So what do we have now? The exhaust is now dual 2.5" pipes merging into a single 3.5" pipe that passes through the crossmember (and it's a tight fit, folks!). I have a Magnaflow 14" long, 6" diameter muffler that's straight-through 3.5" inside. The sound isn't great but that's really not the point here...

Jeff did a ton of work: Front discs went from solid 10.5" rotors and 2 -piston calipers (stock 240Z) to 10.8" vented rotors and 4-piston aluminum calipers ('90+ 300ZX). Rear brakes went from drums (510) to 11" vented rear discs with aluminum 2-piston calipers (again '90+ 300ZX), and the brake master cylinder went from 7/8" (510) to 15/16" (280ZX). The stock 510 tank was replaced with a larger capacity 610 fuel tank with a 300ZXTT internal fuel pump. Lower control arms are now adjustable, and as mentioned before he ran 2.5" exhaust from each side into a single 3.5" the rest of the way back. Take a look at the "3.5" pipe in muffler location" picture and look how well he tucked the huge 3.5" pipe under the half shafts - the "OMIGOD pictures shows it as well. Incredible work Jeff!

Now would be a good time to note a bit of learning on my part It turns out the previous exhaust was not completely to blame for only getting 8-9psi of boost. When we installed the Bosch blow-off valves notice it was only 3 days after the exhaust system. It turns out that these BOV's have vacuum nipples on them and they need to be plumbed to the intake plenum or else they don't hold the boost pressure. So I plumbed them up a couple of days ago and went around the block. Man, is the idle quality crap! It won't idle, but I DO have 17psi of boost. Hmm. A little Internet research finds that at idle and low throttle cruise these BOV's will DRAW air in! Today I tried a little experiment by taping the outlet of the BOV's closed (effectively eliminating the BOV's) and lo and behold, I can actually drive the car again! I imagine if I were to run up the boost and then shift the tape would blow off and the idle would go to crap again.

Since these BOV's draw air in, this air is unmetered, so the ECU doesn't know about it but when the O2 sensors send their input to the ECU it tries to correct it. What needs to be done is these BOV's need to be plumbed as recirc valves - instead of venting to atmosphere they need to vent somewhere after the MAF - this way when they are drawing air it is air the MAF has already measured.

In any case the car is 90% to being a nice driver from an engine standpoint. I currently have about 10psi too much fuel pressure and will be hunting down that problem, but currently I can hop in the car, fire it up and drive around with no major issues. If I feel like 15+ PSI I could turn on the boost controller and blow off the tape on the BOV's and suffer with poor idle. We're REALLY close and I suspect in a couple weeks I'll be looking for a dyno day!

- - - 5/20/04 - - -

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