I wasn't really sure where this should be posted so mods feel free to move if needed.

First, since this is my first post let me introduce myself. My name is Eric, I have a 95 hatch with a b18b and a t3/t4. I am currently a test engineer in the fuel delivery division of Denso, the second largest tier 1 automotive supplier (think spark plugs, alternators, plug wires, instrument clusters, fuel pumps, hvac,... just about anything electronically related in a car).

Anyway, when I bought the car the previous owner had retained the stock fuel pump. With 135k, I was a bit nervous and seeing as a new 255 is only about $70 I figured why not.

Well, I decided to compare the stock pump to the Walbro so I brought them in to work. The following are the results:



As you can see, the Walbro was an excellent upgrade. In fact, even at 6V the Walbro outperformed the stock pump at 12V at the same pressure. Given the stock system was built around the stock pump, I would actually be worried about running the Walbro if the system was returnless, possibly putting to much stress on the rest of the stock components. With a return style, this is not an issue.

I know someone will eventually ask why I went with a Walbro when I work at Denso. To be truthful, the Walbro was so cheap I figured I would pick one up and compare it to some popular Denso pumps at the same time. After I ran these performance tests, I found that the 255 is similar to a few pumps that Denso offers with two differences.

1.) Cost - the Walbro is slightly cheaper than the Denso variants
2.) Design - the Walbro is a gear driven style while the Denso variants are turbine. Neither pump is necessarily a better design but the Walbro does have considerably more noise while in operation. Having the access panel just behind the driver can be a bit annoying for someone who drives around without the radio or climate control cranked.

Anyway, just thought I would share. Let me know what you think!

~Eric

 

Very cool, thanks a lot!

 

on a stock honda {cb7 in my case} do you think running a 255lph with no other mods would be problematic?

personally i dont see why it would be an issue, unless the oem FPR cant return enough fuel to keep the pressure down. which i kind of doubt...

i see some people say a 255lph is too much for the stock regulator, while others say you are fine as long as you dont run the 255lph hp. saying the high pressure one will pop the stock regulator. once again i dont see how that would since its just designed for flow to not fall off at high fuel pressures.

please help me, i am completely ignorant on this subject, my fuel pump went out and i dont want another autozona pump thats going to only last a year. but i may turbo my car in the future, so i figure while i have the tank out, why not put in a pump that will handle my current and future fuel demands.

thanks greatly.
brandon

 

Who makes the equipment used to test the flow rate?

The stock regulator won't flow enough to drop the rail pressure any lower than 40 something psi. I've tried to before with a B&M kit on it. There's still tension on the diaphram, but the rail pressure doesn't decrease as you decrease the preload.

 

so should i opt for the 190, or just get a good regulator?

im under the impression he works for denso and used there in house equipment to test the pumps.

 

I forgot about this thread. I do, indeed, work for Denso. We have a fuel lab full of about 30 million dollars in testing equipment.

kawgomoo, I would stick with the 190. It will still be leaps and bounds better than the stock pump and you don't really need a 255 unless you have plans for a built bottom end (IMO).

~Eric

 

lol oh nooowww you tell me.

i ordered teh 255 because, well i overdue everything. as soon as i ordered it i wish i had just got the 190. of course now im just waiting for e85 to become available here so i have a reason for such a ridiculous sized pump for my application.

haha.. thanks though.

 

Gives you a reason to build the engine and boost it, lol.