Running on the Det limit
05 June 2002, 04:58 AM
#1
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
I'm now convinced that the JDM STI ECU's run on the limit of det all the time. Yesterday after spending some time in flowing traffic, I gave it some stick. 2 pumps of IC water spray prior, with about 30sec stationary.
I got some audible det in 2nd gear with 2 Green LED's on the KL (I don't know why all didn't light up). I've suspected this for sometime, but after yesterday I'm sure.
Anyone have the same gut feel?
MY01 JDM STI RA, 23000km, 98RON fuel, 1X B8T Broquet in tank, 33degC ambient temp.
As a fix, I can only think of an open loop ECU - one that allows you to set the map, and not wait for det before retarding timing as the OEM one does.
I got some audible det in 2nd gear with 2 Green LED's on the KL (I don't know why all didn't light up). I've suspected this for sometime, but after yesterday I'm sure.
Anyone have the same gut feel?
MY01 JDM STI RA, 23000km, 98RON fuel, 1X B8T Broquet in tank, 33degC ambient temp.
As a fix, I can only think of an open loop ECU - one that allows you to set the map, and not wait for det before retarding timing as the OEM one does.
05 June 2002, 09:02 AM
#2
Scooby Regular
RT
General thinking over here seems to agree with you that the MY01 WRX/STi ECU does run much more closely to the det limit to achieve performance/emissions targets.
One of the worst tests you can give it of course is the idle scenario with WOT afterwards - heat soak builds up under the bonnet and intake temperatures soar - made worse if ambient temperature is high, which I guess is probably the case over there.
In reality, the water spray probably makes little difference - you would have to pour a bucket of iced water over the i/c to get intake temps down appreciably after idle.
General thinking over here seems to agree with you that the MY01 WRX/STi ECU does run much more closely to the det limit to achieve performance/emissions targets.
One of the worst tests you can give it of course is the idle scenario with WOT afterwards - heat soak builds up under the bonnet and intake temperatures soar - made worse if ambient temperature is high, which I guess is probably the case over there.
In reality, the water spray probably makes little difference - you would have to pour a bucket of iced water over the i/c to get intake temps down appreciably after idle.
05 June 2002, 10:28 AM
#3
Scooby Regular
Join Date: Feb 2001
Location: Greece, previously Syd Australia
Posts: 2,833
Likes: 0
Received 0 Likes
on
0 Posts
Where is your bosch sensor mounted? It should be mounted the same as in the picture in this link from I club that was posted by Jan Shim, for optimum results. Also is the sensitivity adjusted to the full setting?
http://i-club.com/forums/showthread....threadid=72454
Cheers,
Wrexy.
http://i-club.com/forums/showthread....threadid=72454
Cheers,
Wrexy.
05 June 2002, 11:49 AM
#4
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Tks for the advice guys. My KL sensor is mounted on the manifold with the sensitivity set to max. I shall get it moved to the block the next time the IC comes out.
The idle followed by 1st gear WOT was done accidentally by me once, when I had just got the car. Hot day, wasn't thinking straight, and even forgot to pump the IC with water. VERY VERY audible det, even my wife heard it (good teaching case!).
Even today, drizzly with temps prob in the high 20degC's. Gave her WOT in 2nd again - got 2 sudden Greens, but nothing audible.
I intend to fit a small "radiator fan" under the intercooler. Have seen it done on another car. This, combined with the water spray, should improve things. However, my ultimate goal is to have open loop engine management, MOTEC or Autronic. Running the STI ECU in our conditions for the long term is asking for a re-build.
The idle followed by 1st gear WOT was done accidentally by me once, when I had just got the car. Hot day, wasn't thinking straight, and even forgot to pump the IC with water. VERY VERY audible det, even my wife heard it (good teaching case!).
Even today, drizzly with temps prob in the high 20degC's. Gave her WOT in 2nd again - got 2 sudden Greens, but nothing audible.
I intend to fit a small "radiator fan" under the intercooler. Have seen it done on another car. This, combined with the water spray, should improve things. However, my ultimate goal is to have open loop engine management, MOTEC or Autronic. Running the STI ECU in our conditions for the long term is asking for a re-build.
05 June 2002, 12:00 PM
#6
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
I think you need a remappable ECU, FMIC and water injection unless you just turn down the boost which seems a shame. Some of the posher ECUs will take intake temperature as an input to the timing map - sounds like you might want to reduce the boost as well depending on intake temperatures if you cannot control it with FMIC +- WI.
If you are getting audible det then fitting fans and spraying onto the intercooler is going to do very little.
Fighting uphill in such hot temps sadly.
[Edited by john banks - 6/5/2002 12:08:05 PM]
If you are getting audible det then fitting fans and spraying onto the intercooler is going to do very little.
Fighting uphill in such hot temps sadly.
[Edited by john banks - 6/5/2002 12:08:05 PM]
05 June 2002, 12:42 PM
#7
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
John, agreed! I will need a programmable ECU.
The Autronic does take charge air temp as a parameter. You can set the amount of timing retard as a function of temperature on a graph. A temp sensor is mounted in the Intercooler just before the Silicone joint to the manifold.
Had this setup in my GC - worked like a charm.
The Autronic does take charge air temp as a parameter. You can set the amount of timing retard as a function of temperature on a graph. A temp sensor is mounted in the Intercooler just before the Silicone joint to the manifold.
Had this setup in my GC - worked like a charm.
Trending Topics
05 June 2002, 01:09 PM
#8
Scooby Regular
Join Date: Feb 2002
Posts: 1,343
Likes: 0
Received 0 Likes
on
0 Posts
I guess I may need to look into the same thing RT. Temps here are usually between 30 - 34 degress C with about 90 - 100% humidity during the day and I have a JDM STi-7. I would have thought that they would have taken this into account when they made the car though ??? Doesn't it get hot in the day over in Japan ?
Can you keep me / others informed on your solution and ecu map or whatever it is you decide to do ?
Cheers,
Ray
Can you keep me / others informed on your solution and ecu map or whatever it is you decide to do ?
Cheers,
Ray
05 June 2002, 06:08 PM
#10
Scooby Regular
Join Date: Apr 2002
Posts: 1,404
Likes: 0
Received 0 Likes
on
0 Posts
Erm, what does det sound like and at what stage of wot do you hear it ? I spend all day sat in motorway jams and then move away shaprish when its clear and dont recall ever hearing anything untoward.
MY01-WRX full decat, SS zaust sytem, PPP.
MY01-WRX full decat, SS zaust sytem, PPP.
06 June 2002, 04:54 AM
#12
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Det can be pretty subtle. Very mild det sounds almost like your normal wastegate flutter.
Bad det sounds like someone violently crumpling a large IKEA plastic bag under the hood!
Bad det sounds like someone violently crumpling a large IKEA plastic bag under the hood!
06 June 2002, 08:17 AM
#13
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Quote:
"I think you need a remappable ECU, FMIC and water injection unless you just turn down the boost which seems a shame. "
John,
I don't really think its a question of simply turning down the boost. Det is determined by boost, fuel RON, ignition timing and fueling amongst others. What I think is happening, is that for the stock boost, the timing runs pretty advanced until the point of det. Once it detects the onset of det, it stops advancing and starts retarding. Of course, this is too late as there already has been some mild det.
I know others who are running 1.5bar on their EBC's. While this might not be entirely healthy for the long run, they have survived rebuilds long enough to make me feel that the car does indeed retard timing enough for 1.5bar. No one else I know has a KL fitted, so its hard to compare.
Guess my point is this: If its a simple problem of "too much boost", the chaps with 1.5bar should have blown up long long ago. I think the real problem lies with not having a good boost-timing match.
"I think you need a remappable ECU, FMIC and water injection unless you just turn down the boost which seems a shame. "
John,
I don't really think its a question of simply turning down the boost. Det is determined by boost, fuel RON, ignition timing and fueling amongst others. What I think is happening, is that for the stock boost, the timing runs pretty advanced until the point of det. Once it detects the onset of det, it stops advancing and starts retarding. Of course, this is too late as there already has been some mild det.
I know others who are running 1.5bar on their EBC's. While this might not be entirely healthy for the long run, they have survived rebuilds long enough to make me feel that the car does indeed retard timing enough for 1.5bar. No one else I know has a KL fitted, so its hard to compare.
Guess my point is this: If its a simple problem of "too much boost", the chaps with 1.5bar should have blown up long long ago. I think the real problem lies with not having a good boost-timing match.
06 June 2002, 08:49 AM
#14
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
I have run 1.4 bar in favourable conditions, and just turning down to 1.3 bar can completely remove a run of -6 degree knock correction in warm conditions. Reducing the boost leads to lower intake temperatures AND reduces exhaust back pressure and is the most favourable thing I can find to reduce det - certainly simple. Since it is running plenty rich enough it makes little sense to add more. It makes sense that in hot conditions you don't just retard the ignition - this can make the cycle of destruction worse as the EGTs rise further. Try it before you "knock" it 
If you are hearing detonation then something drastic is called for - little tweaks to the ignition MAY not do the job - the ECU has already taken several degrees off and failed to control the det, and from what I see at least of the JECS it is VERY quick to retard well before the onset of actual knock and the knocklinks in those that have compared tend to stay quiet throughout. The Denso ECUs are supposed to be even better. So it sounds like there are some multivariable serious adverse det inducing conditions in your engine. If you ran no boost it would not det. Small reductions in boost when you are on the edge have a big effect from what I have seen.
If you are hearing detonation then something drastic is called for - little tweaks to the ignition MAY not do the job - the ECU has already taken several degrees off and failed to control the det, and from what I see at least of the JECS it is VERY quick to retard well before the onset of actual knock and the knocklinks in those that have compared tend to stay quiet throughout. The Denso ECUs are supposed to be even better. So it sounds like there are some multivariable serious adverse det inducing conditions in your engine. If you ran no boost it would not det. Small reductions in boost when you are on the edge have a big effect from what I have seen.
07 June 2002, 12:42 AM
#16
Scooby Regular
Join Date: Nov 2001
Posts: 836
Likes: 0
Received 0 Likes
on
0 Posts
JECS is the std ECU fitted to your Scoob 
Forget exactly what it stands for Japanese Electronic Control Systems or similar.
Perhaps your knock sensor is faulty ? As John stated, the ECU normally retards the ignition before audible knock. Hence the two different traces on the Deltadash - Knock correction and Knock.
Andy
Forget exactly what it stands for Japanese Electronic Control Systems or similar.Perhaps your knock sensor is faulty ? As John stated, the ECU normally retards the ignition before audible knock. Hence the two different traces on the Deltadash - Knock correction and Knock.
Andy
07 June 2002, 01:01 AM
#17
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Is this the ECUTEK DeltaDash?
If so, would you recommend it over a fully programmable item like the Autronic? I read the brief on their website. You can reduce ignition advance with it.
If so, would you recommend it over a fully programmable item like the Autronic? I read the brief on their website. You can reduce ignition advance with it.
07 June 2002, 01:02 AM
#18
Scooby Regular
Join Date: Feb 2001
Location: Greece, previously Syd Australia
Posts: 2,833
Likes: 0
Received 0 Likes
on
0 Posts
Andy,
is the Knock signal 1, in the digital data section of Delta Dash the one that shows that the car has been detting? Always wondered what that was for, but I think I've just realised what it is.
Cheers,
Wrexy
is the Knock signal 1, in the digital data section of Delta Dash the one that shows that the car has been detting? Always wondered what that was for, but I think I've just realised what it is.
Cheers,
Wrexy
07 June 2002, 01:29 AM
#19
Scooby Regular
Join Date: Feb 2001
Location: Greece, previously Syd Australia
Posts: 2,833
Likes: 0
Received 0 Likes
on
0 Posts
RT,
Yes it is. The Delta dash can only be used with a stock ECU. You can reduce ignition advance a little and you can adjust idle and aircon idle a little. But you can't map a car with it. It is only for monitoring the ECU, Engine and the sensors. There is other software for re mapping the stock ECU called Delta ECU.
As for recommending Delta ECU over Autronic, the ECUs are only as good, as how good the tuner has mapped the ECU.
However with Delta ECU you can keep the stock driving smoothness, the stock idle characeristics like cold and hot starts and aircon, and all the stock qualities of the ECU that Subaru spent a lot of money on and only map the bits that are required like adding or subtracting more fuel, boost and timing at certain loads and revs.
Cheers,
Wrexy.
Yes it is. The Delta dash can only be used with a stock ECU. You can reduce ignition advance a little and you can adjust idle and aircon idle a little. But you can't map a car with it. It is only for monitoring the ECU, Engine and the sensors. There is other software for re mapping the stock ECU called Delta ECU.
As for recommending Delta ECU over Autronic, the ECUs are only as good, as how good the tuner has mapped the ECU.
However with Delta ECU you can keep the stock driving smoothness, the stock idle characeristics like cold and hot starts and aircon, and all the stock qualities of the ECU that Subaru spent a lot of money on and only map the bits that are required like adding or subtracting more fuel, boost and timing at certain loads and revs.
Cheers,
Wrexy.
07 June 2002, 02:19 AM
#20
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Quote:
"As for recommending Delta ECU over Autronic, the ECUs are only as good, as how good the tuner has mapped the ECU.
However with Delta ECU you can keep the stock driving smoothness, the stock idle characeristics like cold and hot starts and aircon, and all the stock qualities of the ECU that Subaru spent a lot of money on and only map the bits that are required like adding or subtracting more fuel, boost and timing at certain loads and revs."
Agreed 100%! Actually, I had an Autronic on my GC, which is why I'm a little more familiar with it than other products. I agree that an ECU is only as good as its tuner, and I think my tuner's pretty decent...
For the 2nd para, this is why I'm reluctant to throw away subaru's work. Getting the idle qualities right is a black art, my old car took tons of fiddling before it would idle well with and without aircon. Transition between open throttle and idle also could've been better. BUT! All the abovementioned smoothness would be of nil benefit if the OEM ECU is tuned to det the engine given local conditions, eh?
"As for recommending Delta ECU over Autronic, the ECUs are only as good, as how good the tuner has mapped the ECU.
However with Delta ECU you can keep the stock driving smoothness, the stock idle characeristics like cold and hot starts and aircon, and all the stock qualities of the ECU that Subaru spent a lot of money on and only map the bits that are required like adding or subtracting more fuel, boost and timing at certain loads and revs."
Agreed 100%! Actually, I had an Autronic on my GC, which is why I'm a little more familiar with it than other products. I agree that an ECU is only as good as its tuner, and I think my tuner's pretty decent...
For the 2nd para, this is why I'm reluctant to throw away subaru's work. Getting the idle qualities right is a black art, my old car took tons of fiddling before it would idle well with and without aircon. Transition between open throttle and idle also could've been better. BUT! All the abovementioned smoothness would be of nil benefit if the OEM ECU is tuned to det the engine given local conditions, eh?
07 June 2002, 10:10 AM
#23
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
RT, an easy way to reduce your boost is to replace the retrictor off the turbo outlet with a flow control valve or a 0.1mm bigger restrictor. A little goes a long way. It is a temporary solution, but arguably the easiest one you can do if you can hear your car detting now and want to still drive it.
07 June 2002, 02:55 PM
#24
Scooby Regular
Thread Starter
Join Date: May 2001
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
John, my restrictor is already up'ped to 0.9mm from 0.75mm standard.
I've given it a few more WOT runs yesterday and today, with 1 and the occasional 2 greens, but no more audible det (none that I heard anyway). I'm having the KL sensor moved to the block tomorrow, and will see how it goes. Maybe its just a case of a bad tankful.
Several other local STI7's are running EBC's to 1.5bar, and their engines are still in 1 piece. I find it hard to believe that I'm det'ting at 1bar. Hrmph!
I've given it a few more WOT runs yesterday and today, with 1 and the occasional 2 greens, but no more audible det (none that I heard anyway). I'm having the KL sensor moved to the block tomorrow, and will see how it goes. Maybe its just a case of a bad tankful.
Several other local STI7's are running EBC's to 1.5bar, and their engines are still in 1 piece. I find it hard to believe that I'm det'ting at 1bar. Hrmph!
07 June 2002, 10:18 PM
#26
Scooby Regular
Join Date: Feb 2001
Location: Greece, previously Syd Australia
Posts: 2,833
Likes: 0
Received 0 Likes
on
0 Posts
Deep,
Read this m8! It's on it's way!
http://www.mrtrally.com.au/forums/to...p?TOPIC_ID=215
Cheers,
Wrexy.
Read this m8! It's on it's way!
http://www.mrtrally.com.au/forums/to...p?TOPIC_ID=215
Cheers,
Wrexy.
08 June 2002, 08:50 AM
#27
Scooby Regular
DS
Probably no longer away than the PPP LOL
The MY01 WRX and STi7 ECU's are basically the same family, sort one and you are probably 90% there with the other.
Probably no longer away than the PPP LOL
The MY01 WRX and STi7 ECU's are basically the same family, sort one and you are probably 90% there with the other.
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
supshon
General Technical
2
03 October 2015 08:06 PM