boost controll issue.

[dr_jekyll]

slight issue gents,

 

i have a 52mm external wastegate on the car with a 6psi spring.

 

if i run a pipe fron the compressor housing to the top of the gate and leave the rear open with no boost controller i get 5psi of boost.

 

if i plumb in a boost controiller i have overboost issues. io put a T piece in the line from the comp housing to the controller and from the controller t6h the bottom of the wastegate. with the valve fully closede the car makes 8psi to start but after 2 or 3 pulls it nmakes 10+psi and causes det

 

its allmost as if there is a pressure build up in the bottom hose that keeps the gate shut longer.

 

would anybody have any suggestions to enable me to get a consistant 7psi?

[dr_jekyll]

would fitting a 9psi spring an running straight from the housing with no controller solve my problem ?

[Scott]

Not sure if I am reading this right but it seems as if you may be plumbing into the wrong area of the WG. With no boost control you go from the turbo to the top of the wastegate, yet when you want boost control you put it into the bottom of the WG? Surely it should still be plumbed into the same area, ie the top? All the boost controller does is stay closed until Xpsi is reached and then opens, it should be in exactly the same place as the pipe would be if it wasn't there.

[dr_jekyll]

yes the line stays in the top of the WG. i T off that line to the boost controller and then goes back to the bottom of the WG. ill jump on paint and do an indepth diagramme

[dr_jekyll]

this is hoe its plumbed

 

Edited December 11, 2010 by dr_jekyll (see edit history)

[Scott]

I'm probably out of my depth but I don't see the point in the line towards the bottom of the WG if it works OK when you connect to the top? I can't see how having a boost controller connected to top and bottom of the WG helps to be honest.

 

This is new to me though, probably good for me to stay here

[Scott]

This is how I think it would work. Remove the T-Piece altogether and only have the red lines plumbed in.

[dr_jekyll]

i tryed that but it was straing , it made verry lttle boost in low gear and massively overboosted under high load.

 

im thinking of removing the bottom pipe to stop the back pressure build up but leaving the t pices so i can bleed a little pressur off the spring to aloow slighly more boost.

 

what do you think?

[Scott]

i tryed that but it was straing , it made verry lttle boost in low gear and massively overboosted under high load.

 

im thinking of removing the bottom pipe to stop the back pressure build up but leaving the t pices so i can bleed a little pressur off the spring to aloow slighly more boost.

 

what do you think?

 

Honestly, I'm not sure at all. I only have any experience of working with the WG actuator on the TT system. Never looked at anything involving a single with external WG.

 

What is the bottom pipe for? I thought wastegates only had an actuation port and exhaust port and that was it.

 

If you used a ball and spring valve I reckon it would work as per my drawing, EBCs just seem to complicate things for me lol.

[dr_jekyll]

the bottom port is to allow pressure to help the spring stay shut so you can make more boost with a week spring.

[Chris Wilson]

http://www.motec.com.au/filedownload.php/v14.pdf?docid=1307

[Homer]

Couldn't make sense of your pics with the vac lines but think you have it right, maybe the IN and OUT are the wrong way round? It should be like this.

 

The OUT on the BC should go to the top of the wastegate. The IN on the BC should be T'd to the compressor housing and the side port of the wastegate

 

[dr_jekyll]

if i do it that way it keeps the wastegate shut and is detting before im evan on wot.

[Homer]

The picture is the correct way to plumb in the BC unless you have something wierd fitted. What BC is it?

 

Was your car the NA-T that Ryan mapped? If it was, what has changed since then?

[dr_jekyll]

yes thats the one, the only thing thats changed is the B/C itself as the old 1 started to leak. its the same controller thats gone in the same way so im a bit confused.

 

its not an EBC its a manual bleed valve type controller

 

looking at your diagramme that is the way its plumbed in i should add my gate is mounted under the manifold so is "upside down" so by top of the gate i mean above the spring (pushing open) and bottom is under the spring (holding closed)

Edited December 15, 2010 by dr_jekyll (see edit history)