I own a evo IX MR and have installed the following mods:

upgraded Mitsu 20g, six blade
3" TBE, Espilir
Invidia O2 housing
Ported exh manifold
Injen Intake with UICP
Speed Source upgraded LICP
Walbro fuel pump
SUNCO Hyper Force ignition upgrade
Greddi Profec Spec II ebc
Greddy turbo timer
Custom ECU reflash by Torque Freaks, Portland, OR
AEM Uego wideband AF meter
Max boost set at 23 psi for 93 oct

I'm currently running 11.5 a/f at wot, 23 psi, till redline on the dyno. I've been noticing lately that my a/f hits 12.0-12.1 for a millisecond then back down to 11.1-11.5. I'm not sure if this is just a reading error.
I pulled out my plugs the other day and noticed that they are a bright white color. Shouldn't they be a little brownish? I figure that I'm running lean then, but the a/f, for the most part reads otherwise. I haven't upgraded my injectors for the 20g, since it only produces a slight gain in power (12-15 hp). Any reason for this or is this normal. Should I upgrade my injectors?

 

Plugs dont lie. Tune out that 12.0-12.1. You are probalby going that lean at peak torque, which is a no no.

 

I wonder what your IDC is? I bet its probably around 105%. I
would swap out your injectors for some larger units. Mine where
like this at only 362whp on a dynojet. Also you should be running
one step colder plugs as well. I'm using the NGK R7437-8 plugs
for the EVO IX. Then get retuned at a reputable shop with a/f ratios
in the low 11 range.


Later man

 

let's hope it's not coolant

 

Is this on 91?

If your knocking, Keep your fuel the same and pull timing.

If you don't know if your knocking then drive the car easy until you do.

 

Boost addiction, thanks for the advice. What kind of plugs are those, are they Copper plugs? Also, which size injectors should I get? I plan on not going much bigger than a 20g turbo.

 

TestUDO, I live on the Eastern shore of Virginia. I plan on going to AMS in Gathersburg, MD and get a retune for 11.0:1 to see if this will take care of the problem. If not, I guess I'll have to buy some larger injectors, cooler plugs, and a retune. Thanks everyone for your advice.

 

I'm running on 93 octane. The last evoscan I ran on the dyno showed 0 knock.

 

with zero knock forget what everyone is telling you. you are good to go. the stock ecu goes lean on spoolup by design. it comes from the factory lean to the thirteens.

you can check your injector ms in evoscan too. unless you are way high forget that too.

btw white plugs are correct. all you need is a very small ring of dark at the very bottom of the ceramic/ where it comes out of the steel.
besides which it is difficult to get a real read on plugs because few people are willing to cook their turbo to get a real wot plug read.
done correctly, you put new plugs in, do a wot pull, shut it off without idling or coasting. look at the plugs. otherwise you are reading the 14.7 the car reverts to during idle or cruise.

 

Hey man if the porcelin insulator is bright white that is
a sign of an extremely hot combustion chamber where
burnt and or melted pistons can easily occur during
boosted conditions. Also it tends to elevate EGT's
significantly,which is really bad to say the least.
Anyway I prefer the Precision Turbo & Engine injectors
ie PTE. Try to stay as small as possible,due to drivability
issues with large injectors. I run their 780cc type. Any larger
like 880's or 1000's are really unhappy during stop and go
type driving conditions,even when they are properly scaled
during the retune session. There is a section all about
fuel system recommendations on here which you should read.
Also the NGK plugs I had previously mentioned are Iridium type.
There are no such "Copper Plugs" available for the Evo IX application.

Later

 

Thanks for the help. I guess I'll have to finally purchase larger injectors. As far as the plugs go, last night I changed them out with a step colder (Denso Iridiums).

 

I'll run a couple EVOSCAN logs tonight and also check previous logs to see if I have already maxed out my injectors. By the way, what should I gap my plugs at, since I have the upgraded ignition unit (HyperForce)? They are currently gapped at .28

 

Going lean on spool-up is by ECU design.

White plugs are fine. You should check IDC's before buying new injectors. I doubt you need new ones on 23psi with a 20g. That's pretty close to regular ix. But IDC's will tell you.

0.28 on 23psi with an amplifier is fine unless you get spark blow-out or misfires.

 

here is a bit of information on plugs, written for MC it still pertains to cars. Excellent info that everyone should understand. That crap you see on the auto parts store window showing pictures of plugs is worthless.
http://www.strappe.com/plugs.html

if you are impatient just read the last four or five paragraphs