mtcookson

iTrader: (2)

could i theoretically run 2 maxima maf's at the same time and run them through the afc and it still run correctly? i have 2 maf's and i'm thinking i could hook them both up, run them through the afc with the dual maf setup and be able to handle much more power but i'm not sure if the voltage will be incorrect for the ecu to read. any ideas? thanks in advance.

90SEBlack

Pffffffffffffffeeeeeeeee unno man ur on ur own with that one, Sounds like it could be promising but also sounds like it could be a big flop but there only one way to find out, let us know how it works.

mtcookson

iTrader: (2)

yeah... i might try it in a few days.

90SEBlack

Wish i had a spare MAF laying around to mess with the idea but needless to say i dont so i cant do much with the idea but if it does work it may also pose the idea of using 2 Z31 MAFs for even more gains ???? unno u got me thinkin about it now

mtcookson

iTrader: (2)

i think the maxima maf can only handle 250 hp if that. around the power/air flow i'm pushing now its reading nearly 80% airflow or more so i'll need some more room pretty soon. if they do read 250 hp i can run them both and both should be able to support 500 hp or so... depends on the airflow i guess.

DA-MAX

iTrader: (10)

Maxima MAF is good up to 330whp according to Clark at JWT...as for your dual Maxima MAF/AFC idea, personally that sounds like a tuning nightmare to me, ECU will probably blow its brains out trying to figure that **** out. you're probably MUCH better off with the Z32 MAF and bigger injectors.

mtcookson

iTrader: (2)

well, the way i was thinking by having two maf's that would split the airflow two ways cutting the voltage in half from both of them. after that, i run them through the afc and set it to add both voltages then send it to the ecu. i think it would work... but i'm not sure. now that i think about it when they starting reading airflows higher than a single stock maf can read the ecu might freak out. guess i'll have to try it out to be for sure. if i can't get this to work i'm going back to my original idea of just getting a z32 maf.

MrGone

iTrader: (30)

question:

are you thinking of running it like this:
(= is a MAF)

= =

or

=
=

I suppose an easier way to ask would be series or parallel.

mtcookson

iTrader: (2)

for it to work the way i was saying i would have to run them through seperate pipes to cut the airflow in half for both of them. if i run them inline i don't think it would work the way i'm wanting it to.

= = would make them both read the same thing but

= would make them read half i believe.
=

MrGone

iTrader: (30)

when I first read it, I assumed you would have to run it
=
=

but then I thought if you could get away with = = it would be soooo much easier to install.

mtcookson

iTrader: (2)

yeah, if i ran them inline i could go do it right now since one of my maf's is installed right in the metal piping (kind of hacked that one up a bit). the next one i could run right before the turbo pretty easily.

i think if i could run them inline and add the voltages together then cut them in half with the afc it would work just like the seperate pipe idea. arg... i'll have to think this through a bit more. i'm not sure if that idea is correct or not, lol.

MrGone

iTrader: (30)

maybe Addae knows?

DA-MAX

iTrader: (10)

and thats why for a long time I've been trying to find decnt info on the Z32 and Supra setups, but I'm too lazy to REALLY search deep into it, but this is some decent Supra info I found recently-->

http://www.moreboost.org/dual_maf.htm

mtcookson

iTrader: (2)

yeah, that's the kind of setup i think i would need. i think i would try running dual filters as well for better flow if at all possible.

DA-MAX

iTrader: (10)

okay, well then you can rock this....

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2451573638

those stock SOHC Civics need all the airflow possible

mtcookson

iTrader: (2)

sweet, only 30 bucks. lol

they need lots of airflow...? well no wonder they put on those huge 6 inch fart cans.

internetautomar

iTrader: (30)

the MAFs real limitation is size. Port it and increase the bore and you'll see the same gains with less headaches

mtcookson

iTrader: (2)

how would one go about porting and increasing the bore? the plastic is pretty thin as it is. only thing i can think of is to hack it up like i did and stick it in a different pipe. would that work?

MrGone

iTrader: (30)

I always thought it was the MAF itself and its ability to heat up/etc and measure the air?

mtcookson

iTrader: (2)

actually, it measures the air by cooling down the heated element.

oh crap... that makes me think... would hot compressed air coming out of a turbo affect the reading of the maf? (since the element gets hot and it measure airflow by the air cooling it down)

DA-MAX

iTrader: (10)

hmmmmm......

http://www.zilvia.net/f/showthread.p...ght=hacked+maf
http://forums.freshalloy.com/ubbthre...b=5&o=&fpart=1

MrGone

iTrader: (30)

well yeah, thats what i meant, but what if it the ammount of air being pulled at 330hp is the most that it can register, where say a maf that can handle 500 hp might be alittle hotter when there is less air going past it. I'm kind of going out on a limb here. Does that make sense?

(if that idea works, then it could also mean that you'd have to run the MAFS in parallel as opposed to series)

shoult

iTrader: (1)

?????????????????????

Are you going to run dual throttle bodies as well? If you just running two MAF's and running them into one throttle body what is the point? The limiting factor is the resistance to airflow in the intake rather them the ability to measure it. That is why you see people installing larger throttle bodies.

With two MAFs into one throttle body you have created one HUGE bottleneck.

I believe you can accomplish what you want easier by just using the S-AFC II and the stock MAF/TB setup with a lot less money, time, tuning and heartache.

If the time comes that you really need to exceed the capabilities of that you can always go to a GM or Ford V8 MAF/TB and an add on computer or standalone computer.

mtcookson

iTrader: (2)

you don't need two throttle bodies to use two maf's. by using the 2 maf's, they allows me to push more power without the need of reprogramming to use the Z32 maf. (at least i think it should work.) i may try some more maf hacking like the guy did on the freshalloy link.


ahhh crap... guess i better go measure the piping and see what the inside diameter is. its in a 3 inch section of pipe but the way it is set up there is a smaller pipe right before it. that thing better not be the reason why i'm running so rich.

StinkyZ

Why would you want dual afms? The way I've heard it being done is to create a larger afm housing or some sort of bypass to allow extra air to bypass the afm. Of course you need some way to compensate for the extra air. Maybe one afm reading and one afm just letting in more air would work but i think the second afm could just be replaced by some pipe. I thought about putting is some large diameter pcv pipe with a valve in parrallel with the afm and using the valve to adjust how much extra air is let through.

MrGone

iTrader: (30)

the reasoning behind the 'hacked' MAFS is to allow slightly more air into the engine so it will lean out just alittle (more power), but not be enough so that its dangerous. (look at DA-MAX's links, and the descriptions of the AF readings).

MrGone

iTrader: (30)

(oh and Addae, I hate you, because you got me on alittle 240sx spree.... which lead to a skyline spree... I'm talking about trying to buy. Just imagine "would you be interested in a 68 mustang for your car?" "no? oh well" )

DA-MAX

iTrader: (10)

Shawn I tell you man...I'm on a new "spree" EVERY week, but I'd seriously sell my organs for a 510 or 280 right now!!! SC'd V8 swap all day

stephenlc

iTrader: (1)

Where do you have the MAF's? Before the compressor or after the compressor? If it is before the compressor than that is easy, just run two filters. You can always do what Mardigras said. Run 740cc injectors and have two MAFs, one not conneted and one connected. Look for that post in the supercharged forum.

DA-MAX

iTrader: (10)

but there is no solid proof that that will even work

shoult

iTrader: (1)

[QUOTE=mtcookson]you don't need two throttle bodies to use two maf's. by using the 2 maf's, they allows me to push more power without the need of reprogramming to use the Z32 maf. (at least i think it should work.) i may try some more maf hacking like the guy did on the freshalloy link.[QUOTE]

If you problem is that you're running lean just use a SAFC II. You don't need all the extra piping. Dual MAF's won't get you more air flow because the limiter is the throttle body. Because you're using two MAF's you'll have to figure out a way to either combine the signals or toss one out.

It sounds to me like your real goal is just trying to trick the ECU into thinking there is less air then their really is flowing through. If you are lean through the ENTIRE rev range under ALL load conditions you may be able to fool the ECU with dual MAFS. Then again, you could acheive the same thing with a simple resistor bridge.

Personally I've never run a vehicle that was the same amout of lean or rich under all conditions.

If your having problems get yourself a GOOD Air/Fuel meter (not one of those stupid 10 digit units!) AND an add on fuel management tool like the SAFC II.

Yeah, it costs money but so does speed. How fast do you want to go?

mtcookson

iTrader: (2)

my problem at the moment is running rich throughout the entire range at any load but the dual maf idea isn't for those purposes. i'm wanting to do the dual maf for the ability to read more air.

the maxima maf's don't read very much. my maf is reading 80% and more on the s-afc 2 at only 7 psi. i'm wanting to hook up both of the maxima maf's that i have so i can read more air than a single one would be able to. if i can't do this then i would have to get a z32 tt maf and have my ecu programmed to read it.

shoult

iTrader: (1)

Like I said MUCH earlier, ditch the Max's MAF and get a MAF from a Mustang or Camaro V8 then. They'll measure (and FLOW) ALOT more then the Max's. Of course you'll have to figure out how to integrate that into the Max's ECU, but that doesn't sound as hard as trying to tie two MAFs into an ECU that's only looking for one.

But you'll need more then just a bigger MAF (or two small ones) to get any real benefits. You will need to increase ALL the airflow bottlenecks AND control the fuel management.

You also mention that your running 7 psi. Is this Turbo or SC? What type of intercooler? A2A or A2W or none? If you're running 7 psi you'll probably need to lower your compression to get much more then one more pound of boost out of it. I've run cars successfully upto 14 psi at 8.5:1 static CR w/A2A intercooling. But those blocks included tricks like oil squirters under the pistons for cooling and 2 different special coatings on the pistions. The tops get coated with a heat reflecting coating and the pistons sides were coated with a friction reducer.

You can reduce your static CR about .5 by using a 1mm thicker head gasket on most vehicles. Of course it depends on your current CR and the combustion chamber volume. That'll let you crank up the boost a little further before you run problems.

And since it sounds like you are really trying to increase your boost levels you really should install one or two ( one in each bank) EGT sensors and gauge. A/F Meters are too slow to show that your pistons are melting until they already have.

Good luck!

mtcookson

iTrader: (2)

i actually swapped in a jdm vg30et. the cr is about 8.3:1 i believe.

with the s-afc i can run two maf's to its signal wires then have it output whatever signal i want to the ecu through one wire so it actually wouldn't be all that hard. i'm just not sure if i can get it to work properly. i can get my ecu reprogrammed to read other maf's but at the moment we are having a hard time getting it to even control the fuel properly so i have to turn down the afc really low. bernard, the guy doing my ecu, is trying a different way of programming it and we'll see if this will control it better. if it does work then he should hopefully be able to program it for the z32 maf... but i'm not sure yet due to the different programming.

right now on this engine its all pretty much stock. cr of 8.3:1, 260 cc injectors (i think), 84-86 turbo off of a 300zx, and no aftercooler (intercooler). I'm planning on building the stock engine out of the maxima since i just have it laying around so i'm planning on putting the vg30dett rods and crank in a getting forged 9:1 compression pistons. I might go to 8.5:1 compression but i haven't decided yet. i'm planning on getting an upgraded version of my turbo that is much bigger and is supposed to push up to 25 psi. i'm still trying to decide on how to do the aftercooler. i may go top mount or front mount but haven't thought out how to mount it all yet. i'll do all of that in the near future though.