What did you make the MAF housing out of?

 

It's PVC tubing and a silicone 45 degree coupler, Spending the big bux now!

 

Ok I was wondering because it DID look like a piece of ABS pipe. I always figured something like that would melt and get loose from the heat of the engine bay, let alone the heat from turbo air.

 

It should be ok for what I'm doing currently, the engine bay doesn't get much warmer than stock since there isn't a turbo in the engine bay. IAT's aren't getting too hot either. Most PVC is pressure rated from 140f to 200f and that's under pressure and can actually handle more than that under low pressure like I am at since I don't plan on going over 15psi for now. If it all works out I'll probably weld up some aluminum MAF housings that will flow a bit more than this one. I have started to hit the ceiling of the stock MAF at only 7psi @ 5000ish rpm so I needed something to keep moving on with the project and wasn't about to pay $350 for a MAF sensor haha (I'm a cheapskate) Other good news is that I almost have the GT500 injectors tuned out on the 04' G35x. It's still got one spot I am working on for hot starting where I have to tap the pedal to get it started when it's at full temp. The injectors are probably about 755cc at the fuel pressure that I am running for E85 fuel so if we can get them running anywhere close to stock I'll be very happy

 

Ohh I know the ABS can take the pressure, I still have a potato cannon made out of one from decades ago and it was good for 100 yards no problem. Sounded like a gunshot when you would fire that thing and it was used heavily for many years before I retired it. I was concerned mostly about the HEAT, we use torches, blankets, hot boxes to bend PVC conduit at work and it starts to get droopy under 200 degrees. I have no clue how hot is actually is under the hood of these cars though.

Are there any OEM MAF sensors you could snag from a different vehicle that would work for cheaper?

 

I thought about that but couldn't find anything that was the size ID needed for 400-450 whp in the Upull yards. I thought about using a lightning MAF but didn't want to rescale the IAT and whole MAF table. The PVC maf was just for the NA car to get it dialed in and tuned with the stock intake and airbox, honestly I think it would hold up in the boosted car pretty well as low as the IAT's have been in the summer. I also haven't decided on intercooler or using my meth/water sprayer when the IAT's start getting higher. I should have a thin wall aluminum tube on it's way for the boosted car that will make it more seamless when I finalize the cold side. I would like to get the cold side down to 3 sections so there aren't so many couplings.

This weekend we had to fix the 05' turbo car's exhaust work. It kept blowing by the stock MLS gasket at the end of the Y pipe. Even though I sanded the flanges for more surface area they just wouldn't seal under the pressure. I had some 3/8" stainless flanges at work with the same bolt pattern but for 3" exhaust (the turbo setup is 2.5") so we just welded a new SS flange on top of the stock flange on both sides. Had enough room on the inside to weld so it came out pretty clean. It's actually kind of overkill but it won't ever leak again. Also got the GT500 injectors to idle stock and fixed all the hot start problems. Still lot's to go to get them perfect across the board. I have a used set of R35 GTR injectors I'm going to try out also. They flow just a tad less than the GT500's but I'm curious how well they work on this setup.

 

While we were tuning the stock 2004 G35x with the GT500 injectors we were experiencing quite a bit of knock while on stock fuel pressure and 91oct fuel. So I decided to change back to stock injectors and datalog for awhile to make sure this was normal. Like I said we are very new to these ECU's and I haven't driven either of the G's on straight gas very much. I usually run E15 on the stock 2004 and E85 on the 2005 boosted car and experience 0% knock. So far in the last 2 days I get some low knock in the 3000 rpm areas and quite a bit from 4400 rpm and up. It retards about 3-4 degrees of timing to compensate. Looks like they have the ECU set very aggressively on the timing side and running ethanol keeps the timing from being retarded. So more power, smoother power and less engine wear for me If anyone is curious about running ethanol it's actually pretty simple, I don't change a thing for E15 and bump the fuel pressure 1 bar for E85 (need return fuel system or modified in tank regulator to boost pressure).

 

If we actually HAD E85 over here I'd be running it, there's literally 1 pump in these cities of about 500k people and it's always got a massive wait because every racecar in the area fills up there.

 

So just out of curiosity, what do you do for work?

 

Yeah, That sucks to be in a area that doesn't have it at all. Before ethanol was here I had to fill the foxbody up with 92 octane so it was pretty expensive to just cruise around. If I travel the E85 stations thin out. I wish they would make a low content ethanol standard everywhere. E85 in the winter is a little rough but I usually pump 50/50 E15 and E85 in the winter to make E40. My field of work is Computer/Electronics for the last 25+ years. Mechanics/Fabrication is just a hobby.

 

I got a used set of 2009+ GTR R35 injectors and I just finished cleaning and flow testing them last night. As I suspected they act just like the factory VQ35DE and VQ37VHR injectors and have the same minimum pulse width. I also have the factory GTR ECU maps so I can change the factory G35 ECU to match the latency and min pulse width stuff. The GT500 injectors don't go as low as the Nissan injectors and I think that's why I had to fiddle around so much in other areas to get the Gt500's to idle / start correctly at all temps. The GTR's flow about 588cc @ 3.5bar and are plug and play! Just pop them in and tune. I'm still flip flopping between tuning the stock ECU with 3.5" maf and GTR injectors or using the FIC6 with stock MAF clamped and intercepting the GTR injectors..... Probably will play with it both ways to see what has the best driveability.

So far the car is at 1300 miles since the turbo install. Just got inspected yesterday so my plates are good for another 2 years now Even with 5 bar fuel pressure and the 3.5" maf I can't break 5500 RPM because the stock injectors pass 100% duty cycle. Hopefully the GTR injectors will allow me to get to 14 PSI on E85 fuel..... Hopefully

 

You still have the stock connecting rods installed yeah?

 

Oh yeah, 161k miles all original VQ35DE. Don't worry I have another engine Not real worried about the rods though, my SR20DE RR has about the same size small rods and I have been pushing 20 PSI for years on it. I wouldn't push it this hard on gasoline though. I may have a 3rd engine if I have to part out the 04x since insurance is totaling it out.

 

I'm betting that anything over 14psi will bend a rod

 

I'll take bets before I start pushing it harder than that. If I get the built engine finished up and the tranny doesn't crap out I'll push it up a couple PSI per week until death Unless I run out of injector again..... Or run out of turbo...

I also threw in the GTR injectors tonight and they work great! Hot start and fiddling with idle problems are gone. Just have to work on tuning it again now.