It looks like most people run a 10 micron filter between the pump and injectors. I've read that 10um is the minimum, and some people run 1-2um. Is running finer than 10 any benefit? Certainly there is higher pressure drop and likely more frequent filter changes. I will be running e85.

I was all set to run a spin on canister setup but just can't fit it in the space I have so I have to go in-line.

This chart is from a Deatschworks in-line canister filter.

 

I've always used 100 post pump.

 

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100? I don't think that is advised.

 

I stand corrected- it's a 100 pre and 10 post. I just looked.

The definitive answer can be found on Aeromotive's website; it's pretty standard fare.

 

Bringing this back for further discussion. I ended up going with the 5 micron filter, but am having a weird pressure drop issue ( https://ls1tech.com/forums/fueling-i...-attached.html ) that a few people think could be related to the filter size.

Any comments? I can swap the 5um filter element out for a 10um, but don't want to if it's not necessary.

 

5micron mesh should be fine if the overall overall filter surface area dimensions are sized appropriately to meet the flow demand anyway. Reading the symptoms, doesn't sound like a filter size issue. If it was, it'd wouldn't be pulling steady in 3rd gear afterward.

"I have only driven the car a few times before winter set in. Out of the few times I have driven it the fuel pressure has dropped sharply from 44 psi to 15psi. This isn't a gradual drop, it's very sharp. It has only happened in 2nd gear for whatever reason. When it happens, the car instantly loses all power. Then inexplicably, after I let off and get back in it, during the 3rd gear pull it's steady up to 6k."

 

If the voltage is good and the pressure is dropping its most likely the filter. Unless the pump itself is failing.

The 5 micron filter likely doesn't have enough filter media area to flow what you need. In the performance world 10 micron is pretty darn good. The 2-5 micron stuff is more for diesel applications that run a TON of fuel pressure so any particulates in the fuel wear the fuel nozzles and pumps. Those setups usually run 2-3 stages of filters. For standard EFI 10 micron is the minimum for fuel injectors and likely as good as you'll get with any sort of high flow fuel filter. I prefer the large spin on 10 micron farm filters. They are rated for ethanol and flow really well for the cost. (lots of filter media area). Goldenrod 595 is my "go to". But cimtek and napa also have very similar filters.

You can get them with 1" or 3/4 NPT inlets and outlets.

 

It'd be advisable to have a little line distance between the check valve, filter, and alcohol sensor instead of having them all in series.