Johny GTO

Ok. i was reading Svede's post about his home made OTRCAI and his MAF (or was in MAP) reading to judge his intake's effeciency. HE was comparing his Barometric pressure (KPA) to his MAP kpa. HE was saying his Baro was like 102kpa and his map was like 98kpa, being pretty effeicinet.

Well, i have a dash-hawk and was looking at my reading, and saw something odd. On the screen with Barometric kpa, there is the MAP KPA. when the car isnt running, but the battery is on, they were the same. both were reading 102kpa. However, once i started my car, the MAPkpa dipped down to like 70kpa. Now that is a big difference in pressure, meaning my engine is sucking a vacuum. Based on what i learned\understood from Svede's thread, you want the 2 numbers to be as close as possible. Svede's only dipped 3 or 4, mine dropped 30!!!!

I thought maybe my filter is screwing things up, blocking airflow, so i shut the motor off, disconected the air tube from the airbox so that it was sucking air from the open, well open air. No restriction whatsoever. I started the car and it still dipped down to the same number. How is there a restriction in an open tube that is exposed to open air. No bends, no filter, no nothing!! Just a tube running to the MAp, the throttle body, into the intake elbow, then the manifold.

I am in the process of trying to pull any info from my dash-hawk and put it on here for you guys to see, so perhaps u can tell me whats up.

In the meantime, here are my mods....
Dart 225 heads Ported\polished\coated by PMFL, Streetsweeper EDC (ed curtis) cam 236/240 .610 .610 111lsa, Vic Jr. intake manifold with Custom elbow, aftermarket fuel rails, larger injecvtors (i think 48lbs), full cam kit (springs, locks, retainers, pushrods, etc), stock airbox but i did a lil home made modding to connect an air scoop from the bottom grill to the box. Kooks Long tube headers 1-7/8, no cats, custom H-pipe, 18 inch sweet thunder muffs in the 04 location.

Black02SS

iTrader: (36)

At idle with the car running you will never see the same kPa that you do at WOT. If your car idles at 70 kPa at idle, thats normal with a large carm. Smaller cams (224) will idle in the 45-55 kPa range.

If your trying to test your restriction at WOT, do a pass and observe what your kPa is there. That will give you a better idea of what your trying to see.

Johny GTO

ahhh. thanks for the heads up

Johny GTO

i logged this info and uploaded it. not sure if it will be useful at all, because i really dont know what any of it means. HOwever, i figured it might be worth it if someone who knows their ish looks at it and can see something of note.

69LT1Bird

iTrader: (1)

Check with key on engine off (KOEO), should be about 96-101 depending where you live and weather conditions, it is just a boggy for that moment in time. Do a WOT pass, check the number, the closer to being the same the less restriction you have. Sea level is at 101.4 kPa so the elevation above that will drop the base KOEO number.

I drop about 3 kPa with my setup.

Johny GTO

with the KOEO it reads 102. i havent done a WOT pass, as i cant do it anywhere around here without being sodomized by the local Fuzz.