# The difference an OPV adjustment makes?



## chrisalmond (Jan 18, 2013)

Hi all,

So been playing with my gaggia, still waiting for la poste to deliver my silvia wand and the PID that I have ordered from China. However I have been trying to make espresso's, and to be honest the results have not been great, some have been drinkable but still not perfect...

So I am wondering what would happen if I adjust the OPV to the 9-10 Bar? Would it really make the espressos better?

Just to say that yes I am using an UN-pressurised filter, quality fresh roasted coffee, and am using the Porlex had grinder.

Many Thanks

Chris


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## Callum_T (Dec 23, 2012)

My only piece of advice is to read through the OPV mod thread - I wrote exactly what I thought in detail

Here's the summary... Yes it makes a noticeable difference

My pressure valve should have arrived back from a CF member if your wanting to get a hold of one


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## Jason1wood (Jun 1, 2012)

Agree with Callum, I had mine without the mod for a few weeks and wasn't sure I could get into espresso as much as everyone here, but after the mod, it was like a different drink altogether. Get it done!! Haha

Sent from my iPhone using Tapatalk


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## chrisalmond (Jan 18, 2013)

Thanks for the replies. I had read the other thread about the mod, but still was unsure. I always thought that the opv just kicked in when the coffee chocked the machine. Does it actually control the pressure of the flow through he group head???


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## seeq (Jul 9, 2011)

chrisalmond said:


> Thanks for the replies. I had read the other thread about the mod, but still was unsure. I always thought that the opv just kicked in when the coffee chocked the machine. Does it actually control the pressure of the flow through he group head???


Yes. The pressure on a gaggia classic is set to 14-15 bar, realistically most people find it about 12 bar. It's set so high purely for the use of ESE pods. If you are using ground then ideally you should be after about 9 bar of pressure, which is what people modify to on the classic.


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## Xpenno (Nov 12, 2012)

I decided to do mine as I was getting poor results beforehand. The adjustment didn't do much at the time and it turned out that it was poor technique on my part. However it did cross that off the list of excuses and got me back on the path to learning how to make good espresso. I spent 2 months refining my process and am now getting great results.

I'm currently using the bottomless pf from happy donkey with the double basket that comes with it, we'll worth the money as you can see what's going wrong when jets of coffee are shooting all over the kitchen









Sent from my GT-I9300 using Tapatalk 2


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## Xpenno (Nov 12, 2012)

Just out of interest are you guys who modded rinning 10bar static pressure? I only had a static setup so that's what I went for, was thinking about going down to 9 though.

Spence

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## Ricriley (Jan 3, 2013)

Does anyone know if this mod has any effect on the steam wand?


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## chrisalmond (Jan 18, 2013)

WOW!!! This is amazing...

I decided tonight to adjust the OPV and WOW. I did not have gauge so just turned it the 270degrees, and the difference in incredible. I still have to build my gauge and check the pressure but just what I have done has made so much difference.

To anybody not sure about this MOD, DO IT


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## Callum_T (Dec 23, 2012)

Ricriley said:


> Does anyone know if this mod has any effect on the steam wand?


I noticed a dip in steam pressure


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## dimitris (Feb 12, 2013)

Hi guyz i would like to enter the chain..... I just bought a classic and i want to start doing some mods..

Nice to find a very good forum like this one!!


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