87400tpi

There has been post that the maf system runs out of gas around 350 hp.With the help of ski_down_it this myth is shattered.We are in a new reality of maf tuning.The maf system is now in limbo NOT having this mythical, imposed limit..Another bogus myth,don't touch the maf tables for tuning.I have also used the maf tables very sucessfullyThe reason of this post is to find out mafs true limits horsepower wise.Also how many has gained anything from using the maf table as a centerpiece to nailing down certain blm issues.If things go well,we will have a good idea how far the maf system can go.Also it will be nice to see general agreement that modifying the maf tables is ok,if you are carefull.I think focusing on those points we can push through the usual rhetoric.

Kevin Gray

I don't know how a 350hp limit was placed on the MAF system. The size "restriction" of the MAF sensor when compared to a 3.5" pipe might,, repeat might cost you as much as 2% around peak on an engine using a 58mm t/b and pushing around 500 horses. However, in 1992 TPiS was cranking out 487 horses at 6500 rpm with the MAF feeding and the GM ECM controlling a solid roller 383. In 1995 Gary Grimes built a 406 that pumped 525 horse at 5700 rpm and 508 lb/ft torque at 5000,,, through the MAF sensor. Also, there was at least one "street rod" engine builder back then building 450+ cid small blocks using the AS&M long runner set ups generating around 450 horses and something like 550 lb/ft TQ,,, with the MAF sensor. High powered MAF cars is nothing new. People sharing the information is.

doc

I've been running the MAF system in both my '87 and '99 Camaros. I have tuned the MAF table in my '99 to great success. For that car, I have a large table and its in Frequency vs MAF flow rate. The only limit is 512 max value which is not a problem for NA engines.

For the '87, I could do the same thing (I need to increase the values of flow compared to counts) BUT with the '87 $32B ECM, I am limited to a max value at the top of each of the 6 tables. So until I learn how to modify the basic program to elimenated this artificial limit, I am stuck!!!!!!!!!!! For example, of the top of my head, I think the max limit of table 1 is 23,,, but i need about 25. So I am $hit out of luck.

87400tpi

this is howthis just a taste of the twisted propigation I'm here to se straight

87400tpi

That is what the maf scalars can be used for.But pe will compensate so most of the time no need for rescaling.

SATURN5

no.. your missing the point.

CFM x .5663 = Grams/sec

255 gms/sec = 450 CFM

Another little piece of math

1.3 CFM / HP

At 350 HP your of resolution,

mathmatically the maf at 450 cfm should be pegged at 255 gms/sec.

450 cfm /1.3 cfm = 350 HP or the mathmatical limit of the MAF.

This is not saying that 350 HP is the max HP possible just that your out of MAF resolution and into PE. Since you can add additional fuel via PE, obviously more HP is possible.

Grumpy

What's to straighten out?.
Other then you must be missing out on understanding what was said.
What do you need clarification on?.

This makes it 3-4x now in the last few days, you keep going on about this, and reguardless of how many times I respond, you just go on repeating yourself.

I have an idea, how about trying to post something new, and possibly meaningful.

BTW, what is propigation?.

funstick

actually there is unused bandwidth in the stock sensor and tables. check it out.

87400tpi

not much more hp,acording to grumpy.For years he has even said it would be hard for maf(165) to go past 12s in the 1/4.The formula that is quoted is correct but it has no reasonable app to the maf system.That is because of pe,as stated.
255 is NOT the ECM's limit,as grumpy will die believing.255 is the maf sensors MAX CONVERTED OUTPUT.PE uses the maf TABLES to calculate the correct % change to make the a/f ratio .Not the actual maf output,maf tables use sensor output though.We all know most of that.But when someone imposes some kind of limit to the maf sysem's ability,I'm going to call it out.Ask corkvette1,there was a post deleted from here around a year ago.It was my post asking how hard would it be to go faster 12 seconds.Grumpy said there is a law that gives maf aprox 350 hp max.He went on to say this limit can be pushed.But it'll be hard to go much faster.I fought him on that for at least a year.Same thing with modifying the maf tables.He fought me to no end for years,it seems that you can not use the maf tables to tune part throttle.But I can get perfect 128blms at idle,highway,hills everywhere by using my own methods.Some maf users have used similar methods.But like I've stated before ,this is an underground thing.Using the maf tables to get perfect part throttle tune,that is what grumpy has disagreed with me on bigtime.But if the maf people step out in the light we can crush this public restriction/myths of using the maf tables and bogus limits put on the maf system in general.We should know about maf,we tune the system.funny you ask,it is an inside joke

funstick

87400tpi.

im not trying to be a dick. but its a dead horse. we all know that you could in thoery make 700hp with a maf. the problme is controlling the fuel once the sensor bandwidth has been deplted. read some of my posts. ive been digging up ways to get around this. there are sevral projects that will come to light sooner or later. take a chill. MAF is not dead. its just sleeping for a while. the $32 $32b tunning article was a wake up call.

there advantagages to the $32b code. i dont like $6e its a pita to work with.

87400tpi

why do people keep trying to discount me and my methods?(not you funstick)

funstick

becuase your dangerous.your tunning methods in the wrong hands and even my tunning methods in the wrong hands can spell disaster for an engine.but you need to be more concise and thought out in your replys.

TRAXION

This whole thing is fu(king stupid. You want to know why? Because of 87400tpi. Both Glen and I have shown years ago that MAF could be tuned at WOT using the PE Enrichment table. This is not some new thing that 87400tpi discovered. Geez. WTF? You act like you have come along and saved the MAF world by posting this new light. Whatever. People have been doing this for years. It's not new. It's not revolutionary. MAF can't go beyond 350hp? Of course it can. Like I said before - whoever said that is smoking crack. Again - you act as though you are the one and only standing against everyone else screaming "MAF can go beyond 350 hp!". Ummmm - yea. Of course it can. It has been doing this for years. As I have mentioned on numerous occassions - I've seen MAF cars in the 10's many times. It's like me sitting here and saying "The statue of liberty is in New York. Really. Everybody NEEDS to check this out". Duh - of course it is.

Do something different and tell MAF people something that isn't already well known. Your whole theory on 'resolution' was blasted out of the water but you are still refusing to admit it. As well as what I put forth, Eric also clearly showed that the MAF is used at WOT. Voltage or g/s - whatever dude. There is a table that correlates them so stop trying to confuse the situation by saying that one isn't the other. I was one of the first ones to jump out and clearly explain that the PE tables could be used to make up the extra fueling that MAF cars need at WOT. I came to the defense of ski to try to show others how his car is running the times it is. Yet, you are still trying to argue against me? For what? The fact is that I am right and you are wrong. The ECM is pegged at 255 at WOT. True? Yes. The ECM cannot correctly measure the amount of air coming into the engine at WOT on a high output MAF car. True? Yes. Resolution is defined as the ability to measure the amount of incoming air. True? Yes. The MAF does not have resolution at WOT for a high output MAF car. Period. That is the plain matter of fact answer. Any of you MAF guys out there that believe against what I have just said then you need to do your own research. This is a clear and shut case ... it is so clear and so shut I simply do not even understand why Tim (87400tpi) is trying to argue differently.

Now - here is where things make a turn. Does it matter that the ECM / MAF system does not have resolution? NO! This is because at part throttle / closed loop you will not hit the 255 limit. Thus the ECM can correctly fuel the engine. It even works on steep hills (thanks Ski!). At WOT you don't need to worry about resolution either. Why? Because you can use the PE tables to make up the extra fuel. The extra fuel that is added via PE will make up for the extra amount of fuel needed for MAF counts that would normally be beyond 255 (but can't do to the ECM limit) as well as adding the extra fuel to get to 12.x AFR.

This is so freakin' simple that it makes me sick.

1) The stock MAF can support big horsepower as long as you remove the screens and gut it.
2) The MAF ECM can support resolution during part throttle operation.
3) The MAF ECM cannot support resolution during WOT on high output MAF setups because the 255 limit is hit. However - THIS DOES NOT MATTER since you can supply both the extra fueling you need to get back to 14.7 + the extra fuel for PE mode via the PE adder.

Tim

TRAXION

You might as well give it up - he'll never understand. I posted this like 1,000 times already. I tried to explain using different analogies, etc. It's a clear and shut case but, for some reason, he refuses to admit what the ACTUAL MAF CODE DOES. If the MAF code cannot measure more than 255 then you are out of resolution because the ECM cannot determine how to properly attain 14.7. If the ECM cannot determine how to properly obtain 14.7 then the "% Change to AFR" is null and void. It then becomes a fudge factor. The cool thing is that it works. But, instead of 87400tpi focusing on the fact that it works he is trying to somehow put forth lies about the resolution of MAF systems. I don't understand why he can't just come out and say - "yea, the ECM is out of resolution but who cares - you can still give it enough fuel to obtain big horsepower levels. The non-resolution is a non-issue". That's the real answer - which we have all been saying. But - he's in some wierd source code world where MAF sensor input is not needed at WOT.

As with what I said in the other post. This is my last post within this post. I'm done with this post because the answers are all here. Any person that understands anything about code will clearly see where Glen, Grumpy, Saturn and myself are coming from. Now I'm returning to my vacation.

Tim

87400tpi

Please,please lets keep this respectable. no, only the maf sensor output is pegged,not he ecm. This also applies to stock engines too.That is why even GM used(created) pe and a wideband to achieve correct ratios.Is it?Pe overrides this issue.Ski's maf is not pegged at this point,btw.I have brought to the table 255gr/sec is not a limit at part or full throttle.There is no limit to the maf sysems fueling at this point.Traxx,we are in general agreement on methods.But what do you disagree on?I do want you to know I am not trying to steal any tuning tips here.I give you guys full credit for the pe table method.But I am bringing something to dinner also.How can I lose resolution (at part throttle)if my gr/sec is less than a stock l98 ?Furthermore how can I run out of resolution at wot if pe kicks in?I did'nt even graduate high school.I have a hard time articulating.

87400tpi

I have quoted grumpy as stating 350hp is the basic limit to the maf system.So traxx is saying grumpy smokes crack?

funstick

im going to defend grumpy here.

no 350 hp is the average practical limit that you can have absolute control over fuel. the PE vs RPM table is close but not for what grumpy is suggesting. grumpy is a bit pickier then most. for that matter i can be to depeneds on what though. whats hes saying is that for IDEAL fuel control the average MAF METER MAXES OUT at around 350hp. then again SKI's car break the rules by being super efficient.

87400tpi

whatever,I will have my 406 hitting 11s all day long and knock down 20+mpg.I will also have total control of my fuel sysem,if I switch back to maf or not.So this dribble if pointless,goo is coming from my gear head.

87_TA

I really never thought or had a question of making alot of power through MAF .
I had just always read the facts: Far more precise adjustability
by going to SD open and closed loop,and one of the most important to me is the loss of restriction that is present with a MAF sensor.

Granted you can pull mega number through that MAF and build big HP,but my thoughts are if you can make 3% more - why not?

Granted also the MAF system is simple to tune. my reply to that is i'm not in the hobby for the simplicity,i'm in it for the fun of tuning,making a change and seeing the difference.


By the way,do you guys think my 406 will be needing more than my 52mm tb?

ski_dwn_it

87_ta, I think you have missed out on some of the discussion the last few days or did not understand what is being said.

The jist of what has been discovered by me breaking the rules sorta speak, which I don't think I did anything miraculous, other than put together a setup that is running very well, and is making people reconsider the possibilities of MAF. Where I think your wrong is the fact that you keep saying that I would be able to gain 3% more from going to SD. Lets assume I am making 450RWHP which I think everyone can agree I am somewhere around there. You say a 3% gain which is 13.5 HP more. Do you honestly believe that? Even if it were true I would never in a million year switch over to pick up a *possible* .1sec more. The hassle of switching over, the undeniable countless hours trying to get the car sorted out to just get back to where I am now + .1sec. I don't think so....and why the hell would anyone in their right mind do the switch on a lesser HP motor? Assume you are making 300RWHP, thats a wopping 9hp gain I have to drive 3hrs no matter where I go to race, I hardly want to waste my entire summer getting back to ground zero. I can almost bet I would not run nearly as well for the rest of the summer doing the switch right now. I have the utmost condidence in my tuning ability, hell I am only on chip #2 with this car now. LOL.

You brought up the VERY exact reason I started a few of these posts that caused all the hooplaw around here lately. You all have to admit the majority of the reason why people think SD is better than MAF is the superstition that 87_ta just pronounced again, that its a restriction. I think I have clearly shown, as well as corkvette1 that the maf can be pushed and possibly to 10s(haven't done it yet, but increased my MPH yet again friday night to near 124 mph, then my shifter cable broke, so the night was cut short )

I know that cars have done it before, but I don't recall anyone here posting these kinds of results, and I thought I would just share with you all what I am able to do with it, sort of a in house testimonial, rather than someone reporting what some SC Gn did 5 years ago with who knows what tune.

How far can the MAF be pushed till the SD is better? I hope to find out. But please the MAF is not a restiriction in the sense of obstructing flow in its modified state. I clearly showed flow demands for a 406 at 6500 RPM with 100% efficiency and 75* air. The max air supply needed was ~760 CFM. The ported maf can flow 750 CFM. 87_ta do you think your engine is 100% efficient and in need of 760 CFM ~ 430g/sec? I know mine isn't.

Bottom line, everyone knows that each system can be tuned to be equal, up to some point that each system reaches a break point. MAF can be tuned with part throttle, and WOT equal to that of SD. End of story.

I look forward to hearing what your replies are 87_ta, and if you got any new times this weekend with some more tuning....that miniram is something I have been wondering about with my engine...curious to see what you can push it to.....good luck.

87_TA

No SKI,not really.

Absolutely,You are not catching my point either.
Or the reason for my post.
I was merely trying to bring things back to the basics and end some of the maddness about loss of resolution that nobody really cares about unless you are pegging the MAF way early.
In a sense I was defending your system but you can't see that.

As for the 3% increase again,You bet!
Is it worth it - depends what you goals are?
I miss the simplicity of MAF,do I mind the countless hours i have spent tuning S/D -not really ski,its what I like to do.
As far as you losing a whole summer tuning,Doubt it. I had my 400 very drivable with only a Cylinder volume change from my 350 tune. After that made a wot scan pass ,to get BPW around 8.0 ms from 2400-6100.
For you it would be really easy,look at you PW vs RPM now
and simply match it with the S/D about 2/3 burns. that along with timing you are back where you started but may be a little lean due to better breathing.


OK ski,you have proven that a MAF can pull enough air to supply your engine That was never a question!!
Your 2.5 inch dual exhaust ,people have pushed 700 whell HP through them-but you dropped yours and gained ET!
See the point.

Please I do not want to make this ,or add to this arguement.
Just don't misunderstand my intentions.
I was merely trying to tell people ,take the systems for what they are. decide if its worth it to you.

ski_dwn_it

87_TA,

First I was not agruing with you. Look at my last paragraph, I was simply saying that I don't agree with your continued statements that MAF is an air flow restiction...you show no evidence such as calculation etc to back your saying that. The last paragraph I wrote shows that I am truely interested in what you accomplish with your system...I wish you the best of luck with it.

You live handy to a track for testing and driving ~6 hrs minimum each time you want to test a new tune out is not something you have to deal with, trust me its no fun. And when you only get ~2-3 runs in each time, it gets VERY time consuming. And I particually don't like going 130+ MPH on the highway testing the car out. I don't need to kill myself or some innocent family passing through.

Sounds like you are making progress that is all that matters. But please don't refer to the MAF system as a restriction, it give the uninformed/experienced clearly the wrong message. You have to give me at least that much and agree with me there.

I'm not sure I followed your exhaust comments. Yeah mine is 2.5", but in spots its lucky to be 2", since no one in this area can mandrel bend tubes. I ran at 120MPH the first run you saw with the exhaust, maybe it would run equal MPH now, and its something I surely want to try before spending 1000 dollars on another exhaust system like Corky has. I am gonna take it to a test and tune day and slap it back on to see if the MPH is still there with it, but I kinda like the open exhaust sound LOL, it seems more like a race car

87400tpi

I would tell you the truth about some real facts 87_ta,but I dont feel like getting nailed to the cross today.I have defended more than one heartless,misleading attack here.

87_TA

No harm or foul Ski
You have a great setup,If you ever feel like wasting a a few hours or so I would love to swap intakes. that would make a great tech article!! And im curious also.
My setup is not doing so well ,I did get my 60 ft better though.

LOL,I know where you are comming from.
Alot of good guys here,they just need to understnd each other.
I still appreciate the help you gave me when I was running MAF.
mail me if you like.

87_TA

I know this is not the place for it .but I was excited.

87400tpi

Beautiful car

Not trying to be rude but with some drag racing rims wold be the biggest improvement in et.

ski_dwn_it

Nice launch 87,

Yeah after I hit 10s here with this setup, that would be an awesome test to try with the intake swap. I would not look forward to installing this SR again, but really its pretty easy now after 3 installs. Probably could do it at the track now if necessary.LOL.

Lets see where we are at in a month or try to cordinate with Corky, I think he might be pulling his back off here to switch bases. He is not that impressed with the porting results he is getting. Then would be the time to try it, and his setups is running nearly what mine is. I will talk to him and see what he things........

Trust me I am not busting your *****, I really want to see you succeed with your setup. I know the feeling trust me of not being able to reach your goals, my 350 nearly put me in my grave last summer. LOL.

Talk to you all later.

87_TA

Thanks guys,
Yeah,I have some drag lites off my 82, but the rears have only 3.5 back spacing due to drum brakes on that car, and look a little to out dated. I kinda like the "stock" look,but I was looking into
getting the fronts narrowed-too much money though.

Thanks.
Yeah I know ski,I'm just frustrated as hell with it right now-it indeed should be going much faster......

As far as the intake swap goes, the mini is a simple intake to remove and install so would be no problem on my half.
Ski,what size throttle body do you run?

ski_dwn_it

58mm.

anesthes

iTrader: (12)

I'm getting a bit agrivated seeing people like You, and Traxion fly by me with your n/a setups..

That miniram must be really nice ...

-- Joe

87400tpi

well,there is alot of gta style rims out there.You'll just need an adapter.Off the top of my head the grand prikz has the same pattern rim but it is 7 in wide.There is other cars,alot non-GM that has the same pattern.You might find an import with 6in wide gta style rims.But for example I will have the thinnest tires up front and some 15in slicks 10in wide.I want the fronts like bicycle rims.I will exploit all areas for max et.I'll throw on my american racing rims for the street.Never know when your going to bang 150+.Gotta have my z-rated shoes.

I am thinking of getting the holly stealth ram.It seems to be pretty good.How much did you guys have to change the pe table a/f ratio after the intake swap.Did the swap effect closed loop blms in any way?

87400tpi

This is what I'm going to do.I'm on a search for the fatest cars that map has to offer.Do the same for maf.It appears SD was a pimple on the butt efi.Maf has been produced longer and in way greater volume.

SATURN5

Yawn.... so flipping what..

You want to run MAF... then do it.

You want to run MAP...then do it..

In the end... you can go fast with both.. it all just depends on how many points you want to plot.

Oh.... Malibu on the road... and it looks like I am going to have to switch to a 3 bar MAP..

Try that with a F-body MAF code.. boost... it does a body good.

anesthes

iTrader: (12)

What exactly are you getting at??

-- Joe

Bobalos

for those that are afraid of using MAP because "it will take forever to tune in" dont worry. VE Master takes the curves right out of that road.

I have a heck of a lumpy cam & the VE table looks more like an rough ocean than a nice smooth curve, but I got 128's all around now. its almost like cheating.

BW

SATURN5

Me?

Just tired of kvu,tim,87400tpi, whatever, continual bleating that MAF is the Holy Grail of EFI...

2 different systems.. 2 different ways of accomplishing the same task.

MAF's biggest drawback is the lack of boost supported code, along with the phyisical limits if the code. ei (255). Yes you can use a FMU with MAF.. strike two in my book.

The rest boils down to how many point/plots do you want.

MAF has less, MAP has more. Individual preference.

anesthes

iTrader: (12)

No, your posts (especially on $58) have been nothing but informative.

Either he hasnt been tuning $6e/$32 long enough to know better, or he just hasn't swapped to $8d.. A world of difference.

Ever since i put together my 355, I was like "man my old map car (tbi) was soo much more responsive, smoother".. When I started tuning $8d it was an eye opener in efi tuning.

Maybe I just adopted the understanding quickly or something but.. It all made sense to me immediately.. Now i'm saying "I need to mod the code to do this, to do that, etc".. Its a nice base..


-- Joe

87_TA

The Mini Ram will deffinetly change your ve quit a bit,upper and lower. The upper will be much flatter from 3000 to 5600 instead of dropping off at 4200 where the long runner did.
The holley stealth ram seems nice,and affordable.the latest issue of GMHTP did a swap on a modded third gen.

LOL, I should be flying a little faster,I would also like to take a trip to traxions track,
its one of the fastest around (very close to sea level)

That would be a great place for Ski to hit 10's,many keystone peolple have said you will run 2-3 faster there.

ski_dwn_it

WHERE, WHEN, WHAT? 2-3 what faster? ET or MPH.....Trax when you gonna have an old MAF buddy down?

How far is it? I'm game...it can't be any further than freakin E-Town

funstick

if hes racing out at 75/80 dragway then you could go straight down I-80 is it I-80? ive been in michigan to long ? out of harrisburg and be there in a hour. so however long it takes to get from saint marys to harrisburg plus one hr. although if i were you id rather go down to the track in sotuhern maryland. thats at sealevel and you would definately pick up some MPH and ET there for sure. its down off of Maryland state route 5 just north of prince fredrick. about 2 hrs from where traxion stays.

87_TA

M.I.R.
MARRYLAND INTERNATIONAL RACEWAY.
I plan to attend there myself sometime this year when I get this combo ironed out.

87_TA

LOL ,both.
A naturally asperated engine loses 10% HP for every 1000 ft above sea level. That could be 40 HP for you ski

Grumpy

At 10% per 1,000 ft, at ~15,000 ft all piston aircraft would have 0 HP.

funstick

not really

50 hp x 10 = 5 hp = 45 h

45hp x 10 = 4.5 = 41.5 hp

40hp x 10% = 4hp = 36 hp

as the power number goe down so does the exponent of the loss of power.

ski_dwn_it

Details details details.....LOL

383 rocket bird

I am glad for the great information that has been coming to light about tuning maf. I have stayed out of it to this point for the simple fact that i am rather assured that any question I ask will get me ripped. Thanks to all of you guys for the info but i can say that neither side is blameless in this stretch of good posts gone bad.

87400tpi

You should check all my post,also check under kvu.90% of my post ends up this way.Nobody will explain why they don't like me.Nobody will return an email,for some reason.Really this post wast to expose the total hp a 165 ecm can handle.Now it is crap.I just can't figure out why I keep posting here if nobody likes me.Glenn says the past is in the past.Then he is thinking(?) about banning me.Traxx wants me banned too.I would like to continue here.It's hard to walk if you keep getting a baseball bat to the knees.Please feel free to post here.Getting ripped only hurts if you let it.Last time I let it get to me.This time I don't care if I get ripped.What conserns me is what motivates others to act that way.

87_TA

turbo or supercharged cars will lose less than that (about half)
As for the aircraft,hmm maybe ill think twice about that next prop flight.

anesthes

iTrader: (12)

Thats interesting. My max speed at 3,000ft is no different than 500 ft. (cesna 172)

-- Joe

87_TA

That is funny,read this . YOU ARE BEATING THE ODDS!
GENERAL AVIATION RULES OF THUMB

Standard Pressure, Temperature, and Lapse Rate
Sea level standard pressure = 29.92" hg
Standard lapse rate = -1" hg. for each 1000' increase in altitude
Sea level standard temperature = 15°C / 59°F
Standard Lapse Rate = -2°C / -3.5°F for each 1000’ increase in altitude

Take Off
T/O distance increases 15% for each 1000' DA above sea level
A 10% change in A/C weight will result in a 20% change in T/O distance
Available engine HP decreases 3% for each 1000' of altitude above sea level
Fixed pitch, non-turbo A/C climb performance decreases 8% for each 1000' DA above sea level
Variable pitch, non-turbo A/C climb performance decreases 7% for each 1000' DA above sea level
During each 1000' of climb, expect to see a loss of approximately 1” of manifold pressure
During each 1000' of climb, expect TAS to increase 2%
If you don't have 70% of your take off speed by runway midpoint, abort the take off
Level Off – Lead your level off by 10% of airplane’s rate of climb. e.g. – 500'/minute rate of climb; lead level off by 50'
Pressure Altitude – Set A/C altimeter to 29.92 and read PA from the altimeter
DA increases or decreases 120' for each 10°C the temperature varies from standard temperature
Standard temperature (ISA) decreases 2°C Per 1000' increase in altitude
TAS increases 2% over IAS for each 1000' above sea level

MANEUVERING
Maneuvering speed Va = ~1.7 x Vs1
Va decreases 1% for each 2% reduction in gross weight
Vy decreases ~1/2 to 1 knot for each 1000' DA
Vy, Vx and Vg (best glide) decreases ~1/2 Knot for Each 100 pounds Under MGW
Vr = ~1.15 x Vs

Cruise
The width of one finger = ~5NM on a sectional chart (average person)
Tip of the thumb to the knuckle = ~10NM on a sectional chart (average person)
Cruise fuel consumption of a non-turbocharged A/C engine = ~1/2 the rated HP/10
Cruise climb airspeed should be reduced by 1% for each 1000' of climb
To determine a relatively proficient cruise climb speed, take the difference between Vx and Vy and add that sum to Vy. For example, if Vx = 65 and Vy = 75, the difference is 10KTS. Add 10KTS to Vy (75KTS) and you have a cruise climb of 85KTS
Landing
Final Approach Speed = 1.3 x Vso. Also known as Vref
A tailwind of 10% of your final approach speed increases your landing distance by 20%; A headwind of 10% decreases landing distance by 20%
A 10% change in airspeed will cause a 20% change in stopping distance
A slippery or wet runway may increase your landing distance by 50%
For each knot above Vref over the numbers, the touchdown point will be 100' further down the runway
For each 1000' increase in field elevation, stopping distance increases 4%
A 10 Reduction in Approach Angle Will Increase Landing Distance 13%
10° – 25° of flaps add more lift than drag; 25° – 40° flaps add more drag than lift