Technical Options for a new LPFP? Stock one is getting weak....

IQraceworks

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I noticed that during a recent 2nd & 3rd gear pull......my LPFP is starting to drop under 50psi at the end of each gear. I'm assuming my LPFP is getting weak? What do you think?

If it is getting weak....what's my best option for a new LPFP that will support around 500hp (if I ever upgrade turbos)? I want something that's reliable....

Any info would be great!

Here is the log....

 

335is02

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I noticed that during a recent 2nd & 3rd gear pull......my LPFP is starting to drop under 50psi at the end of each gear. I'm assuming my LPFP is getting weak? What do you think?

If it is getting weak....what's my best option for a new LPFP that will support around 500hp (if I ever upgrade turbos)? I want something that's reliable....

Any info would be great!

Here is the log....

You could DIY a 450 in the stock fuel pump and that should work for you. If saving is your goal. If not just grab a stage two from a vender there are plenty that offer them now and I recommend keep bucket if you can.
 

NoGuru

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Yep, LPFP is about one or two pulls away from dying. I would go very easy on it until you replace it. Just get an "Stage 2" or a single Walbro 450, 525, or 535 and you will be good. The DIY is easy if you are semi handy.
I have been bucketless for years and never had an issue but there are lots of opinions on this subject ;)
 
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Torgus

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DIY a walbro 450 it's a hair over $100 bucks iirc.

I would keep the bucket.
 

IQraceworks

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How reliable is the DIY route vs. just buying a complete and ready to go Fuel-It Stage-2 setup?

After doing some research…..it sounds like if I just do the DIY Walbro 450 swap into the stock bucket, I will need to run a special hose if I want to run e85? If so….what hose should I run, and where can I get it? And then people talk about clamps coming off…and being stranded on the side of the road?

Is the DIY setup any less reliable than the Fuel-It? Is all of that “clamps will come off, and hoses will break” talk about the DIY way just talk? Or is there some truth in that?

Thanks!
 

Torgus

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How reliable is the DIY route vs. just buying a complete and ready to go Fuel-It Stage-2 setup?

After doing some research…..it sounds like if I just do the DIY Walbro 450 swap into the stock bucket, I will need to run a special hose if I want to run e85? If so….what hose should I run, and where can I get it? And then people talk about clamps coming off…and being stranded on the side of the road?

Is the DIY setup any less reliable than the Fuel-It? Is all of that “clamps will come off, and hoses will break” talk about the DIY way just talk? Or is there some truth in that?

Thanks!

If you do it correctly it should be just as reliable for 1/4 the price. $130 vs. $400 for fuel-it. Nothing wrong with a retail kit but if you are even semi handy you can save yourself some $$$.

I DIY'd mine and my buddies. Zero failures. There are YouTube channels which go over every step with links to parts or search the forums etc.
 
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IQraceworks

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If you do it correctly it should be just as reliable for 1/4 the price. $130 vs. $400 for fuel-it. Nothing wrong with a retail kit but if you are even semi handy you can save yourself some $$$.

I DIY'd mine and my buddies. Zero failures. There are YouTube channels which go over every step with links to parts or search the forums etc.

Thanks for the info! I guess I will go the DIY route and save some money.
 
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IQraceworks

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Make sure you don't get a Walbro from Amazon, it will most likely be a fake. Do you research.

Yep...I noticed that. Lots of "real" Walbro 450 pumps on Amazon and ebay going for $40-$50....when it's a $100 pump.

I ended up finding a real Walbro on eBay for $140 that came with the install kit and filter. I think I should be pretty safe with that one. I was going to get one from Summit Racing, but they sell the pumps and install kits separate.....and they are out of stock on the install kit.

I think I'm going to cut the buttom out of the bucket, that way it will be a much cleaner install...and I won't have to worry about trying to plumb that venturi ith the extra T-fitting, hose pieces, and clamps....just more stuff to fail.
 

houtan

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just curious. Is there a DIY with the 535? Or would it be the same as the 450 diy?
 

NoGuru

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just curious. Is there a DIY with the 535? Or would it be the same as the 450 diy?
Same.
It's the exact same size as the 450. If you run more then one pump you may need a check valve.
I ran just the 535 and everything was great, but once I activated the 450 on a Hobbs switch my startups have a little stumble. Not that big of a deal but I should put a check valve inline at some point.
 
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houtan

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Same.
It's the exact same size as the 450. If you run more then one pump you may need a check valve.
I ran just the 535 and everything was great, but once I activated the 450 on a Hobbs switch my startups have a little stumble. Not that big of a deal but I should put a check valve inline at some point.

Ok thanks. I saw PR has a DIY option for the 535, but it is still a little pricey at $445. I see a 535 can be purchased for about $145. So basically you guys are saying i can do something similar to the PR kit for maybe under $200?
 

NoGuru

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Ok thanks. I saw PR has a DIY option for the 535, but it is still a little pricey at $445. I see a 535 can be purchased for about $145. So basically you guys are saying i can do something similar to the PR kit for maybe under $200?
Yeah I went the DIY route. I have a KPD bracket that was sold at BMP but it's not listed anymore but I have the owners email.

But any bracket that can hold a 450 will hold the 535 and it pulls the same amps as the 450 with way more flow. I have a chart I will try to link in this thread once I find it.

Here it is, the 295 is the 535 and the 275 is a 450.

Walbro GSS342
Tested flow rate at 45 psi: 246 LPH
Current Draw at max pressure: 14 Amp
Excellent value and proven reliability in a small package. While the loudest of the batch, it is still an OEM quality pump so it is all relative. These pumps have a long history and are used extensively all over the world. They are a popular option for mild upgrades.

Walbro F90000274
Tested flow rate at 45 psi: 382 LPH
Current draw at max pressure: 19 Amp
This pump has been on the market for several years and is an evolution of the Ti Automotive 39/50 DCSS ("Walbro 450" pumps). Radium Engineering uses this pump extensively in many products and customers have been very pleased with it's performance. Compatible with E85 and traditional fuels, it is a great choice for motorsports customers.

Walbro F90000285
Tested flow rate at 45 psi: 424 LPH
Current draw at max pressure: 22.3 Amp
This relatively new pump is a further evolution of the Walbro F90000XXX pumps. It is essentially a more powerful Walbro F90000274 that draws more current. Some customers do not want the extra flow at the expense of the added current, and other customers need all the flow they can get. This pump fits in any Radium product that uses the Walbro F90000274, as it is the exact same physical dimensions. More information on this pump can be found HERE.

Walbro F90000295
Tested flow rate at 45 psi: 485 LPH
Current draw at max pressure: 19.7 Amp
The newest offering from Walbro and once again, another evolution of the Walbro F90000XXX pumps. It is essentially a Walbro F90000285, with the more powerful electric motor, but it does not feature a check valve in the outlet port like all other Walbro F90000XXX pumps. This pump fits in any Radium product that uses the F90000274, as it is the exact same physical dimensions. However, it cannot be used in multi-pump configurations when pump staging is used. Also, fuel pressure will drop to zero as soon as the pump is turned off. However, it is the perfect pump to be used in a surge tank as a lift pump since a check valve is NOT required.

AEM 50-1200
Tested flow rate at 45 psi: 321 LPH
Current draw at max pressure: 16.6 Amp
This E85 compatible pump from AEM is the same compact package as the Walbro GSS342, but is a turbine style pump. This means less noise and more flow. The relatively low current draw helps keep heat down as well. Radium offers this pump as an option in many products.

Ti Automotive BKS1000
Tested flow rate at 45 psi: 577 LPH
Current draw at max pressure: 14.4 Amp
This brushless pump setup is a perfect option for users wanting maximum flow and minimum current. Brushless technology is big leap forward for pumps. Radium Engineering has already released products specifically for this pump setup.

Bosch BR540
Tested flow rate at 45 psi: 404 LPH
Current draw at max pressure: 21 Amp
This Bosch Motorsports pump does not feature a check valve, which means it cannot be run in parallel with another fuel pump and be staged. It comes in with mid-pack performance in line with the Ti Automotive F90000XXX pumps.
Because this pump has a larger body size, it is only available in a select amount of Radium products. Contact us for more details.
 
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Torgus

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The 525 draws more current than the 450 at the tune of 15% more amperage, which translates to heat, for only 8% more flow. I don't think the stock EPK can handle it. It barely handles a single 450. I don't see the value in using 525 pumps in all honestly when two 450s flow more than what most people will ever need.

If you need more flow than one 450 gets you...just put a 2nd 450 pump in. Two 450s flow enough for 99% of people, 875whp on 100% E85.

You should also look at upgrading the fuel regulator assembly as some point if you are looking at anything more than a single pump imo.

You can spend a fortune on fueling upgrades on this platform if you want. 2k on the LPFP side another 2k on the HPFP side if you want. If I was to do it I would run a return style system to a radium surge tank. Do it once right and have more fuel that your car will ever need. That being said if you don't need that much fuel dual 525s or 450s are a waste.
 
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NoGuru

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The 535 draws more current than the 450 at the tune of 15% more amperage, which translates to heat, for only 8% more flow. I don't think the stock EPK can handle it. It barely handles a single 450. I don't see the value in using 535 pumps in all honestly when two 450s flow more than what most people will ever need.

If you need more flow than one 450 gets you...just put a 2nd 450 pump in. Two 450s flow enough for 99% of people, 875whp on 100% E85.

You should also look at upgrading the fuel regulator assembly as some point if you are looking at anything more than a single pump imo.

You can spend a fortune on fueling upgrades on this platform if you want. 2k on the LPFP side another 2k on the HPFP side if you want. If I was to do it I would run a return style system to a radium surge tank. Do it once right and have more fuel that your car will ever need. That being said if you don't need that much fuel dual 535s or 450s are a waste.
The 535 draws 19.7 vs the 450 at 19, it's not even noticeable for a lot more flow.

I will say the duel 450's have been done a lot more and are proven to work while the 535 is pretty new.
 
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IQraceworks

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Torgus

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The 535 draws 19.7 vs the 450 at 19, it's not even noticeable for a lot more flow.

I will say the duel 450's have been done a lot more and are proven to work while the 535 is pretty new.

Ah I was thinking of the 525 vs. the 450 not the newer 535.

Either way two 450s is plenty for almost anyone. Two 535s should be able to support close to 1000whp on 100% E85 I imagine. 100% unneeded unless you plan to drop 10k building the head and block.

I guess I could see using a single 535 if you needed just a bit more flow over a 450 and NEVER had plans to upgrade where you would need more fuel.
 
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IQraceworks

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The 535 draws 19.7 vs the 450 at 19, it's not even noticeable for a lot more flow.

I will say the duel 450's have been done a lot more and are proven to work while the 535 is pretty new.

The spec I found from Walbro said that the 450 draws 14a. I do know that they have two versions of that pump....the 87psi version and a 112psi version. They show the 87psi version only pulling 14a....