Boost query

[ndlibgt]

Hey Guys
After recently getting my ecu reflash, my ecu datascan shows a peak boost figure of 18.4psi. This only happens intermittently (mainly when I tramp it). Tuner says he's tuned it to run 15psi so I guess what I'm asking is if this is normal or if I should go back and see my tuner.
Cheers

[dr20t]

Im guessing yours is auto?

If so then it will occasionally boost spike in between gear changes when you're on it, due to changes in vacuum in the manifold.

its fine as its only for a split second whilst your wastegate readjusts to manifold pressure

[ndlibgt]

Yep auto it is. Thx for your input, btw love your "LIGHTLY" modded gt lol, (reckon that title suits mine moreso than yours) looking on with great interest.
Cheers

[coyote]

Simple answer is that no-one knows. A 15psi boost target should be a 15psi boost target. Make a proper log and post it up.

[dr20t]

Yeah thanks mate. Let's see how it goes. And really it is still a lightly modded Lib in comparison to some out there.

I agree with coyote as well (I had originally written the same thing but didnt know if you had access to a cable and open port)

I'm only speaking from reading various posts on romraider about boost spikes.

Check your wastegate and boost control solenoid too

Mick

[ndlibgt]

Simple answer is that no-one knows. A 15psi boost target should be a 15psi boost target. Make a proper log and post it up.

Ok thx Coyote will do this

Yeah thanks mate. Let's see how it goes. And really it is still a lightly modded Lib in comparison to some out there.

I agree with coyote as well (I had originally written the same thing but didnt know if you had access to a cable and open port)

I'm only speaking from reading various posts on romraider about boost spikes.

Check your wastegate and boost control solenoid too

Mick

I'm hoping the boost solenoid isn't an issue as it's a new Grimspeed 3 port.

[lunchboxsti]

mines a auto and it does it as well. but not on gear change just when i stick my foot down on take off once it comes onto boost for half a second. i was told it was because i changed my rear mufflers to the hitech ones with no tune. wether ther right or not its been like that for 50k and no damage.

[ephesiangts]

Mine does the same.



As per image this is mine after new Turbo, new STi 2.0L Engine and tune.

I have Hitech mufflers and it still does it after tune. Tuner said you can't get the spike out of the Autos. Its the vacuum changes issue mentioned previously.
Mine is tuned at 19PSI

[kiahatsiu]

This thread got me thinking. My car feels like it falls over up top sometimes, and other times feels like it is pulling like a train. I had come to the conclusion that there must have been something wrong with the AVCS timing, but the more I think about it, it may well be a boost control issue. For 135 bucks plus postage and a bit of dyno time I am going to give a grimmspeed 3 port jobbie a try. I don't really care about numbers, all I want is a car that comes on a reasonable point and then pulls to the redline....something to keep me amused whilst I amass parts for a rather silly 2.5 with 6 speed.

Oh, and to the tuning type people, is there an Australian place I can buy a tactrix [sp] cable from.

[kiahatsiu]

So, round at Rusty's today, he notices my boost controller has a line disconnected. So, he connects it. Low and behold, my car now idles, no more random hunting and stalling, and strike me down, it feels like it is holding some boost now. The thing had an intermittent idle problem, where it would all but stall and recover to about 1500 rpm, and continue to do so until the car moved off. I looked everywhere for vac leaks, but couldn't find one. It had been doing that since I picked it up from the dyno.

Back to the strainers me thinks.

[B4ITZUP]

you can get the tactrix cable from
tuspeed ($350)
http://www.tuspeed.com/tactrix-openport-p-1706.html

or car mod australia
on special ($315)
http://www.carmodsaustralia.com.au/tactrix-openport-20-tac01

i think it's cheaper to get it directly

[04GTLIB]

So, round at Rusty's today, he notices my boost controller has a line disconnected. So, he connects it. Low and behold, my car now idles, no more random hunting and stalling, and strike me down, it feels like it is holding some boost now. The thing had an intermittent idle problem, where it would all but stall and recover to about 1500 rpm, and continue to do so until the car moved off. I looked everywhere for vac leaks, but couldn't find one. It had been doing that since I picked it up from the dyno.

Back to the strainers me thinks.

Ian.
Was good to meet you today and the wagon sounds great mate.
I'm also glad we picked up on the disconnected vacuum line.
How did it drive on the way home?
Cheers,
Rusty.

[kiahatsiu]

Much better now. I am doing my best not get stand on it, as i haven't a clue what the tune is like.

[ndlibgt]

Simple answer is that no-one knows. A 15psi boost target should be a 15psi boost target. Make a proper log and post it up.

Ok guys what parameters will i need to log eg boost, knock correction advance. What will i need to log bearing in mind the ecu datascan will only log 8 parameters at any given time (Correct me if i'm wrong)

I've included a list of parameters it supports. You will notice some double ups but these are because your given a choice of PSI or Bar for Boost, Celcius or Farenheit for Coolant temp etc.

* Engine Load (Relative)
* Coolant Temperature
* Coolant Temperature
* A/F Correction #1
* A/F Learning #1
* A/F Correction #2
* A/F Learning #2
* Manifold Absolute Pressure
* Manifold Absolute Pressure
* Engine Speed
* Vehicle Speed
* Vehicle Speed
* Ignition Total Timing
* Intake Air Temperature
* Intake Air Temperature
* Mass Airflow
* Throttle Opening Angle
* Front O2 Sensor #1
* Front O2 Sensor #2
* Battery Voltage
* Mass Airflow Sensor Voltage
* Fuel Injector #1 Pulse Width
* Fuel Injector #2 Pulse Width
* Knock Correction Advance
* Boost
* Boost
* Boost
* Accelerator Pedal Angle
* CPC Valve Duty Ratio
* Alternator Duty
* Fuel Pump Duty
* Intake VVT Advance Angle Right
* Intake VVT Advance Angle Left
* Intake OCV Duty Right
* Intake OCV Duty Left
* Intake OCV Current Right
* Intake OCV Current Left
* A/F Sensor #1 Current
* A/F Sensor #2 Current
* A/F Sensor #1 Resistance
* A/F Sensor #2 Resistance
* A/F Sensor #1
* A/F Sensor #1
* A/F Sensor #2
* A/F Sensor #2
* Roughness Monitor Cylinder #1
* Roughness Monitor Cylinder #2
* A/F Correction #3
* A/F Learning #3
* Roughness Monitor Cylinder #3
* Roughness Monitor Cylinder #4
* Throttle Motor Duty
* Throttle Motor Voltage
* Sub Throttle Sensor
* Main Throttle Sensor
* Sub Accelerator Sensor
* Main Accelerator Sensor
* Memorised Cruise Speed
* Memorised Cruise Speed
* Injector Duty Cycle
* Injector Duty Cycle #2

Thanks for all/any help on this and BTW excuse my noobness
Cheers
Nelson

[lunchboxsti]

what is this ecu datascan you speck of and how do i get one.