After installing my Spoon header and Carsound cat I have noticed that the inside of my Comptech exhaust is no longer gets black like it did. Is the new header causing me to run lean? I know the R runs a little rich in stock form, but is this something I shuld be worried about?

 

Just reset your ECU...

 

It's time for a V-AFC and some dyno time!

 

On the dyno I did notice that changing from a JDM 4-1 to a spoon header caused the need for more fuel. Not sure I can still find that A/F plot of the two, but the Spoon did lean it out a bit...


Jason

 

I know when i installed my carsound cat and JDM 4-1 my mileage went +30, when before it was right around 28. A header will make your car run more lean.

 

Is it lean enough to warrant attention or is it nothing to worry about?

 

Isn't better to run lean than to run rich...???

 

Its not lean enough to worry about, my spark plugs were the perfect gold/tan color with the header on. Lean makes power, but a little rich is safer. You basically gotta tune so your right on the perfect A/F ratio for your motor. Wideband O2 Sensor while at a dyno works wonders.

 

I'm wondering. Did you all reset the ECU after the header install?
The ECU should adapt to the increased air flow if it's reset....

 

So I guess the only way to determine if you're running a little too rich or too lean is to be on a dyno... even though you can tune the A/F mixture or ratio.... you can't detect anything with the naked senses.... right..???

 

I agree. My problem is I know of nobody around here that knows how to properly install the VAFC let alone tune my car with it...

 

a header shouldnt cause it to run so lean that the stock ecu can not compensate, BUT you NEED TO RESET IT or else it will take a long time to relearn.

IF that isnt adequate you can get a fuel pressure regulator & guage to turn up the fuel a lil bit. B&M works for me... cheap and it works AND the instructions are great. (even comes with a formula to calculate how many psi to raise it depending on modifications)

 

You need to reset your ECU.

As for the V-AFC, you should talk to Kenji about his wire harness - no splicing onto your ECU

Some of the ITR owners should be able to give you some baseline V-AFC settings (with Spoon header and stock airbox), and walk you thru how to tune using the V-AFC, but you need dyno time with a wideband O2 sensor for the best results.

 

If you can install the Spoon header, you can install a VAFC. Just remember to solder all the connections.