Comparing 1st run a year ago with CAI only vs JDM Header with Carsound Cat vs JDM Header and Test Pipe.
All this runs have the AEM gears but they were not tuned until Runs 10 through 14. Runs 15 through 19 were fuel adjustments runs.





Now comparing
Note: I made a mistake when inserting the comments for RUN 8, Run 8 has the JDM Header and Test Pipe
Run 8- JDM Header, Test Pipe, AEM gears(not tuned)
Run 13 - JDM Header, Test Pipe, AEM gears(tuned see image notes)
Run 19 - JDM Header, Test Pipe, AEM gears(tuned see image notes) fuel adjusments as well.





The biggest problem is the high AF ratio, about 17.5, we tried to adjust as much as we could but no matter how high the adjustment the change was minimal, could not get anything less than the 16.5 in Run 13. Anyone have any ideas why we could not change the AF.
Do I need a bigger fuel pump, injectors? As far as I know it shouldn't unless I upgraded the cams.

I should mention I have the VAFC.


Enjoy





[Modified by Renegade, 7:20 PM 3/10/2003]

 

If you were using the AFC to change the AF, thats the reason you couldnt do anything.
The AFC can lean out the mixture, it cannot richen it.

 

What can I do to richen?
Advance / Retard the timing?

thanks

 

Fuel pressure regulator is the easiest way.

 

increase fuel pressure, get larger injectors or reprogram the ecu

 

Did you advance timing too much ?

 

I'll have to get one.
Any idea what the pressure should be at by looking at the graphs?

Does the second O2 sensor affect what the ECU sees and would adjust to? should I get the O2 eliminator since I have the test pipe?
I'm going to buy the Cat next week but it is good to know how to make adjustments.

 

I have a question for sgT and the rest of the H-T tuning masters regarding this... Once you get a straight A/F line with a FPR/VAFC... do you ever need to do it again? Or does every mod you add essentially change your air fuel ratio?

 

I have not touched the timing. It is at whatever the dealer set it last time they looked at it.

 

what do you mean need it again. the settings will only hold if the afc is in place.
remove it and you are back to where you started

 

the 2nd o2 doesnt do anything performance related.

 

Strange.... using my VAFC I was able to fix my a/f issue.

 

Like say for example I dyno tune with my exhaust, vafc, and buy a FPR. If I bought a header and cat could I just bolt those on, or would that force me to re-tune my A/F ratio?

 

Some cars are close to 0 vacuum at WOT and some are not as close.
Those that arent as close wil be able to make changes(as yours did)
since you have some room before you reach the end of the fuel map.

 

its up to you if you want to retune. but i would.

btw, i personally dont tune for a/f ratio. i tune for power. a/f ratio is a marker to
let you know where you are, not something you shoot for while tuning.

 

When I get all the stuff I want to have for my car I'm going to have to drive out to DC for tuning

 

I am somewhat confused, If you were tunning my car you would tune to get the most power and forget about the A/F?
I was told that 17 is dangerously high.
After adjusting the for power we tried to adjust the A/F to make sure I don't blow my motor.

What is your process for tunning?

 

i would make it richer and see what effect it has.

 

which way?
leave the timing alone and get a fuel regulator and or bigger injectors
or the other way around?

I guess the easiest would be to adjust the timing first.

 

leave the timing, get more fuel

 

thanks, I'll try that this week.

 

Look like running a test pipe really make the engine run a lot leaner.

 

nice grammar, and no it doesnt.

What sgt is saying i would agree with. Add more fuel. FPR is the easiest, but it wont help if its an injector issue. If the injectors are at 80% duty cycle, they will not deliver more fuel. It is real easy to remove fuel using a VAFC, if you were to add RC 310 CC injectors, they would be balanced and flow identically, and not run at 80-100% duty cycle, giving you additional headroom for additional mods, IE Cams, headwork, in the future.

 

I am referring to this graph here:

 

:shrugg:

checked on the way home this evening...
+- 0.00 mm/hg

next check
+ 0.01 mm/hg

I guess that is somewhat close to 0 pressure at WOT.