[Mk2] [Turbo] rev2 boost problem

[porscheeater]

today I have had a few bits done to the car
did a big service,
changed the gearbox oil too
and had my gauges fitted.... only to find out that the ct26 turbo is not boosting right.
it seem to be making 0.4bar of boost but doesnt hold the boost for long.

can someone please let me know what the standard boost pressure should be and what can possibly be causing this problem

Thanks

[Ryan S]

What gear did you check the boost in? The boost is limited in 1st and 2nd gear to around 7psi i believe. Try a pull in 3rd, the boost does tail off at about 6k rpm.

[porscheeater]

What gear did you check the boost in? The boost is limited in 1st and 2nd gear to around 7psi i believe. Try a pull in 3rd, the boost does tail off at about 6k rpm.

i tested and noted a loss in boost through all the gears took it on the m6 so was able to hold the gears. However, it loses...drops boost while driving and doesnt boost pass 0.4bar
surely it should be doing more than that??

[Ryan S]

Yeah that doesn't sound right, make sure the actuator is moving freely, i would also check for error codes, i assume it doesn't have a boost controller?

[porscheeater]

Yeah that doesn't sound right, make sure the actuator is moving freely, i would also check for error codes, i assume it doesn't have a boost controller?

no no boost controller not yet
tomorrow I am going to check the actuator
now what am i looking for when i do this sorry I am a novice but i am a quick study
and what boost pressure should my turbo be reading?

[Ryan S]

I'm not 100% what boost a rev2 should run, i'm sure fuel cut is at 12-13psi so maybe around 10psi? Bear on mind again the boost is limited in 1st and 2nd. Adding a boost controller will sort this. Makes a massive difference.

[porscheeater]

I'm not 100% what boost a rev2 should run, i'm sure fuel cut is at 12-13psi so maybe around 10psi? Bear on mind again the boost is limited in 1st and 2nd. Adding a boost controller will sort this. Makes a massive difference.

ok so a manual boost controller will sort the drop in boost? I hope so.
i havent checked it yet but if the actuator is not working or setup right wouldnt that be the problem.

I think i need a local turbo guru

[Ryan S]

I'm not 100% what boost a rev2 should run, i'm sure fuel cut is at 12-13psi so maybe around 10psi? Bear on mind again the boost is limited in 1st and 2nd. Adding a boost controller will sort this. Makes a massive difference.

ok so a manual boost controller will sort the drop in boost? I hope so.
i havent checked it yet but if the actuator is not working or setup right wouldnt that be the problem.

I think i need a local turbo guru

sorry bud, what I meant was, a boost controller will stop the boost being limited in 1st and 2nd gear, basically when you fit the controllers, you disable a thing called t-vsv. then you'll get full boost in first and second gear. as for the boost tailing off, the CT26 is known for tailing off dramatically. it does sound like something is up though, check for error codes, check actuator. report back

[porscheeater]

I'm not 100% what boost a rev2 should run, i'm sure fuel cut is at 12-13psi so maybe around 10psi? Bear on mind again the boost is limited in 1st and 2nd. Adding a boost controller will sort this. Makes a massive difference.

ok so a manual boost controller will sort the drop in boost? I hope so.
i havent checked it yet but if the actuator is not working or setup right wouldnt that be the problem.

I think i need a local turbo guru

sorry bud, what I meant was, a boost controller will stop the boost being limited in 1st and 2nd gear, basically when you fit the controllers, you disable a thing called t-vsv. then you'll get full boost in first and second gear. as for the boost tailing off, the CT26 is known for tailing off dramatically. it does sound like something is up though, check for error codes, check actuator. report back

oh i see.
ok when i'm off to get some more work done on the motor
I am taking picture of my progress (lol the fualt finding progress) but i haven't a clue how to upload them.

[Ryan S]

you need to upload your pics to a website, flickr, photobucket etc....I use facebook as it's easy to do from the phone, anyway, once you upload them, you need to right click on the photo, then go to "copy image URL" come to your post on here and above the text box you'll see a wee button that says Img. click it once you'll see this >

your image url goes between the two. .

when you post it will show the photo

[porscheeater]

you need to upload your pics to a website, flickr, photobucket etc....I use facebook as it's easy to do from the phone, anyway, once you upload them, you need to right click on the photo, then go to "copy image URL" come to your post on here and above the text box you'll see a wee button that says Img. click it once you'll see this >Image Replaced With URL For Quote paste the url then click Img again and ... see this >

your image url goes between the two. Image Replaced With URL For Quote image url here.

when you post it will show the photo

thanks mate i will get them uploaded and start my build thread soon.....as soon as i fix this lazy turbo problem

ok well I had a look at the actuator and didnt want to play in it so i sat back and call the RAC (fooking waste of time that was) the engineer didnt know shiz and didnt have a equipment to attempt to service the issue.... something i imagine his wife complains about too.

so I am back the where i started.
I have found out that it should be running 0.8bar of boost i have 0.4
while driving i can here the turbo spooling and the engine runs smooth and pulls hard (not as hard as it should but it pulls) so it must be the actuator right?

[Ryan S]

Check it and see could be a couple of things, my old rev2 had a knackered cat, it wouldn't boost and felt really restricted.

[porscheeater]

Check it and see could be a couple of things, my old rev2 had a knackered cat, it wouldn't boost and felt really restricted.

well that will be removed very soon and i have something special planned in the way of my exhaust system

i need one of those fault finding gizmos

[danjama]

Could be wastegate stuck open...

Can you check the two hoses coming off of the actuator? Where do they go?