Hi guys,

When fitting an upgrade air take that eliminates the hole std box, what do I do with the sensor wires to stop it going into safty mode?

A diagram of the loop out or reconnections

would be pukka.

 

cheers harve

Erm.. Aerm...

 

You don't eliminate any sensors when replacing the airbox... The MAF (thing attached to the airbox with the wire coming out of the right hand side) stays..

 

Assuming you want your car to run, that is..

 

Az

 

------------------

Stage: Rather Ill

The only thing that you might be doing I suppose is splitting the airflow and mounting the MAF on one side only, or going for the full dual entry (fnar, fnar) twin MAF setup, then getting the special reprogrammed JWT chip to make it all work.

Oh yeah.. durrrr I just read the subject heading again.. (slaps forehead)

 

OK - let me retry my answer

 

Single POP/filter, my advice stands.

 

Dual POP - you have two choices..

 

Dual filters, one MAF, one dummy. ECU reads half the input air flow, therefore you need a remapped JWT chip or a AFC computer to 'fudge' what the ECU thinks is going on (so that it sees basically twice what the MAF is outputting).

 

Dual filters, dual MAF. I *believe* you still need a remapped ECU for this.. Not 100% sure..

 

FYI dual filters, single MAF seems to be the most popular setup for the sub 600bhp cars in the states..

 

Az

 

------------------

Stage: Rather Ill

BUT, if you've got the twin set up that is 2 cones on 1 pipe going to AFM adapter, then no chip required, working on building this kit for me own Zed, will let you know when it's done, Smithy

p.s there are currently 4 different types/setups of induction kit available for the Zed, so plenty of choice

OK OK I missed one out, so sue me

 

One question though, is there really much advantage to having two filters joining to one AFM, then back into two intake tracts?

 

Aren't you just creating a restriction that is equal, possibly worse, than the standard restriction of the AFM?

 

Az

but whats the point then smithy you still only get the same maximum air out of the air flow metre, which is the restricting part on the system. Hence the reason they create a twin pop in the first place.

No it's infact quite the opposite, have worked on induction kits over the years on many cars and the Zed is the most unrestricted version i've come across, other turbo cars have the sensor/hotwire tucked away inside the AFM behind an alloy wall, only about 5mm opening to read air mass, the other ends are then reduced in diameter by nearly 50%, the Zed however is 80mm all through with a mother fucker large hot wire bang in the middle, no alloy wall, that's why our AFM are snapped up, they are used for upgrades on smaller turbo engines, the AFM reads the air mass coming in, sends a signal through engine and onto ECU, once read, the correct amount of fuel is then dumped in engine to match, hence more power, you don't see much improvement with an average induction kit do ya ? with twin filters and 1 air flow meter linked, the mass air flow is increased by 250%, and that will make a difference, a decent one too, basically then the AFM will read what ever you chuck at it and tell the ECU, there is a simple reason why the Stillen set ups require a chip, will explain if you want.

when i do this for mine in few weeks, we will then be selling it as a kit, again in stainless including the cones, anyone who has a fairly standard car and fancies one, they can have it half price, with a money back gaurantee that it will produce POWER, Smithy

Hmmmmm! money back guarantee? Smithy m8 can

you name me an induction kit that does not

give you more power?How much will you be asking?

 

------------------

 

[This message has been edited by MAC 1 (edited 22-10-2001).]

the airflow metre on a 300zxtt can only read a maximum of 5.17 volts which equates to a figure of a maximum of 475 Horsepower. basically when you are trying to suck enough air into the metre to obtain the horspower, the litle thingy maxes out at that voltage, which in return stops the system from taking in any more air than is required to create more power. This is the reason companys move over to a twin induction kit, and dummy the air flow metre to one side, tricking the engine into thinking it can take twice the ammount of air into it. My two cents, and i have this on good authority..

AHHHHHAAAA! now that makes sense Wazza!

Iain when i mention more power, i mean more POWER, i.e alot more than single on it's own, yes all kits offer more, but usually very very low unless coupled with new Zorst. price is unknown yet, will let you know when my own is done, interested to know how those volts equate to that amount of bhp, what calculation is used, cos we all know there are some really big bhp Zeds out there, using an HKS single or similar, if the reading stops at 475, they will run as lean as fuck, even taking a 500bhp one, this is quite an easy level to attain, with out a chip as well, they don't lean off at 475, if they did, 1 knackered engine, don't forget it is not just voltage that the ecu relies on, mass air is pulsed whilst inside the pipe work, believe it or not if you could get the AFM closer to the throttle body, the pulse would be stronger, hense more power, that's straight up !

First off i would like to see a genuine 500bhp single intake 300zx with charts to prove it. And i think you will find most of the Big power HKS cars have a vein pressure converter, which effectivly does away with the airflow metre then.

 

Im not saying 500bhp is not possible, hell i think im around that power, but then my mines ECU is a compleetly seperate unit, and my airflow metre has been played with.

 

By the way i have read about this in Options magazine from Japan, the article actually comes via Escort (Big name jap comapny)

But if it runs out of air (bad description) at high rpm then it will run rich not lean. The trick must be in the remapping of the ECU that can take account of the extra air being flowed, even if the voltage has maxed out- kind of a scale shifting thing, which is what all JWT maps do actually.

 

The only reason I can see for it running lean at high revs is if the ECU gets confused with the volume of air being passed and cuts the fuel too much, while more air than expected is getting through. Also, you should not discount the 'ram air effect' that you tend to get on the road, but not on the dyno, assuming that the airflow around the front of the car has been designed properly.

That's it Andy ! you can't stop the air coming in, so if the AFM can't equate to more than 475, you still end up with masses of massed air in the system,still being pulsed and not enough fuel to cope if this equation is correct, so hence lean, chips as we all know increase the fueling cycle and timing settings to retard it to get more fuel higher up the revs, but then the injectors starting to run out puff, Smithy

my brain hurts now, i'm going to bed !!!

Smithy don't go to bed yet!!! This is just getting warmed up matey

 

------------------

Interesting stuff,

I dont really want to go to a new chip & gear, just optimum cool air flow.

IF I have two rubber pipes off the two steel side pipes going to two cones,(all 65mm) with a 65mm bridgeing pipe between the two to read air flow. To make like a H section

would it read ok?

 

Or senario 2, put lastnights work back together, & have a 80mm twin branch off the std meter to 2 80mm cones going down to behind the bumper?

 

Anythings got to be better than the shoe box I ripped out last night.

 

Oh yea i found a sparrow! in the front rad,

the birds just cant leave it. LOL

The H-pipe won't work...

 

The MAF will still read the incorrect airflow, so the car wil stall, hesitate, etc.

 

If you don't want to buy the dual-intake chip, you would need something that doubles the output-signal of the MAF.

I'm currently looking if this can be done with our conZult-software, but probably a small electrical amplifier that doubles the signal would do the job as well

 

BTW: if you choose to use two MAF's you'll need to get an Apexi AFC (or similar) as well, since the ECU isn't able to read two seperate MAF-signals..the AFC combines the signals into one signal that the ECU understands again

 

-Eric

 

[This message has been edited by lymon (edited 23-10-2001).]

Ok here goes, exuse the length.

 

The Nissan factory air flow metre has niether the airflow capacity or the hotwire voltage resolution to supply the needed air or ecu headspace for an engine supplying more than 478 horsepower.

 

Nissan uses a hotwire airflow metre to measure the ammount of airflow comming into the engine. The airflow metre works by having a wire heated to a certain temperature set in the intake air stream, while controll circuitry in the airflow metre keeps the wire at a constant temperature.

 

As more air flows past the wire, the cooler it becomes, so to maintain a constant temperature, the controll circuitry increases voltage to the wire as necessary. The ecu reads this voltage so it knows how much air the engine is ingesting, and thus calculates the proper ammount of fuel it needs to inject.

 

The Nissan ecu can only recognise up to 5.115 volts of signal from the hot wire airflow metre. Now Engines modified to produce more than 478 bhp will have a signal of over 5.115 volts.

Therefore it doesent matter how many air filters you put onto the airflow metre you will only get a maximum of 478 bhp

Hi,

 

Just thought I would add my pennies worth.

 

Surely the best solution is two MAFS, one on each intake. This will ensure an equal balance of air intake is read for each half of the engine, and provide twice the airflow.

 

We need to then make the signal to the issue correct because it cant take two readings. So we need a little OP-AMP circuit which will set to provide the difference bewtween the two signals. This will be the average airflow of the two readings and more accurate than the existing setup, and more acurate than the one MAF sensor with dual filters.

 

Leigh.

 

 

you will only be able to MAP for 478bhp, and have to best guess everything above that.

 

you also need to find out how much air is passing through to make the max voltage, and compare that with the actual max flow achievable for the afm

 

this will help you determine what the real max bhp the AFM will flow, and how much you will have to blindly adjust the fuel maps for...

 

otherwise, you recalibrate the afm so that it sends 5.115v at it's max actual flow rate, and then adjust all of the maps on the ecu to compensate, rather than the high rpm maps

 

if you run two afm's, and do some jiggery-pokery™ to send an average, then you still have the problem where the ecu thinks you have half as much air as you actually have... you still need to adjust the maps

 

 

imho

 

------------------

UK 92 TT White(ish)

Mongoose K&N AVCR

KYB Eibach

RLTC

 

[This message has been edited by craig (edited 23-10-2001).]

Okay, without getting to technical or giving meself a sore brain working all these things out, going back to the beginging, standard or near standard Zed owner wanting as much air in there as poss, is better buying a twin stainless cone set up, going to one AFM adapter, yes or no ? suppose yes, this same guy then a year later decides to go large in bhp terms, we all know chances are he is going to chip, so the full advantage of the twin set up can be used again, yes or no.

I'm looking for a test pilot come end of November, must have standard car or no more than induction and Zorst and MUST be willing to go on rolling road for before and after figures, kit will be half price and using all stainless parts, cones included, if you already have induction, will take 30mins max to swap, i will fit to my car 1st then post pictures, no rolling road in i.o.m see.

let me know if interested, Smithy

will be interesting to see, cause i dont hitnk it will make more power, cause you get back to the root of your limiting factor of the airflow metre, but will be good to see. why dont you coinside it with our dyno day that i am just about to get on the blower to find out

If you use the Apexi AFC I believe it has inputs for two MAF sensors so the ECU can understand what's going on.

 

Anyhow, I've got the JWT dual intake chip which works great. I've also got the driveability upgrade which stops it from becoming a pain when at low revs/idle with the revs all over the shop. (This is a mod to balance the left&right intakes under idle... something like the right hand side of the plenum with the left re-circulation valve... or there abouts...????)

 

 

Never have i learnt so much from one thread,

the input is most impressive.

After making a heap of phone calls today, and reading the above the sensor is expensive to overcome. So leaving the std pipe & sensor where it is - is the way to go for now.

Is there any big no-no's with making a 80mm curved T section that custom fits onto the sensor, taking 2 80mm cones on it, (going at 85 degrees forwards) behind a removeable frost screen to stop them freezing up in the winter months.

Spring etc take 'em off.

 

As I intend to make this tommorow, because i had to muller the box to get it out & can't drive my Zaby.

 

Next problem which cones will do the job,

K&N-GREEN-PIPERCROSS etc, bearing in mind the intake area will a total of 160mm, not inc the manufactures (area of surface).

Preferances welcome guys.

 

thanks - harve.

 

 

K&N - oiled - no question. (IMHO)