Can anyone out there help me with my Rancilio Silvia. I have had it now for about a month and have yet to find any consistency in my shots. Now 90% of this has to do with my grinder but for now it is all I have. I have read and watched videos about installing a PID and reducing the pressure at the group head. Just wondering if any of this makes that much of a difference.

... 90% of this has to do with my grinder

To give us a starting point... Can you explain what you mean by this ?
..What grinder are you using ?
What beans ?
can you achieve the 2oz shot in 30sec target using a double basket ?
do you understand and use "temperature surfing" ?

EDIT:.. just noticed you list the Baratza Encore as your grinder.
Maybe not ideal, but it can grind espresso shots (reportedly)

This might be helpful: Diagnosing Espresso Extraction Problems - Espresso Guide

if you havent changed the brew pressure to 9 bars, do that. If you dont have a clue what your brew temp is, look into temperature surfing for silvia (theres a ton of info out there), these are all variables that need to be controled to a degree for consistency.

if your grinder does a fine enough grind to choke the machine, it will work. the encore seems to be able to do that in most cases ive seen.

the answer to your question is YES, it makes a difference.

You mention that you've had your Silvia for about a month, I'm assuming that you are also about a month into your espresso making as well.

I actually would not recommend you start playing with pressure or installing a PID at this point. Temperature surfing is a pain, but if you do it the temp will be quite consistent from shot to shot. A PID does make this MUCH easier, but rather than going down that path at this point get comfortable with your technique.

Adjusting your brew pressure could improve your espresso but I don't think this will actually help with consistency (I may be wrong here). I just think it adds one more variable that you will worry about. The factory setting is probably close enough for now.

Instead I recommend you strive to keep your process and technique as consistent as possible. Do the temperature surf as Beenbag mentions, use the double basket (easier than the single), keep your dose the same (best done by weighing with a 0.1 gram resolution scale; you can get one for $10), distribute/level the same way (very important step), use freshly roasted coffee (it needs to be in the 2 day to maybe 2 week post-roast range, though some may say you shouldn't go that long), and grind right before you use it. The objective is to do everything the same and then you can try to address one variable, the grind. Actually before you go there, try pulling a few consecutive shots without changing anything, including the grind.

Once you start to consistently produce ~2oz/30sec shots you can then start to take your game up a level. The guide ggcadc pointed you to is excellent and I recommend you peruse the other sections as well.

Lastly, you'll learn a lot if you can hook up with someone locally who is knowledgeable. (Hopefully there's another HBer that lives near you.) I was lucky when I bought my machine the vendor spent over an hour with me and we pulled shot after shot using my new machine and grinder.

Thank you guys for your replies. I should have described my problem much better. The main issue I am having is with the timing of my shots. I use the double basket that came with my machine 99% of the time. I use fresh quality beans usually from a local roaster. I try to keep my routine the same (distribution, tamp pressure) but struggle keeping the dose the same. This is a problem because it seems that there is no happy medium for me. 14-16g and the shot is done in around 15 seconds. 17-18g and the coffee is hitting the screen and shots can take around 45 seconds. I use my encore and have re calibrated it to be the finest it can but it just hasnt worked. I know that this is my biggest problem and it will be fixed eventually. I was curious if lowering the pressure would at least slow my shots down in that 14-16g range enough to where I knew I was getting the best out of my coffee as possible. While I do temperature surf I was wondering if the pre infusion capability of the PID would make any difference. I still havent found anything that tells me exactly if pre infusion truly matters .

Thanks for clarifying. If you want to experiment with lowering the pressure and doing a "preinfusion," you can try having your steam wand open at the beginning of the shot and then closing it during the pour. You'll need to experiment to find the best timing on when to close the steam valve. Overall, however, it does seem that you are pushing up against the limits of your grinder as you stated.

your Silvia can make excellent espresso without pre-infusion.
Pre infusion will not compensate for a bad grinder, poor temp control, wrong pressure, or any other possible issue.
Dont add extra complication to your problem solving.

And, paradoxically, reducing pressure can actually increase flow. Don't look to pressure as a flow-rate variable. It will affect flavor, yes, and it will affect flow rate, but it is one variable of many and the last you should be chasing, unless it is waaay off.
Are the beans you are using light or dark roasted?
If light, and you are already as fine as you can go on the grinder, you might try experimenting with a darker roast - it can make an acceptable extraction with a coarser grind than a lighter roast. That might give you some more wiggle room for now to get a good dose and acceptable grind.

The actual QUALITY of the "doubles" basket that arrives with current Silvia's is pretty good BUT the capacity leaves a lot to be desired. From what I have experienced with Baratza grinders in the Encore class, they are sitting "on the fence" as regards espresso capability but perhaps the larger capacity basket will help matters.

Purchase a couple of each of these baskets: http://www.espressoparts.com/EPMZ_107A? ... id=2001554 and http://www.espressoparts.com/EPW10813?& ... id=2001554

I know you said that the Encore is "what I have for now" and I understand that. But, as an FYI, Baratza happens to have some Preciso refurbs available now ($240) and I assure you that these are fully capable of doing great espresso in the 14g baskets.

Thank you all for your help. Eric I ordered both of those baskets and a bottomless portafilter. Hopefully this helps and the frustration Ive felt can subside a little until I get a better grinder. Thanks again.