Jump to content
SAU Community

Recommended Posts

well it has FMIC and big exhaust but ever since i did those to my std skyline 10 psi is the lowest i can get it too.I put a manual bleed valve on it and wound it right down to try lower it to no avail.

Trying to problem solve i look out the bleed valve i put in and hooked up the actuator straight to the intercooler pipe(manifold) with nothing inbetween and the boost is still 10 psi???It is actually more gradual and smooth but it would be good if i could get it down to 7 psi again to problem solve my cutting out under load.

I also just found no 2 spark plug(but all others like new) with white powder on the outside like a battery clamp goes powdery!!????like what tha!

a picture is in the general maitanance thread

does a actuator work on pressure forcing it open and holding that psi?

put the factory black runner hose back on the actuator

or due to the exhuaust restriction being removed thats what your stuck with

so less preasure to actuator= less boost?im confussed which way it works

I have a feeling its your boost controller (t-peice)

Ok so i tested my friends turbosmart single stage controller. On lowest setting it was still at 0.6 bar-0.65 bar- spiked to 0.8 bar at times..

im like, hmm lowest setting and its still more than stock boost (0.5 bar)?? *confused*

But sorta didnt bother me for a while...

Anyways, put my old gfb bleed valve back on, and i can seem to turn it right down and be stable.. I mean, it will still spike at times under full load, but that would be normal since we do have bigger exhaust, pod filter etc.. (since more air is still coming thru, its pushing more in)

Thats the way i think of it.

Maybe try another bleed valve and see if it helps in any way..

Ps- change all your spark plugs again.. Then check after a week and see if that plug is still going white.. If so, take it to a shop n see what it could be..

Edited by siddr20

I think everyone has missed the most improtant question. r32 actuators run 9-11 psi (depending on how much restriction is removed).

r33 actuators run 4.5-6psi (depending on how much restriction is removed).

What car do you have? What actuator do you have?

If you have an r32 or 32 actuator, then put a 33 actuator on, and the boost will be lower.

I have a 33 actuator here if you wanna swap

I think everyone has missed the most improtant question. r32 actuators run 9-11 psi (depending on how much restriction is removed).

r33 actuators run 4.5-6psi (depending on how much restriction is removed).

What car do you have? What actuator do you have?

If you have an r32 or 32 actuator, then put a 33 actuator on, and the boost will be lower.

I have a 33 actuator here if you wanna swap

its a 96 series 2 GTST RB25DET with almost no intake or exhaust restriction and i just seen 13psi(spikes) with no bleed valve installed!(just 4mm hose to actuator)

can someone pls clarify how it works ,less presure to actuator =more boost or the other way around?

can someone pls clarify how it works ,less presure to actuator =more boost or the other way around?

i think bleed valves work by restricting the air going to the acuator. if you tighten the bleed valve the actuator read's that it doesn't need to open yet, allowing your boost to be higher.and if you loosen the bleed valve it doesnt restrict the air flow to the actuator so it will actuate at a lower PSI. this is what i've gathered from other peoples threads.

if im wrong "can someone pls clarify",

good luck.

Aif

Bleed valves work by bleeding off some of the pressure that would otherwise be seen by the actuator. As a result, you need to produce more boost so that the actuator "sees" the boost you want.

The wastegate is opened by excess boost. It has an internal spring that sets the opening pressure. So you can never get less boost than the setting of the wastegate spring. If you only want 7psi, then remove the bleed valve (put it back to standard).

DO NOT EVER EVER EVER remove the hose from the wastegate. Unless of course you enjoy patching the holes the pistons will make as they fly skywards through your bonnet.

i think bleed valves work by restricting the air going to the acuator. if you tighten the bleed valve the actuator read's that it doesn't need to open yet, allowing your boost to be higher.and if you loosen the bleed valve it doesnt restrict the air flow to the actuator so it will actuate at a lower PSI. this is what i've gathered from other peoples threads.

if im wrong "can someone pls clarify",

good luck.

Aif

all my manual bleed valves say tighten for less boost and u cant breath thru them for lowest boost is what i have ??exact oposite to what people have said :)

As I have have recently found, In standard form they boost around 5-7psi but when you open the intake and exhaust it flows better cos it has less restriction, so inturn boosts harder.

If you plug a hose straight from your actuator to your intake pressure nipple, whatever that reads is the lowest it can go.

Mine has Cold airbox, FMIC,and Full Exhaust and 12psi is the lowest I can get.

Hope this helps.

Dave

As I have have recently found, In standard form they boost around 5-7psi but when you open the intake and exhaust it flows better cos it has less restriction, so inturn boosts harder.

If you plug a hose straight from your actuator to your intake pressure nipple, whatever that reads is the lowest it can go.

Mine has Cold airbox, FMIC,and Full Exhaust and 12psi is the lowest I can get.

Hope this helps.

Dave

yes 10-12 (min) is what mine is at and i have had to go to .5 plugs to stop spluttering!

Im starting to get it the spring is pre set to go in one direction but the presure on the oposite direction can altered to fight the spring into opening?

should i have bleed valve from near manifold or near turbo nipples?

I've tested this. No matter how much retsriction was removed - fmic, full exhaust, no muffler, metal cat. The boost was still 6 psi. shouldn't be 10-12.

So with just a line running from a pressure source, straight to the actuator, it still ran 10-12?

post a pic up of your wastegate actuator?

It appears that you either have a 32 actuator, an aftermarket actuator, or someone has shortened the rod on your 33 one (increases boost).

I've tested this. No matter how much retsriction was removed - fmic, full exhaust, no muffler, metal cat. The boost was still 6 psi. shouldn't be 10-12.

So with just a line running from a pressure source, straight to the actuator, it still ran 10-12?

post a pic up of your wastegate actuator?

It appears that you either have a 32 actuator, an aftermarket actuator, or someone has shortened the rod on your 33 one (increases boost).

I have a few pics I just took in the dark, Actuator..Sorta,Actuator Rod and Plumbing.

post-34973-1184752868_thumb.jpg

post-34973-1184752896_thumb.jpg

post-34973-1184752927_thumb.jpg

Im interested in this guys. My car turns into a giant vacuum cleaner at over 4500 revs cause the boost hits about 14psi. Makes little power here and goes way harder if i back off a little.

I have full straight through exhaust, front mount and a stainless steel intake. I run no boost controller and have a straight tap off of mr piping. the car used to run normal boost and i havnt touched the actuator since my mods. Is my system just too free flowing?

I think it might be to do with more flow, bigger exhaust and better intake, as I have got the same thing here freed up my system than installed an Auto Meter boost gauge and im hitting 1 bar (14.7psi) on high boost.

The way I look at it is now it is freed up it will be harder to get less boost, bleed valve might work but the system is working better, one way is to maybe put in an exhaust valve half close to restrict flow and noise, and when ya want to have some fun just open it to full open and wala.

i have FMIC, 550cc injectors, dump with 3inch stainless, hks pod, bigger turbo, walbro fuel pump, microtech ecu, and im not running boost controller, but my car runs 7psi, sometimes spikes around 10psi and i dont have the bov hooked up

its a 96 series 2 GTST RB25DET with almost no intake or exhaust restriction and i just seen 13psi(spikes) with no bleed valve installed!(just 4mm hose to actuator)

can someone pls clarify how it works ,less presure to actuator =more boost or the other way around?

If you put a different hose running from your intercooler pipe to the actuator you are running more boost because there is less pressure going to the actuator so the wastegate doesn't open and keeps building boost. The standard vac line that runs to the actuator has a restrictor in it that reduces the diameter inside the hose. A smaller diameter means higher pressure - higher pressure means wastegate opens earlier creating less boost. Imagine it like having a pea shooter - with the thin pipe it will shoot quite far due to the greater pressure but if you had a large diameter pipe with a pea in it it wouldn't go very far. - hope that makes sense :pirate:

That coupled with your new exhaust.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...