Precison Raceworks Stage 3 LPFP DIY/Tips

[Diggs24]

Just go Eurodyne?

 

[El_bigote_AJ]

Just go Eurodyne?

Please sir may I have another

I’d like to see if UM or LITTCO actually has activated Mpi on a 2019 car also, cause Im thinking due to the 2019s using the new ecu that’s on the EU mqbs they don’t have factory dual injectors anymore, so maybe it’s not a case finding and activation the coding now.

 

[iwannagofast]

Up top he's injecting for like 330-350* of crank rotation.... I don't know exactly when the exhaust valve is closing, but he is running 15* of ign advance. It's hard to imagine he isn't spraying fuel when the exhaust valve is open and getting very very close to the spark event. Very much so pushing the limits of the fuel system and I fear what's going to happen when the temps get in the 30s or whatever. Based on what I can see, either way probably too close to the limits for comfort for me personally. This kinda data shows me that MPI is definitely the way to go for straight E85 on IS38 even. Might be smarter overall to run E50 or so. My 2 cents anyways.

View attachment 174733

Wow, this is exactly why I post on here, this is extremely informative. So you're suspicions about injector pulse width have been confirmed. When I had the stock LPFP, I was having very similar issues to this. EQT told me that "the LPFP isn't keeping up and is dropping pressure to the HPFP." The datalogs showed the same events here along with fuel cuts, the logs looked very similar. I didn't notice anything strange about the HPFP. EQT at the time gave me 3 options...install MPI, install a larger LPFP, or pull back to E50 or E40. I chose to go with the LPFP. After installing the LPFP, the logs were showing the same fuel pressure losses and fuel cuts. EQT's exact response was "Ok, this is strange, can you please check your LPFP install and look at the venturi / o-ring on the pump in particular? You should be holding pressure for a lot longer than you are." After checking about 5 different times, I found the O-ring was forcing itself out of place, so that's when I made my first post and started zip-tying it into place. That's how I confirmed it was definitely lpfp issues.

I'm thinking EQT is just using their experience as to how far the 450 fuel pump can be pushed. Keep in mind, I'm not finished with tuning yet. I have a feeling that as long as my knock stays at 0, then I can pull back to E50 or 60 and they can keep winding me up. I don't know how much further though, what's max timing for full E85 IS38, lol?

Looking at my last log where I was getting a fuel cut at 6400rpms in 3rd, I really don't know if it's the same lpfp issue or if my fueling is just maxed out. All I can do is keep you guys updated and tell the next person trying to run full E85 to just go mpi and save a bunch of headaches.

 

[jimlloyd40]

When did this thread quit being posted in English? Just kidding. I'm going to stay under 450 HP to avoid this stuff. Very informative though to the point that I know I want to avoid it.

 

[aaronc7]

Wow, this is exactly why I post on here, this is extremely informative. So you're suspicions about injector pulse width have been confirmed. When I had the stock LPFP, I was having very similar issues to this. EQT told me that "the LPFP isn't keeping up and is dropping pressure to the HPFP." The datalogs showed the same events here along with fuel cuts, the logs looked very similar. I didn't notice anything strange about the HPFP. EQT at the time gave me 3 options...install MPI, install a larger LPFP, or pull back to E50 or E40. I chose to go with the LPFP. After installing the LPFP, the logs were showing the same fuel pressure losses and fuel cuts. EQT's exact response was "Ok, this is strange, can you please check your LPFP install and look at the venturi / o-ring on the pump in particular? You should be holding pressure for a lot longer than you are." After checking about 5 different times, I found the O-ring was forcing itself out of place, so that's when I made my first post and started zip-tying it into place. That's how I confirmed it was definitely lpfp issues.

I'm thinking EQT is just using their experience as to how far the 450 fuel pump can be pushed. Keep in mind, I'm not finished with tuning yet. I have a feeling that as long as my knock stays at 0, then I can pull back to E50 or 60 and they can keep winding me up. I don't know how much further though, what's max timing for full E85 IS38, lol?

Looking at my last log where I was getting a fuel cut at 6400rpms in 3rd, I really don't know if it's the same lpfp issue or if my fueling is just maxed out. All I can do is keep you guys updated and tell the next person trying to run full E85 to just go mpi and save a bunch of headaches.

Honestly for a E85 tune on stock turbo...your best option is using a dyno. Because you may hit MBT/peak power well before knock. And you could increase timing well beyond where you made peak power and actually start to lose power again. EQT I'm sure has the expertise to know where similar setup cars ended up timing wise, so they probably just go with that and call it good enough...nothing wrong with that at all. I bet E50 makes very similar power...

Can you post a log where you're getting this fuel cut? Just want to see it in a log. You threw out a bunch of links before and I got a little lost in what each one was trying to show etc. A 450 should not be close to running out of fuel on this setup, even without a PM4. Anyways yeah, please show me a log with a good fuel cut example you're talking about if you can.

 

[iwannagofast]

Honestly for a E85 tune on stock turbo...your best option is using a dyno. Because you may hit MBT/peak power well before knock. And you could increase timing well beyond where you made peak power and actually start to lose power again. EQT I'm sure has the expertise to know where similar setup cars ended up timing wise, so they probably just go with that and call it good enough...nothing wrong with that at all. I bet E50 makes very similar power...

Can you post a log where you're getting this fuel cut? Just want to see it in a log. You threw out a bunch of links before and I got a little lost in what each one was trying to show etc. A 450 should not be close to running out of fuel on this setup, even without a PM4. Anyways yeah, please show me a log with a good fuel cut example you're talking about if you can.

Sure, here is a very obvious one from before I found out my o-ring was failing.

https://datazap.me/u/ssjneko1/log-1590682709?log=0&data=6-15

This was the one where EQT told me that I should have been holding pressure much longer and to check my lpfp install.

 

[aaronc7]

thanks, yeah it's strange to me that we don't see any affect or dips on high side fuel pressure, but maybe it just reacts quick enough by pulling boost etc. Also rail pressure target wasn't logged so I don't know exactly what it was trying to do.

takeaways- E85 on DI only is sketchy, and LPFP installs still suck lol.

 

[daconchslop]

Pull it. Make sure the basket is in the tank before installing the float assembly. Shouldn’t bind on anything once attached properly. No coding.

 

[2slowvw]

Yup has to be the float getting hung up on something.

 

[PowerDemon]

I recently completed the install of a Pagparts 450LPFP/8mm fuel line and thought all was well after getting some initial codes sorted out. But I was doing some more data logging with my tuner (Nick@EQT) and he told me that apparently the low pressure side is struggling despite the pump and line install. He recommended that I pull the pump and check the install. When I put it in everything looked ok to me. I mean obviously else I wouldn’t have put it in lol.

The only thing I could think of is when I was trying to take the fuel pressure sensor off the old pump to swap onto the new one I accidentally unscrewed it so that the spring came out. However I put everything back in the way I found it and screwed it back in to the exact same position that it was in originally. (I took a lot of photos)

So what should I look for if I pull it? Has anyone had a similar situation? I don't even know where to start. Thanks all.

Here are some photos I took during the installation process. Please let me know if anything looks funky to you.

 

[billbadass]

great posts and makes me feel good about keeping my car at E55 fuel levels. gains after ~E50 are minimal anyway.

I will have a full post once the issue is resolved also, but i have the PagParts 450 pump installed by a local shop everyone here knows....and somehow it ruptured that black line because it was vibrating against the electric connectors, so make sure you zip tie it away from everything or whatever you need to do so you don't get stranded on the side of the highway 60 miles from home in 110* heat with no AC and a pissed off young child and wife while you sweat and wait for an hour and half for a tow truck...

 

[daconchslop]

On my second install, I removed that large plug connection and used heat shrink connectors to free up space inside the basket area. Also make sure when you compress the hat all the way nothing is being crushed.

 

[PowerDemon]

On my second install, I removed that large plug connection and used heat shrink connectors to free up space inside the basket area. Also make sure when you compress the hat all the way nothing is being crushed.

Thanks. I found the issue. I forgot to install a clamp on the hose that goes to the blue top.

I think that black hose is a little more crushed than I would like but I couldn’t find a way to situate it where it wasn’t being compressed a bit. When I pulled it out that black hose that’s curved in those photos was flattened out. Any suggestions?

 

[Diggs24]

It needs a right angle fitting like it has on bottom.

 

[PowerDemon]

That or just shortening up the hose like 1.5-2” ought to do the trick.