Will the car run lean
10 June 2004, 11:27 PM
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Will the car run lean
Looking to put a full H&S decat also an STI panel filter on my MY99 2000 Turbo, car totaly standard at the moment,.
By fitting a STI panel filter will this affect the air fuel ratio and cause the engine to run lean.
Does the reduction in back pressure cause turbo lag or should it spool up quicker
Any other helpfull advice would be greatly appreciated
By fitting a STI panel filter will this affect the air fuel ratio and cause the engine to run lean.
Does the reduction in back pressure cause turbo lag or should it spool up quicker
Any other helpfull advice would be greatly appreciated
11 June 2004, 12:24 AM
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The filter won't make a significant difference, BUT the full De-Cat WILL!! 
That alone may be enough to make the car run lean. You may think it will be safe, but is it really worth the risk!??
That alone may be enough to make the car run lean. You may think it will be safe, but is it really worth the risk!??
11 June 2004, 08:27 AM
#4
Originally Posted by PICKLE
The filter won't make a significant difference, BUT the full De-Cat WILL!! That alone may be enough to make the car run lean. You may think it will be safe, but is it really worth the risk!??
That alone may be enough to make the car run lean. You may think it will be safe, but is it really worth the risk!??I would guess that 90% of the people on here with a full decat are still running on a standard ECU Map.
For a start the MY92-96 is pretty much limited to ScoobyECU/SubaChip mapping
Hardly anyone maps the MY97-98
And 99> is all ECUTEK and I doubt the % mapped using ECUTEK matches the % running full decats.
11 June 2004, 09:14 AM
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As Scott says there is only a limited risk with that set up of running lean as it used the MAF sensor to know how much fuel to inject.. so the extra air sucked in and the speeder spool with the decat will again suck more air past the MAF sensor..
You would benefit from a remap and could get a lot more out of the car with a decent map in there though.
As pointed out to me in the past by Scott and having then witnessed it on my own car the worst thing seems to be an induction kit as it seems to screw the load the ECU sees (although I have no idea why?) and it then runs more timing than it should, hence why fitting an induction kit appears to give a huge power increase.. when infact it is just running a different section of the ecu's timing map when it is not safe to do so.
imho of course.
Simon
You would benefit from a remap and could get a lot more out of the car with a decent map in there though.
As pointed out to me in the past by Scott and having then witnessed it on my own car the worst thing seems to be an induction kit as it seems to screw the load the ECU sees (although I have no idea why?) and it then runs more timing than it should, hence why fitting an induction kit appears to give a huge power increase.. when infact it is just running a different section of the ecu's timing map when it is not safe to do so.
imho of course.
Simon
11 June 2004, 09:38 AM
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I ran my MY99 for 50k miles with a full decat and panel filter, without a re-map. First it was a 2.5" full Scoobysport then a 3" BPM. Didn't have any problems what so ever. And the current owner had it rolling roaded this year at 255bhp, 248ft/lb with 70k on the clock.
BUT I would advise caution, mostly beacuse I don't want you to damage your car. So considering the cost, I'd plan to get a re-map with the decat to keep your mind at rest.
Dave.
BUT I would advise caution, mostly beacuse I don't want you to damage your car. So considering the cost, I'd plan to get a re-map with the decat to keep your mind at rest.
Dave.
11 June 2004, 05:02 PM
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Panel filter & exhaust is fine - add huge boost & you might be getting to the edge of the map, though, which is when things could tricky (on top of running a turbo past the edge of its efficiency envelope - ie outputting more heat than air...)
Induction kits can screw up the airflow past the MAF, which means it misreads (air takes a different path to the intended one/ on for which is was calibrated for) & so underfuels. Key thing that's noticeable about this is that spool-up becomes 'hesitant' - time to switch back to a panel filter before things get too hot!
Induction kits can screw up the airflow past the MAF, which means it misreads (air takes a different path to the intended one/ on for which is was calibrated for) & so underfuels. Key thing that's noticeable about this is that spool-up becomes 'hesitant' - time to switch back to a panel filter before things get too hot!
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11 June 2004, 05:25 PM
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Sorry, didn't read the post properly! 
I thought the car was an STI in which case the car would be more sensitive to the changes, that said, if you speak to the 'experts' on here, they would advise you ran Optimax etc as the de-cat will lean the car out from standard.
I thought the car was an STI in which case the car would be more sensitive to the changes, that said, if you speak to the 'experts' on here, they would advise you ran Optimax etc as the de-cat will lean the car out from standard.
11 June 2004, 11:31 PM
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Cheers for the advice guys, anymore is much appreciated.
just got to make up my mind H&S or the new Scoobysport fulll decat
I know it has nothing to do with this thread but any recomendations
just got to make up my mind H&S or the new Scoobysport fulll decat
I know it has nothing to do with this thread but any recomendations
12 June 2004, 06:12 AM
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Just had a full H&S Decat now - DeCat D/P, Non resonated centre and 3.5" tail BackBox.
It sound awesome - it is quite loud but on full chat sounds unbelievable.....well recommended
This is running on a MY00 Classic
It sound awesome - it is quite loud but on full chat sounds unbelievable.....well recommended
This is running on a MY00 Classic
12 June 2004, 10:29 AM
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get a knock link. £150 for piece of mind. nine times out of ten just get the green light on, but get more activity every now and then with certain temp / humidity so i know to take it steady
turbo should come in about 500 rpm sooner
stevie
turbo should come in about 500 rpm sooner
stevie
12 June 2004, 11:42 PM
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Originally Posted by jmc1968
Looking to put a full H&S decat also an STI panel filter on my MY99 2000 Turbo, car totaly standard at the moment,.
By fitting a STI panel filter will this affect the air fuel ratio and cause the engine to run lean.
Does the reduction in back pressure cause turbo lag or should it spool up quicker
Any other helpfull advice would be greatly appreciated
By fitting a STI panel filter will this affect the air fuel ratio and cause the engine to run lean.
Does the reduction in back pressure cause turbo lag or should it spool up quicker
Any other helpfull advice would be greatly appreciated
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