i am getting a big loss of power after 6500 rpm's. i took it out yesterday and gave it some on the highway. i noticed that after 6500 rpms my car would drop off in power quite a bit. in 4th gear at 6500 rpms is was having trouble going over 120mph.... it seems like it is getting choked up. i replaced my plugs about 2 months ago ( 500 miles or so ). i run all 9's and a crane hi-6s on the leading. my timing maps at just about base. except i removed 2* from p15-n13 and up. i am running 10 psi right now. i plan on running 11-12 psi once i figure out this problem. my afr's are 10.8 by 7k rpms. any ideas what it could be? , i am thinking it is something with ignition. any help appreciated.

 

(1) How did you record your AFRs? I have a PLX M-300 and a DATALOGIT. Until I calibrated the DATALOGIT to the PLX, the DATALOGIT recorded .3 AFR lean. If yours is the same, then you really are running 10.5AFRs.

(2) 10.8 AFR at 10 lb boost is too rich unless you have megaports and are making over 400HP. Try 11.7-11.5 at 10psi boost with stock or mild porting.

 

lol, i recorded them with a passenger reading the plx. i thought 10.8 afr is where i was saposed to be. i always thought 11.5 afr was too lean. but you are the expert, you even helped me figure out how to tune timing . i have stock ports on the engine. so i will take some fuel out and see how that works out. also i read your last post about the plugs and i think i am going to switch to 10's all around also.

 

I am running 11.7 at 10PSI, 11.5 at 12PSI, and 11.2 at 15PSI.
Stock intake ports, mild exhaust port.

Have tuned from 18C to 40C. Do not forget the Air Temp vs INJECTOR table.

B9EGVs are better for under 380RWHP than the B10EGVs.

 

are the b9egv's much different then the stock ngk 9's that the fd uses?\

btw which is the air temp vs. injector table?

also since i am running 10 psi now , do you think a full stock base map will be ok? right now i did what you recommended for me -2* timing p15-n13 and up, that was what you said for 12 psi , but i have turned it down since.

 

The B9EGVs are like the B10EGVs as far as design goes. They require a special socket for installation. Go to http://www.sparkplugs.com/ then select the TUNER box and then look up the plugs. They have pictures and specs on them.

You need a DATALOGIT to PROPERLY tune the PFC! If you tuned your AFRs perfectly when the air temp is hot, most likely you will go lean in winter. The AT vs INJ table adjust the amount of fuel change in proportion to air temperature change. Mazda's preset values do not match real word modified engine values.
That is why many tuners go for richer AFRs because they will not have the car for tuning under large air temperature changes. That is why it is best to buy your own tuning equipment such you can tune through out the seasons.

It is also important to move the air temp sensor from under the UIM to either the throttle body elbow or IC outlet.

This has been discused on the PFC forum and should be in the tuning document from Kyle and I.

 

Contact me at cewrx7r1@yahoo.com.

 

i tuned my afr's at 22*c so it was nice and cold. and i will make sure its cool again to tune. my car usually runs at 29-35*c all the time. only at night when its about 50*f out is when i can get it down to 22*c. i am going to get myself a datalogit asap. the air temp vs. injector can only be corrected by datalogit right?

 

sent you an email

 

10.8 really isn't that rich. Its pretty safe in my opinion. Is the ignition breaking up?

 

i think the ignition is breaking up. my plugs have about 500 miles on them. but i am probably going to replace them anyway. i am also going to check the coils to make sure they are ok. i am running a crane hi-6s on the leading. also i have been searching around and noticed that some people have trouble with the 10mm magnicor wires? could that possibly cause my problem.

 

Magnacores fit poorly. They easily slip off the coil terminals and don't make good contact. Best fitting wires are the oem mazdas and the ngk stock replacements. The racing beat are also decent but expensive.

 

well did some testing. my coils are all in spec. i checked the resistance on my wires and they are under 2k ohms. i also check the resistance on my old stock ngks and they were under 2.5k ohms. i am going swap out my magnecor and go back to stock. also took out my plugs here is how they look after 500 miles. the 2 plugs to the right are the rear rotor, and the 2 plugs to the left are the front rotor. the plugs dont look to even, my trailing plugs are much blacker then the leading. any reason for that?

 

are you sure that your leading is really leading and not the trailing? usually, trailing will burn leaner than the leading because of the nature of the hole size in the rotor housing. From looking at your picture, your leading is much leaner than the trailing (too lean to be 10.8:1 a/f). I also see that the trailing plug (you wrote) has more wear on the electrode than the leading which leads me to believe that you have an ignition amp on those plugs. I'm pretty sure you have those two plugs written backwards.

 

im positive that those are my leadings. i have a crane hi-6s on the leadings. my afr's are 11.1-11.5 between 4 and 6.5k rpms, then it starts to richen up in the high 10's. i have maybe redlined my car 4 times so it mostly runs in the 11's when im on it.

 

that doesn't make sense to me since if you look at the very tip of the electrode on the rear trailing, you can see a light white residue (which usually means high voltage).

 

could it be my timing?... its basicly stock base map right now. i am only running 10psi right now. i am going to change my timing when i get my datalogit.

 

well i switched out my plugs. i put in ngk 5820 plugs. they are heat range 10. i also switched back to my stock ngk wires ( which fit real nice now. ) and i changed my oil from mobil 1 15-50 to royal purple 10-30. i didnt like the mobil because i noticed with the 15-50 my turbo would die right off when i shut the car down. now it spins for like 15-20 sec. before the turbo stops. also i am noticing some stumbling at very low rpm and sometimes when i let off. worst of all the car feels slower, like it doesnt rev through the rpms as fast. dont know if i like these plugs. i think they might be too cold for my car. any imput would be great. thanks.

 

has this been an ongoing problem or is it something new? what are the specs on your turbine?