Real Fiero Tech

I am posting this up mainly for the forced induction guys who might be curious about whether or not they are close to maxing their fuel pumps out. I think a couple of the 3800 guys are running the walbro as I am too. I was thinking I might need to upgrade my pump, but after reading this I might be good.

Pumps tested are a
Walbro 255
Denso Supra pump
Aeromotive 340 pump
And the bosch 044 inline pump

http://realstreetperformance.com/store/ ... est-5.html

+1 Internetz to you!


That's a very interesting read. I run the Supra pump, and it's good to see that I'm not going to outflow it anytime soon and it shows that is is a bit of an upgrade over the Walbro for the vast majority of engine swaps in a Fiero (I don't think many people will run over 75psi. That Bosch 044 is a beast though! That's definitely the way to go for an extreme build.

It's always nice seeing real comparative data.

Good shit. I do wonder about noise level and longevity. I'm so tired of noisy Walbro's failing, this looks like a hopped up 255.

My Walbro is noisy but hasn't failed yet. I don't remember how long I've been running it, ever since I got my black car running on the 3.4. Then the 3.4 turbo, the wreck and into the white car.

I do know that on a long highway drive a couple of times it has overheated and stopped working. But after a lengthy cool-down it starts working again. There were a few other guys here having similar issues and I think we narrowed it down to the return dumping right at the pump inlet. I'm going to address that when I put the new pump pickup assembly in. I removed the vent line/EVAP completely when I first did the swap for weight, and now it's biting me in the ass.

Much happy with my 044. Now I just need another 200+ hp to max it out...

Emc209i wrote: I'm so tired of noisy Walbro's failing, this looks like a hopped up 255.

What looks like a hopped up 255?

If I saw this comparison before I bought my Supra pump, I would have bought the Aeromotive pump based on the data shown. I honestly didn't know of it when I was looking for a replacement for my destroyed Walbro. Plus it's roughly $30 cheaper than the Supra pump. Oh, and it's smaller too so it looks like the install would be easier.

But, I do like how quiet the Supra pump is. I'm pretty sure the Aeromotive is probably louder, but that isn't much of an excuse not to buy it. It's kinda like people who do V8 swaps for the 'sound'

I don't know about the longevity of the Aermotive, but if it has a similar setup to the Walbro I would probably have the same concerns and would never run it under a 1/4 tank to help with longevity.

AkursedX wrote:

Emc209i wrote: I'm so tired of noisy Walbro's failing, this looks like a hopped up 255.

What looks like a hopped up 255?

The Aeromotive pump. I'm sure the inner workers are different, but the cases look similar. Considering it outflows the much larger Supra pump the smaller space constraints bother me. Conventional thought would lead me to believe smaller pump housings combined with a high volume drive would lend to a less reliable unit - The Walbro's have been burning up left and right. However, in terms of flow for an in tank pump, it looks like a great pump. I was planning on using the supra pump like you had, because I didn't want to fasten the Bosch pump to the firewall like Jinx had done.

Emc209i wrote: The Aeromotive pump. I'm sure the inner workers are different, but the cases look similar. Considering it outflows the much larger Supra pump the smaller space constraints bother me. Conventional thought would lead me to believe smaller pump housings combined with a high volume drive would lend to a less reliable unit - The Walbro's have been burning up left and right. However, in terms of flow for an in tank pump, it looks like a great pump. I was planning on using the supra pump like you had, because I didn't want to fasten the Bosch pump to the firewall like Jinx had done.

I found this thread: http://www.ls1tech.com/forums/fueling-i ... -pump.html which had a decent bit of info on the Aeromotive pump. I now know why I didn't find this when I was looking for a fuel pump because it's pretty new. This thread also has a guy who had a quick failure. Apparently he did run e85 on it and who knows what effect that had.

aeromotive claims their 340 pump to be e85 compatible. However the internals are made of materials that are known to corrode when exposed to E85. So who knows. I doubt the e85 was the cause for that failure so quickly. Alky takes a bit of time to wear things down.

AkursedX wrote:If I saw this comparison before I bought my Supra pump, I would have bought the Aeromotive pump based on the data shown. I honestly didn't know of it when I was looking for a replacement for my destroyed Walbro. Plus it's roughly $30 cheaper than the Supra pump. Oh, and it's smaller too so it looks like the install would be easier.

One thing to consider when you're running *WAY* more fuel pump than you need is that that large volume of fuel that's pressurized, warmed by the engine, regulated and depressurized on its way back to the tank is going to make your fuel and fuel tank run significantly warmer than they would otherwise.

For reference, here's a *REAL* fuel pump... http://www.summitracing.com/parts/RPU-1601/

The Dark Side of Will wrote:
One thing to consider when you're running *WAY* more fuel pump than you need is that that large volume of fuel that's pressurized, warmed by the engine, regulated and depressurized on its way back to the tank is going to make your fuel and fuel tank run significantly warmer than they would otherwise.

This is true. This is part of the reason why I ruined my Walbro. I was sitting in stop and go traffic for over an hour at the Woodward Dream Cruise. I had a bit over a 1/4 tank (And yes, my gauge reads properly) and my car stalled out like it ran out of gas. I let it sit awhile and was able to start it again and drove it to the gas station, filled it up, and it ran fine. Except that anytime I went into boost, I went super lean and my fuel pressure dropped significantly, meaning my fuel pump was destroyed.

Ryan (Darth Fiero) concluded that the fuel super-heated and vaporized and due to the fact that the return is so close to the pickup, I sucked the vapor right back through the pump and deprived the gears of proper cooling and lubrication. When we installed the supra pump in my car, Ryan drilled a hole in the upper part of the return so if in the same situation, the vapor will escape at that high point and not right next to the pickup.

Although I wasn't sitting in traffic, my fuel pump may have done something similar last evening. Once good and warm, the car started to feel like it was fuel flow limited.

Justin and I have killed 5 "e85 rated" OEM pumps due to brush/commutator failure.

Called the manufacture, and they said it was due to an installation in a metal tank, creating an "annode / cathode" ionization situation on the brushes and commutator. The pump I disassembled did have uneven, but not significant wear on the brushes. The pumps never had more than 1000 miles on them.

darkhorizon wrote: Called the manufacture, and they said it was due to an installation in a metal tank, creating an "annode / cathode" ionization situation on the brushes and commutator.

Complete bullshit.

well, I dont have any other explanation... care to offer one?

Crappy pumps?

In an electrolytic reaction, the different electronegativities of the two elements involved cause an electrical current to flow through the solution in which one element can dissolve. Electrons flow one direction, positive ions flow the other direction. This corrodes one element (the anode, I think) and deposits material on the other element (and is the operating principle behind electroplating). What's being deposited on or corroded from the commutator or brushes? You said that they had very minimal wear.

IE, is sounds to me like they're trying to feed you a line of bullshit to avoid replacing your pumps under warranty.

darkhorizon wrote:Justin and I have killed 5 "e85 rated" OEM pumps due to brush/commutator failure.

What do you mean by "killed"? Did they refuse to start?

What do you mean by "killed"?

Yes, they would not turn on, aka, they died.l

due to brush/commutator failure.

Have you checked continuity and isolation on each segment of the commutator? The brushes?

There are two possible failure modes from plating: creating a short by plating metal between two conductive surfaces where it shouldn't be OR plating a non-conductive coating between two surfaces that should conduct. You should be able to figure out which fairly rapidly with intelligent application of a meter.

Are you running extremely high fuel pressures that would cause the pump to slow down to the point that it would burn out?