• Register Today It's free! This box and some ads will disappear once registered!

On my way to the Supercharger!


MikeP

Active Member
Joined
September 19, 1999
Messages
179
Reaction score
0
Alec Do you have details as to how this air/fuel ratio gauge works? It is my guess that the gauge takes the signal from the oxygen sensor and "guesses" at what the air/fuel ratio is based on the oxygen sensor reading. If the sensor reads 0.00000 oxygen in the exhaust gases it may "guess" that the air/fuel ratio is about 14.6 lbs air/lb fuel. But at air/fuel ratios less than 14.6 lbs air/lb fuel, supposedly all the oxygen is used up but to my knowledge, there is no sensor that measures the hydrocarbon conc. in the exhaust gases. Does this air/fuel gauge somehow measure the flow rate of gasoline into the engine (which would give the lbs fuel/time) and take some info. from the mass air flow sensor (which would give the lbs air/time) and combine this info. into the air/fuel ratio? I had a fuel miliage gauge on my 3/4 ton 4x4 GMC truck which took the speedometer info. + a flow meter reading from the fuel line to give miles/gallon on a gage. I see on the internet some discussions whether these air/fuel ratio gauges give "trustworthy information" with some complaints that some of the gauges are phoney.
Mike with 91 XLT 4x4 in Seattle "Go Huskies"
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
I installed an Auto Meter air/fuel gauge in my 97 Sport last summer. It taps into the O2 sensor. The stock computer in the Explorers (post 95) continually adjust the air/fuel ratio. When idling, the gauge moves from lean to rich to lean again over and over. Only when I hop on it does the meter peg out at lean and when I decelerate it pegs out at rich. The gauge is really not needed. The computer protects the motor from excessive lean conditions. If there were ever a problem, a check engine light would come on. I just like gauges. These gauges give you a general idea of what's going on. If you wanted exact information such as the percent of air to fuel, you would need to get a scanner. Something like http://www.obd-2.com/.

Just my 2 cents.
 




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
On adding boost.

If you were to add boost to a normally aspirated motor, wouldn't you need to get a 2 bar or 3 BAR (if you wanted that much boost) MAP sensor? The stock 1 bar MAP sensor is good for 14.7 pounds which is the normal atmosphere. If you wanted to add 7 pounds of boost, wouldn't a 2 bar MAP sensor be needed? 2 bar MAP sensors handle 15 pounds of boost and a 3 bar MAP sensor handles up to 30 pounds.

The reason I'm asking is because when I ordered my Heltech E6k fuel and ignition control system the guy said I needed the 2 bar MAP sensor if I was pushing under 15 pounds of boost and a 3 bar MAP sensor if I was going 16 to 30 pounds of boost.
 




flyguy

Well-Known Member
Joined
October 17, 1999
Messages
1,858
Reaction score
0
City, State
Gilbert, AZ
Year, Model & Trim Level
'07 XLT V8
bar?
 




Chav

Active Member
Joined
September 20, 1999
Messages
183
Reaction score
0
Cameron I'm pretty sure explorers have mass air flow meters and not manifold absolute pressure sensors. If we were turboing a civic we would need a new map sensor, but since the explorers have a maf the maf will tell the engine the amount of air entering the engine so that it can adj. the injector pulse width.

-Chav
 




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
Originally posted by flyguy
bar?
I believe bar is short for barometric pressure. That is, normal air pressure at sea level we feel every day is about 14.7 pounds or, 1 bar. So 2 bars would be 14.7 pounds over normal or, about 30 pounds. But, because 14.7 pounds is the base, when somebody has 2 bar of boost, it's said they have about 15 pounds of boost. 3 bar of boost is the same as saying 30 pounds of boost.
 




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
Originally posted by Chav
Cameron I'm pretty sure explorers have mass air flow meters and not manifold absolute pressure sensors. If we were turboing a civic we would need a new map sensor, but since the explorers have a maf the maf will tell the engine the amount of air entering the engine so that it can adj. the injector pulse width.

-Chav
Very interesting. I will definitely talk to the guys at Heltech about that. Thanks.
 




flyguy

Well-Known Member
Joined
October 17, 1999
Messages
1,858
Reaction score
0
City, State
Gilbert, AZ
Year, Model & Trim Level
'07 XLT V8
The only map I have is in my glove compartment.
 




blk mk8

Active Member
Joined
September 30, 2000
Messages
821
Reaction score
3
City, State
brother
Year, Model & Trim Level
Troll's
the stock explorer computor will compentsate for a lote. to give you a idea. my 97 lincoln markVIII with 15 pounds of boost ran fine with only biger injectors and fuel pump with a matching calibration in the mass air. all most all fords computers compensate the same way and work similar. the only thing else was the timing adjuster to take out six degrees of timing. Haltects are a very good engine managment i belive i have recomended it to you before. they are only 1200 dollars around there some where. the stock computers will compentsate using the mass air reading crossed with o2 sensor readings. the car should all ways have a 12.5 to 1 air/fuel ratio at WOT. the problem with the gauges is they dont all ways work well. the best gauge to get is EGT.but that is a whole nother story all to gether.
 




Alec

Elite Moderator
Moderator Emeritus
Joined
April 25, 2000
Messages
15,997
Reaction score
1
City, State
Houston, Texas
Year, Model & Trim Level
2008 JK
My response will be short: on an old 28.8 modem that's slowwwwwww. The blower got shipped yesterday, so it will be installed on time, probably around Jan 14th. As for the MAP sensor, its my understanding that it either comes with a new one or the new computer chip alters it or something. The kit might come with a new fuel pressure regulator, I'm not sure. I'll install what it comes with! Here goes my factory extended warranty, though. I have about 6 months left on it, oh well. I got the a/f gauge for looks and semi-functionality. It probably won't be totally accurate, but give me an idea of what's going on. Updates soon.
 




Goober

Well-Known Member
Joined
May 23, 2000
Messages
1,402
Reaction score
0
City, State
Lexington, SC
Year, Model & Trim Level
'91XLT4x4
Alec, before you start tinkering with the motor and lose the factory warranty(if that would void it), you should take it in and tell them you have a slight miss or something with the motor and let them run a fully diagnostic just to check things out. This way you get it checked out/replace any bad parts for free before you start doing anything.


What's that smell?... Oh yeah, I had a thought :D
 




SteveVB

Elite Explorer
Joined
July 8, 1999
Messages
2,525
Reaction score
1
City, State
Gaithersburg, Maryland
Year, Model & Trim Level
04 Rubicon w/stuff
BBK kit pics

Alec ,
dont know if you saw this yet or not. Posted on the ranger 4.0 board. The BBK seems to be shipping! Pics show a FPR, and timing retard control.

http://my.athenet.net/~mlaporte/blower/blower.html

Hopefully yours will be on its way soon.
 




95ExplorerLtd

Well-Known Member
Joined
May 24, 2000
Messages
1,455
Reaction score
0
City, State
Hymera, IN
Year, Model & Trim Level
'95 Limited 4x4
Somebody said that will a charged 4.0 he'd barely be able to beat a V8, so does that mean if I had a supercharged V8 I could barely beat a V10? :D
 




scott

Active Member
Joined
February 14, 1999
Messages
142
Reaction score
0
Alec...

BBK should supply you with everything you need to install their product properly. If they don't supply you with a aux fuel pump then either the chip compensates(by possibly increasing the injector dwell time, whatever) or they want you to spend extra money. I can't say for the BBK but Vortech needs the inline pump that comes with the kit. After my trans rebuild the guy forgot to reconnect the ground for the aux pump so it obviously wasn't running and even with the FMU it was starving around 5000-5300 rpms. 2 wot runs is all it took for it to hit me that the pump wasn't running, I reconnected the ground and all was fine.
As for the MAS and/or TB upgrade... I can tell a difference in mine. The stock MAS was 55mm and I now have a 77mm(big difference). The TB was 58mm and my new one is 66mm(not a huge difference but every bit helps).
 




scott

Active Member
Joined
February 14, 1999
Messages
142
Reaction score
0
oops

I got the sizes for the MAS wrong in my above post but the increase was 20mm over stock anyway
 




Chav

Active Member
Joined
September 20, 1999
Messages
183
Reaction score
0
Hey Cameron did u find out if Explorers have map sensors? I am starting to wonder if i was right about that. I thought it was either maf or map and not both, but maybe its maf and map or just map.

-Chav
 




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
Originally posted by Chav
Hey Cameron did u find out if Explorers have map sensors? I am starting to wonder if i was right about that. I thought it was either maf or map and not both, but maybe its maf and map or just map.

-Chav
The Explorers do not have a MAP sensor. But I don’t know if one is needed if I plan on adding 10 + pounds of boost. I sent an e-mail to the tech guys at Heltech and MSD to see if I could get a straight answer. They still haven’t responded to me. I think it’s due to the Christmas season. I’ll let you all know the second they reply.

I hope the MAF does the job of a MAP sensor, I just don’t know.


[Edited by Cameron on 12-24-2000 at 07:03 PM]
 




MikeP

Active Member
Joined
September 19, 1999
Messages
179
Reaction score
0
As the MAF or mass air flow sensor measures the mass of air flow going past the MAF sensor, I am not sure what the MAP or manifold absolute pressure sensor is needed for. Unless the MAP reading is used to fine-tune the signal from the MAF. Write up on how the hot-wire MAF sensors work at
http://www.kemparts.com/tt06/tt06.html
By the way, someone mentioned the lbs air/lbs fuel ratio was something less than 14.6 (like 12.6 or something) - was this a typo? - never heard of an air/fuel mass ratio as low as 12.6 for a gasoline engine operating at about stoichiometric which is no oxygen in the exhaust gases and theoretically all the fuel is burned. I would think that an air/fuel ratio of 12.6 would be pretty rich and black smoke would be emitted from the exhaust. Have a Happy Holiday season & Merry Christmas.
 




Cameron

Well-Known Member
Joined
April 18, 1999
Messages
1,103
Reaction score
0
City, State
Streamwood, IL
Year, Model & Trim Level
97 Sport
MikeP,

I thought that the MAF sensor "read" the airflow and a MAP sensor "read" the manifold pressure. Are they synonymous? Are there any turbocharged vehicles that you know of that don't have a MAP sensor? I'm still trying to figure this thing out.

Based on that article you linked to in your last post, it would seam that the MAF reads the density of the air as well. This would lead me to believe that it does the job of a MAP sensor. In that case, wouldn’t one need to have the MAF sensor after the turbo/supercharger? That way it would read the density of the air more accurately.

More questions then answers.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




MikeP

Active Member
Joined
September 19, 1999
Messages
179
Reaction score
0
Cameron Apparently the MAF and MAP are not the same. I copied a writeup from
http://www.racer-x.f2s.com/proc/tpi2.htm which is shown below. It appears that the MAP only measures the air pressure - partially for the vacuum caused by the engine "sucking" in the air and the engine system computer uses a "memorized" program to guess at the air flow and other parameters measured by a MAF. I have not yet found anything about a system having both a MAF and MAP. The only advantage of the MAP (as mentioned below) is that it is less of a hinderance to air flow rate compared to a MAF. It is my guess that a MAP is less expensive than a MAF and motor vehicle companies are famous for working very hard to cut manufacturing costs as much as possible.
I am putting quote marks around the below stuff I borrowed from that http://www.racer-x.f2s.com web site.

"3. The Mass Air Flow Sensor (MAF)
The ECM needs to know how much air is being taken in so that it can perform a variety of engine
management functions. Until 1989 GM used the Mass Air Flow sensor (MAF) for this purpose. While in
terms of function it is a nearly perfect sensor, in terms of performance it is a hindrance to air flow, and
therefore just begging to be hot rodded. 305 and 350 engines used the Bosch design MAF almost
exclusively, which is capable of flowing a measly 529 cfm. With some smart modifications, this number can
quite easily jump to over 700 cfm. For these procedures, click HERE. A word of caution, though: MAFs
are pretty sensitive, but more importantly, they are pretty expensive - up to $400 or more for a new one
(rebuilt units are available also). Be ready for the possibility that you will botch the job and have to pony up
the dough for another one. For the faint of heart, there are companies such as TPIS that will sell you a
modified one, or modify yours for you.

Starting in 1990, GM began using a Speed Density system. This system uses a Manifold Absolute
Pressure (MAP) sensor in place of the MAF. The MAP differs from the MAF in that it measures engine
load (using manifold vacuum) instead of intake air mass. The speed density system has the advantages of
reliability and zero intake restriction, but the MAP sensor is a far more limited sensor than the MAF, and
therefore less flexible; you can modify your MAF engine to the hilt, and the MAF will go about happily
reporting air mass, temperature, humidity, and pressure to the ECM without a complaint. The MAP sensor
on the other hand delivers only intake manifold vacuum values, and the ECM must rely on "fuel maps"
stored in memory to properly calibrate engine function based on the MAP readings, along with the input
from other sensors. What this means is that major engine modifications on speed density systems
generally require a revised PROM with the new fuel maps in memory.

Despite it's shortcomings, speed density systems are generally the choice for most high performance
systems. It is possible to convert your MAF system to the speed density type, but this switch is expensive
- it can approach $1000 for the new harness, MAP sensor, air ducting, and PROM. If you decide to make
this move, make sure that you really like the combination that you settle on - remember, modifications such
as camshaft changes will necessitate burning a new PROM so that the ECM can keep up."

Some other web sites on MAPs are:

http://www.racer-x.f2s/com/proc/maplearn.htm

http://www.autoclassroom.com/straight/sensor3.html

Mike in Seattle 91XLT 4x4


[Edited by MikeP on 12-26-2000 at 07:46 AM]
 




Top