bishiboy

iTrader: (10)

After owning my Evo for over two years now, I'm FINALLY getting the tune down.
I didn't realize how important the plug gap was. I always checked the gap and made sure it was as recommended (.030 depending on were you read).
My idle has always sucked. I blamed the 272 cams. Then I installed a H2O/Alcohol injection kit and cranked the boost to 24psi. I would get a high RPM miss. I was fouling plugs like crazy. Then a guy from a Supra forum recommended dropping the gap down .005.
So I installed a new set of NGK BPR7EIX plugs set at .025. WOW!
Car idles like a dream and pulls smoothly all the way to 8K (24psi with h2o/alc injetcion on) with no miss!

I just thought I would share this, because I know there are others out there that didn't know the importance of plug gap on our cars.

krafty

iTrader: (17)

Nice!!

Curt@MrLed

iTrader: (107)

i guess i never relized how many people dont know the little things like this.. and you put a good heading for people when they search.. see people this is how it should be done when you have useful info..

MalibuJack

iTrader: (5)

Yep, I gap my plugs at .026 and have a great idle and no misfire (keep in mind I don't have cams) but the larger gap and colder plugs really can hurt your idle unless you have an upgraded ignition (CDI type)

bishiboy

iTrader: (10)

As a side note. I am building my own coil-on-plug set-up.
I already have the coils, (Chyrsler 300M sticks), I made the mounting plate, (work of art), I have two different power transister from DSMs, 5 and 7 pins style. Now sure which one will be best yet. I just have to buy an AEM C2DI, wire it and install. Then I CAN go back to a larger gap with no ill effects.
I should have it built for around $325 in parts.
I'd like to know where to get electrical connectors that match up to the transistor and the stock Evo coil connectors.
Anybodu know....Jack??

Chris@nolimitmotors

iTrader: (277)

whats the difference between bpr7es and bpr7eix ???

bigjhoney

iTrader: (12)

the eix is an iridium plug, es is a regular pkug. Ive got the bpr7iex now, and my gap is .028. Idle is somewhat ok, up top feels somewhat ok too. Ive got the basic mods( tbe, 21 psi, tuned on afc-2, intercooler piping, drop in filter, other stuff I probably forgot). Think dropping the gap more will help? thanks

IE Evo

Been there done that. I had a missfire issue also at high Rpms but once I gapped the plugs in the 24 range no more missfire from blowin out the spark. No Iridiums for me. tried that and the missfire was so pronounced u couldn't even drive the car.

MalibuJack

iTrader: (5)

Everyone was very tightlipped on those connector parts.. I ended up making my own connectors. I used Honda motorcycle sticks, and either of those packs should work as long as their for a two coil, two channel ignition I think the 5 pin powers only one coil. Are you sure you actually need the power transistors for the AEM C2DI? I was under the impression you didn't as long as it had a trigger signal from the ECU since the transistor only controlled the switching and primary voltage to the coils which is handled by the box, the Motec CDI was a different story and required the modules. I never used the AEM C2DI I ended up using a different CDI setup and coincidentally, am in the process of aquiring a new setup to test.

bishiboy

iTrader: (10)

I am going off the DSM section on the AEM forums. The guys that built COP set-ups with the C2DI used the transistor (PTU).
I thought about just wiring the ECU in also. I need to find out the ECU voltage output and compare to the C2DI requirements.
I know the guys using the MSD DIS-2 use the PTU from DSM.

As for connectors, I'm going to shop the junkyards for a harness.

Once I finish and test everything, I'll post my results.

BlackEVO

bishiboy,

I looked high and low for that 2G service manual. All I came up with was a Chilton and '90 service manual, which both pretty much blow. The Chilton doesn't do anything except tell you how to test the transistor (they use a 1.5V battery, though I doubt that's the V from the ECU?). I really don't know if the 5-pin transistor will work, but that should be pretty easy: 2 in's from ECU (one per coil), 2 outs (one to each coil) and a ground.

I will keep digging for the 2G service manual, but I expected it to be with the others (still packed in boxes from the move 2 years ago). I might have loaned it out and never got it back

The transistors are used to fire the coils (ie. would tell the CDI box when to dump the charge), so unless the C2DI has something to handle that on its own, I don't see any way around wiring the transistor. My buddy was supposed to send me his spare transistor, but I haven't gotten my hands on it yet. I have spare 2G coils from my Talon to "work with", but if things work OK, I'll switch to single COP.

Have you tried PepBoys by any chance? IIRC, they have a lot of GM-style connectors in there...one may be a close match for the pins.

bishiboy

iTrader: (10)

I looked at several posts on the AEM forums. The power transistor is a must with the stock ECU. If you have the AEM EMS, you can wiring directly into C2DI.

fugiwara

iTrader: (124)

Good post thanks for sharing.

Erik@MIL.SPEC

iTrader: (94)

Necrobump.