Any of you guys scanning on a regular basis manage to demonstrate a HP increase vs. MAF rate increase?

There must be a direct relation between the two. HP is directly affected by the amount of air you can effeciently use in your combustion.

Take a look at these graphs. The Oct 21 runs show the installation of 1.6 roller rockers.

The other runs are my best ETs and MPH at the track


There is a marked increase in my MAF rate with the new rockers

 

45-91 MPH

 

73-100 MPH

 

With proper tuning you can get about 1.0 HP per .75 gm/sec of actual air consumption. Indicated can differ from actual.

 

Is that RWHP or at the crank?

 

I use the old rule:

potential Hp =(CFM x .257 x number of cylinders)

if you can find your bottle neck in your setup, accurately measure it, you can pretty much bet that is your HP you will get.

So in your case, if you can pull out of the MAX CFM, maxing the assumption that everything is tuned properly, you will be putting out about that much power.

I have done this many times with my setup working backwards through the information I have: Uncorrected Dyno numbers: 437 rwhp x 17% drivertrain loss =~512 fwhp My heads flow ~260 CFM therefore Potential HP= 260 x .257 .8 = 534.5

Correct my dyno figures for DA and your probably right around the potential HP the motor can make.

This can be double checked with weight of the car, and MPH in the 1/4....they all give ~ the same numbers.

 

The problem with that formula is that the measuremant I have is the MAF rate which measures the air supply for all the cylinders, not 1 individual.

Do you have dyno charts with ALDL data logs for your 350? I would love to get a look at both.

 

Ponch,

With both the 350 and the 406, on the dyno both MAF meters are pegged at 255+, so that really wouldn't give you any useful data to go off of.

 

My MAF readings are usually pegged with the lil ole' 350 here too and I know it isn't even tuned to its potential yet.

 

So how's the ecm know to calulate the fuel for 255, or 400 gm/sec?.

 

I also wonder how my '165 ECM has a clue on how to do ANYTHING above 6000 or even 4500 in some cases.

 

At what RPM do you peg the 255 gm/sec?

 

It just uses the data from the last table entries.

I won't mention that using the MAP stuff gets you table entries up to 5,600 RPM. Nope not me, no sir.

 

Think I have been over this 100x, and reasons why its really doesn't matter....

Hint: Has to do with:
(1) PE being enabled (more fuel than air = rich AFR)
(2) Having enough power to max the MAF means you should be making decent power, therefore not alot of reason to be driving around at 3/4 throttle like I had to in Ireland on vacation in my 4cylinder renta-speck
(3) If you are maxing the MAF meter, your most likely past 1/2 throttle, in PE mode, please refer to #1 again.
(4) At WOT the PE vs RPM is used to control desired AFR.


I just don't see the need to gain resolution in an area that you spend about 2% of your driving time in? Ask yourself how many times do you decide to go WOT and apply the gas at less than 3.1% incriments (which I recall from a long time ago as I think the delta of the Throttle to envoke PE?). Or are you driving along and you see the ***** come up beside you and you go from 1/4 throttle to WOT in a split second? In which case refer to #4 above.

If your road racing/autoxing. I'm sure your in and out of the gas as quick as possible, and surely envoking PE, in which case refer to #1 or #4.

It just doesn't get any simpler than that. Sure if you want perfect AFR at 9/10ths throttle SD is your system. But let me ask.....how many people are going to spend the time/effort/money to determine what that PERFECT AFR is at 9/10th throttle. If anyone says they would....I call because the friggin DA changing on a given day would effect the car more than a little rich AFR would.

Real world people....Not a pipe dream of perfect BLMs across the board. Anyone that says that perfect 128 blms are a definate must and a world of difference between 126-132 with most of the cells at 128....is not being realistic with themselves or anyone else.

 

Well we're at least now to the point of you saying it's just your opinion, rather then you stating it as fact. Which by the way is a signifigant change on your part.

Now, all you need to do is convince all the aftermarket / racing folks why your opinion is better. Since they all use MAP systems. And their claim to fame is ease of tuning.

Since your way only requires the fuel being right at WOT, and you have to set that fuel amount just as the engine is like at 2/3's of it's actaul air flow potential, where is this excess fuel going?. Washing the cylinders down?, or changing the acoustic signature of the engine, and NOT or falsely triggering the knock sensor?. Or just not making the HP it could since it's so rich in that area?.

While things may change slightly due to various factors, it's not a 50% error like calling 255 gm/sec, 450. You've proven your own error on that. You way is the one with a huge error.

Why do you want to call, BS?
Just because you don't like it?.
Sorry but I hate to be the one to inform you it does matter to alot of folks, and your in a small, small, minority.

The tangent about 128s is a tangent, the topic at hand is HP and Gm/sec..

 

Grumpy,

Look...not going to play your games with your contiued over exaggeration of engine devistation....hell corky and I just spoke of this the other night on the phone...how a few of you guys talk of nothing other than how a motor is made of fragile glass. And the slightest disturbance will send it to pieces. I asked Cork...how many times at the track do you see a motor go in a car....we are there almost every weekend watching hundred of cars...some ALOT quicker and some ALOT slower rip up the track ginving it their best. Not ONCE can I remember anything worse than maybe a guy blowing a head gasket on a fully blown allout race car....so cut the theatrics of major engine devistation.....maybe on the motors you build they are fragile as glass, but I think you will have to do a little more than run ......THIS IS FACT on my car...at 3/4 throttle, PE envoked, MAF pegged to high heaven, an AFR of 11.9.....BIG friggin deal.. on the dyno I have proof backing up I went from 10.0 lowest the WB they had would read to mid 13.5 AFR with a whole whopping ~12 hP difference....Yeah I am really going to notice that on the street.....REALITY.

Anyone here says that 12hp is going to matter I call

As for the Aftermarket stuff....At $3k dollars....do you think that cutting the cost by ~400 dollars makes a difference? YEAH! Do you think its easier to rig up a MAP sensor to most applications when someone buys one of these kits, YEAH......While these are all YEAHS, they are also all irrelevant when you already have a MAF system. You could offer to buy me one of these system and hook it up for me on my car and I wouldn't take you up on the offer. It would be just more crap for me to try to dial in and play with, when my time is limited. I am already making the exact potential of my engine...which has been confirmed by not only AFR, but several other outfits. None of them can believe the numbers Corky and I are putting down....

yeah it must be from the washed out cylinder walls......

let me ask.....how much did you gain with your setup going from MAF to SD? It seems we always discuss my setup inside and out, upside down and right side up.....but we seldon if ever hear about yours........Why is that?

I mean people normally do not buy a house without seeing it.....they normally do not buy a car without sitting in it, they normally do not get a pet without first playing with it....no matter how good the sales pitch sounds...most people want a little something more concrete than words....guess that is why I am asking you for a little something more concrete than your allegation of the perfect tune on a perfect system.

Nearly all the people here and on other boards share freely their HP numbers, ETs, MPH etc...with little hesitation. Why is it that a few of you better tuners always keep to yourself with regards to these things. Seems sorta odd to me.

PS: Yeah that small small minority I belong to, is probably the bunch here that are the top 5 fastest N/A cars, if not the top 2 fastest. Yeah more chest beating right, naaah just pointing out reality?

 

Gentleman,

Both of you need to chill out with the MAP vs. MAF debate. This kind of childish bickering turns what could have been an informative post into a downward spiraling piece of crap.

Both of you (Ski and Grumpy) have proven that both MAF and MAP systems can produce abundant amounts of horsepower with the right tuning. Whether someone wants to take the time to tune a MAP system for 128's across the board at 9/10 throttle or not is STRICTLY a matter of personal choice- some people find a great deal of self satisfaction in that accomplishment, others may not. The fact that the capability is out there pretty much should be the extent of the discussion here.

I am not trying to be a mod, but I am tired of reading you two bicker back and forth like a couple of 3 year olds. Perhaps your reinstate on this web site was a little premature?? The mods felt you two could behave like the adults you are, try not to prove them wrong...

Flame away guys.......

 

Bridgman,

Your opinion is duel noted.

However there has been for a while, how should I put it. Gross exaggerations of the incapabilities of the MAF systems. Guess I just want to set the record straight. As you can see I fully admit to the potential of the SD system. As you said its a matter of choise.

But it gets frustrating to see newbies, people at almost every track I go to, old and young, say to me....HOW the hell you running that quick with that MAF meter? Or without seeing the cars run, you guys need to get rid of that MAF meter (that just makes me laugh and I agree with those people usually).

At the end of the day, its a VERY relevant issue that people should be able to read, and make their own decisions. When I first came here all you heard was MAF sucks, SD is the only way. Now things are a little more even based. Personally, as I said before, I could really care less if everyone went to SD.

But viewing myself coming in here and wanting to research the topic, my time and money are valued and I would not want to be pushed into making a decision that was based on other people shear word. Sorry I am not that trusting. I would base my decision on people's credibility, proof they put forth, and results they are getting.

Trust me I spoke of guy with a Mustang with a super duper Sc on it running 8s. Now if I was seeking advice at the track that day. There were probably imports running 15sec 1/4s with SCs there were muscle cars running SCs in, and there was this guy with a 4.6 liter mustang running a sc cranking on high 8s on what he said was a light peddle. I think I am going to spend my time picking his brain. Call me crazy, but I think my time would be better spent in that venue.

Maybe I just have a different outlook on things.

 

You said it not me.

 

MAF systems that are maxing on on Mustang usually get corrected by using a larger MAF with a smaller sampling tube, then increasing the resolution within the MAF tables to correect for the smaller sampling rate. I've spent lots of time with some guys running mid to low 9's on a 10.5" slicked SC'ed '98 Cobra running Fast Ford weekends and Mustang club events throughout the midwest. That car maxed the MAF at 3300 RPM on an 8000 RPM engine. Think he would stick with PE type tom-foolery to fuel his baby?

I agree that MAF systems can be made to go just as well as any other system out there, I just don't agree with deminishing the ECU's visability to any part of the system when I know there's a way to correct it. I understand though, it's hard to change from something that's working for you...

 

Yeah thus far in the history of the TGO, My mis-type has been the most damning evidence of your claims associated with MAF.

Of course you could just put some proof forth that would do the same, but we never see any of that from you. Just claims of perfections on a perfect system.

 

And all I wanted was some insight on how much the MAF rate affects HP.

I am taking the car to the track tonight so I will get a pretty good indication of the power.

I also want to get the car on a dyno in the next week or two.

By the way I agree there is no good reason to switch from MAF to SD, especially with a very mild engine. I happed to find tuning AMF very easy and with good results thus far. I know I wouldn't see any performance increase going to SD in my case.

By the way Ski_dwn_it, you never responded to my query on when you max out your MAF rate(what RPM), on your current setup and your 350 before that.

Another question, is @200-210 gm/sec inline for a 13.7@100 MPH car? or is that low? I estimate from MPH and ET that I have around 270-280 RWHP and according to Grumpys statement .75 gm/sec = 1 HP I am right on the money, once again if that calculation is RWHP.

 

Poncho,

Sorry thought I responded to that...maybe not. Anyways.

With my 350 it was in the mid to very high 4000 range where I started to max it out. With the 406, to be honest with you I really couldn't tell you. This is due to the fact that on the street I Very seldomly am on the car hard enough to reach that level. It just gets too fast and hairy. I have too much at stake to kill a family screwing around on the street. On the strip, I would say its still about the same but about 6-700 less.

Its really insignificant when you look at the whole picture. Its nearly impossible for several reasons to reach that RPM level on the street.

1-2 gears are your only chance of getting there. I can tell you right now, even with the slicks on the car on the street, your not going to do it without breaking traction. ESPECIALLY with street tires. Hell even on the strips, if the track is not fully prepped with full slicks, the car kicks sideways on me. And the 60' are still in the 1.5 range!

Getting there in 3 gear would be your only chance without risking loosing control. And to put that into perspective that I think everyone can see....I trap at about 4600 RPM in 3rd gear at 123MPH. How often are you at 123+ MPH on the street?

The above is exactly why you do not need to concern yourself with this magical mysterious 255 g/sec. Its all bogus.

At WOT you just use your PE to adjust the AFR you want to have. Grumpy threw out I am nearly double over the limit of the MAF's resolution...but what happens as RPM increase? g/sec increase respectfully. What is the PE % chng to AFR directly linked to? RPM. So as the RPMs increase so does airflow. So at the end of tehe day, I have perfect control over my AFR at WOT. What more do I need grumpy? And how would SD be any better?

This is only about the 3 thousands time I have explained this.

 

Nope, just used YOUR numbers.

 

I realize that....I am just trying to use a maf rate as a guage on engine power. Obviously the more air you are flowing and using efficiently the more power you are making.

I have no problems with the MAF system and happen to agree with what Ski is saying. I see no obvious benefit going to SD from MAF, on the contrary there are many benefits of MAF as seen in this post and easy and quick way to measure performance.

I'll be the first to admin I don't know much about SD, I have a MAF and this is my first fuel injected performance car I am toying with. That being said I like the fact that I can see the actual amount of air I am using, and the impact on my cars performance. With enough logs and analysis you can begin to predict your cars ET at the track, or atleast help to determine whether it will go faster or slower.

MAF is like an dyno on your car and a weather station. Maybe because most the SD guys started off in SD and that's what they presume it to be the best. Truth be told you can use either system to go fast, as has been proven over and over again.

All I want is a weigh to accurately measure my cars performance increase or decrease without driving out to the track or dyno each time.

I was/am interested in seeing different MAF rates from various engines along with Dyno charts or time slips, if available, to help prove/disprove the .75 gm/sec = 1 HP formula or come up with a more accurate one if needed.

Overall I have increased my MAF rate over 15% but I beleive that I have increased my power by @18%(determined by HP from MPH and ET vs weight)

I am just looking for data to prove/disprove this.

 

poncho,

Not all that was directed at you.

As you can see from the remarks of sum that are asked to give solid proof, they can only play word games. Offers a whole lot in way of proving their point

To your point. I really think its going to be difficult to pinpoint accurate enough results based on other setups and flow number to put collectively something together that will be valuable.

However. On your own engine. You can definately track your progression, for instance if you record g/sec gains vs RPM as you move through the mods, you could effectively deduct that your going to see an increase. So long as other items like fuel and spark advance also are adequately adjusted properly to reep those benefits.

A good starting point is your 15% more air to I'm assuming your either dynoed or MPH increase of 18%. That is a VERY health gain. That is about 54hp on a 300 hp motor. Or on the track about ~20MPH gain! WOW.

One word of advise you should not use your ETs as HP calcs, they are VERY subjective. MPH and weight put you very close. That really is the best way to see if you gained or lost. But another word of warning, you should try to try these gains and losses to a DA. If you read about Corky and I trying different things. The DA is always provided also. The DA can really effect how things are preceived.

 

I am using a both MPH and ET versus weight of car for HP numbers. Yeah I really need to get a weather station so I can record my DA at different runs.

With the mods I have made I have gone from 15@89 MPH to 13.7@99.9 MPH with a 15% increase in MAF

 

I'm not trying to start this all over again but I haven't said anything and it's about time I did. Again, sorry if this isn't related to your posted topic but it's good reads. Oh, yes, your MAF Rate is a direct correlation of torque, more air in, correct AFR!!!, and you've got torque since everything else in the engine is constant (valve lift, duration, compression, etc.)
Back to the original reason for my reply, to address this MAF vs SD. I have some proof, and it's very strong proof when you look at the actual ET and trap speeds. More details on this MAF to SD would be appreciated to make final opinions but from Grumpy's website there is a GN doing 9's! 9.4 at 141 with SD, 9.6 at 138 with MAF. That's at least 45hp depending on the vehicles weight.
Another point to be made: If MAF is so great because it measures exactly how much air is being brought in, then why did anybody every think it could become a restriction in somebody's stock system? Well...it's a MAF, it's an actual meter with some form of air resistance, properly sized it isn't a problem because the throttle shaft alone is worse, but stuff like heating up a wire, and other small stuff don't help.
I would say a MAF system is good for the non-DIYer and the relatively stock. Peeps with not a lot of time on there hands should use the system for instant gratification with bolt-ons.
Oh, any why would anybody care about being perfect... well that's the point of this board and life in general. If you didn't want to be closer to perfect why the engine swap? I also drive my car around at 9/10's throttle more often than most. Mainly because I have more power than tire. And it's a daily driver. What does this mean, well... I need my engine to perform at it's best no matter what.
I like MAF, I like that your car is fast, and I like how you help guys out, I just don't like your attitude towards guys that play devils advicate. They are not trying to get a rise out of you, they are trying to broaden your knowledge base.
I was just like you ski when I did my engine swap and kept TBI, even you will tell me TBI is not a performance setup but hey, get ready. I've gotten so good at TBI tuning that even if I were limited by airflow (which I'm not, proven with actual facts) I wouldn't consider a carb. There is just know way a carb is as versitile as TBI for a daily driver. Not to mention tuning to pass emissions is a breeze. When people sit in my car and I tell them how much I spent years ago and how little I've actually put into the setup they are amazed, even Ford guys, go figure.
My point being, just chill out and step outside the box. We ALL heard you when you said you CAN make power with MAF. Nobody said differently, we just pointed out that you can make more with SD, it's just that simple. Infact, when you get down to just drag racing only and pure ET, screw SD, go alpha N with fuel trim for weather conditions! Like you said, you don't need exact resolution, what you want is something with EFI idle and part throttle manners no matter the weather AND you want ET, you are a minority here. Most of us don't have the money to go track testing whenever, or build a vette (hence the f-body site) like yours. JUST CHILL. We all have our ways, we all are trying to help so understand that to the majority of people here, running out of range in any sensor parameter is just unacceptable no matter the results. It'll never change, nore do I think it should. Post your comments but don't get so defensive over people hounding on you.

 

Jprev,

Look, Trust me I am not at all getting upset in any way over this topic.

I have my points...that up to this point in time NO ONE has been able to disprove or weaken. There has not been one shred of evidence that says one is better than the other.

If you come out here with some staggering proof that I will gain .1 sec,...believe me I will be the first to be switching. You know I am an ET/MPH freak, so believe me, my pride is not that deep that I wouldn't be the first to make the switch if I thought SD was better. But there are many many other 406s on this board and others, along with other vettes some from major shops that aren't even close to where Corky and I are. Most of them are outfitted with SD. Not to say they are going slower because of the SD, well maybe I am, but they surely are not going quicker....some not sporting all their original equipment. So until I see something more enlightening than that...I guess my opinion will be unwaivered.

As for the 9/10s throttle. I do not buy for one second anyone continually drives around in that range. Also you in PE when you doing that? If your at 9/10ths, why not just go WOT? Sorry I just don't buy it. Furthermore....let me ask....how much power do you think your loosing at say that 9/10ths throttle?

I am not trying to be a jerk. THis all is relevant to make me a believer. I have tuned MANY SD car and also MAF. 350CI up to 427CI......trust me when I say I have not see a difference in SD, that would make me want to switch. I'm sure it has its points with hacking etc, or more tinkering points. But to get the job done. They both are great compared to a carb.

Well I have to go drive 3hrs to get my fix, at the track. Talk to you all later! Again, I am not trying to ruffle any feathers. There is no difference in me telling someone I prefer MAF over SD, and this is why when they ask. To someone over in the tire section saying they like tire X over tire Y for these reasons. I am not holding a gun to anyone head saying they HAVE to use it. We can make our own decisions, and you guys can have your opinions, as I can.

I just would like to see some proof. 9.6=>9.4 could have been because of a zillion other factors. Was the MAF even tuned correctly...Also at 9.6 sec MAF ran the car.....what makes you think it will not run our 10sec and up cars? Well I have to go.. Talk to you all later.

 

Yep, when you just continually ignores the facts, yoy can't see the evidence.
Ya the guy was running 9.6s and didn't know how to tune. LOL

For proof of your first sentence, see your second.

Well, I've got some new stuff to try tuning wise, I spent some time on the bench analyzing how some changes effect the data the ecm generates. It was nice to be able to do it from the comfort of the living room, rather then having to make 14 passes at WOT, now I just need to go data log ONE to verify the results.
It's nice not running out of resolution, it avoids having to bandaid the tune.

 

If anyone is interested in actually knowing, rather than speculating, there is a way to figure out if a maf meter is actually a restriction costing you hp or not. At 28 in h2o, corrected air to 60 deg dry air, 29.92 baro, a sharpedeged orifice (which is what a maf is) flows 146 cfm /sq.in of area ideally (without restrictions such as screens, fins wire etc). Measure a maf, and do the math. I would guess you would lose around 25-30 % airflow with the screens/fin/sensor stuff in the way. That would tell you whether its a restriction at the observed hp you are making. Everyone knows you can make more hp that whatever figure is shown, it just proves that if you are above that, the maf (or restrictor plate or whatever) is a restriction and without it in place, there is more potential hp. The only thing after that would be tuning ability to get system a to run as good as system b. I too am very tired of reading all this crap between you 2. I used to come here alot, and the last 6 - 8 months have not been. I return to read the same old same old. Everyone here knows a little something, and we should not get into petty bitch sessions constantly. Grumpy, you have alot of knowledge computerwise, but I am sure there are eople with as much or more. Ski, your car runs decent, but there are faster cars, and better engine builders for that matter. I wont get into a chest beating contest, but will gaurentee no one here has built anything faster than myself. Anyone can learn things if we just ignore our egos and read things with an open mind. I am sure I'll take some flaming on this but really dont care. Now, I'll get off my soapbox. Both systems can run fast, as has been proven. Skis car runs decent, and I have personally been involved with pro mods running 6.20s using s/d or alpha n.

Flameproof suit on

 

OK....so I figure I gained 20-25 HP

I went 100.5 MPH last night with all runs at 100+

I ran better ET and with worse 60ft & 1/8 then days when traction wasn't such an issue. Last night was near freezing and traction was horrible.

I still feel that I am losing on top, should've MPHed more for the ET I put down, but next I am installing the ported plenum/runners and a cold air package.

I also ran lean the first run, and was running out og gas on the last run, which might have resulted in a slightly higher MPH.

Track closes tomorrow for the season so it's back to bench racing till next year!!!

 

Just thought i'd throw this out.

I've only been on here once or twice, but I've already found the solution to my problem, much the same as ski_down_it did.

Of course, I'm on a V6. I'll never max the maf, without the turbo, so if I'm tuned nicely for anything except boosted applications, I should have no problems, follow?

In order for me to go into boost, I need to be using almost full throttle, which sets me in PE mode as it is. A little WB tuning, and I'm set, for my boost levels. The ONLY downside I'm seeing about that, is the fact that if I increase boost significantly, I'll need to burn another chip, for that boost range (and fuel addition @ WOT)

Just my .02