Should I gap my plugs down?

[supergoat]

History: Ported 14B turbo on NT block with stock NT 9:1 Pistons at 10psi.

Ok, I am also running a Walbro 255hp pump, stock 450cc injectors and aftermarket AFPR. After 6000rpm my car likes to sometimes bog. 1st gear is fine, hits redline like a champ. 2nd gear though sometimes bogs or cuts out at 6000+rpm. 3rd does the same.

I thought the computer may be pulling timing but I ran many logs and am not getting ANY knock at WOT at any rpm so I know that's not it.

All I can think of is either my plugs are not gapped correctly for my set-up or I'm just running too rich. My 255hp is over-running my AFPR. On it's lowest setting I can only get 45psi base which is causing me to run very rich.

Any ideas on what to try next? Or what to gap my plugs too?

 

[hose101772]

had to run .025 on my plugs to keep it from missing under heavy boost.try it and see.

 

[TimG]

Try gapping your plugs a little closer like the guy above said, but it seems you are running WAY too much fuel. A 255HP without fuel management is crazy. Oh well, better to run rich then lean and destroy your pistons.

Log a 2nd gear pull. If you have a O2 Voltage over 0.9V, you are running too rich.

 

[loreak]

your walbro isnt overflowing your afpr, it can only do that to the tiny stock fpr, and it is only on part throttle and idle......you could be running too rich but you should know because you have a logger...

 

[supergoat]

My 02 voltage reads anywhere from .7 to .93. I have no idea wht it fluctuates unless it;s due to my knock sensor picking up a misfire and counting it as knock. Then the computer pulls timing and maybe that messes with my 02 voltage.

Also when my throttle was held at 22% my voltage fluctuated from .28 to .89

I'll gap and install new plugs tomorrow and see what happens.

And yes I know running the 255hp without an AFC is crazy, but with the glass NT pistons I'd rather be safe than sorry.

 

[TimG]

Here is a quote from a guy on DSM Canada's web site, Mike Jackson. Very knowledgable guy...

"In second gear around 2000 rpm go wide open throttle at least to 6,500 then pull over. Have a look at the log. First make sure that the the throttle posistion is registering at 100% when you had your foot mashed. If it didn't find out why and fix it first.

Look at the knock sum:
-if it stays flat at 0 that's a good thing... it means you have room to lean the a/f ratio out. It also means it's safe for you to do 2nd gear and 3rd gear wot runs from now on. So lean out the high setting -2% at each rpm point and go for another run. Do this until you start to see the knock sum jump up. When you see that happeb look to see what rpm that knock occurred at and richen that rpm point back up the 2% you took off that run. You can run again like that until you knock another point and then richen that up. Keep doing this until you think you are as lean as possible without causing knock. "

 

[supergoat]

Sounds like it's time to invest in a S-AFC

 

[TimG]

Yeah. Those 450s were meant for 11.1 psi on 7:8:1 compression pistons. SAFC should be used to help see what the fuel problem is.