seconds. After that put the car into drive ASAP and drive at or just below 2600 rpm. The cars run really good in that range.