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So this is more of a curiosity than anything else, but i figured id ask.

We all know cars are tuned rich from the factory, for safety, my question is, can you increase boost safely without tuning the car? Common sense would suggest no, but is it possible? Has anyone done this?

Ive got a 92 GTSt with an RB20 and considering the lack of tuneability with the stock ECU (originally came from the world of open source tuning subarus), can you dial in 1 or 2 psi safely without actually going to a NIStune or standalone and not compromise AFR pr ultimately your engine?

Hopefully someone has some answer cause here in the states i mostly get a blank stare and "dunno".

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One or two extra psi will not kill your car. More than 10 or 12 may kill your turbo. People routinely increase boost to 10 psi usually without problem (there are no guarantees in this business). But since you will inevitably want more power down the track consider getting a Nistune chip anyway☺️

I'm pretty sure you can.........

My mate has an R32 GT-R that was 100% stock including radio and exhaust.

He added a boost controller and cat back exhaust and picked up approx 25awk.

No tuning was done. I think the problem will start if you start changing injectors etc.

Just ring any respectable tuning mob and they will tell you.

Cheers...... Bob.

2 hours ago, KiwiRS4T said:

One or two extra psi will not kill your car. More than 10 or 12 may kill your turbo. People routinely increase boost to 10 psi usually without problem (there are no guarantees in this business). But since you will inevitably want more power down the track consider getting a Nistune chip anyway☺️

I thought stock boost WAS 10 psi?

I was told the stock turbo was prone to breakage over 13 psi?

Im going full stand alone but thats down the road so im more curious whats possible as is with just a little fiddling. I have an old Perrin Manual boost controller from an old Subaru Liberty build

Edited by Hcr32typem

It should be fairly happy with 12psi. Just remember to reset ur ecu by taking the battery off for 10 min with headlights turned on. Then let it learn. Stock is 10psi with decent exhaust and intake. Dead stock about 8psi

Wow.  So much information in this thread that is just a little bit wrong (except for one post above - I'll leave you guys to work out which one I'm talking about).  And this after the real information has been known for like.....25 years.

Point 1.  Resetting an R32 ECU by pulling the power and putting it back on after long enough for the capacitors to drain has precisely zero useful effect.  The ECU will lose its learnt long term fuel trims, which will possibly make it run worse in the immediate short term.  But whether you do the zap or not, the ECU will learn the trims back to wherever they need to be AT THE SAME SPEED!  it might even take longer if you flatten the caps.

Point 2.  R32 ceramic turbos, like all other ceramic turns, can die at ANY BOOST LEVEL AT ALL.  At any age and after any usage history they can die at stock boost (10 psi), or anything up to 20 psi.  If you choose to try to run it at 20 psi it will probably die within a few minutes.  I ran mine at 14 psi for years and years.  In the middle of that it even ran for a while at 17 psi for a while.  I consider myself lucky that it didn't explode at 17.  But it was fine at 14.  Others have exploded for no apparent reason without being boosted.

Point 3.  Nissan ECUs of the era are tuned very rich and very retarded in the top-right hand corner of the maps.  They are of course rich in the normal stock area of the maps, and they only get richer as you add boost.  This is not a good thing.  This does not mean that you have "fuelling" to spare to keep adding boost without worrying about a tune.  The problems are in fact multiple;

a) Rich is slow.  You can add boost and not get any extra power.  What you are doing is wasting fuel.  I ran 14 psi for ages without tuning the car.  With Nistune in it and all the extra fuel removed from the top end of the map, it made 15 rwkW more.

b) If you look at the RB20 fuel maps in Nistune, you can see how much of the top right corner of the map is actually aimed at 100% injector duty cycle or more.  What this means is that there isn't actually as much "spare capacity" as people expect.  All that is required is that the fuel pump goes a bit soft or the filter gets a bit too dirty and you can very rapidly fall off the rich cliff into the lean ocean and toast the engine.  And people who run their cars like this very seldom have any form of AFR monitoring installed.

c) There's more, but thinking about the nature of the problems is self-educatory.  So worth a try anyway.

  • Thanks 1
19 hours ago, GTSBoy said:

Wow.  So much information in this thread that is just a little bit wrong (except for one post above - I'll leave you guys to work out which one I'm talking about).  And this after the real information has been known for like.....25 years.

Point 1.  Resetting an R32 ECU by pulling the power and putting it back on after long enough for the capacitors to drain has precisely zero useful effect.  The ECU will lose its learnt long term fuel trims, which will possibly make it run worse in the immediate short term.  But whether you do the zap or not, the ECU will learn the trims back to wherever they need to be AT THE SAME SPEED!  it might even take longer if you flatten the caps.

Point 2.  R32 ceramic turbos, like all other ceramic turns, can die at ANY BOOST LEVEL AT ALL.  At any age and after any usage history they can die at stock boost (10 psi), or anything up to 20 psi.  If you choose to try to run it at 20 psi it will probably die within a few minutes.  I ran mine at 14 psi for years and years.  In the middle of that it even ran for a while at 17 psi for a while.  I consider myself lucky that it didn't explode at 17.  But it was fine at 14.  Others have exploded for no apparent reason without being boosted.

Point 3.  Nissan ECUs of the era are tuned very rich and very retarded in the top-right hand corner of the maps.  They are of course rich in the normal stock area of the maps, and they only get richer as you add boost.  This is not a good thing.  This does not mean that you have "fuelling" to spare to keep adding boost without worrying about a tune.  The problems are in fact multiple;

a) Rich is slow.  You can add boost and not get any extra power.  What you are doing is wasting fuel.  I ran 14 psi for ages without tuning the car.  With Nistune in it and all the extra fuel removed from the top end of the map, it made 15 rwkW more.

b) If you look at the RB20 fuel maps in Nistune, you can see how much of the top right corner of the map is actually aimed at 100% injector duty cycle or more.  What this means is that there isn't actually as much "spare capacity" as people expect.  All that is required is that the fuel pump goes a bit soft or the filter gets a bit too dirty and you can very rapidly fall off the rich cliff into the lean ocean and toast the engine.  And people who run their cars like this very seldom have any form of AFR monitoring installed.

c) There's more, but thinking about the nature of the problems is self-educatory.  So worth a try anyway.

Appreciate the info! This is the kind of info were lacking in the US. Its true that people have been swapping RBs into various cars here but the general knowledge base is very thin.

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