john banks

Little bit chilly today

I worry about the STi 7s out there with decats, some are boosting to 1.55 bar + with decats and detting. Look out guys.

EvilBevel

John, I'm actually amazed my boost control is rather "behaving" still. Weather has been colder here than in the UK (up to -15°C ), but max boost in 5th is 1.3 bar instead of 1.2 bar in summer. That's acceptable IMHO.

So the standard ECU is trying to do it's job

mega_stream

Took me 30 minutes to do 4 miles this morning

Bladdy Christmas shoppers and people taking the kids to school

ChristianR

iTrader: (1)

not today, but the other day, 1.81bar.

LG John

I've seen 1.29 bar in 5th when it's really really cold but I've not been too concerned. Didn't have my car today - petrol saving mode

wacky.banana

John,

On the train today so I did not have the opportunity to enjoy the cold air. I assume your concern is on cars with full decats as opposed to partial decats?

WB

john banks

There seem to be some suppliers selling full systems with the claim that they do not overboost. If they are freeing up the breathing in a useful way, IMHO, they will overboost, but I have not tested it on the STi.

Razor2001

Hey John,

What do you think is the max 'safe' spike we should see on a decatted STI-7 with restrictor. Is 1.3 ok ? how about 1.4 bar ?

If I get 1.3 bar spike and 1.2 bar held on my STi-7 with full turbo back decat and restrictor fix and delta dash shows all postive knock correction (above +5 at all boost levels) with all lean / rich mixture readings showing greater than 1.00 on delta dash 02 readout.....can I view that as my car is running 'safe' ?

Cheers,
Ray

Razor2001

Just to add temp can range from 20 - 35 degrees celcius during winter months but max spike 1.3 bar (no matter what type testing I do can't get more than 1.3 bar)

LG John

My car seldom 'spikes' I assume thats the dawes On a very cold day in 5th with load it'll slam round to somewhere just shy of 1.3 but usual settle and waggle a little between 1.25 and 1.29. Under normal conditions it'll get 1.25 in 5th. I think I'd crap myself if it spiked, even if very brief!!

paul w

Saxo matey,

What does the ol girl boost at during wot in 3rd going through the gears flat out.


Cheers Paul

LG John

Not sure - its defo shy of 1.25...probably about 1.2 or slightly less. I only get full boost in 4th and 5th.

Why do you ask?

john banks

I would be happy with 1.3 Razor.

paul w

Just curious,wanted to know the difference between full load and acceleration with the dawes as i made a mbc some while back and it spikes a bit with a full load.

Cheers

Rob D

John,

Don't forget my has has a sports cat in the d/p.

As John has said make sure to check for signs of detonation on your cars especially now it's cold.
My STI7 was detonating on full boost for the past week or so with the Milltek full exhaust, thank god for the Knocklink.
I now need a change of restrictor to stop the car overboosting, where as before the standard fitment was ok in the warmer weather.

Thanks John for your help.

Rob.


[Edited by Rob D - 12/21/2002 9:07:43 AM]

Kempo

Hey Guys

What is the sound like if the car is detting?

Cheers
Paul

Andy.F

TRRRRRRRRRRRRRRRRRRR
or
GRRRRRRRRRRRRRRRRRRRR
or
BRRRRRRRRRRRRRRRRRRRR
or
Nuts and bolts shaken in a can ??

john banks

A (usually) faint metallic tinkle like dropping drawing pins in a metal tin.

LG John

Is det noticeable??? If I get it, will I think 'oh **** what is that!!! Ah, that'll be det!!!!'

gareth

John,

My MY01 WRX with PPP was pretty settled with 1.2 bar and occasionally 1.3 bar - in fifth only I think. Since adding decat uppipe/downpipe boost is generally a little higher - say 1.25 bar - but still never above 1.3.

I haven't got a knock sensor, AFR meter etc, just a boost gauge. From your comments it would seem that if I can keep an eye on boost everything else should look after itself?

Despite assurances from the suppliers, I still worry about things going bang and the financial consequences

Thanks for any advice,
Gareth

john banks

Gareth yours sounds fine, it is the overboosting STi 7s that worry me.

gareth

Thanks John

Razor2001

Hi John,

If my 02 sensor reading on delta dash is always above 1.00 under any kind of accelleration (well about .95 from 2000 rpms to 3000 rpms 4th gear wot, then above 3000 rpms it will stay above 1.00 and sometimes hit 1.02 for the rear 02 sensor), wot, cruising, etc I guess this means I am running rich ?? I noticed that some people are running high .80 and .90 mixtures. Can I do any damage to my car with it running so rich ? Is there anyway to run a little more lean without getting a ecu remap (ie: turning up the boost slightly) or should I keep it running this lean as it is safer in a hot climate such as mine ?

Big thanks
Ray

ScoobyDuck

iTrader: (1)

managed to get 1.21 bar last night (about 17.7psi?) from my stnd uk MY97. drops all the way back down to 0.8 (about 11.7psi?) tho! & then when it gets to 4.5k-5k rpm it drops off even lower!

oh well .. re-map time... (chance'd be a fine thing!)

Steve

[Edited by ScoobyDuck - 12/18/2002 1:22:48 PM]

Razor2001

Hi John,

When you get a sec please see my post above

Oh yea, any others can comment as well

Cheers,
Ray

john banks

Ray that sounds about right from STi 7 logs I have seen. .8 to .9 was probably for 99/00 cars.

Raising the boost will not make it leaner. Best leave it as it is.

Razor2001

Cheers John

stanmo

iTrader: (1)

So without a remap, what would be a good temporary solution ?

A banana/potato up the tailpipe to add some restriction ?

john banks

Restrictor valve as per the very long STi 7 overboost thread.

Dave T-S

Rob D
I thought the MillTek was supposed to not have any boost spike issues? If yours is detting, I would be very concerned about holing a piston I trust you are always running on SUL.

Ray
Both our UK spec STi7's peaked to 1.35 or sometimes 1.4 bar when standard (the PPP peaks no higher).