I'm looking to upgrade my MAF on my S14 and wondering what the Z33 maf can flow...

I could just go the 300zx MAF route but I got a killer deal on a Z33 maf and was just wondering what everyone is maxing out flow-wise (psi/horsepower before voltage runs out).

Thanks

 

Around 12-13 PSI of boost on a 60-1 compressor is what I have seen. That was well over 40 lb/min...

 

It should really be around 6psi without using a piggyback to rescale it.

 

I don't use a piggyback and the reflash shouldn't affect the voltage reading of the MAF sensor...

 

Damn that's not enough...I have a S15 T28 60 trim and want to do 15/17psi but the stock S15 afm maxes 4.8V at 15psi and causes break up. Too bad since the price is a steal on the Z33...

Looks like I'll have to get raped and pay marked up 300zx maf costs

 

I'd save the hassle and use the Z32 MAFS like most others in your situation.

 

They changed your settings in the ecu with the reflash. Im sorry but our maf isnt big enough to effectivly meter 20psi of boost, or even 15. There are ways to do wide open throttle fueling without changing your maf out but its not a very good thing to do. Basically in simple terms your MAF would be maxed out at say 6psi, but the ecu keeps dumping more fuel in and ignoring the MAF readings. I would like someone to check thier turbonetics reflash MAF with a voltage meter at wot and see when its maxing out or what the voltage is.

 

My MAF voltage at 13.5 PSI on a Dynapack was 4.85~ volts. Explain to me how the reflash alters the voltage reading with a multimeter. A quote from Gurgen regarding his MAF max out point with twin turbos:
and please show me where I stated 15-20 PSI of boost. I said 13 PSI and greater then 40 lb/min.

 

I said i would like to know the voltage of the MAF with a multimeter under boost on a reflash. I have never seen this data. 4.85 is a little close to the edge. 13.5 psi is pretty good on the stock one but i have also read on this forum that it maxes out at 6psi. But you are getting 13.5psi through the stock one. The TN setup uses a blow through setup right?

I would just like to see more data on this and why some people say it maxes out at 6psi and others at 12-13psi. I have also read you can get up to 600hp on the stock maf with a reflash but that just does not seem right.

The reflash will not alter the voltage reading with a mutlimeter but i was wondering how technosquare recalibrated it to work underboost, and to see when your voltage maxes out on the reflash, to see how they did do the fueling under boost.

 

Like I said measured with a Voltmeter (Fluke 77B) the voltage for the MAF signal pin was 4.85 volts at 13.5 PSI on a 60-1 compressor section. This was under boost of course (blow through setup) on my car on a Dynapack dyno in Simi Valley, CA. There's more the one person running 9-10 PSI daily on their Turbonetics equipped 350Z/G35 without the MAF maxxing out... FYI 13.5 PSI is the point at which my car maxxed out on the dyno... It read 4.85~ volts and then went into limp mode...

 

Thanks mia whats what i wanted to know. So the stock MAF should be good and safe for 10psi. Im not trying to question you I just wanted some information, as I am trying to figure out some things.

 

Like MIA said

I saw 5.05-5.10 volts at 4000-5000 rpm on PE Twin Turbos at 6-7psi. I think this is because PE flow a LOT more in the mid range because of their extremely high efficiency at 4000-5000rpm and lower boost levels. Granted, this was on an older MAF (type I car - first half of 2003 model year G35 sedans). But I do not see it being much higher on the newer MAF that I am utilizing now (current model). In fact, the newer MAFs in VERY well controlled experimental runs goes to 4.5volts (it's technical OEM usage limit) on near-stock N/A VQ35 car (4.5v at 6600rpm). Here is the log to prove it. The last orange descriptor is MAF voltage, 4.48V at redline (6680rpm).

 

Thanks for the info Gurgen. The thing people need to remember is that its not PSI but CFM thats causing the MAF to max out. Two PE1420s at 8 PSI may very well be greater CFM then one 60-1 at 8 PSI..

 

actually, PSI is more related to back pressure rather than one compressor flowing more than another at a certain "psi."

This is more easily understood if you were to think about a setup like a belt-driven vortech.........

For example, take a car setup with a vortech and stock exhaust, cats, etc on it. Let's say that the blower is moving 600 cfm of air and you are getting a manifold pressure of 10 psi, all at 6000 rpm.............

Now, let's change the exhaust, headers, test pipes, etc on this car. Now, the exhaust is significantly improved on this car and the engine can expel spent gases with greater efficiency. Without changing any pullies on the engine/blower, we are still moving 600 cfm of air at 6000 rpms, but now the manifold pressure is only 8 psi.

In a turbo application, you are likely to have significantly higher back pressure between the exhaust ports and the turbine due to the size and length of the piping to get to the turbine and also the T3 turbine on the 350Z Tn kit as that kit was only designed to be able to support upwards of 400 rwhp. MOst of the twin kits on the market will have significantly better exhaust flow, hence the lower "psi" reading of a twin kit as compared to the single at similar power levels.

In my car, I achieved the same power levels with the Greddy TT as the TN ST but at very different boost levels. The TN was just about 9 psi....The Greddy was rigth at 5 psi. It would have great to have a CFM comparison of the 2...I bet it would have been the same.

 

Your supercharger model does not apply hear. PSI is the reading the compressor is perssurizing the air above ambient pressure. This is in direct correlation to the amount of CFM being flowed. In either a single or twin turbo setup unless the exhaust valves and intake valves are stuck open there will be a pressure increase in the intake tract. I don't care if you have 50 turbos if their wastegates are set to 8 PSI they are all going to pressurize to 8 PSI above ambient. I also could care less if you had a 7 inch turbo back exhaust and a 2.05 A/R T4 turbine housing you are STILL going to run 8 PSI if your wastegate is set to that. What makes the difference between the singles and twins is the CFM output of the compressor. A 60-1 compressor at 8 PSI is creating ~42.5-45 lb/min of outlet air flow. Conversely each one of your Greddy TD05-18G turbos are producing 23-25 lb/min at 5.6 PSI above ambient. When you combine their independent flow you can see why at 5.6 PSI you are equaling what the 60-1 produces at 8 PSI. This has ZERO to do with exhaust back pressure or intake pressure. I gurantee you if I added a second 60-1 compressor to my car also running at 8 PSI I would see much more power then I am right now. There is a reason Jim Wolf draws a direct correlation to his turbo nomenclatures (BB530, BB700) and the available HP with a PAIR of these turbocharger. Neither of those units are anywhere close to capable of that on their own. He rated them as a pair on a Z32. Consequently if you half those numbers (530 and 700) you get the quote power potential of each unit from Garrett. As an FYI your supercharger example while completely not related to this topic has its merit. The reason opening up the exhaust side on a supercharger reduces pressure above ambient but increases or maintains horsepower is that yes the engine is more efficient but you have not increased the shaft speed of the compressor to maintain the amount of pressure above ambient ou previously had. Bascially the supercharger being belt driven is going to the same shaft speed it had pre headers or whatever mod you added. With the decreased pumping loss the amount of pressure build decrease as the engine is able to better handle/flow that air. On a turbocharged car the shaft speed WILL increase as the wastegate will stay closed longer until it reachs the set pressure ratio independent of shaft or engine speed and regardless of pumping loss.

 

Important to measure the pressure drop [with a manometer] across the MAF as even the Q45 MAF has 7" H2O [1/4 psi] at 255 g/sec [330 HP].

The Q45 MAF reads ~~4.34v @ ~~420 CFM at that restriction so in theory it has enough range for 450-500 HP.

Decide on the largest diameter housing then assume the housing and element track

 

Interesting read... however I thought this was only true for positive displacement screw type superchargers like Eaton/Magnusun (Stillen), not the centrifugal types (ATI, Vortech). Or is it true for both but more true for one?

 

It should hold true for both superchargers. Neither of them increases shaft speed based unless the pulley is replaced. That means that regardless of the volumetic efficiency change of the motor the shaft speed remains the same but the pressure over ambient will drop as the motor can better flow the added air/compression. The only system that would don't this is a turbocharger where a wastegate is preset to a specific pressure ratio and the shaft speed of the turbocharger will increase to meet the set pressure ratio level.

 

You are right on that one.

 

I'm not following you on this one...... earlier you stated that "Around 12-13 PSI of boost on a 60-1 compressor is what I have seen. That was well over 40 lb/min..."

Turbonetics Compressor maps show that at a 8 PSI (1.5 Pressure Ratio), a 60-1 could be flowing any where from about 12 - 42 lb/min. You stated max flow for the 60-1. That is assuming too much!!! If you have a small engine/plenum, and also a restrictive turbo manifold/exhaust, someone might only be flowing 12 lb/min @ 8 psi....where as another person with a BigBlockChevy V8 maxed out for full potential may be at the 42-45 lb/min end of the spectrum @ 8 psi.

http://www.turboneticsinc.com/cm_t4601.htm

My whole point to this was not to argue with you, but to point out to the OP that one cannot use "psi" to judge just how much air an Air Flow Meter can handle. going by "psi" is very misleading, but it is, unfortunately, a commonly used measuring stick by people. About the only place where a "psi" comparison means anything is if you are comparing 2 identical setups. Turbochargers, their flow, PSI rating, and potential HP, are very misunderstood by so many people. I think it's great to see that Turbonetics is thinking of implenting a compressor wheel rpm pickup into the cartridges of their turbos....knowing just how fast the turbine is spinning will help alot of tuner/racers out when diagnosing theirvehicles.