Jump to content
SAU Community

10 Psi Boost With One Peice Hose To Actuator On Std Skyline

cosworth1971
 Share

Recommended Posts

bilbo117 Rising Star

bilbo117

Posted
Posted
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 :)

That coupled with your new exhaust.

Dude that sounds so wrong.

the smaller pipe will not give you a higher pressure. are you saying that the air pressure in my intercooler piping could be say, 10psi, and because my piping to the actuator is smaller, the pressure inside here will be around 15psi? It doesnt work like that. use common sense.

In actual fact, because an actuator has little air flow to it, the restrictor wont do alot other then slow movement and proberbly make boosting smoother on the standard setup.

Where is everyone taking there actuator tap from? my problem has been fixed, i moved it to the piping immediatly after the turbo and fitted new BIGGER hose straight to the actuator.

R33silverS2 Mentor

R33silverS2

Posted
Posted
Dude that sounds so wrong.

the smaller pipe will not give you a higher pressure. are you saying that the air pressure in my intercooler piping could be say, 10psi, and because my piping to the actuator is smaller, the pressure inside here will be around 15psi? It doesnt work like that. use common sense.

In actual fact, because an actuator has little air flow to it, the restrictor wont do alot other then slow movement and proberbly make boosting smoother on the standard setup.

Where is everyone taking there actuator tap from? my problem has been fixed, i moved it to the piping immediatly after the turbo and fitted new BIGGER hose straight to the actuator.

It doesn't sound wrong at all Dude.... It is common sense. Reducing the diametre of a hose increases the pressure inside the hose. Hence why do you think taking the restrictor out of a gtr or an s15 for example ups the boost when replaced with a generic piece of fuel line or silicon hose... Because the pressure to the actuator is reduced hence the turbo creates more boost as the wastgate doesn't open as early or as much.

Cheers 'dude'

R33silverS2 Mentor

R33silverS2

Posted
Posted (edited)

Btw 'slowing airflow to the actuator :huh: ' is not going to make boost come on 'smoother' If anything it would ramp up faster and harder because the wastegate is not opening as much.

Which is why that is Not what it is doing in the stock setup.

Edited by R33silverS2
bilbo117 Rising Star

bilbo117

Posted
Posted
It doesn't sound wrong at all Dude.... It is common sense. Reducing the diametre of a hose increases the pressure inside the hose. Hence why do you think taking the restrictor out of a gtr or an s15 for example ups the boost when replaced with a generic piece of fuel line or silicon hose... Because the pressure to the actuator is reduced hence the turbo creates more boost as the wastgate doesn't open as early or as much.

Cheers 'dude'

Your analogy is completely wrong. As i said before.

You seem to not understand the relationship between pressure and flow. are you saying if i block off a pipe, and plug the other end into a compresser, that as the pipe gets smaller and smaller it will have higher pressure until it reachs the end? You cannot deny the fact that when flow ceases pressure will equalise on both sides of a restriction. For this reason, I don't see how having a smaller pipe will give you less boost.

can anyone else clarify? perhaps with some more in depth arguements?

bilbo117 Rising Star

bilbo117

Posted
Posted

LMAO

Because the pipe going to my boost gauge is really small, MAYBE, just MAYBE i am reading a much higher boost then i am actually running.

DEAR GOD

the problem is solved, maybe we have different boost gauge piping!

what size is the pipe running to your boost gauge R33silverS2? :huh:

R33silverS2 Mentor

R33silverS2

Posted
Posted (edited)

Your boost gauge is calibrated to run off a certain diameter hose. Go plug in a bigger one than it came with and see how you go....

Also please give us your expert analysis on why boost increases when the restrictor hose is removed... >_<

Also enlighten us to what the brass restrictor is for...

Edited by R33silverS2
R33silverS2 Mentor

R33silverS2

Posted
Posted
LMAO

Because the pipe going to my boost gauge is really small, MAYBE, just MAYBE i am reading a much higher boost then i am actually running.

DEAR GOD

the problem is solved, maybe we have different boost gauge piping!

what size is the pipe running to your boost gauge R33silverS2? >_<

>_<

  • 3 weeks later...
bilbo117 Rising Star

bilbo117

Posted
Posted
Your boost gauge is calibrated to run off a certain diameter hose. Go plug in a bigger one than it came with and see how you go....

Also please give us your expert analysis on why boost increases when the restrictor hose is removed... :laugh:

Also enlighten us to what the brass restrictor is for...

heres what I've figured so far.

Ive been talking to some pneumatic gurus at work and you are WRONG. smaller diameter in the pipe does NOT mean there is greater pressure. in actual fact, the pressure remains very much the same. Flow only increases. Because of this, and we all know the restrictor lowers boost, the guys believe that the restrictor is in place to keep the gate open longer, after pressure is removed from the actuator side. This means that the wastegate, once fully opened, takes a while to close again, meaning that the boost pressure is kept lower. There is NO such thing as a restrictor to increase pressure, it simply holds pressure at the diaphram for longer. (unlike what R33silverS2 has stated several times, pressure does not increase as the pipe gets smaller)

I fitted a restrictor to my car last week (went and bout 2 inchs of copper tube that fitted my vaccum hose) and my boost has dropped to around 8 pound consistently. The restrictor does work. Obviously, the most efficient way to control boost is electronically. Because of the restrictor, the wastegate also takes longer to open and this means it would be easier to have 'boost spiking' present.

Hope this clears a few things up.

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
 Share
Go to topic listing


  • Latest Posts

    • TurboTapin
      boost source Size Garrett gt28 gen2

      By TurboTapin 路 Posted

      You just need to remove the compressor housing, not the entire turbo. I would not be drilling and tapping anything with the housing still on anyways. 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah 路 Posted

      So, I put my boat on a boat. First of all, I'm going to come out and say it. Why is Tasmania not considered a holy goal, an apex that all road-legal modified cars go to, to experience? This place is an absolute wonderland of titanic proportions. If people are already getting club runs for once in a lifetime 30 person cruises to Tassy then I've never seemed to see it. It is like someone replaced the entire place with an idyllic wonderland for cars, and all of the people living there with paid actors who are kind, humble, and friendly. Dear god. After doing a lap of almost all of the place I've found that it's a great way to find out all of the little things that the car isn't doing quite right and a great way to figure it all out. All in all, I drove for 4 hours a day for a week and nothing broke. I didn't even need to open the engine bay. This is by all means a great success, but it has left me with a list of things to potentially address. I also now have a 3D printed wheel fitment tool which annoyingly hasn't got any threads in it to actually assemble it. I might be able to tape it together to check the sizing I actually want to use, but it'll likely involving pulling the shocks out to properly measure travel at least at the front, and probably raise the car while I'm at it, at least in the rear. I scraped on quite a few things and I'm not sure how else to go about it. I was taking anything with a bump at what felt like 89 degree angles. And address those 10 other tasks. And wash the car. God damn it is dirty. And somehow, the weather was perfect the entire time - And because I was on the top of Mt Wellington it turns out it was very much about to freeze up there. I did something I typically never do and took some photos up there in what must have been -10 and the foggy felt like suspended ice, rather than mere fog. If you own a car in Australia, you owe it to yourself to do it.
    • QB6SAGR
      Battle of the broken skylines

      By QB6SAGR 路 Posted

      Damn that was hilarious, and a bit embarrassing for skylines in general 馃槀 vintage car life ey. That R33 really stomped. Pretty entertaining stuff
    • cosline
      R32 gtr transmission strength, billet plate

      By cosline 路 Posted

      Hi, I have a r32 gtr transmission. Does any of you guys have an idea how much power it will hold with the billet center plate and stock gearset? At what power level and use did yours brake with or without billet plate? Thanks, Oystein Lovik
    • Rezz
      Spotted on the street....

      By Rezz 路 Posted

      Saw this replica police car based on a Mitsubishi Starion XX parked next to a 'police box' (it's literally a box) in Hirohata, Himeji City in Hyogo prefecture the other day. It's owned by Morii-san who is a local Mitsubishi Starion enthusiast. According to a local radio station blog post, he always wanted to make a police car himself based on ones he saw in his favourite Manga comics.  As it's illegal to modify a car to look like a police car and drive on the road, Morii-san tried many times to get permission from Aboshi police station headquarters nearby. They refused initially by after they got tired of that they granted him permission. However, the car can only be displayed on private property and obviously can't be registered as long as the police livery is present. The car was completed at a cost of 1.5 million yen (US$ 10,000) in addition to the car cost. A location was chosen outside Hirohata Police box where the car can easily been seen from the street. Morii-san has two other Starion road cars, both widebody GSR-VRs.
脳
脳
  • Create New...