How Much Boost Can I Run With This Setup?

[stuartlaw_78]

Hi all..

I want to know how much boost I can run with what I've done to the motor..

I will be getting a stand alone management system soon but here is what has been done..

I've put forged pistons in (Weisco 8.4 comp).. shot peened the rods, ARP rod bolts, balanced and polished crank, everything has been balanced, new rings of course, bored and honed, square decked. ARP head studs, port and polished head, standard cams, re ground valves, standard springs, hi flowed the turbo (capable of up to about 250kw at the wheels), front mount intercooler, 3 inch exuast.

(I havent got upraged fuel injectors yet but will be doing so, just not sure what to get yet)... I have a series 1 skyline but apparently when I took my turbo in, the guy said it was a series 2 turbo, maybe the whole motor is series 2 which means the injectors will be. I've heard that the series 2 injectors flow alot better!..

Anyway, what you think guys??

[paulr33]

injectors are same for series 1 or 2. your bulder should have given you a power target and boost level. you will need an aftermarket ecu and injectors before you can up the boost pressure. also what exhaust? 3inch what? what dump? what front? what cat? what air intake have u got?

[stuartlaw_78]

Well that's interesting caus I was told series 2 had better injectors... hhmmm...

Standard intake atm, dunno brand of exuast, mandrel bend, yeah, i'm aware that you need bigger injectors, aftermarket ecu, etc... I've done my homework.. I think I'll just run 15psi when it's setup correctly...

The machinist aren't building my engine.. I'm doing it myself with my cousin (who builds engines quite a bit.. they are just preping the block and parts...

[paulr33]

exhaust will make a big difference to your final output and how it runs so don't just seelte for "should be good enough" find out. you should have at least a 3" split dump system hiflow cat and 3" catback.

series 2 injectors are same as series 1, 370cc will max out after 200rwkw

[knore]

you did bearings too yes?

boost isnt really the question you should be asking, its power

ide say you could make 300rwkw reliably with that motor and all the other bits needed

[chaos]

i thought you could run close to 15psi on a standard Rb25?

[paulr33]

well it depends on how its been built and whats been used

15psi doesnt mean much as far as power is concerned

airlfow makes power, not boost

more boost means more heat

[RRR32_GoDzIlLa]

all that engine work and only a hi-flowed turbo???? why

[paulr33]

and stock ecu and injectors

[chaos]

all that engine work and only a hi-flowed turbo???? why

<{POST_SNAPBACK}>

was that referred to me?

[RB30-POWER]

well over 300rwkw easily supported on that setup, considering you have forgies and lowered compression ratio from standard.

get some good cams and just add boost from a decent size turbo and watch the power skyrocket

[chaos]

as Paul said, injectors will be holding him back. Should get some 720cc injectors, then boost it up.