MK7 "Random / "Stupid" Questions Thread"

[Diggs24]

hpfp should never be first option

 

[StorableComa]

For some reason people really like their HPFPs. You mention MPI and they have a fit about incorrectly installed pump internals being superior.

 

[EpicTech]

The general consensus is upgraded HPFP not needed if MPI is setup, however I would do it just for peace of mind.

 

[Ezekiel81923]

Yea I I guess the assumption here is a big one but my question is assuming everything is installed correctly. You don't have to look too hard to find people having issues with both but troubleshooting and fixing a LPFP / MPI setup seems more of a pain than swapping out a HPFP.

I guess the real question is if LPFP/MPI setups on this platform have gotten to the point where they are relatively trouble free when installed correctly and when not pushed to their limits.

 

[StorableComa]

Yea I I guess the assumption here is a big one but my question is assuming everything is installed correctly. You don't have to look too hard to find people having issues with both but troubleshooting and fixing a LPFP / MPI setup seems more of a pain than swapping out a HPFP.

I guess the real question is if LPFP/MPI setups on this platform have gotten to the point where they are relatively trouble free when installed correctly and when not pushed to their limits.

If you use correct fuel line and clamps along with install injectors correctly I don't see much that could go wrong. MPI comes stock on ROW models, we're just changing the injector size and when it fires.

I've been trouble free other than a runner flap code that popped recently. Using a China euro mani, so more than likely need to swap the diaphragm from my stock unit.

Other than that I've only heard of the rare injector issue, but you also get those with your DI injectors.

Personally it seems like 1 out of every 4 autotech posts is a failure. I'm sure a lot of that is on the install and not the part, but I'm also 1.8 so HPFP wasn't really an option until recently.

As for LPFP. Go RS3, don't bother swapping a new pump in your existing basket and that'll remove almost all possible issues. Most lpfp problems are install related.

 

[Diggs24]

^

 

[Ezekiel81923]

Right on. Thanks guys.

Fuel lines had not even crossed my mind. I'll do some research on setups and see where we land but the goal is to get this stuff installed this spring

 

[StorableComa]

Right on. Thanks guys.

Fuel lines had not even crossed my mind. I'll do some research on setups and see where we land but the goal is to get this stuff installed this spring

I'm using these guys with their single ear clamps and tool:
https://www.anhosefittings.com/fkm-viton-sae-j30-r9-push-lock-fuel-hose.html
https://www.anhosefittings.com/single-ear-oetiker-hose-clamp-tool-kit.html
15.3mm clamps are what they recommend for their 5/16 hose, which is stock size.
Gates also makes a good hose a lot of others are using with no issue:
https://www.ebay.com/itm/233865574292

Regardless, make sure your hose is rated for the fuel you'll be using - both of the above are e85+, methanol, etc. Oetiker or Single ear clamps would be a must IMO, they work so much better when sized correctly than worm gear or others, plus it's fuel line, I really don't want it going anywhere.

Other than that you can do braided, Anhosefittings.com has good prices if you're willing to build it yourself. If not I'd recommend looking at Precision Raceworks kits. They have a full 3/8ths from LPFP to bay or just a bay only kit.

 

[Kdubya]

As for LPFP. Go RS3, don't bother swapping a new pump in your existing basket and that'll remove almost all possible issues. Most lpfp problems are install related.

Dumb question but is the RS3 fuel pump direct bolt On?

 

[StorableComa]

Dumb question but is the RS3 fuel pump direct bolt On?

Yes, You need a tune to use it without damaging the pump, controller or both, but it's a plug and play drop in swap.

 

[Ezekiel81923]

Yes, You need a tune to use it without damaging the pump, controller or both, but it's a plug and play drop in swap.

One more time for us noobs. The controller comes with the RS3 pump? So I just need to source am OEM RS3 pump online and it'll be good to go? That's way less expensive than the alternatives.

 

[StorableComa]

One more time for us noobs. The controller comes with the RS3 pump? So I just need to source am OEM RS3 pump online and it'll be good to go? That's way less expensive than the alternatives.

It's not quite that simple. So the pump and the controller are from the RS3. They're sold separately, and yes, you can source them to use if you'd like to save a few bucks. Though you'll need hardware that is AWD or FWD dependent to make the pump and controller play nice with the MQB.

FWD you need the center plug hardware and the male bundy, the controller harness, and the fuel level sender harness. This is in addition to a pump and the newer black controller.
You can buy premade kits as well to simplify things:
https://scskunkwerks.com/products/brushless-rs3-low-pressure-fuel-pump-upgrade-for-fwd-mqb

 

[mrmatto]

Rando Q: Why do tuners generally set the oil temps lower? I have a guess that the lower baseline temp helps keep components protected as the car is pushed and heated up. But I don’t really know. Just curious.

 

[scrllock]

Rando Q: Why do tuners generally set the oil temps lower? I have a guess that the lower baseline temp helps keep components protected as the car is pushed and heated up. But I don’t really know. Just curious.

They don't. They set the cylinder head temperature targets lower, which causes the ECU to run the water pump more aggressively. The oil is cooled by coolant, which then in turns lowers oil temps somewhat.
It's a nice trick for street-driven tuned cars to keep them alive longer.

 

[mrmatto]

They don't. They set the cylinder head temperature targets lower, which causes the ECU to run the water pump more aggressively. The oil is cooled by coolant, which then in turns lowers oil temps somewhat.
It's a nice trick for street-driven tuned cars to keep them alive longer.

Neat! Thanks