Nissan 370Z Forum - View Single Post - GTM Stage II TT

DIGItonium · 02-23-2012, 12:01 AM

Alright guys, here's a quick summary. I'm an idiot (maybe). :P

However, I learned a lot about how my FI system works over the past few days. This is great because I have a bit more confidence working on this stuff on my own as long as I don't have to get underneath the car. Earlier the tech rerouted the MBC boost input from passenger intake pipe to the intake plenum. Made almost 7 turns and did not see more than 5 PSI in 3rd/4th at WOT. It was steady, but felt sluggish.

I got the call from support at Hallman. I was told to take the MBC out and blow through the inlet while tightening it down. If I felt restriction, then the MBC works. It was confirmed working! Interesting because I started having a better idea how this thing works.

The next suggestion was the unthinkable. Plug everything and leave WG hose open. I took the car around the block and loaded it at 4k at half throttle, and I was able to get past 6 PSI (almost 9!). The car felt so good!

So I put everything back, used bigger zip ties, and made sure to tighten the hoses correctly without slipping over the barb lip. I did a quick test with the MBC disabled and boost was steady at 5 PSI past 5k RPM. It took 7 full turns to start noticing steady 6 PSI, which was familiar. At 8-9 turns, it was steady around 7 PSI. At 9-10 turns, it wanted to exceed 8 PSI at 5k RPM WOT so I dialed it back by half a turn.

Afterwards I drove casually to test response. Wow, it is so much better! I was able to get out of vacuum easily and push about 3 PSI. At half throttle, something felt different. What's nice now is boost appears to be very steady. Boost gauge wasn't wiggly and confusing. It was a clean sweep to 8 PSI.

Anyhow, I'm going to take it in to revert to the old setup to be safe with the wastegate hose. I just need to dial past 7 full turns to see results!

02-23-2012, 12:01 AM	#12 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	Alright guys, here's a quick summary. I'm an idiot (maybe). :P However, I learned a lot about how my FI system works over the past few days. This is great because I have a bit more confidence working on this stuff on my own as long as I don't have to get underneath the car. Earlier the tech rerouted the MBC boost input from passenger intake pipe to the intake plenum. Made almost 7 turns and did not see more than 5 PSI in 3rd/4th at WOT. It was steady, but felt sluggish. I got the call from support at Hallman. I was told to take the MBC out and blow through the inlet while tightening it down. If I felt restriction, then the MBC works. It was confirmed working! Interesting because I started having a better idea how this thing works. The next suggestion was the unthinkable. Plug everything and leave WG hose open. I took the car around the block and loaded it at 4k at half throttle, and I was able to get past 6 PSI (almost 9!). The car felt so good! So I put everything back, used bigger zip ties, and made sure to tighten the hoses correctly without slipping over the barb lip. I did a quick test with the MBC disabled and boost was steady at 5 PSI past 5k RPM. It took 7 full turns to start noticing steady 6 PSI, which was familiar. At 8-9 turns, it was steady around 7 PSI. At 9-10 turns, it wanted to exceed 8 PSI at 5k RPM WOT so I dialed it back by half a turn. Afterwards I drove casually to test response. Wow, it is so much better! I was able to get out of vacuum easily and push about 3 PSI. At half throttle, something felt different. What's nice now is boost appears to be very steady. Boost gauge wasn't wiggly and confusing. It was a clean sweep to 8 PSI. Anyhow, I'm going to take it in to revert to the old setup to be safe with the wastegate hose. I just need to dial past 7 full turns to see results! __________________ Last edited by DIGItonium; 02-23-2012 at 12:05 AM.