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Discussion Starter #1
Here is the proof that the return-less fuel system in the Z causes the last few cylinders on the drives side to run the leanest due to the fact they get the ass end of the fuel pressure and heated fuel under forced induction applications..You can clearly see in the picture of the heads how the bottom right cylinder ran the leanest.Now keep in mind the way the picture is taked the bottom right would actually be cylinder #6 which is the rear drivers side cylinder. The heads would actually be inverted and reversed upon install, causeing the bottom right chamber to be the inside of the #6 combustion chamber..You can see the carbon deposits get lighter and lighter...This was off a car with an ATI procharger tuned at XXX tuning in CT to a 12.6 A/F and it POPPED the very next day..
The Red numbers indicate the order in which the cylinders recieve their fuel..#1 being the passenger side rear and #6 being last in line at the drivers side rear.The proof is in the picture that you can clearly see the cylider chambers running leaner as you get to the end of the fuel rail at the drivers side..
 

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Discussion Starter #3
That picture of the heads was this cylinder that detonated.Notice the red circle where the piston cracked off..Notice how the cylinders progressively get leaner as the fuels pressure falls off towards the drivers side rear of the engine.If this is not proof enough to go RETURN style fuel system then I dont know what is...This proves the theory that the car runs the LEANEST at the rear of the motor on the drivers side not due to the plenum design but due to the fuel system design..The passenger side rear cylinder was rich as **** due to the fact it recieves cooler fuel and recieves it first..This throws the whole plenum theory out the window in my opinion..
 

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OW! Were those the factory pistons? If so, I can see why we would need to upgrade those if we went FI. Also, wouldn't it be safer anyway to upgrade the plenum to equalize the air pressure? Just in case? Gotta cover all the bases, I would think.

So now we need to upgrade the fuel system along with everything else. What would upgrading the return system do for a stock engine w/o FI? Just curious. Wouldn't that improve the efficiency of the engine performance?
 

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Discussion Starter #10
It says in the first post..This was an ATI PROCHARGER tuned by XXX tunning in CT .This was from last year in November of 2003..
 

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That's nuts. So you're saying the plenum won't make much of a difference? Would an upgraded fuel system matter if you are staying NA?
 

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Would a plenum that gets more air to back of the engine than the front contribute to running lean in conguntion with a fuel system that doesn't deliver as much fuel to the back? seems like they both add up to the same thing.... less fuel and/or more air both will lean the mixture, no?
 

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I was thinking about a new fuel pressure regulator/SAFC anyway....looks like an added incentive, even w/o boost.
 

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Originally posted by lionkiller@Nov 9 2004, 02:10 PM
I was thinking about a new fuel pressure regulator/SAFC anyway....looks like an added incentive, even w/o boost.

Me too. I'm running extremely lean right now.
 

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Discussion Starter #16
You have to remember when staying N/A the car is tuned lean from the factory for emmisions.Anything you do to flow more AIR and not Fuel will lean it out even further..N/A a super AFC should work fine..
 

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Yep. >5 grand, & you're in the sh!tter...

With the SAfc & adj. regulator, I'm thinking it shouldn't be too hard to get back to stock cnf. for 'smog' purposes.... With the new intake, it'd be nice to add some fuel to the mix.
 

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Originally posted by Daking350Z@Nov 9 2004, 02:54 PM
You have to remember when staying N/A the car is tuned lean from the factory for emmisions.Anything you do to flow more AIR and not Fuel will lean it out even further..N/A a super AFC should work fine..

Yeah, guess I forgot the MAF was before the plenum, so it souldn't make much diffference... for some stupid reason I was thinking if the front got more air then the back would get more fuel. Stupid, I know. Man, I'm gonna have to start thinking before I post....

Hmmm, I guess more reason I shouldn't bother with a popcharger yet...
 

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Discussion Starter #19
Originally posted by Dissident+Nov 9 2004, 04:32 PM-->
<!--QuoteBegin-Daking350Z
@Nov 9 2004, 02:54 PM
You have to remember when staying N/A the car is tuned lean from the factory for emmisions.Anything you do to flow more AIR and not Fuel will lean it out even further..N/A a super AFC should work fine..

Yeah, guess I forgot the MAF was before the plenum, so it souldn't make much diffference... for some stupid reason I was thinking if the front got more air then the back would get more fuel. Stupid, I know. Man, I'm gonna have to start thinking before I post....

Hmmm, I guess more reason I shouldn't bother with a popcharger yet...

No man you got it all wrong..The only thing the MAF sensor does is monitor the A/F at idle and part throttle with the O2 sensors keeping it within specs..Once you go wide open all bets are off and the ECU loops into a pre set timingand A/F map..The only thing you do when you add an intake,plenum,headers,catpipes,and exhaust is make the engine more efficient in flowing Air in and out of the engine, which leans the car out..Goos if your running rich already..To maximize you hp you need to tune the A/F levels to about 12.5/13.0 ish...The whole reason for the Technosquare reflash,that you can do for half that with a super AFC and be able to tune it as you add mods that increses airflow..that whole ECU resetting stuff is BS...
 

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I'm WAYNE BRADY BEE-YOTCH!

Thanks for dropping the science...I thought the TS reflash was a bit pricey for just changing feul maps in upper rpm's & upping the rev limiter. The guys @ weapon & I were looking at the stock fuel reg. thinkin 'there has to be a better way'. I hope to get to F.I. eventually, but for now all mods will be for N.A., with an eye towards the future, where warranties are void & wives have hondas to drive.

Thx, Daking, nice to have people on the leading edge.
 
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