Safe PSI to run boost?

[ENGINR]

It happened to me a few days ago on a cool and crisp morning - WOT on the freeway on-ramp and the airflow meter craps itself and backs the power off!!

 

[JAP63]

It happened to me a few days ago on a cool and crisp morning - WOT on the freeway on-ramp and the airflow meter craps itself and backs the power off!!

It pulled timing?
You could feel it?

 

[ENGINR]

Not pulled timing - it just cut the power and gave the car a helluva jolt.

 

[youda]

i had a similar problem in my gsr 93t. the guts fell out of my turbo tech boost controller (my fault i didnt lock it off properly) the car went to 23psi and hit boost cut. made a loud poping noise and nearly put me through the winshield. was racing another car at the time was pretty embarassing.

 

[WADADLIG_EVO]

Those last two comments describe it exactly...!!!!

I thought I had blown the engine. All is well though.

WADAD

 

[mrcyborg]

ok guys, just to recap. say evo 3 engine the normal 3inch exhuast and pod filter mods, and having plenty of fuel and all. how much boost would you put max psi into a standard motor? i have a dyno comp coing up, and i am running 18psi max on street at the moment with no issues.

 

[DOUGMO]

i dont think you would have much luck going higher than 18psi with out the risk off issues

 

[mrcyborg]

hrmm. i kinda had a feeling i would get that answer. and i really dont want nasty issues with a daily driven car.

 

[mrcyborg]

you cant tell me what type of psi i should get doing a comp test can you? i havent done this engine, i dont know exactly what it is.

 

[Liberoz]

you cant tell me what type of psi i should get doing a comp test can you? i havent done this engine, i don't know exactly what it is.

All depends on the build, but as a rule of thumb you should be reading pretty evenly across the board
for eg.
165, 169, 170 168 ect

 

[JAP63]

you cant tell me what type of psi i should get doing a comp test can you? i havent done this engine, i dont know exactly what it is.

180-190 X 4 and its very healthy

Mine at 100K blew 180x4

 

[Liberoz]

180-190 X 4 and its very healthy

Mine at 100K blew 180x4

All really depends on the build and head gasket compression ratio, to say 180-190 he might think he needs a rebuild lol

 

[mrcyborg]

i know they have to be fairly even, just didnt know what it should read. i havent comp'd this engine yet, with rocker cover off it looked just about new. seems to be good. i know i have done a e1 engine that read pretty much 180 across the board. will try mine and see how i go.

 

[JAP63]

All really depends on the build and head gasket compression ratio, to say 180-190 he might think he needs a rebuild lol

Im talking a standard motor. A standard Evo III motor.

 

[Smutt]

Boost cut does not kick it at any particular boost. Its calculated by the Air Flow Meter- when it see's too much air being drawn with not enough AFR's to keep the car happy, it will start cutting out. For example, on a very efficient setup, it might kick in on 16 psi with a 16g, or with an in-efficient setup with a 14b it might kick in at 20psi.

Okay.. I have experienced this... with stable AFR's, does this mean I have max'd out my A/F meter? how can I get around this for 20plus psi? Go aftermarket Ecu?

I would prefer to be able to get around this by using an Evo I-III Ecu with matching AFM and injectors, will this work?
(Built 4G93T 8:1 comp, stock Ecu tho...)

 

[JAP63]

Okay.. I have experienced this... with stable AFR's, does this mean I have max'd out my A/F meter? how can I get around this for 20plus psi? Go aftermarket Ecu?

I would prefer to be able to get around this by using an Evo I-III Ecu with matching AFM and injectors, will this work?
(Built 4G93T 8:1 comp, stock Ecu tho...)

Id say so. Your motor sounds like its flowing well (efficient setup) and therefore it is seeing high Karmaans at low pressure.

Be happy how it goes as is, or chip it, and add a pump etc.
Or go full ecu i guess.

Theres is a real quick way around it with an SAFC2, i dont reccomend it tho.

 

[Smutt]

So, to confirm, you believe if I get a matching ecu, afm and injectors off and an Evo 1, 2, or 3, I should be able to over come this problem on my 1.8ltr?

 

[JAP63]

So, to confirm, you believe if I get a matching ecu, afm and injectors off and an Evo 1, 2, or 3, I should be able to over come this problem on my 1.8ltr?

yeah i dont see why not, especially if you use the evo range turbo etc...dotn forgetthough, youd need a pump of some sort and a reg.

 

[Smutt]

Yep, have pump and reg. And a GT28R, just cant push it past 20p without it cutting out...AFR's are fine..

Ok time to go shopping..

Anyone know where i can get an Evo 1,2 or 3 matching Ecu, Afm and injectors. Or how much they go for? (Will post in WTB section as well)

 

[3zercrowd]

So, to confirm, you believe if I get a matching ecu, afm and injectors off and an Evo 1, 2, or 3, I should be able to over come this problem on my 1.8ltr?

yeah i dont see why not, especially if you use the evo range turbo etc...dont forget though, you'd need a pump of some sort and a reg.

Id be also looking into a custom written chip to go with these mods at least, or go an aftermarket ECU.

Meek does write very good chips and all you need to do is tell him what you want and your mods and He will tailor make it for your car.:thumbsup:

Have you done up a members rides thread yet with build up specs and pics???