And also made in China lol. That matters to certain people. Not arguing with you at all, just giving a potential reason. Walbro 255s always come highly recommended for basic setups by almost all tuners. You've got tuners who have been in the game for 10-20+ years still recommending the 255, and I'm positive they've seen them all. Not sure if they're just creatures of habit or what, but typically genuine Walbros have bulletproof reliability. The Walbro 255 in particular uses a georotor design vs a turbine, that's why it's louder. If you take a look inside you can see the all metal construction; it's pretty nice, and reassuring for some people I guess. I'm sure the Aeromotive, AEM, FB, DW pumps are all fine, I've run 2 of those brands before without issue.....Afaik though they're all manufactured in the same place.

Check out the inside:

https://cimg1.ibsrv.net/gimg/www.s2k...a93641ad5.jpeg




Basically it just comes down to use whatever you like that best fits your application. If you must have a Walbro for the reason listed above or you've always used them I'd choose the one that best fits your power goals. The 400 & 450 are newer turbine designs right? Also, the genuine 255s aren't as loud as people make them out to be.....I had this discussion with a few people, but most of the hella loud Ryobi drill sounding WALLBORUs are Chinese knockoffs with plastic internals and subpar electrics and assembly materials.

Back 8-10 years ago when the walbro 255 was the only option I ran it both my s2000 and my evo 8. They ran on E85 just fine for many years. I never had a problem with them besides the low hp capability on E85 and the winning noise especially on a hot day and when the fuel was low. Now a days with the new style fuel pumps and them all being so cheap now it makes zero sense to run a walbro 255 pump. I now run the walbro 450 in my s2000, evo and bmw 335i. But since the new walbro 525lph came out a few months ago if I were buying now I would just go for the new walbro 525. I also strictly run E85 in all my cars.

THanks for all the answers. As far as the reason I’ll only use Walbro is it’s hard to ignore the fact a lot of AEM320 and FB pumps fail, tons of reports of people having multiple AEM’s fail back to back. I won’t use any AEM products as I’ve found all their stuff to be junk in my experience with them. I’ve also owned a few 255’s and never had a problem with noise, I daily drove a turbo EK hatch for years with one, but on 93.

The 255 is dead reliable as I’m sure the 400 is, but this car truly won’t ever see even 400hp. I’m not one of the those guys that’ll be thirsty for more, I know the use for this motor in this car, it will never will. This car is just a fun car to drive with my wife on the weekends or to our property in Austin (4 hours away). Reliability is above max HP on this car for its use. I want to LS the car like I did my last one but my wife doesn’t like the harshness of the swap and if I decide to not run AC then she’ll never ride in it again lol. She likes the s2k and we’ve enjoyed using it on the weekends, I’m just gonna give it some better mid range.

So with that out of the way....I’m still open to the 400 but I assumed I was going to have high base Fuel pressure on a stock rail and a returnless system given my power goals. I’ll be on ID1050x. SOS sells there machined adapter so it’s just as easy to install.

And let me say again, I would prefer to use the larger Walbro if I can get away with it at ~350 wheel.