RS3 Build and low pressure fuel pumps

[Kaliking]

So I am in the beginning phase (planning stage) of going stage 3 on my 2018 Audi RS3. What are your thoughts and experiences on LPFP? Which ones do you guys recommend for a built engine hybrid build?

[cseaman]

Subbed. LPFP sure was a pain when I was doing my TTE700 SB build from being APR stage 1+. Iroz wouldn't assist as they were "backordered until 2074", so I initially ordered a SRM LPFP, because APR requires one for their stage 3 E85 TTE700 file..and SRM is not a brand I ever hoped to send money to. SRM ended up dropping the ball, which I honestly expected, and I had to make a quick decision to switch to Unitronic, because they have a stage 3 E85 TTE700 file for the stock LPFP, which is where I'm at now. In a perfect world, someone reliable would come out with a LPFP and I'd go back to APR ECU.

[mtwallace85]

The RS3/TTRS chat group I’m in is praising the A2B Motorsports LPFP and was being looped into other tuners saying the HPerformance one builds too much pressure so the tune needs to manage it and that’s not the best way to do things. I of course heard this after I ordered an HPerformance LPFP. Trying to see if I can cancel my order since it hasn’t shipped yet but at the same time everybody is going to have their own opinion so if I get the HP one so be it. I’ll test it out and see what happens.

https://a2bmotorsport.net/products/a...t-for-mqb-cars

[8STTRS]

So, I have limited experience in this area due to the fact that both builds I've done utilized the same LPFP. I use the PAG Parts pump made by Arnold. It's a dual fuel pump that has the second pump come on at 15psi. It has enough coverage to go well beyond the power I'm running at the moment and in theory, it will be less strain on the fuel pump(s) than simply running one large pump. The only thing I didn't like about this setup, was the adjustable Hobbs switch that came with the kit. At some point the Hobbs switch either fell out of spec or something with awry with it. I tried another adjustable one and I didn't care for that one, either. So I bought a static 15psi Hobbs and it's worked perfectly since. I'm not super sure why it doesn't just come with a static switch in the first place.

Keep in mind, however, that you cannot use that pump with Unitronic software as it only supports a single pump setup. My fuel setup overall should cover me to well into the 1000+whp range.