420A How much can a 420a boost with internals?

[lxeclipsegsx]

okay guys this is the deal how much can a 420a engine build boost? some guy told me you could only boost to 12psi due to the block being Aluminum.

well so far i have my .40 low compress pistons 8.5.1 my eagle rods that can take to 600hp aftermarket crank and stage two cams i think is the 272lifted not sure my undriven pulley, cam gears and a rebuild kit that i got from top line.
pretty soon i'm buy my turbo kit or i'm custome it i'm thinking of going with the t3/t4 and boosting them 20pounds.
I wanted to know if i can with those new internals? if u can help me please e-mail me at [email protected] thank you

 

[XMasta19]

Moral of the story....yes we can feel even 5psi

 

[speedy13]

cool.175 whp with 5 psi is definatly a kick in the butt..Yeah, I been on the 120 whp mark ,don't wanna go back, I took the easy way out. .thanks for the response guys.

 

[opie1]

just a question for yall running 8 to 10 are you running a fmic or smic

 

[XMasta19]

+1 for FMIC.....unless you're on some super low budget and have the hookup on a sidemount, go ahead and fill that grill You can find new intercoolers for not very expensive, why skimp out on something you might want to upgrade later on.

 

[BigRand]

"let ya see my what?"

"ya grill, ya ya, ya grill"

+1 FMIC

 

[XMasta19]

"let ya see my what?"

"ya grill, ya ya, ya grill"

+1 FMIC

That's hilarious...I was gonna do that too

Anywho, just go ahead and get a front mount, you eventually will want one

 

[lxeclipsegsx]

i know the 420a engine can boost around 8psi stock engine i was wondering if the fuel system would have to change or is it the same stock? how much can i boost with my stock fuel system i have a fully built engine almost completed my turbo just need my gauges dont really know what to get but boost gauge air fuel ratio gauge what else? thank you for any help that is given. The turbo is a 16G going 3inch all the way for exhaust.

 

[Blitzeclips]

The feul system for supporting 8psi would need to provide extra feul and raise of vacuum under boost. For that, a 255lph pump and FMU (feul management unit) would work for you. The FMU raises vacuum under boost, and the pump outflows our stockers ten fold.

If you have a fully built engine then you can raise boost with the proper feul set-up. Theres many different units and set-ups for this, so searching would be your best bet. Just look up 'Megasquirt' or 'portfeuler' to get started. I think the single most rpoblem under high boost aside from feul delivery would be timing. Supposedly it becomes tricky around the 15psi mark without spark control.

 

[DSMcrazy3]

The feul system for supporting 8psi would need to provide extra feul and raise of vacuum under boost. For that, a 255lph pump and FMU (feul management unit)

12:1 FMU, at that.

 

[dr1665]

Humor me: Doesn't the FMU raise fuel pressure under boost, rather than vacuum. Boost and vacuum are polar opposites, imo.

 

[Blitzeclips]

Humor me: Doesn't the FMU raise fuel pressure under boost, rather than vacuum. Boost and vacuum are polar opposites, imo.

Oh, my mistake. Sorry for any confusion. Thanks for the correction driggs.

 

[lxeclipsegsx]

yeah i have a 255walbro fuel pump wasnt planning to install it till i get my fuel system completed i was thinking of going with the porteuler not enough money broke building this engine so i was just wondering if i can just boost with stock fuel system if not 255 fuel pump with a 12.1 fuel pressure regulator would be fine tuning with a acf II?larger injectors as well 440cc thank you

 

[lxeclipsegsx]

so i'll take it that i cant boost 8punds with stock fuel system

 

[VelocitàPaola]

so i'll take it that i cant boost 8punds with stock fuel system

You can't boost at all with a stock fuel system. For 8psi, you'll need a 12:1 FMU and a Walbro 255 (or equivalent), minimum.

 

[lxeclipsegsx]

I see thank you very much is there anywhere that i can read about this any thread posted about this before?

 

[lxeclipsegsx]

okay getting boosted next month i'm going with 450cc injectors with a 255lph walbro fuel pump.questions would a 12.1 fmu be fine is a adjustable fuel pressure regulator work the same i'm getting tune in L.A so i just need a simple set up to get boosted for awhile.or how about the AEROMOTIVE FUEL PRESSURE REGULATOR rise 1:1 would that work?thank you

 

[BigRand]

Okay I'm gonna straighten some things out for ya.

Here are you options

1. Walbro 255 fuel pump, W/12:1 or 10:1 fmu, stock injectors


2. Walbro 255 fuel pump w/ 1:1 fuel pressure regulator, and 450cc injectors (dont' forget about the injecotor resistor box if they are peak and hold injectors)

3. Walbro 255 fuel pump w/ SFMU (which allows you to dial in the correction of fuel from 3:1 to 12:1 I think), any kind of injector you want from stock to 550cc or so.

Basically I want you to understand that w/ the fuel pressure being raised as high as 12psi for every pound of boost, you won't need bigger injectors at 8psi. And not even the SAFC can lean out your fuel mix enough.

You can run a SAFC w/ any of those set ups, but I'd see it as a waste of money if your saving for a different fuel set up in the long run. I would stick w/ number 1 if I were in your possesion.

 

[Shadow98]

The most cost efficent way is Rand's first option. Just buy 225 hp fuel pump and a 12:1 FMU. And guess what, you're done with the fuel system. Of course there is a limit on how much boost you can run with this set-up. I wouldn't go more than 9psi, though I have seen people run 10 psi with this set-up.

 

[DSMcrazy3]

I wouldn't go more than 9psi, though I have seen people run 10 psi with this set-up.

Don't go past 8 psi with that set up(255 and 12:1). Anything more than 8 psi and you'll start experiencing fuel problems resulting in a lean condition.

 

[Shadow98]

Don't go past 8 psi with that set up(255 and 12:1). Anything more than 8 psi and you'll start experiencing fuel problems resulting in a lean condition.

Listen to the wiseman. BTW, Josh, how much boost are you running?

 

[lxeclipsegsx]

is a 255 LPH fuel pump okay? it s a little cheaper. okay i really want to thank you all for helping out.

 

[4UH8ERS]

is a 255 LPH fuel pump okay? it s a little cheaper. okay i really want to thank you all for helping out.

what? of course it is man. a 255lph fuel pump is exactly what everyone is telling you that you need.

 

[BigRand]

is a 255 LPH fuel pump okay? it s a little cheaper. okay i really want to thank you all for helping out.

www.extremepsi.com has the install kit and fuel pump for like $95.

LPH is okay still, HPH would be better cause it flows more, but anything is better than stock.

 

[VelocitàPaola]

LPH is okay still, HPH would be better cause it flows more, but anything is better than stock.

WTF

LPH = "liters per hour"

so that means there's the...

Walbro 255lph
and Walbro 255lph High Pressure

Sorry, Rand.

 

[BigRand]

WTF

LPH = "liters per hour"

so that means there's the...

Walbro 255lph
and Walbro 255lph High Pressure

Sorry, Rand.

Good catch Paul,

While were at it, care to explain to everyone (and me especially) what makes the high pressure walbro 255 pump, pump out more fuel if they both flow the same liters/hour?

I've seen that chart that shows the fuel pressure systems and how much they can handle compared to the stock oem pump, 190lph, 255lph, and the 255lph high pressure.