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im still not convinced. Is that manual for S1 or S2? Everything i have read, and tested points to the S2 (atleast) running 6psi/8psi factory boost, using the dual stage solenoid. Earthing that solenoid makes it run 8psi all the time. Thats regardless of if its manual or auto.

Ive driven two auto 25Ts now, and both have done 8psi (one is my own one, and that runs 9psi due to free flow panel filter, no other engine mods), and the other one had exhaust done, ran 8psi. The second one was a S2 sedan.

I havent driven a manual one yet, so cant comment on them.

yes you are right, and the nissan service manual is wrong...........................................

i mean, its written in plain english, with a clear disticntion between AT and MT

im not sure how clear it needs to be ?

AUTO runs less boost in the factory setup

So does that mean there's no 2nd stage boost for an auto? My auto car hits ~5psi fairly quickly with just a bit of lead foot from standstill.

I have never fully floored it so I (never revved over 4,500 rpm) don't know if there is the 2nd stage boost or not, where it hits ~7psi.

dual stage still exists

its just lower pressure for AUTO

yes you are right, and the nissan service manual is wrong...........................................

i mean, its written in plain english, with a clear disticntion between AT and MT

im not sure how clear it needs to be ?

AUTO runs less boost in the factory setup

yes, im aware its in the manual, i have the same copy you have and its in it. What i want to know, is why i have never heard of anyones auto R33 actually running this lower boost? Everyone i have talked to, and everything i have come across has shown in real world use, the auto makes the same boost as the manual.

The main reason for the lower power output seems to be the auto box sucking so much power.

Edited by KwS
  • 2 weeks later...

ive got a (chipped in japan) manual ecu.

Unplugged the auto compute and ecu r, plugged in the new ecu and it works great.

Getting a rb20 actuator and will put that on after the new exhaust and cooler goes on.

Thanks for the advice guys.

  • 2 years later...

ive got a (chipped in japan) manual ecu.

Unplugged the auto compute and ecu r, plugged in the new ecu and it works great.

Getting a rb20 actuator and will put that on after the new exhaust and cooler goes on.

Thanks for the advice guys.

hi guys

I have a S1 auto coupe rb25det r33 and it is running 5psi stock and average in low range rpm but after 4500 it opens up nice, I want to have it boosted to 10/11 standard instead of 5.

I have been told by local mechanic they can remap the comp and make the turbo run 10psi and it will increase my stock rwkw by at least 30... but ive now been reading about an rb20 actuator? is it as simple as plug in and thats it, I mean just take out my actuator and put in this rb20 one? and then the car will run 10psi standard or???? can someone explain it plzzzzzzzz

If your mechanic told you you can get 10psi by remapping the ecu, you need to get a new meahanic.

An increase in boost can only be had by using a boost controller or in this case upgrading the actuator to one with a stiffer spring like the rb20det

The rb20 actuator is a direct swap and something you can do yourself with basic tools and boost should be in the vicinity of 10psi maybe a little more if you have bigger exhaust

However you may experience what we call R&R (rich and retard) which bacially makes the car loose power up in the revs but this varies from car to car, so the only way to find out is to actually try it

If your mechanic told you you can get 10psi by remapping the ecu, you need to get a new meahanic.

An increase in boost can only be had by using a boost controller or in this case upgrading the actuator to one with a stiffer spring like the rb20det

The rb20 actuator is a direct swap and something you can do yourself with basic tools and boost should be in the vicinity of 10psi maybe a little more if you have bigger exhaust

However you may experience what we call R&R (rich and retard) which bacially makes the car loose power up in the revs but this varies from car to car, so the only way to find out is to actually try it

okay well im all new to this... i was under the impression it was in the comp... they said they can put the boost to 10/11 psi rather then 5, for like $200 something to do with the dyno or some thing, my turbo is stock rb25det and no boost controllers.

it runs stock 5psi, but i want 10/11 which is max ive been told from a stock turb..

Haha....Ill do it for $190.

Its recommended that you get a cooler and exhaust before you do this though....do some reading there is plenty info around concerning this.

in previous posts, i have said there is, I HAVE a decent FMIC and K&N filter and 3inch turbo back xzhaust with hi flow cat.... just 5psi and but need more go :P

my A-hole sillypants!

i dont believe this 5 psi crap!

i took a ride in an auto 4 door 33 the other day that had a manual box installed but retained stock ecu and had no boost controller or nothing.

no way in hell was that thing running 7 let alone 5!

i have heard before that auto 33 (and possibly 34s) have boost set to around 9 instead of 7 on manuals.

there is a possibility that this was different between series. ie: that handbook might have just been looking at series 1 33 when maybe the boost is higher in S1.5/2.

i hope someone that actually has real experience with this matter on a large scale can give a proper answer to this topic because i do not believe that 5psi stock is the final answer.

my A-hole sillypants!

i dont believe this 5 psi crap!

i took a ride in an auto 4 door 33 the other day that had a manual box installed but retained stock ecu and had no boost controller or nothing.

no way in hell was that thing running 7 let alone 5!

i have heard before that auto 33 (and possibly 34s) have boost set to around 9 instead of 7 on manuals.

there is a possibility that this was different between series. ie: that handbook might have just been looking at series 1 33 when maybe the boost is higher in S1.5/2.

i hope someone that actually has real experience with this matter on a large scale can give a proper answer to this topic because i do not believe that 5psi stock is the final answer.

WELL mine is auto and stock turbo and ecu and the guy who did the dyno said its at running at 5psi stock s1 r33 (no boost controller), and going to get it boosted to 10psi, becoz 5 is okay but average in low rpm

WELL mine is auto and stock turbo and ecu and the guy who did the dyno said its at running at 5psi stock s1 r33 (no boost controller), and going to get it boosted to 10psi, becoz 5 is okay but average in low rpm

Are you sure on what series your ecu is from let alone whether its an automatic ecu ?considering your car was converted from non turbo to turbo.

Are you sure on what series your ecu is from let alone whether its an automatic ecu ?considering your car was converted from non turbo to turbo.

true, well I took my car to the local import specialist and he told me some things and he was telling me, yes the car was NA factory but he says there has just been a RB25DET put in the car, the rest is stock, 4 stud, no lsd, no boost controllers all stock auto. but im telling you he said it was 5PSI and it was only 134rwkw, and I plan to get it boosted to 10 as its only average atm like up to 60ks its average, so I am going to get them to boost it to 10PSI.

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