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Discussion Starter · #1 ·
 
Take the car for a test drive and with the engine at normal operating temperature, select third gear (manual or automatic) and accelerate at full throttle from below 1500 RPM (avoid the kickdown on models with automatic transmission). As the engine speed approaches 3000 RPM, press the brake while holding the accelerator, to achieve full load at 3000 RPM (pressing the brake pedal also causes Trionic to drop the boost pressure to base boost on non-LPT models). Note the pressure on the gauge.[/b]
I have taken this from BillJ's website to adjust the basic boost pressure on my 96 9000 LPT with Speedparts ECU. I'm having a little bit of trouble in finding the boost reading.I have an aftermarket boost gauge fitted to take readings

I have taken onboard the above text and spoken advice from another source.
The way I read the above is that when pressing the brake pedal, the boost needle will drop to display base boost.
On the otherhand, I was told that when pressing the brake, boost will read maximum boost pressure.

Which should it be? I am somewhat slightly confused
 

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My two pennies worth...

With the LPT, you are running ONLY base boost, no matter what.

With the FPT, you disconnect the electrical connector to the solenoid valve, this will cause the turbo to boost only at base boost.

The best idea is to find a long, straight, steep hill. This will keep the engine under load much longer than on the straight and level. You also have to floor the accelerator pedal; make sure that no mats, etc get under it either!

The reason brakes are mentioned is that if you're on the straight and level, you will go through the rpm range too quickly. You brake not to slow the car, but to keep the boost needle at it's peak for as long as possible. (Left foot braking; your right foot should still be firmly planted on the floor...)

The boost reading is only a guideline from which you start. It is not the holy grail.

This is what I do; ATTEMPT THIS ONLY AT YOUR OWN RISK, especially if you have modifications to your engine. Mine is still stock.

1. I pull the electrical plug to the solenoid, and do a few runs in the car in third gear (manual) so the gauge shows at least half yellow.

2. I put the plug back, and do a few runs (with the pedal floored through the rpm range) for the engine to adapt.

3. I wait for the engine to cool down, then up the boost by half a turn. Then I do my runs again.

4. When I do a run and finally hit fuel cutoff, I let the engine cool down, lower the boost by half a turn, and I'm there!

I don't have to do this often as the weather does not fluctuate as much here as it would in colder countries. Don't forget that boost is also temperature sensitive!
 

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Discussion Starter · #4 ·
Originally posted by chris-edinburgh:
[qb]definatly base boost when the brake is applied,

try holding it at 3000 rpm, with accelerator to floor, then just use the brake to keep it at the same speed, this works for me [/qb][/b]
Just as I though Chris. I'll give it a few more tries as last night it read 0.7bar-ish. Tiredness didn't help either!
 

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Hah. I was just giving some Subaru guys advice about base boost. NONE of their tuners even mentions it when upgrading exhaust parts. So it's a common occurance not to get the boost/power you want without a "custom tune". I think it's just a ploy to get you to pay even MORE money for the tune personally.

After re-adjusting the basic boost pressure on a tuned WRX the max-boost went from 12 up to 16!
It also significantly reduced some high end boost flutter. Apparently they are very sensitive to base boost; which again makes me wonder why it's never talked about on the Scooby boards.


Dubbya~
 
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