Spark Plugs-Map Vacuum Pressure-S-AFCII Mapping Q's

[PazzaAE86]

Hi guys,

My ITB setup is coming on but my current plugs are looking a bit worse for wear these days and im going to get some new ones. I'll be buying NGK-R ones and at the moment im using the "6" heat range... Should i try 7's since i'll be runing ITB's and have an altered fuel map?

Secondly, my S-AFCII is controlling fuel and it has the ability to read the vacuum pressure from the Map Signal.. Now it runs at about 450-60 mmHG or 60 kPa (roughly) when its idling. Does anyone know what a stock AE86's vac pressure will be at idle? Just want to see how far off a stock, fully working vacuum i am with my current vacuum setup. I think at the moment my vacuum setup is better than its ever been so im hoping its good.

Third, S-AFCII mapping.. I know every engine is differant and no 2 maps are the same but does anyone have a basic map they can post up here? The Ne-Points and the Low and High Correction factors? My Engine is an AE92 Big Port with 40mm ITB's and a 4-1 Trust Manifold and Exhaust. Also, what percentage do you use for your "Hi" and "Low" throttle posisitions?

Thanks guys!

Paz

[Knudsen]

The standart manifold vacc. has to be atleast 590 (factory info) with a idle at 850 rpm, but mine is giving around 540 at a idle of 950-1000 rpm. I think this is because i have a open freeflow airfilter. I think yours is lower caused by your ITB´s.
High an low throttle: Mine is set for 0-100%, you have to use the Throttle angle sensor to do so. NOT the closed throttle signal.

When you map the engine, you MUST do it on a dyno. I havent experimentet with mine S-AFC, unless giving it suffecient fuel to die when reving the engine ( just to find oyt, that the shit really works), so i really cant help you out with that.

[20vWill]

If your fuelling is sufficient, I would keep the 6 heat range and try reducing the gap by 0.1mm increments. You will get a stronger spark which should help with the low-medium rpm rich-running characteristic of the throttles. Changing to heat range 7 will make running worse in these conditions.

You'd only need to move up a heat range if you're running substantially higher combustion temps with higher power. I doubt you will be at this stage, especially on stock or even mild cams. Maybe try 7's when you are pushing 160 ponies? Even the 20v runs 6's and that is a very hot running engine (in terms of combustion temps).

And yeah, stick to pikey copper NGK-R's, but keep them fresh. They are an excellent plug and produce the best spark (better than platinums, iridiums and all that other HKS/Blitz rebranded Denso stuff), just don't last that long, especially when experimenting with fuelling and ignition.

Once your halfway sorted, you can change them every other oil change. Until you have a decent map, you will need to change them frequently. Just buy a box-load at bulk discount. I can get them for you cheap if you want mate.

[mo-racing]

because of apexi hi and low throttle setting i would go to about 10% low and something about 70 to 80 at high throttle (or 20%low 90%high). difficult to explain this in englisch .... its mainly bacause you get a closer erea the apexi is interpolating in. but thats a point i would not worry to much about.
for tuning use a lambda meter. on a dyno it is best cause its easy to hold constant rpm. but if you have a mobile lambda meter you can do this with left foot breaking to keep constant speed (thats what i will have to do if we loose our connection to the dyno )

hey, what lambda is best for an NA engine roughly by the way? i would say around 0.9 on full stick. is this right? (i just worked on turbos til now...)

a good tool i can recomend is a chassis ear http://jcsonlinetoolshed.com/product.php/3668/129/
this is good to detect pinging!!! just in case...