A/F Ratio Problem,some help Needed.
Thread Starter
Joined: Jan 2002
Posts: 1,065
Likes: 10
From: Skopje
A/F Ratio Problem,some help Needed.
Hi guys,I have Driven my since January this year with stock Comptech SC but I have a Free Flowing exhaust,4-1, Test pipe,Supersprints and Ported and polished Head,Ported and polished Intake manifold and 68mm Port matched BDL TB.
SO I ask Help For A/F Ratios.
I have a Zeitronix WB Dataloger on the car and I can see that the Car is in the LEAN Best torque before Vtec 13-13.3 and it jumps up in VTEC at 14.5-14.8 from 6-8000Rpm and from 8 to 9K it richens up and hits 12.9 just on the redline.
Now every Technical Paper I Read is that way too lean and that 12.5 is best for NA and that For boosted applications it should be bellow that just above 11.
Now on what I have tried to do to correct this.
I tried turning the Comptech FPR to correct this but it has done nothing in VTEC and it has been hitting 15 and way too rich On Lower RPM before VTEC sometimes 9.5-10.5 Which is not good.And still too lean from 6-8 and you can feel the car making more power from 8-9 when it richens out.
I turned the FPR back to the original position that I cam from Comptech and its back to old AF.
OK.I been wanting to Drive the car NA for some time and I decided to do it ...I took off the Belt,take out the Aftercooler,put the OEM Gap spark plugs(NGK 7173 for SC),Turned off the Aftercooler pump and connected a Hose from the TB to the Comptech ICEBOX .Since the FPR works only in Boost the Fuel should be ok for NA.
And Surprise-surprise The car is still lean in VTEC from 6-8000 Rpm.Even hitting 15.5 A/F
So what's the problem here?
I have an AEM EMS sitting at home and I haven't put it in since there is no tuner here in my country for it(probably the Only EMS here) I bought it to use it when I get a 10psi Pulley and larger Injectors but haven't found a S2ki member that can donate a MAP for it so I have a base map When I UP the BOOST and than correct it on my car.
I am planning to fine correct the tune myself when I get the necessary Knowledge.Tune it on a Local Dyno of course.
The nearest tuner I think is in Neighbor Greece in Athens which is around 500miles away and I don't have a VISA to go there...:
)
I have been thinking on putting the AEM and running the Stock NA s2000 MAP from AEM site and see what happens than...But not found the Balls to do it.
So
Any Smart Advice is appreciated on what to try and do.
Thanks guys,see my Sig for additional info...
PS.
When you Get used to the SC you think that the car was faster when you first put the SC and that now the car isn't as fast as it used to be,but take off the SC belt and you will know what you have had before....
Dyno tested the car and it makes 211WHP NA and 270WHP with every mod I have listed.Only 60whp gain.
SO I ask Help For A/F Ratios.
I have a Zeitronix WB Dataloger on the car and I can see that the Car is in the LEAN Best torque before Vtec 13-13.3 and it jumps up in VTEC at 14.5-14.8 from 6-8000Rpm and from 8 to 9K it richens up and hits 12.9 just on the redline.
Now every Technical Paper I Read is that way too lean and that 12.5 is best for NA and that For boosted applications it should be bellow that just above 11.
Now on what I have tried to do to correct this.
I tried turning the Comptech FPR to correct this but it has done nothing in VTEC and it has been hitting 15 and way too rich On Lower RPM before VTEC sometimes 9.5-10.5 Which is not good.And still too lean from 6-8 and you can feel the car making more power from 8-9 when it richens out.
I turned the FPR back to the original position that I cam from Comptech and its back to old AF.
OK.I been wanting to Drive the car NA for some time and I decided to do it ...I took off the Belt,take out the Aftercooler,put the OEM Gap spark plugs(NGK 7173 for SC),Turned off the Aftercooler pump and connected a Hose from the TB to the Comptech ICEBOX .Since the FPR works only in Boost the Fuel should be ok for NA.
And Surprise-surprise The car is still lean in VTEC from 6-8000 Rpm.Even hitting 15.5 A/F
So what's the problem here?
I have an AEM EMS sitting at home and I haven't put it in since there is no tuner here in my country for it(probably the Only EMS here) I bought it to use it when I get a 10psi Pulley and larger Injectors but haven't found a S2ki member that can donate a MAP for it so I have a base map When I UP the BOOST and than correct it on my car.
I am planning to fine correct the tune myself when I get the necessary Knowledge.Tune it on a Local Dyno of course.
The nearest tuner I think is in Neighbor Greece in Athens which is around 500miles away and I don't have a VISA to go there...:
)I have been thinking on putting the AEM and running the Stock NA s2000 MAP from AEM site and see what happens than...But not found the Balls to do it.
So
Any Smart Advice is appreciated on what to try and do.
Thanks guys,see my Sig for additional info...
PS.
When you Get used to the SC you think that the car was faster when you first put the SC and that now the car isn't as fast as it used to be,but take off the SC belt and you will know what you have had before....
Dyno tested the car and it makes 211WHP NA and 270WHP with every mod I have listed.Only 60whp gain.
Registered User
Joined: Sep 2003
Posts: 362
Likes: 0
From: Calgary
Most people asking about 7psi pulleys are running OEM cats and exhausts. The more restricted flow from the stock exhaust system allows the car to run 7psi within safe AFRs.
If youre running an SC, testpipe, aftermarket exhaust and no form of fuel management, you will most likely run lean regardless of how much psi you're running. If you dont have a tuner available and you're uncomfortable with using AEM EMS, i'd say go with emanage. That way you can ramp up the fuel pressure via FPR and then take out the fuel where needed with the emanage.
Also, keep in mind... a lot of people running simple NA boltons dont check their AFRs either. I imagine a lot of them are running lean and simply dont know it.
If youre running an SC, testpipe, aftermarket exhaust and no form of fuel management, you will most likely run lean regardless of how much psi you're running. If you dont have a tuner available and you're uncomfortable with using AEM EMS, i'd say go with emanage. That way you can ramp up the fuel pressure via FPR and then take out the fuel where needed with the emanage.
Also, keep in mind... a lot of people running simple NA boltons dont check their AFRs either. I imagine a lot of them are running lean and simply dont know it.
Thread Starter
Joined: Jan 2002
Posts: 1,065
Likes: 10
From: Skopje
I had been thinking of putting the cat back on and see what happens...(this is called De-Tuning:))
Also can somebody elaborate on how the FPR works?
I had the impression that it was acting as stock FPR on vacuum and That the Membrane inside was increasing the Fuel pressure on Boost as the boost rises and that what the Know on the FPR is for.To change the Rate of rising pressure under boost.All that changed was the amount of fuel in between 2-5900Rpm WOT to richer and nothing happens in VTEC....
On the other hand I can Try and use a VAFC2 From a friend of mine.
He offered it to me to try it since he isn't using it ...And I don't know if I should..
stefce
))Also can somebody elaborate on how the FPR works?
I had the impression that it was acting as stock FPR on vacuum and That the Membrane inside was increasing the Fuel pressure on Boost as the boost rises and that what the Know on the FPR is for.To change the Rate of rising pressure under boost.All that changed was the amount of fuel in between 2-5900Rpm WOT to richer and nothing happens in VTEC....
On the other hand I can Try and use a VAFC2 From a friend of mine.
He offered it to me to try it since he isn't using it ...And I don't know if I should..
stefce
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