Max Hp LPFP

[InnovativeAuto]

Hey guys, I’m installing a set of Pure stage 2 turbos in the near future along with my FBO. I will also be using 100% meth direct port (twisted kit) so I can up the boost. My goals are hitting 600whp. Question is will I be ok with the factory lp fuel pump or will I need to upgrade? I have read the Z4 pump puts out a lot more fuel vs the 335 setup. Has anyone found the limits?

I will also be testing the limits of my recently installed 335is clutch. Should have went with twin disc!

 

[doublespaces]

I wasn't aware of that being the case, but generally if you're using meth that will help your trims a little bit so if you're using gasoline+meth you should be able to hit 600. But if not, there are several fairly inexpensive LPFP solutions out there.You'd only need a stage 2 setup.

 

[Twisted Tuning]

First and foremost that 335is clutch will not handle 600tq for long. So if you are going for that, whoever you have tune it, make sure they keep the torque down to get some life out of the clutch. Im not sure how much flow the Z4 pump is, but you are correct, as i do believe it flows a bit more than the 335 but i would still invest in a Stage 2 at a minimum for the LPFP. Bbecause i don't think the pump itself is a higher flowing pump, but the stuff around it is less restrictive. Dont qoute me on that though. The direct port kit will help make up for some of the fuel, but better to have too much fuel capacity than too little.

 

[Torgus]

Yeah get a stage 2 at least. Small money and you can DIY if you want. Videos on youtube.

 

[InnovativeAuto]

Thanks for the responses guys. I will order up a Walbro 450 just to be safe. I have not seen any diy vids for the Z4. I did see Fillippos write up though, sounds like it’s not a fun job.

Anyone know if the 450 is plug and play? I don’t think I will need the Hellcat pump for my power goals. I saw Fuel-it offers a kit but don’t see the point of purchasing a new bucket? Am I missing something?

Regarding the EPK, do these pop like a fuse when they see too much amperage? Will the 450 cause this? When they do pop do they disable the car? Should I carry a spare with me? Are they plug and play or do they require programming? Is there an upgraded unit available?

 

[fmorelli]

Ok ... look for advise from the tuners for the LPFP on the Z4. It's not like the E82/E90 LPFP. @BQTuning can provide first-hand experience as he's tuned many of the Z4's out there. I did the 450 as insurance for running E85. I would hardly call it necessary on the Z4. Unfortunately the Z4 lacks the LPFP pressure sensor so ... but guys tuning these cars can sort it out. My goal is circa 600whp with single barrel, E85 and 450 LPFP with all other stuff fresh (e.g. low miles hpfp, et al). I'm not there though, so my comments at that level mean nothing at this point.

It is a PITA to do on the Z4. Every other BMW owner on the planet has it elementary easy, in comparison. My advise would be do it when you need it. Making power is a staged development activity. If you have money to burn and time to burn, then just swap it. But ....

The 450 runs within amperage spec. I would not advise the 525. Fuel-It is selling it but to my knowledge, they actually have not done the homework to figure out how to actually run that pump in electronic components built for a 25A max, not 30A draw the 525 likes to hit. YMMV!

Good luck!

Filippo

 

[InnovativeAuto]

Just an update, I have started to up the boost from 17psi to 20 and we are seeing rail pressure drop to an unsafe level. I would have thought with the direct port meth this would not happen till higher boost!

Will be throwing in a 450 in the next week or two to see if it improves or if I have a hpfp issue (I don’t have any of the typical symptoms of a bad one).

 

[doublespaces]

Just an update, I have started to up the boost from 17psi to 20 and we are seeing rail pressure drop to an unsafe level. I would have thought with the direct port meth this would not happen till higher boost!

Will be throwing in a 450 in the next week or two to see if it improves or if I have a hpfp issue (I don’t have any of the typical symptoms of a bad one).

Upload a log here: https://datalogs.spoolstreet.com

Then copy the BB Code and paste it into a reply here so we can see.

 

[Crazy8]

Hey sorry to bring up an old thread but @InnovativeAuto any updates on the 450 install? I'm looking at going to PS2s and running an e85 mix in the near future and am trying to determine what to do about my fueling.

 

[InnovativeAuto]

I threw it in last week. Pretty easy install on a lift. It did not fix my lean issue, turns out my hpfp is failing. I would throw one in for safe measures. No need to spend money on a fuel -it as it’s an easy job. Just make sure to get new corrugated hose ($20 on Amazon).

 

[InnovativeAuto]

Photos...

Any questions about install pm me.

 

[Crazy8]

Thanks for the info and pics!

Since I don't want to go PI, TBI, or run meth, you think running the 450 will be enough to get to the 500+ whp range safely? I'm FBO (just need inlets) and plan to go PS2 and run an e85 mixture.

 

[KAIZZER]

A bit curious also... in the process of changing my snails, but if its not imperative that I replace the lpfp, I'll leave it alone for now. Aiming for around 500whp on pump (e85 here and there) More info if possible please.

 

[Crazy8]

After talking with a few people, I ended up going a different route all together since I wanted to make closer to 550whp with some headroom. I haven't got anything on the car yet but I'm going PI and also going to run the new Walbro 535 lpfp. Yes, 535, not the 525. The 535 doesn't have a check valve and thus doesn't take as much juice from the stock ekp as the 525 does. There are a few guys that run them without any issues since the BMW fuel system stays pressurized and primes before start-up anyways. I'll be FBO plus Pure Stage 2 High Flows with a custom MHD flash. I'm hoping for 550whp+ on an e85/91 tune..... time will tell.

 

[KAIZZER]

Interesting.... be sure to share some more details about your journey! It seems our goals are similar.

 

[Crazy8]

Will do! The turbos are being built now so I'm hopping to get everything on the car in the next couple of weeks.

 

[Krampus]

Has anyone found the limits yet for e89 oem lpfp? It would be nice to know before replacing the original pump. Thanks.

 

[Crazy8]

I've heard it's very similar to the limits of a Walbro 450 (stage 2) lpfp.

My recommendation would be to run the new Walbro 535 pump. After a long wait, I finally got my car up and running (PS2, PI, 535 pump) and I'm pleased to report that I have no ekp overheating issues whatsoever! Since the 535 pump doesn't have a check valve, my car does take a few more cranks to start up on average. Other than that it has been working great on my base 91 map in mixed driving including in extreme heat (bumper to bumper traffic in 100 degree heat). Will report on more once we start adding e85 an turning up the boost.

 

[doublespaces]

Interesting, since there are no rear seats the hats are accessible from the bottom/exterior? It makes sense but I never realized that until now.

 

[fmorelli]

Has anyone found the limits yet for e89 oem lpfp? It would be nice to know before replacing the original pump. Thanks.

I've heard it's very similar to the limits of a Walbro 450 (stage 2) lpfp.

No one has because, in part, easy question to ask but since everything relates to everything else, hard to answer. @BQTuning has a good sense on it, I suppose. On the Z4, if you are FBO on regular fuel, you're good. If you are FBO with E30-E40, you are good as long as the fuel system is in good shape (LPFP, HPFP). Anything else ... you're changing the LPFP.

My recommendation would be to run the new Walbro 535 pump. After a long wait, I finally got my car up and running (PS2, PI, 535 pump) and I'm pleased to report that I have no ekp overheating issues whatsoever! Since the 535 pump doesn't have a check valve, my car does take a few more cranks to start up on average. Other than that it has been working great on my base 91 map in mixed driving including in extreme heat (bumper to bumper traffic in 100 degree heat). Will report on more once we start adding e85 an turning up the boost.

Good news and agree with you. I'm headed to a 535 pump as well, and likely with some EKP headroom work. We have threads going on these htings.

Interesting, since there are no rear seats the hats are accessible from the bottom/exterior? It makes sense but I never realized that until now.

Head in the sand is best. You have no idea how good you have it. Trust me. It's a royal PITA to do that work on the Z4. Not to mention, can't find anyone in Australia with a Z4 and deep pockets to take their car to @martymil so some of that work going on can translate. Like how to run bucketless hydramat in a Z4 tank .

Filippo