I was off from work yesterday, so I had time to finish my APS intake plenum mod. The APS plenum was relatively straight-forward to install and only took about 1.5 hours. I measured 20.5" of vacuum at idle with all accessories off and the engine at normal operating temp, before (with the OE plenum), and then after I installed the APS plenum, so I’m pretty sure I have no vacuum leaks.

I bought a used engine cover from someone with a G35 with a Crawford plenum who didn’t want to hold on to it anymore. This way I still have my original engine cover if I want to go back to stock. Cutting down the engine cover was a pain in the a$$ and took over 4 hours. There’s just no good way I could find to get an accurate tracing of the outline of the plenum to use as a template to cut down the engine cover, so the best I could do was to cut off the bulk of it then trim it down a little at a time until I got the fit I wanted.

Overall I like the way this mod turned out. My “butt-dyno” tells me I’m getting a nice torque increase around 2K to 3K rpms which is about the same range as I saw in a dyno chart of the Crawford plenum. I really haven’t had a chance to check the gains at high rpms or get some track times yet.

 

looks pretty damn sick...hope you enjoy your mod....how much did it cost you...i might want to get that for my G...looks pretty slick

 

The APS ran me $450 delivered. I know that's about $150 more than the Crawford plenum, but to me it was worth it. The casting and machining on the APS are really outstanding.
The engine cover cost $60.

 

looks great let see some slips after you get it to the track

 

Very Nice! Congrats