Author Topic: Boost gauge  (Read 5883 times)

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Boost gauge
« on: 22:07, Mon 26 November 2012 »
Hi all what should my boost gauge be connected too the manifold ?

Ash-Lee

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 4208
    • View Profile
Re: Boost gauge
« Reply #1 on: 22:56, Mon 26 November 2012 »
Standard boost gauge is connected to the carb elbow, it is 'T'd into the pipe that wanders off into the top of the fuel pressure regulator.

Aftermarket boost gauges are 'T'd into the vacumn pipe that connects the AEI unit to the inlet manifold (at the rear, base of the carb).

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #2 on: 09:34, Tue 27 November 2012 »
Thanks mate I'm having trouble with boost pressure so am fitting another boost gauge to check psi I also spoke to the place that built turbo he said it hasent any numbers on it but it's a t25/t28 sized turbo t25 shaft ect it's done 1mile since rebuild so it shout be good turbo

markey mark (bd)

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 1851
    • View Profile
Re: Boost gauge
« Reply #3 on: 10:41, Tue 27 November 2012 »
Quote from: "Home built turbo"
Thanks mate I'm having trouble with boost pressure so am fitting another boost gauge to check psi I also spoke to the place that built turbo he said it hasent any numbers on it but it's a t25/t28 sized turbo t25 shaft ect it's done 1mile since rebuild so it shout be good turbo

Did you preload the actuator up?
BD Autosport - Renault 5 gt turbo tuning and repairs.

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #4 on: 22:22, Tue 27 November 2012 »
Quote from: "markey mark (bd)"
Quote from: "Home built turbo"
Thanks mate I'm having trouble with boost pressure so am fitting another boost gauge to check psi I also spoke to the place that built turbo he said it hasent any numbers on it but it's a t25/t28 sized turbo t25 shaft ect it's done 1mile since rebuild so it shout be good turbo

Did you preload the actuator up?
I did but it didn't do much mate need to take to some where something's not right

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #5 on: 22:31, Tue 27 November 2012 »
Quote from: "Home built turbo"
Quote from: "markey mark (bd)"
Quote from: "Home built turbo"
Thanks mate I'm having trouble with boost pressure so am fitting another boost gauge to check psi I also spoke to the place that built turbo he said it hasent any numbers on it but it's a t25/t28 sized turbo t25 shaft ect it's done 1mile since rebuild so it shout be good turbo

Did you preload the actuator up?
I did but it should boost at around 7 psi without even turning it up I think it I took it for mot today and it's so slow!would it be slow because of fueling or what? The engine sounds sweet it doesn't smoke or any thing it doesnt tick over very well bit lumpy off choke ,it passed its emitions at mot with ease I don't no why it's slow it just doesn't seem to boost it sounds like it is a bit and it dumps but is still slow? Do u think I should take it for dyno set up it it the set up possible timing etc

Ash-Lee

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 4208
    • View Profile
Re: Boost gauge
« Reply #6 on: 23:56, Tue 27 November 2012 »
A large turbo like that only running at 7PSI will feel sluggish, when does it spool up 3500RPM+?

Check for leaks first, you don't want to keep winding the actuator in only to find out it's just leaking out anyway.

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #7 on: 13:53, Wed 28 November 2012 »
Quote from: "Ash-Lee"
A large turbo like that only running at 7PSI will feel sluggish, when does it spool up 3500RPM+?

Check for leaks first, you don't want to keep winding the actuator in only to find out it's just leaking out anyway.
I wouldn't say it boosts hardly at all I'm sure I don't have a leak iv set the actuator low my rev gauge don't work so can't see rpm in a bit stuck ATM mate

markey mark (bd)

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 1851
    • View Profile
Re: Boost gauge
« Reply #8 on: 17:19, Wed 28 November 2012 »
An actuator needs a certain amount of preload to build boost, it won't build any boost if it hasn't got enough or any preload.
How much did you adjust it up by?  Do you have a standard or after market actuator?
BD Autosport - Renault 5 gt turbo tuning and repairs.

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #9 on: 18:23, Wed 28 November 2012 »
Quote from: "markey mark (bd)"
An actuator needs a certain amount of preload to build boost, it won't build any boost if it hasn't got enough or any preload.
How much did you adjust it up by?  Do you have a standard or after market actuator?
It has a big ally one I adjusted it a few turns then pulled it and hooked it back that didn't seem to do much so I did nearly till it wouldn't reach and it still didn't seem to do anything

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #10 on: 21:15, Wed 28 November 2012 »
Quote from: "Ash-Lee"
Standard boost gauge is connected to the carb elbow, it is 'T'd into the pipe that wanders off into the top of the fuel pressure regulator.

Aftermarket boost gauges are 'T'd into the vacumn pipe that connects the AEI unit to the inlet manifold (at the rear, base of the carb).
My pipe from aei isn't connected to any thing is a thin hose comes out the black plastic cover and is this the hose that should be into manifold with boost gauge t in it?

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #11 on: 21:54, Wed 28 November 2012 »
Quote from: "markey mark (bd)"
An actuator needs a certain amount of preload to build boost, it won't build any boost if it hasn't got enough or any preload.
How much did you adjust it up by?  Do you have a standard or after market actuator?
If I put it all the way down and then turn it up 2-3-4 Turns ? it should be making decent boost yeah ?

Ash-Lee

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 4208
    • View Profile
Re: Boost gauge
« Reply #12 on: 22:42, Wed 28 November 2012 »
Quote from: "Home built turbo"
Quote from: "Ash-Lee"
Standard boost gauge is connected to the carb elbow, it is 'T'd into the pipe that wanders off into the top of the fuel pressure regulator.

Aftermarket boost gauges are 'T'd into the vacumn pipe that connects the AEI unit to the inlet manifold (at the rear, base of the carb).
My pipe from aei isn't connected to any thing is a thin hose comes out the black plastic cover and is this the hose that should be into manifold with boost gauge t in it?

Yes. It should connect to the rear of the inlet manifold, a small port at the base of the carb.

If that port is left open then that would be a reasonable sized air leak.

Home built turbo

  • 150BHP Member
  • **
  • Posts: 47
    • View Profile
Re: Boost gauge
« Reply #13 on: 12:05, Thu 29 November 2012 »
Quote from: "Ash-Lee"
Quote from: "Home built turbo"
Quote from: "Ash-Lee"
Standard boost gauge is connected to the carb elbow, it is 'T'd into the pipe that wanders off into the top of the fuel pressure regulator.

Aftermarket boost gauges are 'T'd into the vacumn pipe that connects the AEI unit to the inlet manifold (at the rear, base of the carb).
My pipe from aei isn't connected to any thing is a thin hose comes out the black plastic cover and is this the hose that should be into manifold with boost gauge t in it?

Yes. It should connect to the rear of the inlet manifold, a small port at the base of the carb.

If that port is left open then that would be a reasonable sized air leak.
Could u post a pic of where it sposed to be ill see what's on it I'm sure everything is connected up on manifold mate

Ash-Lee

  • Global Moderator
  • 200BHP Senior Member
  • *****
  • Posts: 4208
    • View Profile
Re: Boost gauge
« Reply #14 on: 22:55, Thu 29 November 2012 »
It's quite difficult to take a picture of. I'll try and describe it.

It's at the rear of the inlet manifold, facing the bulkhead.

Locate the two larger black pipes. One will lead off to the brake cylinder, the other to the oil breather setup (assuming still standard).

In the center of those two black pipes is a small port (approx 4mm), that is where the vacuum pipe needs to connect to.

If you don't know it's there, it's easy to overlook. A mirror might help.