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Discussion Starter · #1 ·
Hello guys,

I just got the car back from Nizpro.... did the intake pipe and they have done a great job... and it surely does look very nice!!! And guess what?! THere is absolutely NO power gain at all from this gain (which I have sort of already expected because the plenum/throttle is not changed), but love the look of that...

The intake consists of:
1. 84mm bore diameter intake pipe with integrated MAF sensor (SS)
2. Aluminium bell mouth (a lot larger than the standard piece and down to 84mm)
3. Silicone hoses and clamps
4. Modify airbox to accommondate larger bell mouth...

I even lost 1 rwKW at the maximum rpm and a few rwKW in between 2680rpm all the way to 5000rpm and the rest of rpm ranges stay roughly the same... Simon from Nizpro says that this does not indicate the car actually loses power, but he would say it stays the same as the dyno conditions weren't the same (16/06/2005 vs 13/07/2005)... there is always a few kw gain or loss here and there sometimes when you re-dyno on different days...

So I guess most of the intake in the market should be roughly the same and the power will not change much unless you have changed to a larger throttle or a plenum since the amount of air going through the throttle is the same anyway plus there is no extra pressure to push the air into the throttle with just an intake....

Here are a few pics and enjoy them!

cheers,

richie
 

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yeah was going to say, at least it looks good

so apart from stock pipe Rich, you've just lot the air resonator?

my K&N intake pipe is red hot after a drive, yet the air pickup pipe is ice cold, i doubt there's a gain and i cant comment for sure since i couldnt go past 4000rpm before fitting the intake, but man does it sound good. With a plenum spacer it may make some power as itll shift more air on both ends

Rich any reason why u havent fitted a crawford plenum or spacer yet? I think thats a good move now u have the larger intake pipe. Ill split the shipping cost with ya if u go Motordyne :cheers:
 

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Discussion Starter · #4 ·
Sam:

I made my own air induction pipe from the front air dam to the intake area too.... and yes... the pipe is very cold while the pipes are slightly warmer... but not hot during this type of weather though...

I cannot do mods too quickly as it will run out of fun earlier... and also just bought a nismo oil cooler lately... so the plenum mod might be the mod early next year... I am still waiting for a pure n/a plenum to be released to be honest...

cheers,

richie
 

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I experienced similar results at the dyno with a Weapon-R prototype. No real gains to speak of. We have since revised the intake, but haven't gotten back to the dyno....They've nad good results with a G-35 tube....

Jinxxy, you're right in many respects. We found that by adding more air, we got.....wait for it......Lean. Air w/o fuel doesn't do a heckuva lot of good, & if you can't push it through (free flowing exh.) you got humjob. The 'unmodability', if you will, says a lot about the quality of engineering work Nissan did on the Zed.
 

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Nice one Richie that looks great!

Im sure this mod will come in handy once you make those other modifications to the intake path.

Is the transition from the bell mouth to the intake pipe smooth? or can I see a slight step which could be affecting the flow of air into the pipe?
 

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Discussion Starter · #9 ·
Murray:

the bell mouth and the intake pipe joint up pretty alright... quite smooth without any step.... but from the pipe to the throttle... there is a bit (the step is being the throttle itself) since the pipe diameter is larger than the throttle body already.... I will include some pics now..

Tell me what you think..

cheers,

richie

ps. I also found out that I "lost" around 6rwKW and 10 lb/ft of torque at around 4500rpm(although we cannot really compare the dyno results directly, it is indicating something else I would say.... I reported this to Simon and we might play around with the cams and the VTC again the week after next week to see how it goes...

cheers,

richie
 

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Originally posted by lionkiller@Jul 14 2005, 02:56 AM
We found that by adding more air, we got.....wait for it......Lean.  Air w/o fuel doesn't do a heckuva lot of good, & if you can't push it through (free flowing exh.) you got humjob.  The 'unmodability', if you will, says a lot about the quality of engineering work Nissan did on the Zed.


Yeah, in some ways its complete shyte.

If your engine is getting more air, an engine with an AFM that's been tuned properly will detect the fact that its getting more air and add more fuel to maintain the stoichiometric mixture.

That's the whole point of having an AFM, which is a much better system for tunability (and driving the car in a range of conditions).


If its not adapting to these changes in airflow, imagine what happens if you do some alpine driving where the air density changes? Guys with hard-tuned carbied sports cars have to adjust their carbies based on the temperature, relative humidity and air pressure to ensure the mixture is right. A modern engine is meant to be able to do that for you - it seems Nissan's is not.
 

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Discussion Starter · #11 ·
Just found out one thing on those 2 dyno curves... within the range that I lost both power and torque simultaneously, the Lambda reading of the latest dyno shows that the car is running slightly richer than the previous result... so that might cause the loss of the power... and other rpm range areas show the same power and lambda reading (nearly exactly the same)...

so I THINK it might just be the tuning on the cams profiles... since the new dyno sheet ID says..."Intake pipe plus 2 deg minus 1.5f"... and most likely it is due to the cams setup...

cheers,

richie
 

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If your engine is getting more air, an engine with an AFM that's been tuned properly will detect the fact that its getting more air and add more fuel to maintain the stoichiometric mixture.

That's the whole point of having an AFM, which is a much better system for tunability (and driving the car in a range of conditions).


If its not adapting to these changes in airflow, imagine what happens if you do some alpine driving where the air density changes? Guys with hard-tuned carbied sports cars have to adjust their carbies based on the temperature, relative humidity and air pressure to ensure the mixture is right. A modern engine is meant to be able to do that for you - it seems Nissan's is not.
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The Nissan does all of that.
The MAF sensor has an air temp sensor incorperated into it. It also has a fuel temp sensor in the fuel tank.
One of the reasons for the small power loss could be that it is now running slightly leaner, I'm not sure but Simon would probably have checked that.
The Z MAF sensor is a hot wire system. The voltage that goes to the ECU changes as the hot wire cools down as more air passes over it as the revs increase.
The OE MAF sensor has an inside diameter of 72mm, this sensor has now been placed in an 84mm pipe, so at the same revs the air flow will not be as fast in the big pipe as in the smaller pipe & the voltage will be different. Probably only by a small amount but unlike the OE ECU, the MoTeC can be tuned to compensate
 

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Discussion Starter · #13 ·
Peter:

I am not too sure how to read Lambda reading... where I lost around 6rwKW has the lambda reading of 0.92 (previous) vs. 0.88 (current) after it was retuned for the larger pipe...

And I think you are correct there about the pipe diameter... I would reckon the air flow will be slower.... but will the larger bell-mouth compensate that? or is there anyway to accelerate the intake air in the pipe at all?

cheers,

richie
 

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Discussion Starter · #15 ·
Murray:

Yes.... Simon spent around an hour to re-tune it... and most likely due to the a/f ratio that makes the diff. of the power... because other than the mid range, lower end and top end on both before and after dyno numbers and the lambda readings are VERY close... only the mid range numbers are off...

cheers,

richie
 

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I cant see the inside of the pipe but it looks to be quite step/change where the intake pipe meets the throttle body. Perhaps see what options are available to smooth that transition before you get another tune. Ask Simon what he thinks is possible.

The intake pipe is alot bigger than the TB but you could bore it out a bit and give it a bit of a bell mouth. This should reduce the difference a bit so the air isnt hitting that step. It will be interesting to see what he says.
 

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Discussion Starter · #17 ·
murray:

I get what you meant.... because the whole intake pipe basically EATS (covers) the engine throttle body... but many turbo pipings are like that though... so would you think that will affect anything? I am sure if it is bored out slightly to give the bell mouth shape at the front of the throttle body...

cheers,

richie
 

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I think we should have a mythbuster team on this forum, we already have the intake pipe and I'm also willing to submit my plenum.
 

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Discussion Starter · #20 ·
Sam:

I busted that one already.... the grounding kit does not give any effect to my car at all though.. cannot feel ANY different what so ever from this Apexi grounding kit + reverse electricity prevention box or something... but it grows in the dark... will show a photo or two later...

cheers,

richie
 
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