Minimal Boost Pattern

[Jit]

Took a look under the rats nest today top try and sort out the boost prblem i was having (low boost from both turbos - probably no boost lol!).

I found a few vaccum lines had come undone...i redid them up. Anyhow, i took the car for a spin and its sems to be better but its like th boost has been electronically turned down....

I dont have a commander or dataloggit so i cannot see what the levels are...however, what id like to know is, what is the minimum boost possible (in bar) to set the pfc to....

Cheers

[John Yorke]

stock boost is .8bar if that helps

[Jit]

i realise that! But thanks for replying and taking the time! Basically, what i want to know is what is the minimum boost possible to run the car on....

[John Yorke]

i realise that! But thanks for replying and taking the time! Basically, what i want to know is what is the minimum boost possible to run the car on....

zero!!! not quite sure what you are looking for. To do ANY fault finding you need a boost gauge. How do you intend setting up the PFC if you do not have a commander / datalogic?

[Jit]

Basically, i have a digital boost gauage...i took the car to a speciailist who turned the boost down for me at my request because i wasnt sure if the engine had a problem. At the same time, he put the car back on the base map...it turns out i had a faulty knock sensor and ive since put the engine back to standard (apart from the street port it has on it which i cant reverse lol!)

Basically, the car is on a base map as it stands and the boost might have been turned down....I cant remember if it was or wasnt....and I dont have access to a commander or dataloggit to check.

Since i hadnt boosted the car while i was fearing it was knocking, i couldnt tell the boost pattern. Then installed the new knock sensor and checked all the vacuum actuation and found a few bits undone. I have done everything back up...

Basically on the road now, I cannot tell if I have a boost leak somewhere becuase I do not know what it has been set to!!

My boost gauge shows 0.3-0.4 bar peak boost which is roughly 5-6psi? My guess is this is too low, but i cannot be sure...

[John Yorke]

you should see 10 -8 - 10 psi patern on you boost gauge on a base map if you are seeing 5-6 psi your boost is way to low.

[GeckoGareth]

Mine had a boost pattern of 5-3-4.

Have had it looked at and no problems found. It\'s a weird one. If you do find out what\'s going on let us know please.

G

[Jit]

Im gonna take everything apart on the weekend i reckon and have a look...I might pull of the UIM and have another look at the vaccuum lines again...otherwise il have to get it on a dataloggit and see exactly whats going on!

John - I think its on a base map, but i cannot remember if he put it on a base map and then lowered the boost further! I think i might need to get someone in to help me!

[nikp]

Have had it looked at and no problems found

Who looked at it? One of the specialists like WGT, RX motors, RE:Worx etc should be able to diagnose it easily.

[GeckoGareth]

One of the guys on here who know\'s more than a bit about them. Builds his own engines etc...

Certainly had him puzzled. He said it does pull ok but it\'s still not making what you would consider to be full boost. Next step was to try the poor mans route of going non-sequential just to see what boost readings I was getting like that.

Might see if I can get him to try that soon and possibly swap the pre-cat for a standard or wide down pipe in case that is the issue.

Unfortunatly money is a serious issue right now so I can\'t really afford to be taking it to one of the big guys, plus I trust this guy

Cheers

G

[BlitzBoy]

approx 0.4/0.5 is 7 pounds of boost, this indicates that you guys are running off the wastegate actuator. The standard boost solenoid on your cars are either not working or have been disconnected in some way to the actuator!!!! The standard boost solenoid intercepts the vacuum/boost signal to the actuator therefore making the actuator close longer which in turn the wastegate is shut longer therefore increasing boost.

[nikp]

The wastegate and pre-control solenoids are right next to each other, and are exactly the same type - the electrical plugs can sometimes get muddled up on them.

[Jit]

could it just be as simple as a split boost pipe causing this? I was just examining them now and noticed that the lower boost pipe coming from the turbo outlet to the IC has split really badly....

Could this be the source of my woes?!

[GeckoGareth]

approx 0.4/0.5 is 7 pounds of boost, this indicates that you guys are running off the wastegate actuator. The standard boost solenoid on your cars are either not working or have been disconnected in some way to the actuator!!!! The standard boost solenoid intercepts the vacuum/boost signal to the actuator therefore making the actuator close longer which in turn the wastegate is shut longer therefore increasing boost.

W-O-O-S-H!!!

that was that going straight over my head  :Hammer

I\'m sure the guy who looked would understand though. I will run that past him. If I could have got it through the MOT in time for RSIII then would have been good to have brought it along and seen if the collective experience of the whole of MRC could figure it out!

Cheers

G