So it was looking like a complete engine bay but like an idiot I left all the fab work until the end.
I was pretty dead-set on running the ARC box especially after I got my hands on a NOS stock air filter. My turbo location made a Z32 MAF impossible to run, had to make some tight corners to meet the turbo at all.
Hypergear recommends a 3.5" intake pipe for this turbo, to make things more fun.
A handful of pie cuts later I had this mocked up
I read good things about R35 MAF sensors and they're really small - tucked it away to keep the bay looking clean. Also put the catch can return line on the intake pipe. Had Mitch @ Unit2 weld it all up for me. Turned out awesome.
I decided to build an overkill catch can setup, because why not? It's 3 layers baffled with some fuel cell foam in one layer to separate oil from air. It was really fun designing this and putting it together. I had a friend weld the tub for me and then had Mitch finish weld it.
Here it is all plumbed. The -AN fittings on the cylinder head mean trimming the hood bracing, the fittings on the catch can were the same story. Glad I never painted the underside of the hood..
The car ran like crap with no tune and all the changes but it finally moved under its own power!! I had it towed to Unit 2 and they did a great job tucking the downpipe/exhaust up for maximum ground clearance.
Brought it to my work and did a full nut and bolt check, aligned it and then cranked the coilovers all the way up for the trailer. Time to tune!
When I first got to the tuner everything seemed to be going well. He didn't find any issues with the car and seemed pretty happy with what I'd brought him.
I threw in some fresh plugs, we set the ignition timing and he calibrated the MAF and injectors. All seemed to be off to a great start... but then we had a problem with the MAF signal.
Completely unexpected and overlooked on my part was the placement of the MAF. I was so stuck on running the ARC intake box I put it too close to the turbo and the bend in the intake pipe. The air is so turbulent at idle its almost impossible to tune. Voltage was seen fluctuating from 600mv to 1200mv at times! Disappointed, I asked the tuner to do as much as he could so that I didn't completely waste a trip. He put a rough base tune in but I have to figure out a solution to this sensor so we can get it running really well. It idles like crap and doesn't cruise well, but under load the signal and tune smooths out. We only tuned to 6k at low boost levels.
The silver lining of the day was having no other issue appear on the dyno. No fluid leaks, no overheating issues, motor was healthy when the air was moving fast enough to provide a stable MAF reading.
Oh, and with the full straight pipe it sounded AMAZING. I was so happy but also so frustrated.
As soon as I got in the truck to drive home I was racking my brain for solutions. I've started with something really easy that might make all the difference - a honeycomb cell in the intake right before the MAF. Should really help straighten the air out before it hits the sensor.
Part should be here this week, in the mean time I've been putting a few KM on the car to shake it down. Anyone who's had their project car off the road for more than a few years at a time knows how good it feels to be behind the wheel again. I wish it didn't take me so long, but I'm glad I did everything (*ahem*intake*ahem*) the way I did without rushing or compromising.
The interior needs a really good detail, I'll get on that - stay tuned for another update soon
