Safe MAX boost ?

[WRCVR4]

After experiencing boost of >20psi
Iv decided to see what's the safe level of boost i can run.
Assuming a AF <12.5-13 is maintained, and knock is less then ~2-3 ?

Whats everyones thoughts ?

 

[DOUGMO]

on a standard motor and pump fuel and standard pump

no more that 17psi max

 

[WRCVR4]

:shock: opps then, im around 17-18 now

 

[DOUGMO]

i would not go any higher

 

[WRCVR4]

i would not go any higher

Your no fun :evil: And iv just spent the last 2hrs looking at water injection kits :cry:

 

[DOUGMO]

try driving a skyline that has a turbo with a ceramic wheel that
will fall off if i boost over 15-16psi,

...now thats no fun.

if only i cound run 18psi i would be laughing

 

[tharaka]

try driving a skyline that has a turbo with a ceramic wheel that
will fall off if i boost over 15-16psi,

...now thats no fun.

if only i cound run 18psi i would be laughing

over 14psi on a standard rb20/25 turbo, its just blowing hot air anyway
so there would be no point in running more

 

[tharaka]

troy
as for safe boost
i cant comment, because, well, you know why

 

[DOUGMO]

try driving a skyline that has a turbo with a ceramic wheel that
will fall off if i boost over 15-16psi,

...now thats no fun.

if only i cound run 18psi i would be laughing

over 14psi on a standard rb20/25 turbo, its just blowing hot air anyway
so there would be no point in running more

i did run on about 16.5 for a while, was def a little quicker,
now just run 1bar (14.7psi) and its been very relaible so far.
it wouldnt last though

 

[to4garret]

are we talking stock motor, or stock injectors, turbo, maf/afm, ecu..?

cause that makes a big difference.

i've seen personally stock VR4 engines do 430hp atw for two years with right fueling and tuning.

 

[WRCVR4]

Stock motor (head gasket was replaced when it got to Aus)
it does have 550's, 2G MAF, 16G..... But motor is stock internals (this is the item in question here)

 

[JSTYLE]

with a comp ratio of 7.8:1 why not i say

Jon

 

[brisvr4]

Mine is a stock unopened motor and all I have is bolt-ons and I have been running 23psi with no problems at all for months now.

My mods are as follows Troy.
255 Walbro, 800 Sards, Aeromotive Reg, Big16g, 63mm cooler pipes, Keydiver chip, SAFC2 etc etc.
I get zero knock and afr's of 11.3:1.

As long as it is in good condition and you can keep the fuel up to it it should be fine, that said be careful and keep a good eye on everything.
I would keep the AFR down to around 11 - 11.5:1 to be safe. 12.5 - 13:1 is asking for trouble and a rebuilt motor.

 

[bazeng]

low comp stock motor, i'd say you'll be safe max @ 22psi with good fuel.

i ran my tdo5/6 22g hybrid at 24psi for a long time on an old/tired motor without issues... blow by was the reason for pulling it apart though...

but for daily driving, keep it at 1 bar for longevity...

 

[WRCVR4]

ill be running a dual stage/setting turbo smart bleed valve, so i can run 16-17psi everyday, and 20-22 when i need the extra

It i get this electronic thingy im looking at, i can have it lower the boost, if the AF becomes to lean :wink:

Ill need to upgrade my boost guage, to support more then 20psi but :?

 

[CLuTZ]

Why not put it on a dyno to check the AFR's whilst adjusting the boost and timing?

 

[Seagull]

20ish is safe, but make sure you keep the afrs richer than 12.5-13.0, try something like 11.5-11.8, run it fat and it will last, you might sacrifice 5-10kw but it will be reliable.

 

[JAP63]

20ish is safe, but make sure you keep the afrs richer than 12.5-13.0, try something like 11.5-11.8, run it fat and it will last, you might sacrifice 5-10kw but it will be reliable.

Couldnt agree more..at that boost,unless your internals are schmick,it'll wear premature..ive seen 20-22 pound for 18 months or so..went strong..no issues..it was kept well short of limiter though....Theyre quite strong..I didnt think the headgasket would hold..it did though..still is.

 

[CLuTZ]

How do you change the AFR's with a factory ECU?

 

[i2obert]

i know a evo 6 can handle upto 1.4bar on stock motor with fuel pump mods some guys are even running 1.5bar on stock block with no issues

i will tell you on tuesday what i have my one tuned to :twisted: