boost issue

[gtrjerry73]

This happened with my car exact same thing. I'm 99 percent positive just bad gas. Ever since I started putting 94 octane (husky) gas in, it hasn't done it just knocking a bit. I really doubt at any level that would be noticeable but just enough for the factory knock sensors to revert to factory boost levels use an octane booster if you have to but I find it runs good on 94

[jrhdohc]

most common reason for knock is incorrect timing. for the given situation... rpm, load, fuel, heat, maintenance level, engine design- hotspot, compression ratio etc...
goal is to have MBT (Minimun advance for Best Torque) with no knock.
no knock MBT may be different depending on fuel octane.
try better gas!

CAS (Camshaft Angle Sensor) tells the ECU the position of engine in it's rotation.
when you check your base timing. it's like setting a watch to correct time of day.
your watch can be working great but not display the correct time if it's not set properly.
if your timing is 5 degrees advanced (for example) past it's normal setting (ex: 20), it's like the watch reading 5 minutes fast.
your spark plug will fire 5 degrees to early. just like you will arrive everywhere 5 mintues early.
that extra 5 degrees may push your total timing (5 + 20) past no knock MBT.
i would check the timing.

plus check the ecu. it might have a chip. ecu chips are for use with hi oct japan gas. in this situation it's not incorrect timing tricking your ecu. it's the ecu advancing more becasue it was set-up for a different situation. and the timing is too much for your fuel's octane.

like someone else said... might not be knock. don't worry too much. just take it easy on the engine and check free and easy stuff first. gas and timing fit on that list.

[jrhdohc]

oh i forgot to say..
knock.... like the name states. it's a sound. sound emitted when junk is going wrong in the combustion chamber(s).
rb26 and other engines have a microphone mounted to the engine block. RB26 has 2 knock sensors.
if the knock sensor (microphone) hears a "knock"ing sound. it tells the ecu.
the ecu retards... "pulls" timing. for example: 20 - 5... 15 degrees.
pullings timing helps protect the engine.

that is very crappy and basic explanation... more more info on this forum or via google.

[91BNR32GTR]

It sounds like your car was knocking so the ECU reset to safe boost.

is knocking bad?>

[canadiancarguy]

I don't think your car is knocking, it is doing the same thing as mine. You can just turn the key off and on and your boost will be back. Knocking would be happening everytime you hit boost. I think the wastegate or actuator spring just needs to reset itself sometimes. Knocking is bad, it puts holes in pistons, blows head gaskets and other nice stuff like that!

[GTRADDICT]

If you have stock turbines with stock boost <1 bar you dont have knock or low chance... I say your waste gate actuators are tired of starting to seize. You can probably still run the car with no danger but less power until you swap the actuators.

[91BNR32GTR]

If you have stock turbines with stock boost <1 bar you dont have knock or low chance... I say your waste gate actuators are tired of starting to seize. You can probably still run the car with no danger but less power until you swap the actuators.

so im seeing alot with waste gates and what not people are saying to those are the stock recirc valves right? if so a nice set of BOV's would fix problem?

[GTRADDICT]

Stock GTR turbines have an internal waste gate (google). When the target PSI/boost in the intake piping is reached, the waste gate opens to insure there will be no boost spike. It's a bypass valve for the exhaust. The exhaust will not touch the exhaust wheel and just go through the exhaust. BOV will not solve the issue. Well... it will if your BOV are leaking just like any other parts in a pressurized system.

[91BNR32GTR]

Stock GTR turbines have an internal waste gate (google). When the target PSI/boost in the intake piping is reached, the waste gate opens to insure there will be no boost spike. It's a bypass valve for the exhaust. The exhaust will not touch the exhaust wheel and just go through the exhaust. BOV will not solve the issue. Well... it will if your BOV are leaking just like any other parts in a pressurized system.

ohhh ok. seeings how u braught up wasste gates how can i change from internal to external? any benefits or just the sound like a BOV?

[GTRADDICT]

No need to change to External... Replace actuator with new ones

[91BNR32GTR]

No need to change to External... Replace actuator with new ones

sorry i confused the wastegate thing unless screamer pipes r the same which i dont believe so. i like the sound of them and would like to buy one do u know where i could find a screamer pipe for n r32 GTR?

[canadiancarguy]

Ok look at the little thing with a boost line attached to your turbos. That circular brass thing is your actuator. Boost compresses a spring (or diaphragm?) inside that opens the wastegate letting excess exhaust gas bypass the turbine housing to control boost. They are pretty cheap and ya wanna get real trick you can make the rod to the wastegate threaded so it takes more boost to open the wastegate. Another cheap way add more boost, but removing the boost restrictor already puts the stock turbines at the max safe boost level anyways.

[91BNR32GTR]

Ok look at the little thing with a boost line attached to your turbos. That circular brass thing is your actuator. Boost compresses a spring (or diaphragm?) inside that opens the wastegate letting excess exhaust gas bypass the turbine housing to control boost. They are pretty cheap and ya wanna get real trick you can make the rod to the wastegate threaded so it takes more boost to open the wastegate. Another cheap way add more boost, but removing the boost restrictor already puts the stock turbines at the max safe boost level anyways.

ya atm im at max power completely stock with out dropping some good cash. jsut bought the car a month ago so im gonna add some things it needs like a turbo timer, and a Bee R power builder and a couple more touches before she goes away for winter. then spring im hoping to do engine like upgraded turbos, inter cooler, ect....

[derk]

ya atm im at max power completely stock with out dropping some good cash. jsut bought the car a month ago so im gonna add some things it needs like a turbo timer, and a Bee R power builder and a couple more touches before she goes away for winter. then spring im hoping to do engine like upgraded turbos, inter cooler, ect....

lol. does not NEED either of those.

[91BNR32GTR]

lol. does not NEED either of those.

IMO i need a turbo timer because i dislike the fact of sitting in the car for an extra couple min. and i believe its better to let the car run for a lil after a drive. k maybe it dont need a bee r haha but i wouldnt mind one.