Advice re: mapping classic STI
20 June 2009, 07:42 PM
#1
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Advice re: mapping classic STI
I have just bought a 1997 STI Jap import. The car is pretty much standard engine wise - all it has is an induction kit. I'm wanting to get it remapped to get the best out of the car but have had so much conflicting advice. Can anyone recommend the best way to map it, or point me in the direction of info already on the site? All advice appreciated.
Thanks, Lisa
Thanks, Lisa
20 June 2009, 07:57 PM
#3
I have just bought a 1997 STI Jap import. The car is pretty much standard engine wise - all it has is an induction kit. I'm wanting to get it remapped to get the best out of the car but have had so much conflicting advice. Can anyone recommend the best way to map it, or point me in the direction of info already on the site? All advice appreciated.
Thanks, Lisa
Thanks, Lisa
20 June 2009, 07:57 PM
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Thanks for the advice but I've been told that you can use a piggy back ecu. I don't have the money for a new ECU (I wish I did) so I need a cheaper option. I just don't know what the best option would be. Perhaps I should have mentioned that I've only about £600 - 700 to spend.
20 June 2009, 08:07 PM
#5
Thanks for the advice but I've been told that you can use a piggy back ecu. I don't have the money for a new ECU (I wish I did) so I need a cheaper option. I just don't know what the best option would be. Perhaps I should have mentioned that I've only about £600 - 700 to spend.
. patience is a virtue
20 June 2009, 08:13 PM
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20 June 2009, 08:13 PM
#7
you dont need a ecu yet not unless you are going to do a few more things. i have a v3 sti and run standard ecu with a few mods and can see off the new age stis and so called 300 bhp newage cars running flashed ecus. what mods you going to do?
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20 June 2009, 08:45 PM
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Thanks but I do think it's necessary to remap once you start doing mods for safety as well as to get the best out of the car.
20 June 2009, 08:49 PM
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Hi Lisa 
for sale section is a good bet, may take some time finding a mappable ecu though, and just ensure you run your car on the highest octane fuel available, they dont like normal unleaded, it disagrees with the engine 
Tony
for sale section is a good bet, may take some time finding a mappable ecu though, and just ensure you run your car on the highest octane fuel available, they dont like normal unleaded, it disagrees with the engine Tony
21 June 2009, 06:09 PM
#11
stick it on the rollers first this will tell you if she is fueling ok. i cant see adding a exhaust or a bit more boost will break the car subaru put in conservative maps and have overfueld it any way. the mods you metion do not need a remap for sure. how much boost you running? the decat down pipe on ours does make it boost a lot more hence stupid power claims from fitting them like 30bhp more. its the overboost and higher boost pressure that does it not the downpipe. the sti is much more clever then then wrx cars from the start. most of the cars running power fc run about the same power as stock ecus.whats the point? on my 3sgte totyotas i had mines ecu,hks ecu,stock and power fc so i have experamented a little bit with ecu,s. a good maper can get a lot out of an ecu but i just dont think its worth it unless you are talking major changes. waffle over with. cheers max
21 June 2009, 06:41 PM
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STI's dont like having decat downpipes fitted, they boost a little high plus they can det which kills the engine
If your going for a full decat then your best option is an after market ecu to control the fuelling and boost
Tony
plus they can det which kills the engine If your going for a full decat then your best option is an after market ecu to control the fuelling and boost
Tony
22 June 2009, 09:34 AM
#13
not strictly true. i fitted new headers,up pipe,down pipe,full system all 3" boost was way of the scale 1.6 bar nocking and engine check light etc. its all to do with the brass rescricter pill. once its the correct size pill boost is fine and controls well. i have also tried the bung and pill combo this seems a waste putting a 3" system in then to reduce it. i am going to book my car in at the rollers soon to confirm all this. cheers max
22 June 2009, 11:22 AM
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not strictly true. i fitted new headers,up pipe,down pipe,full system all 3" boost was way of the scale 1.6 bar nocking and engine check light etc. its all to do with the brass rescricter pill. once its the correct size pill boost is fine and controls well. i have also tried the bung and pill combo this seems a waste putting a 3" system in then to reduce it. i am going to book my car in at the rollers soon to confirm all this. cheers max
You still have to control the air intake, the fuelling (which will be up the shoot) as well as the boost (as seemingly controlled by that brass pill) but run your car how you want, when it goes bang then figure out that 650 quid is cheaper than 2.5-3k
Tony
Last edited by TonyBurns; 22 June 2009 at 12:02 PM.
22 June 2009, 03:49 PM
#15
i lifted these off the net for a scooby he has rolling road proof as well. which is always handy. as far as i can see from all the turbo cars i have had over the years well over 20 types. i have allways back garden moded them my self and proved the cars on the strip,track and road. you dont need half the stuff people say you need and can and cant do. untill you try yourself what can and cant be done then you can never say. reading it off the net or hear say dont mean a thing. i am allways happy to listen but how will my engine go bang running the bits i have done to it at 1.1 bar? the turbo can only flow the same amount of air at 1.1 bar it cant force any more in the cylinders,the point it makes full boost will be nearly the same. if you change the blower then yes a remap or diffrent ecu is needed, but running simalar boost pressure and just freeing the flow making the engine breath easy will be fine.
sorry about my spelling regards max
Fuel Mixture: Fuel is metered by the ECU from information derived from the mass air flow (MAF) sensor in the air intake and lambda control from the exhaust oxygen sensor. This results in the ECU quite happily providing sufficient fuel (in fact very rich - as per usual) at higher boost levels (up to 18 psi) - suggesting that there is probably no need to consider uprating the fuel pump or injectors (verified on the dyno runs).
Ignition Timing: As boost pressure rises, the ECU retards the timing - in fact by 15 degrees between -10 and +15 psi of boost. Originally I had assumed that boost pressure (i.e. output from the MAP sensor) was used by the ECU as a major input to the ignition map. On further investigation, it appears to have a minimal effect. I would guess that the MAF sensor plays a more significant part (along with RPM etc).
--------------------------------------------------------------------------------
MAP Sensor: As well as closed loop boost control, the MAP sensor signal is also used by the ECU to cut the engine if it detects overboost. This is an important safety feature - something sadly lacking from low cost boost kits. The trick here is to still provide overboost cutout, but at a higher boost pressure. Also the standard MAP sensor is not very linear above about 15 psi.
sorry about my spelling regards max
Fuel Mixture: Fuel is metered by the ECU from information derived from the mass air flow (MAF) sensor in the air intake and lambda control from the exhaust oxygen sensor. This results in the ECU quite happily providing sufficient fuel (in fact very rich - as per usual) at higher boost levels (up to 18 psi) - suggesting that there is probably no need to consider uprating the fuel pump or injectors (verified on the dyno runs).
Ignition Timing: As boost pressure rises, the ECU retards the timing - in fact by 15 degrees between -10 and +15 psi of boost. Originally I had assumed that boost pressure (i.e. output from the MAP sensor) was used by the ECU as a major input to the ignition map. On further investigation, it appears to have a minimal effect. I would guess that the MAF sensor plays a more significant part (along with RPM etc).
--------------------------------------------------------------------------------
MAP Sensor: As well as closed loop boost control, the MAP sensor signal is also used by the ECU to cut the engine if it detects overboost. This is an important safety feature - something sadly lacking from low cost boost kits. The trick here is to still provide overboost cutout, but at a higher boost pressure. Also the standard MAP sensor is not very linear above about 15 psi.
22 June 2009, 04:14 PM
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So really you could have spent £70 quid on an MBC and achieved exactly the same thing for 600 quid less 
As your new to subaru's and dont quite understand that they can be a little "tempremental" to some tuning (especially STI's) and you never mentioned 1.1bar before (uk turbo or older wrx), which most subaru's will quite happily run at, try 1.3 and see the det (been there, seen it, done it etc etc), running a full decat on an STI (new age cars really dont like this) and some of the later versions (5/6 especially) are also not immune to having difficulties due to the slight "lean spot" on the map, you still have a bit to learn (well we all do)
The older classic ECU's are NOT that good, no where near as good as say the MY03 cars which adapt to knock far better than the older cars, classics can take so much, their knock correction is minimal compared to newer versions, it doesnt take much to push them over the edge, hence we are advising THE saftest route to Lisa as we dont want her left with a big bill for the engine.
Ta
Tony
As your new to subaru's and dont quite understand that they can be a little "tempremental" to some tuning (especially STI's) and you never mentioned 1.1bar before (uk turbo or older wrx), which most subaru's will quite happily run at, try 1.3 and see the det (been there, seen it, done it etc etc), running a full decat on an STI (new age cars really dont like this) and some of the later versions (5/6 especially) are also not immune to having difficulties due to the slight "lean spot" on the map, you still have a bit to learn (well we all do
)The older classic ECU's are NOT that good, no where near as good as say the MY03 cars which adapt to knock far better than the older cars, classics can take so much, their knock correction is minimal compared to newer versions, it doesnt take much to push them over the edge, hence we are advising THE saftest route to Lisa as we dont want her left with a big bill for the engine.
Ta
Tony
22 June 2009, 05:06 PM
#17
i only wanted the exhaust for the deep burble, and thought i might as well replace it all while i was on the case. i will be uping the boost to 1.25 soon. the v3 cars run 1.2 bar standard i belive? so i am actually running less boost then standard.
i hear what you are saying tony, but why is it going to knock with tesco 99 or optimax @1.3 bar. and lisa did not say she will be winding the boost up just fitting a decat which in turn will raise the boost, or like loads of other posts said boost creep. what i am saying is this is not true it can be controlled with the brass pill.
the lean spot on the map you mention on which version sti is that please and what rpm out of intreast?
can any one also confirm the standard boost settings for wrx and sti jdm cars with the version or years please?
good to chat thanks a lot max
i hear what you are saying tony, but why is it going to knock with tesco 99 or optimax @1.3 bar. and lisa did not say she will be winding the boost up just fitting a decat which in turn will raise the boost, or like loads of other posts said boost creep. what i am saying is this is not true it can be controlled with the brass pill.
the lean spot on the map you mention on which version sti is that please and what rpm out of intreast?
can any one also confirm the standard boost settings for wrx and sti jdm cars with the version or years please?
good to chat thanks a lot max
22 June 2009, 05:58 PM
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To be honest - having so restricted funds I would leave the idea of remap for now and spend these money maybe on a bit better brakes- which are not the best in older Subarus, or simply would spend these money on fuel and maybe some rally school. And I'm not joking...
Even with standard map it's seriously fast road car and I would say good driver is the key... especially if you want to get as much as possible from the car...
Even with standard map it's seriously fast road car and I would say good driver is the key... especially if you want to get as much as possible from the car...
22 June 2009, 11:09 PM
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Thanks guys. Definitely a lot to think about there. But still not decided on what to do.
@Ami, I've had a scoob before - a 95 wrx. She was running about 280bhp and I really wanna get this one to the 300 mark. I'm not a bad driver already, but I did put my WRX on her roof in a field so maybe those rally lessons would be a good idea.
@Ami, I've had a scoob before - a 95 wrx. She was running about 280bhp and I really wanna get this one to the 300 mark. I'm not a bad driver already, but I did put my WRX on her roof in a field so maybe those rally lessons would be a good idea.
24 June 2009, 12:06 PM
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Version 5/6 cars, and classics have like naff all knock correction above about 5k rpm, interesting eh!
Now remember your little brass restrictor, still doesnt control the airflow going out of the engine (which you enhanced by changing the headers and exhaust btw) which will (and probably has) changed the fuelling/air mixture (better flow, lower down response, possably slightly leaner up top, even with a restriction on the boost!) you cant control those gasses from the engine with a better flowing exhaust and expect the car to not be pushing its limits in other area's of the ecu!
Just to demonstrate
First car, PPP MY00 turbo, did a few mods to this car (gauges, brakes, PPP, decat pipe, knocklink etc) now the decat pipe knocked the boost up by .2 bar, that was controllable by the restrictor plug because the map was still reasonably good and I had not changed the 2.5 inch exhaust system, just the cat, so it was flowing better, BUT it would have benefitted from a remap to make use of the change.
Next scoob, MY03 JDM STI Spec C, Jap map, considerably better knock correction than previous models (including higher up the rev range) and greatly enhanced ECU's, even running it on V power AND octane booster (over 100 ron fuel which the car is mapped for) it still detected knock (standard exhaust, different backbox, 3.5 inch H&S, similar to the standard item), so there are many more issues to contend with, hence remapping and being able to control the levels of knock correction better.
Have a chat with some of the mappers on here (Bob Rawle, Alan Jefferies, JGM, Andrew Carr, Andy Forrest etc) as they will go into minute detail with you but its not as easy as it seems.
Tony
Now remember your little brass restrictor, still doesnt control the airflow going out of the engine (which you enhanced by changing the headers and exhaust btw
) which will (and probably has) changed the fuelling/air mixture (better flow, lower down response, possably slightly leaner up top, even with a restriction on the boost!) you cant control those gasses from the engine with a better flowing exhaust and expect the car to not be pushing its limits in other area's of the ecu!Just to demonstrate
First car, PPP MY00 turbo, did a few mods to this car (gauges, brakes, PPP, decat pipe, knocklink etc) now the decat pipe knocked the boost up by .2 bar, that was controllable by the restrictor plug because the map was still reasonably good and I had not changed the 2.5 inch exhaust system, just the cat, so it was flowing better, BUT it would have benefitted from a remap to make use of the change.
Next scoob, MY03 JDM STI Spec C, Jap map, considerably better knock correction than previous models (including higher up the rev range) and greatly enhanced ECU's, even running it on V power AND octane booster (over 100 ron fuel which the car is mapped for) it still detected knock (standard exhaust, different backbox, 3.5 inch H&S, similar to the standard item), so there are many more issues to contend with, hence remapping and being able to control the levels of knock correction better.
Have a chat with some of the mappers on here (Bob Rawle, Alan Jefferies, JGM, Andrew Carr, Andy Forrest etc) as they will go into minute detail with you
but its not as easy as it seems.Tony
25 June 2009, 12:43 AM
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Thanks guys for all your views. The car is now playing up. Typical lol. It's boosting fine but is hesitating once it gets to 0.9-1bar. I've put up another thread about it. Anyone have any ideas of what could be causing this?
25 June 2009, 05:12 PM
#26
u the same lisa that was racing an Astra SRI with Scooby Killer on the back of it when u clipped the grass on the right hand side of the road and flipped over cutting a p&t post then landing on your roof by any chance.
