Walbro! Go walbro!

 

walbro 450 is good but it doesnt like high boost 40+ psi

 

i went with walbro 450 with ID1300 injectors. not looking to go over 400 whp since its a stock long block.

 

Walboro 255 unless you need to make more than 450whp. Even then, I'd mod it and use it further.
For some reason they seem to flow more than they "should".

 

From my experience and observation, they don't actually flow more than they should. What happens is that under high boost/flow conditions, the pressure at the pump drops below where its supposed to be, and this allows the pump to flow more (pumps flow better at lower pressure). In this situation, every drop of fuel that is making it to the rail is going through the injectors. Nothing is going through the regulator and into the return line. The car can work perfectly well like this as long as the pump doesn't loose any capacity, so it gives the initial illusion that the pump is up to the job, but its really not. Fuel systems aren't meant to be operated like that because it leaves no buffer for changes in pump capacity due to different conditions (hot weather) or from slow wear of the pump. Operating like this will cause greater variability in AFR under high power conditions, and will eventually cause a lean condition.

People unknowingly tune around the pressure loss issue by richening up AFR in the fuel table. Reports of people swapping out a W255 for a higher flow pump system and seeing AFRs go much richer are the sign that the W255 wasn't working as it should and was causing the fuel system to operate below its target pressure. From the fuel system pressure logs I've gathered, I'd say 450 whp is a good safe limit for a punched W255 on stock fuel system with E85.

 

Those walbro pumps are great.

 

hm. i never really thought about the "why" LOL. good to know. i was at 450 with my old 255, on e85. i assumed all was well. my new setup will never see above 400, so i feel even better, now. man. staying in the 400-450 is sooooooo much easier, in like a million different ways haha.

 

hp is overrated.

 

That must be somewhere above 800 whp, because I've loved every high HP Evo I've driven.

 

we cant even get close to 450whp on our mustang dyno with walbro 255-

they really cant flow much more than a 1000cc injector anyway- with E85- its not doable-

We have rewired dw300's which worked well for basic setups to around 400-425 with a 1300 or so-

and rewired (for dual voltage) the walbro 450 (as hondaguy mentioned) with 1000+ cc injectors

cb

 

I'd guess it's the different dyno readings? I'm reading lots of varying results with a 255 and E85. Anywhere from 400-475.
My car was around 425ish, I think. IDC was WAY too high for my liking (90s), so we dialed it back.

 

Um, none of this is correct.

 

Agreed. Not true.
Someone probably told you e85 uses 30% more fuel. That is different than burn rate.
The rest of your post is partially true, under certain circumstances.

 

I'm new in this and my first time owning an EVO and i want to go on E85 to get lil more HP. Just dont know what is the list to get to that. Would be a lot of help you guys can help me out. Thanks!!

 

1000cc and higher for injectors, a walbro 255 pump, and a tune.