The questions in the title.
Did ask the garage but can't remember the answer.

Also my mildly modded MY00 (full ss x-zorst , ITG panel filter run on superplus and octane booster since new) is hitting 1.1bar under full acceleration in 3rd , 4th and 5th and dropping back to .9 - 1bar . Is this the norm or slightly low/high.

cheers,

scottdg

 

1.0 bar = 14.5psi

 

thx wrexy. Take it i'm running a little too much boost then - if you can do such a think.

 

The standard boost for a 99MY is around 0.88 bar or 13 psi. (I assume the 00MY is the same) Increasing the boost beyond this figure should require checks on ignition timing and fueling to prevent det.and/or lean running.
JohnD

[Edited by JohnD - 1/16/2002 11:18:30 PM]

 

On MY99/00 (ONLY - other years are different!) your dealer can fix this boost spike (if you want or need to) by increasing the orifice in the restrictor that sits inside a hose between the turbo outlet nipple and the T-piece which diverts to boost solenoid at the right wing and the wastegate actuator.

You may find in cold weather that the ECU will start oscillating the boost - you may hit 1.1 then drop to 0.8 then settle on 0.9-1.0 after a few swings.

From what I have observed this starts to occur with peaks over 1.1 bar or thereabouts.

Welcome to the world of overboost with breathing mods

If it doesn't give you a problem I would leave it alone assuming all is safe as outlined above.

Held boost is controlled in an (inadequate when you have significant mods) closed loop system, and should not be affected by reducing your peak unless you overdo it. Orifice up from 1.2 to 1.3 mm should do the trick.

If you want to up your boost you need either a manual or electronic boost controller or an ECU incorporating the latter. You cannot safely increase held boost on a MY99/00 with just a bleed valve or orifice change - I have tried them all!

Dawes man boost controller (£26), Apexi AVC-R (£600) or Link ECU (£1000+ with mapping and all the monitoring toys) would be my recommendations.

On a late UK car I think they would all give about the same power (as much as a little TD04L can anyway) with increasing levels of finesse, except the first two you are limited to 17PSI unless you twaddle with your MAP sensor which is dubious ground unless the sensor is properly remapped at the top end and safety is properly checked. You may get a bit more out of a Link with extra ignition advance, but the other two may give you quicker spool up from the way they control boost.

[Edited by john banks - 1/17/2002 9:12:10 AM]

 

I have an MY00 that peaks at 1 bar, and settles constant at just over 0.9. I have also seen this on another MY00, so it appears to be pretty normal ?? I've done 24000 trouble free miles so far.

 

Sounds spot on Blue.

 

Runs great at the moment John, but I'm looking into ECU upgrades. The general feeling seems to be 1.2 bar maxon a UK car as long as its mapped correctly - would you care to comment

 

If you are electronically minded (I'm talking microcontrollers, bit of BASIC coding and some assembly/soldering skills as well as a willingness to guddle around at your ECU) look out for my forthcoming DIY electronic boost controller for £11 thread.

If not I suggest a "proper" electronic boost controller if that is all you will do, or a proper ECU if you will change other bits later.

 

Hmmmmm...upping boost without fueling & timing alterations will raise a few eyebrows on here won't it

 

So what do you think the ECU does? - it measure mass of air in and adjusts fuelling to suit. At higher boost it retards the ignition a bit using its knock sensor and its mapping up to fuel cut.

I am running my car within 1 PSI of fuel cut with 9% CO at the top end and good but conservative ignition advance courtesy of the ECU. What else is there to it ?

 

John
You obviously have a much better understanding of this stuff than me - I trust all will become clear in your £11 post Can't wait

 

Just got the Scooby solenoid operating nicely at 15.3 Hz with a duty cycle set in software. Weird visions of man blowing through one end of solenoid and feeling air pulses on hand - except at 15.3Hz it is pretty much a smooth jet Small things. Must stop posting so I can crack on with it whilst it is sunny and light!

 

Very interesting thread - my MY00 peaks at 1.1bar and then settles around 0.9 or 0.8 bar just as John described - with a fully de-catted system and ITG panel filter

John - I am in need of your expert advice at the RR Day on Sunday re: boost/Link etc - are you still planning on putting in an appearance?

Chris

 

Don't know about expert, but I like a good fiddle about with the electronics and boost control. I will be running either with a MY00 PPP decat ITG with Dawes or with my DIY EBC if it is working satisfactorily - overall results will be virtually identical - boost is boost, and whatever system I am running my wastegate will be closed at peak power.

You can see what my car is like for figures and come for a ride if you want. Of course folk like Sam Elassar will be able to advise you on the Link etc, but he came out in my car (pre-EBC) and thought is seemed as quick as a Link car give or take.

 

John - you've got me totally confused. Are you saying you've modded a ppp ecu yourself! (surely there's more to it than blowing on it )

 

Blowing on it is one small stage

I have a PPP, which is quite good for what it is. But it is further transformed with a downpipe and a few extra pounds of boost here and there.

It is a little easier to work with as fuel cut is a few PSI higher

 

Now you've totally lost me!!

Interesting thread though, good to know my car is not far off the mark. Sadly, I can't start fiddling with the ECU on mine as I have a maintanence contract which rules this out. Bummer!!

Thanks all.

Scottdg

 

Scottdg
Don't tell me some guy in a contract fleet garage is going to know you've been into the ECU !! He probably stillcalls it an Im-pret-zza

 

What , you mean you don't call them that!!!!!

Blue, are you saying a Subaru dealership mechanic couldn't pick up on an increase in boost above standard settings or if the ECU had been fiddled with?

If so tell me more.