UK MY99 ECU's - was there a recall?
20 August 2010, 02:03 PM
#1
UK MY99 ECU's - was there a recall?
just carrying over from a post on scoobyireland where a member stated
just wondering does anyone have any info on this?
in 99 , most 99 uk subaru's came with a ecu that caused pistons to melt , subaru did a recall and changed the ecu for a new one ,, not all cars got the upgrade ( as owners could not be traced ect ) . they ran with with a little less boost . not sure of the new ecu part number .. have it wrote down somewhere but cant find it ..
20 August 2010, 02:25 PM
#2
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
Totally untrue.
To expand a little, the ECU that most MY99 UK Impreza Turbos came with is the AE801. It does not cause engine failures/piston damage and was not recalled. The revision used on the early MY99's (the AE800) similarly does not have a rep for causing damage. There are a few changes in the firmware between the two but the actual mapping is, to all intents and purposes, exactly the same.
To expand a little, the ECU that most MY99 UK Impreza Turbos came with is the AE801. It does not cause engine failures/piston damage and was not recalled. The revision used on the early MY99's (the AE800) similarly does not have a rep for causing damage. There are a few changes in the firmware between the two but the actual mapping is, to all intents and purposes, exactly the same.
Last edited by Splitpin; 20 August 2010 at 02:28 PM.
20 August 2010, 03:42 PM
#4
Scooby Regular
Join Date: Apr 2005
Posts: 558
Likes: 0
Received 0 Likes
on
0 Posts
There was a detailed write up on Ecutek what the difference's between the AE800,AE801 and the AE802 for the my00 but can't find it know.But what i can remmember the AE802 ran richer than the other ecu's.
20 August 2010, 03:55 PM
#5
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
F'ing bogtrotters. Can't believe a word they say
801 uses a different firmware base to 800 (inc quite a few bugfixes), but the mapping is, as above, pretty much identical.
802 (the late '99/MY00 one with a rep for being less powerful) uses same basecode as 801, but with different mapping. Runs richer above 4000rpm with less ignition advance, and has a throttle-indexed boost map (801/800 will permit whatever the turbo can produce at lower throttle openings, 802 will only allow full boost above 70% throttle). Other less significant changes too.
The biggest reason for the changes in ecu'a afaik was the emission regs.
802 (the late '99/MY00 one with a rep for being less powerful) uses same basecode as 801, but with different mapping. Runs richer above 4000rpm with less ignition advance, and has a throttle-indexed boost map (801/800 will permit whatever the turbo can produce at lower throttle openings, 802 will only allow full boost above 70% throttle). Other less significant changes too.
Trending Topics
20 August 2010, 09:21 PM
#9
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
Basically yes, but it's a bit simplistic to simply give a number. All have the same peak boost target of 0.94 bar. There's a 0.02 bar error margin either way so the ECU will consider anything from 0.92 to 0.96 "on target".
However the boost is on a 3D map. As such it's only 0.94 up to 5400rpm on 800/801 and then starts to taper down. As I said earlier 802 has a progressive target which rises the further you press your foot, only giving full boost above 70% throttle opening.
Nominally, yes, but that's not really worth much to you as it isn't as though the 800 and 801 maps are on the limit in any respect on a properly maintained engine.
802 offers the most headroom for playing around at the margins with things like external boost controllers, or poorer quality fuel, but in practice, in standard form, it is also noticeably less powerful on a standard car. Both because of the mixture and timing changes, and also because the altered boost mapping makes the other two feel subjectively quicker on part throttle, even though, in practice, what Subaru did is increase the effectiveness of the pedal in controlling output.
However the boost is on a 3D map. As such it's only 0.94 up to 5400rpm on 800/801 and then starts to taper down. As I said earlier 802 has a progressive target which rises the further you press your foot, only giving full boost above 70% throttle opening.
802 running a little rich would make it the safest ecu outa the bunch then?
802 offers the most headroom for playing around at the margins with things like external boost controllers, or poorer quality fuel, but in practice, in standard form, it is also noticeably less powerful on a standard car. Both because of the mixture and timing changes, and also because the altered boost mapping makes the other two feel subjectively quicker on part throttle, even though, in practice, what Subaru did is increase the effectiveness of the pedal in controlling output.
21 August 2010, 03:37 PM
#15
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
Yes, that's what its peak target is. However, you would, under normal conditions, expect the actual attainable boost to vary a bit. First of all you will get more when the ambient air is cold than you will when it's hot, as UK ECUs don't have any boost air temp compensation.
Secondly, you will get more in the higher gears than you do in the lower ones, because again the OE ECUs have no gear-based boost compensation.
Try flooring it up a slight hill from about 3000rpm in fifth and see what it settles at.
Secondly, you will get more in the higher gears than you do in the lower ones, because again the OE ECUs have no gear-based boost compensation.
Try flooring it up a slight hill from about 3000rpm in fifth and see what it settles at.
21 August 2010, 06:02 PM
#17
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, STi5/6 does it. And shouldn't is the operative word. The standard duty temp compensation is a bit imprecise - it doesn't actually reduce the duty cycle unless intake air temp is below freezing, for example, so you can still get a bit of overshoot if you're driving around in single figure air temps.
It can lower the boost target at high air temperatures too - although because the sensor's in front of the air filter, it can't respond to changes in intercooler efficiency, which would be much more useful.
If you know how you can make it work much more effectively, although whether Ecutek know how, I have no idea.
It can lower the boost target at high air temperatures too - although because the sensor's in front of the air filter, it can't respond to changes in intercooler efficiency, which would be much more useful.
If you know how you can make it work much more effectively, although whether Ecutek know how, I have no idea.
Last edited by Splitpin; 21 August 2010 at 06:04 PM.
21 August 2010, 07:14 PM
#19
Scooby Regular
Join Date: Jan 2006
Posts: 3,695
Likes: 0
Received 0 Likes
on
0 Posts
Not sure that's quite justified in this particular case. It would be fairer to describe it in the same way you would most of the other maps - i.e. they were clearly designed to do as good a job as possible under as wide a range of conditions, but can be optimised to a significant degree.
Although as a general point there's a stack of potential in the hardware and firmware that hasn't been "made the most of", by some, anyway.
Although as a general point there's a stack of potential in the hardware and firmware that hasn't been "made the most of", by some, anyway.
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
