I've done some searches but most talk and show off their PEMS. I've gotten a set of "fake" PEMS and I would like to remedy the front one, I have my original that I can attempt it on.

I can't find specific L36 EM porting threads, how big do I make it, how much do I take off, etc etc.

If anyone knows, I would love to hear it.

what do you mean by "fake" PEM

i think he means that he has gotten an extra set of manifolds and wants to port them himself.

fake PEMs means I brought PEMS that I thought was ported but instead the ends are just rounded (nowhere near a real porting job)

You have to build up the material under the 'neck' of each runner with a welder. Since the front is cast iron, you need nickel rod. After building it up, you can port it to match what you do to the rear.

is it good to port the maximun you can whitout welding . or its no use taking it off because i did see tj front and they are awfull .are they all as bad as this

I would make sure it'* welded otherwise the material could crack and cause a exhaust leak.

Ed

i was thinking more to port the upper end than the lower you can see that the outline of the exhaust port is much smaller.i would only smooth the lower end

Boy, that manifold looks pretty restrictive. Kinda glad that guy bought a powerlog Even without tuning it must do something

I installed an...ahem..."fake" front PEM on my 98 LeSabre a few days ago. :P

"Fake" here meaning no added material and essentially what Firebuick said; I simply bought a stock front EM cheap off clubGP (that a guy had already begun to "fakely" port), drew a circle around the ports with a Sharpie (matching to a FELPRO exhaust gasket), then ground out the port to the circle with a dremel. I would say I just smoothed the short side radius (bottom), and took off a little on the insides at the top. Took maybe 30 minutes total, probably an hour if the first guy hadn't done half the "fake" work already.

I'm sorry I didn't get any pictures, but just imagine Firebuick'* pic above with the holes in the flange ground out to match the carbon rings.

If you can wait a few days, I will be qualifying this "fake" mod this weekend with the PowrTuner, and I can report what my "fake" front PEM did for volumetric efficiency, KR, and ability to advance spark.

(Butt dyno says "maybe", but nothing to write home about)

I did consider having a front PEM done at W-Body store, but the cost was prohibitive. Thus, my "fake" job.

I also considered a PowerLog, but couldn't justify $140 or so for something even zzp doesn't put a "fake" hp number on. Also, the kids at ClubGP seem to think their used, rusted out old PLog'* are worth their weight in gold.