M35 Standard Boost

[GTAusMotive]

Hey everyone, I'm at the mercy of anybody's professional opinion on this as i've searched the forum and around the web but can't seem to find a solid, definite answer to the question I have. Our 2001 M35 Stagea RSFour is showing boost past the +1 mark on the boost gauge and I know the standard gauge isn't the most glorified accurate thing in the wold but at this stage it has no problem with responding to throttle input so I can rule out if its being over optimistic or not because it appears to function fine.

However, I've read that from factory stock standard trim the M35 is designed to run at .8bar or 11.6psi something around that mark, can anybody verify this?

As our car is essentially still 100% stock I don't want anything to go boom and was hoping somebody could point me in the right direction to start looking at where and why our M35 is currently making close to, if not spot on 100kpa / 1 bar mark on the boost gauge.

The car still has its stock exhaust and SMIC so I know pushing that much pressure isn't a good thing.

If I wanted to revert back to the stock boost .8 bar (if that is what it's suppose to be) could anybody give me a few pointers in how I'd go about doing that?

I know that theres a handful of vac lines going back and forth between solenoids and actuators and what not but I haven't got a clue where to start looking to see if the previous owner in Japan has maybe removed a restrictor or something.

All help is greatly appreciate and many thanks in advanced.

[andy65b]

Hey everyone, I'm at the mercy of anybody's professional opinion on this as i've searched the forum and around the web but can't seem to find a solid, definite answer to the question I have. Our 2001 M35 Stagea RSFour is showing boost past the +1 mark on the boost gauge and I know the standard gauge isn't the most glorified accurate thing in the wold but at this stage it has no problem with responding to throttle input so I can rule out if its being over optimistic or not because it appears to function fine.

However, I've read that from factory stock standard trim the M35 is designed to run at .8bar or 11.6psi something around that mark, can anybody verify this?

As our car is essentially still 100% stock I don't want anything to go boom and was hoping somebody could point me in the right direction to start looking at where and why our M35 is currently making close to, if not spot on 100kpa / 1 bar mark on the boost gauge.

The car still has its stock exhaust and SMIC so I know pushing that much pressure isn't a good thing.

If I wanted to revert back to the stock boost .8 bar (if that is what it's suppose to be) could anybody give me a few pointers in how I'd go about doing that?

I know that theres a handful of vac lines going back and forth between solenoids and actuators and what not but I haven't got a clue where to start looking to see if the previous owner in Japan has maybe removed a restrictor or something.

All help is greatly appreciate and many thanks in advanced.

Don't worry all is good.

The standard boost seems to vary between RX/RS and ARX models. RS/RX seem to be stock boost of around 12psi and the ARX seems to be 13-14psi. This is the stock boost from the factory.

So it sounds like your boost is just fine.

The turbo is a ceramic turbine with ball bearing. The turbo on the M35 is different to the RB motor's turbo and as such can handle this level of boost without a problem. Well at least it will handle it for about 100km +- 30k before it will need reconditioning.

If you want to reduce/increase your boost you will need to look at installing an aftermarket boost controller.

The other things that can vary your boost could be ECU (check if it is a remapped one, behind the glove box), the Solonid boost controller being loop off (passengers side of the plenum in front of the 3 plugs, you will need to remove the engine cover).

Also check the accuracy of your gauge, the OEM one is known to be a little off in it's reading.

BTW; you have a FMIC that flows very well but is a bit small to stop some retarding in our summer temps.

Cheers

Andy

[GTAusMotive]

Thanks for the very informative reply Andy, every bit of that info helped ease my mind about the boost issue. Had a good look over the points you mentioned and unless whoever owned it previously had done a seriously good job of making it look un-changed then just about every hose and wire looks as just how Nissan put it together.

I'll plumb up a boost gauge that I got from supercheap and get some readings off that and compare them to what I'm seeing on the factory gauge but if its anything like you mentioned then I can expect to see at least something around the 12PSI mark and not have to be extremely concerned.

Again thanks for your helpful info. Nothing like getting the info from knowledgable people