Sonny

I have a 2002 Supercharged Nissan Frontier. It uses the same M62 Eaton supercharger that is in all of the Jackson racing kits.

It's nice to have another OEM boosted car, but I noticed something about Nissan's setup. They put the intake air temp sensor in the airbox. This makes no sense to me at all because the ECU never knows the true intake air temp. This truck does NOT have an intercooler either, so it is very common for the performance to drop off after the air temp starts to go up.

I'll have to check the specs on the sensor to see it can easily be relocated to the manifold.

Thoughts?

Here's a few pics:


BTW...the CRX is for sale to help fund this truck. PM me if you want a screamin' deal on a 1900lb smog-legal car with a built motor that will easily do 11's with a decent turbo.

Sonny

mrbsponge

i dont see why you couldnt move the sensor i moved mineon my supercharged civic si and it ran just fine.

if you mod the truck i would suggest either some water injection, or a pwr type set up for the cooling duties

RacerXI

It's nissan. Ever try to work on a 300zx? Nice to see you're still around and tinkering.

green_GSR

You're right. The air temp sensor should be on the boosted side. Why did Nissan put it on the vacuum side? I have no idea. Maybe because the intake air temp sensor is so flimsy that it'll exploded into many pieces when pressurized. Or maybe their air temp sensor is so crappy that it's an maintenance item, and it'll be a b!tch to access the sensor if it's located on the boosted side.

Sonny

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RacerXI &raquo;</TD></TR><TR><TD CLASS="quote">It's nissan. Ever try to work on a 300zx? Nice to see you're still around and tinkering. </TD></TR></TABLE>

Tinkering is in my blood.

My buddy has a 300ZX twin turbo. That engine is sooo tough, but it needs to be. That has to be one of the all-time nightmare cars to work on!

Sonny

Enthalpy

becasue it is just there for OBD2 compliance.

the truck runs off the MAF sensor. it isnt speed density. see that thing at the end of the intake pipe...with the red plug. yes...thats your mass air meter. us nissan guys deal with them all day

Sonny

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Enthalpy &raquo;</TD></TR><TR><TD CLASS="quote">becasue it is just there for OBD2 compliance.

the truck runs off the MAF sensor. it isnt speed density. see that thing at the end of the intake pipe...with the red plug. yes...thats your mass air meter. us nissan guys deal with them all day

</TD></TR></TABLE>

Well, I have to admit that I am a MAF n00b. Does the MAF-based system not care that the discharge temp of the blower can be vary by over 100 degrees?

Every boosted car that I've worked on has the IAT in the manifold, but they were all speed-density (MAP) based systems (Honda and Mazda).

Sonny

green_GSR

Well, the MAF has the air intake temp built in. Most of the MAF's, especially the OEM ones, are not meant to be boosted, so the only option is to put it on the vacuum side. Remember that OEM cars also have other sensors like the knock sensor, 02 sensor, etc. to monitor the engine. So if the engine does knock from the hot discharged air produced by the blower, it'll just pull the timing. That's the way I see it.

VTC_CiViC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RacerXI &raquo;</TD></TR><TR><TD CLASS="quote">It's nissan. Ever try to work on a 300zx? </TD></TR></TABLE>

&lt;-- Ever so glad I didn't buy one

beepy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Most of the MAF's, especially the OEM ones, are not meant to be boosted, so the only option is to put it on the vacuum side</TD></TR></TABLE>

You make it sound like a MAF is bad. It's not. The fact is that even a car with a MAP sensor has to calculate airflow. The problem is to accurately calculate airflow based on a pressure signal, the ECU needs to know the temperature of the air in the intake manifold. Not so for a MAF, it only needs an IAT sensor somewhere close to the MAF so that the reference temperature across the "cold" wire is known.

So don't move your IAT sensor. It is where it needs to be. move it, and you will jack up your mixture.

sporkcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sonny &raquo;</TD></TR><TR><TD CLASS="quote">

BTW...the CRX is for sale to help fund this truck.</TD></TR></TABLE>

Worst sentence I've ever heard on HT.

Sonny

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sporkcrx &raquo;</TD></TR><TR><TD CLASS="quote">

Worst sentence I've ever heard on HT.</TD></TR></TABLE>

LOL...I know, man. It sucks, but using the CRX as a daily driver is not doing it justice. With another kid on the way this year and me getting back into kart racing, a 4 seater truck makes a lot more sense than a 2 seater street warrior with no a/c and no airbags. I hate to do it, but I love Hondas too much to stay away from them for long.

Sonny

MooreBoost

Put a pulley on that bitch!

Sonny

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MooreBoost &raquo;</TD></TR><TR><TD CLASS="quote">Put a pulley on that bitch! </TD></TR></TABLE>

I'm working on it.

2.4" pulley (2.65" is stock...6 psi), AEM brute force intake, custom catback (Flowmaster muffler), and an electric fan conversion. That should do the trick. I'm dyno'ing the truck on the 19th to get a baseline reading.

Sonny

MidShipCivic

MAF measures the weight of the air, if you know how temperature affects air you will leave that IAT there. Its for start up conditions.

shortyz

FLOWMASTA

honda9369

get in contact with nismo. they got goodies for your frontier

accord387

i thought those frontiers superchargers had problems... as in around 60,000 miles the **** could be screwed. I read about that on the nissan boards when i was going to buy one.

boostedcivicsir

the eaton has been around for ever. and it is a tried and ture piece.

accord387

i knwo eatons typically are, for the first nissans that used them though a lot of people had problems according to what i had read. I dont remember i looked at this **** about a year ago. the frontiers and xterras

Sonny

As pointed out, the Eaton M62 is a very tried and true and reliable unit. Eaton used to warranty them for 100,000 miles...although I am not sure if that is still the case.

IMO, a lot of the reliability problems with the supercharged Nissans are due to people overtightening the belt. People do that all the time on JRSC'd Hondas, too.

Magnusson will usually do a complete blower rebuild for about $500 anyway.

In short, I am not worried.

Thanks to all who posted in this thread. There is some good info in it. That's what honda-tech is about.

Sonny

Accord94DX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RacerXI &raquo;</TD></TR><TR><TD CLASS="quote">It's nissan. Ever try to work on a 300zx? Nice to see you're still around and tinkering. </TD></TR></TABLE>


Best answer ever. God bless this man. Before trying to dive into Nissan's logic, try an easier task like curing cancer or teaching blind monkeys how to dribble

Engloid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by green_GSR &raquo;</TD></TR><TR><TD CLASS="quote">Well, the MAF has the air intake temp built in. Most of the MAF's, especially the OEM ones, are not meant to be boosted, so the only option is to put it on the vacuum side. </TD></TR></TABLE>

All turbo 300zx's have OEM MAF setups. Why couldn't you put the temp sensor on the pressure side?

Full-Race Javier

nice truck

Nissan MAF theory straight from my b13 FSM...just in case ya want to know

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">

Mass Airflow Sensor

Mass airflow sensor is located in main air intake duct. The sensor uses a hot-wire type sensing element. Incoming air passing through the airflow sensor causes the hot wire to cool. As a result, ECM must apply additional current to maintain hot wire at the precalibrated temperature. The ECM measures airflow by monitoring the amount of additional current required to maintain hot wire at the
precalibrated temperature. If airflow sensor output current is outside normal
operational range, a malfunction in airflow sensor is indicated. ECM will go to throttle position sensor for information on driving condition. During this period, ECM will limit engine speed to less than 2000 or 3000 RPM, depending on model. This will inform the driver that the vehicle is driving under fail-safe conditions and needs attention.

Since the hot wire is exposed to atmospheric contaminants, the ECM is programmed to clean the hot-wire each time the ignition is cycled off. This is accomplished by heating the hot wire to 1832 deg F (1000 deg C) for one second after ignition has been turned off for 5 seconds. This function will not occur if engine speed has not exceeded 1500 RPM, vehicle speed has not exceeded 12 MPH, engine has stalled with ignition on, or engine is overheated.

</TD></TR></TABLE>

Sonny

Cool, javier.

But how does the MAF based system compensate for a really hot intake charge?

Let's look at 2 scenarios.

1) I start the truck up in the morning and as soon as it is up to operating temp, I run it hard and register 16.5 in the 1/4 mile on my Gtech. On this run, blower discharge temps are at about 100 deg F at the start of the run and they are pushing 160 by the end.

2) I make a U-turn and repeat. Now the blower discharge temps are starting at about 150 and getting up into the 200's.

Run #2 is slower. The air temp is hotter, but does the ECU compensate? If so...how?

This is the exact scenario I (and many others) faced with the 99-00 Civic Si. The IAT sensor is in the intake boot. When switching over to a standalone, it must be relocated or the ECU will not be able to lean things out when the air temps rise.

Sonny