Why NOT to upgrade from your stock MAF
 

Many people think they need to upgrade their MAF. The truth is you dont need a new MAF until the stock one is pegged. Its not so much as to what amount of hp will peg one, but the amount of air going through it. But as a rule of thumb, we will go with 400rwhp. Now Im not saying go out and buy a new one if you're at 400rwhp, you need to datalog the MAF counts and such to see if you need a new one. VERY rarely will someone with a NA car peg the stock MAF.

What does upgrading to a larger MAF do?
Basically it will lean you out and cause the car to run very poorly. As a result you will need to get the car retuned. If you dont, then the lean condition your new MAF causes will lead to a blown motor. Now after you get the new MAF and have the car retuned the gains are very minimal. So that makes your new MAF pointless.

Also, just as a side note, intakes with a bend before the MAF cause bad readings. So stay away from those too.

It gets into more detail here. And for those who dont know who Ed Clark is, he is a VERY reputable tuner at Steen Racing. http://forums.modulardepot.com/showthread.php?t=25092

any intake mod is rather pointless...

the biggest point of restriction is heads

Agreed. Everything from the t/b down is pointless to upgrade. The only thing Id do is get a k&n and remove the silencer. Also, that little screen is there for a reason, so leave it alone. If I had to do it over again, I wouldnt even bother with a plenum and t/b. Money can be spent better else where. Now I have a Bullitt intake and stock 98 cobra t/b.

Im running a C&L inlet tube because I wanted a better tube to mount my nitrous nozzle in. Stock MAF, and K&N filter. Im at 366rwhp 449rwtq with the nitrous. This is a perfect example of why it depends more on the amount of air going through the MAF rather then the power. When I spray, there is no increase of air going through the MAF compared to NA. So even if I up the shot to 150 or 200 I might never have to upgrade the MAF. Well have to see where I am after ported heads, but I doubt it. However, a supercharger and turbo will significantly increase the amount of air flow.

Not sure, cause when someone puts a K&N filter in and gets 1-2 HP and then you see a dyno of someone putting a CAI on and getting 10HP, there must be something right about a CAI. Also why would they even do it in mustang magazines? It's not to advertise, it's cause they want to squeeze all they can get out of it and when i see a 10HP increase 5-10 up the rpms, it must be worth something. And they've all stated the rubber inlet tube is restrictive.
But should a CAI be your first, second, or third mod, hell no.

For MAF's they can take a lot of HP before you peg one.

Id like to see some legit before and after graphs. On more then just one car.

The thing is the money spent on a CAI can be spent better else where. Not only that, but a CAI is just made out of piping that you can get anywhere. You can go ahead and replace the rubber tube with some piping and save a lot of money. But dont give it a bend before the MAF.

I've done before and afters on dozens of bolt-on GT's and I can say from my experiences that good CAI's (not fenderwell models) that use the stock MAF are good for 1-5hp on an otherwise stock car. TB gives about 3hp, add a plenum and you're up another 5-8. All 3 together usually get 8-12 hp. They reduce restriction a little but the real restriction is as has been said many times more in the heads and cams than anywhere else. If you stuck the 600 bucks that those 3 bits cost into cams then you'd be up 25hp or more.

4V cars, particularly the Mach1's have been known to pick up 15-20hp and more with the intake upgrades.

Upgrading to a larger MAF is almost always a bad idea. Blower/turbo cars are the only ones that I'd even consider it on and those have to be doing 400-425 or better just to be candidates. The rubber inlet tube is a source of perturbation in the air stream which lowers sound and power and that's the only part that I'd think of changing, and I'd change it specifically because the mod motors love RPM and high RPM needs smooth air for max power and safety.

The test cars i've seen had TB, plenum, exhaust, pulleys and then they tested the CAI, and it gained 10HP but up the RPMS it was lower than that, but like i said, a CAI wouldn't be my 1st mod, be the last mod as a easy bolt on. But if i could go back, my first mod would have been atleast cams or heads. I wish i would have done the 5.4 and just bought the heads and cams, then the rest could have followed.

Oh, and all cars are different, some like certain bolt ons and some don't. Just like some people can put a 75mm TB on and they feel gains and some put in on and say the car lags some.

yes...

however the largest point of restriction on mustangs is the heads / valve train...

so spending money on a MAF or CAI is just plain silly... for a mustang...

5.0 Mustang & Super Fords magazine did a "Cold Air Shoot Out" in August of last year, where they tested 11 different C.A.I.'s on the same 2005 GT on the same day. The testing method and "rules" as outlined in the article were this:

"The same car will be used for all testing on the MD Motorsports chassis dyno. Rear-wheel horsepower will be measured in 100 percent stock form. The car will then be tuned to a set air/fuel ratio and set timing level. Each cold-air will be installed according to the manufacturer's instructions. Rear horsepower will again be measured with the cold-air in place with run conditions (coolant temperature, inlet-air temperature, timing, air/fuel ratio, and so on) as close as possible to the baseline pull. All efforts will be made to adjust the air/fuel ratio to the exact same as the baseline run to avoid this variable causing a change in horsepower. This testing procedure will be continued for all of the cold-air systems submitted for the story, which should ensure we have the same weather, car, testing facility, and tuning for equal comparisons."

There were some concerns and questions from some of the manufacturers, and the article continues for a couple paragraphs about how those were all addressed.

The summary of results:

Lowest Individual HP Gain: 17HP

Highest Individual HP Gain: 27.9HP


Lowest Individual Torque Gain: 14lb-ft

Highest Individual Torque Gain: 21.5lb-ft


Average HP Gain: 22.8HP

Average Torque Gain: 18.6lb-ft

Article is located here:
http://www.mustang50magazine.com/tec...ake/index.html

again... different car with a different engine... and if you get a CAI for an 05 don't you HAVE to get a new tune?

EDIT^ it also appears we swayed topic a bit... the topic is MAF... but its ok... good arguement

CAI Discussion
 

Hey all,

All of you have posted some very interesting points in regards to low budget add ons. I just finished putting in a fenderwell CAI. I originally had the stock Air Intake with a K&N filter(first mod) as well as removed the fenderwell inlet tube.
As soon as I did this, I felt a tiny increase in high end torque. I soon followed with underdrive pulleys and a 70mm throttle body. I felt a noticeable increase in power with these three mods alone. Not to mention that it growled very nicely. A few hours ago I put in a fenderwell CAI I purchased on ebay, I figured the $40 wouldn't break the bank and it would let the car breathe easier and a little cooler air. I have to admit, I felt another bit of power from the CAI.

I understand that every engine is different and they all respond better to different mods but I feel the$400 or so I have spent has given the car a lot more pep.

My question is directed at those of you who have a fenderwall CAI. I noticed a loud whine coming from the CAI now. I checked all the connections, tightened all bolts and made sure all hoses were secured so there doesn't seem to be a leak. I am usually overly paranoid anyway but it would definitely make me feel better if anyone is experiencing the same thing.

It was a beatch to put in but I'd rather go ahead and swap it out instead of damanging the engine.

Thanks fellas,
Narsh

The sound you hear is normal. Its that CAI sound that everyone gets. However, like I said above, the bend in piping before the MAF can cause bad readings. Id stay away from that. You might also want to get your car on the dyno and check a/f to see if it changed any. That $400 could of been spent on gears and you would of gotten a better increase. Not necessarily in HP, but lots of HP doesnt necessarily mean quick 1/4 times.

I hear ya.

But gears are expensive and my wife would have killed me! (Couch isn't very comfortable)

I live in South Florida and getting gears down here will set you back close to $700. (If anyone knows any shops in the Boca to Miami Area please let me know)
So I figured a little bit at a time wouldn't be bad.

I'll be getting an SCT tuner next month followed by Exhaust, OR X-Pipe, and 4.10s during tax season.

But thanks for the reply!

-Narsh

CAI's may help a small %age of cars but most of us see exactly jack. Especially for the cost of a CAI. Fenderwell CAI's are even more hit and miss with the messed up MAF readings. Throw the car on a dyno and check the AF if it's ok and not showing spikes of rich and lean then you lucked out.

On a side note:
why bother with an offroad pipe? The modern high flow catalytic converter doesn't plug much and costs almost nothing power wise but you'll be doing your part as a responsible over user of petrol.

I hate to harp on that point but we are the people that are going to have fingers pointed at us in the coming 20 years and if we want to keep our hobby legal we need to show at least a modicum of attention to the environmental effects caused by running without cats.

BTW... the 05's are showing up to 20+hp with a CAI because the factory plugged the crud out of the stock inlet with filters and narrow tubes and all that. It's not surprising to see those gains on them. All of the hating on CAI's is exclusive of those models for 05+ GT's.

r3dn3ck,

Thanks! I'll definitely consider "doing my part" and putting in the correct mid pipe as opposed to the Off Road one.

Do you all know if the SCT tuner will be able to tell me if I am either rich/lean. If they can, I'd rather purchase that right away as opposed to a Dyno tune. In SFL they can be rather expensive since there aren't that many around.

-Thanks,
Narsh

the tuner will help you change the AF ratio but it won't read it. You need a wideband O2 sensor to get that kindof info. We're not saying to get a dyno tune to check the AF, just do a single dyno run and they'll usually data log the AF from a wideband sensor as part of the run. Most places will give you a single run for 75 bucks or thereabouts.

My tunableinduction cai has the bend and my A/F was actually pretty good and almost a straight line. just ran a tad on the rich side and they set it perfect on the second run, but i've heard of people getting crazy readings from some too.

Yeah, i think they say it's a few ponies less with the cats but no big loss and you keep the air clean. i bet in a few or more years, all states will probably have emissions testing.

Ed Clark tuned my vehicle also..

He told me my MAF pegged out at 5,200 rpms. He told me that if i were to buy a 90mm, id be looking at 400whp with no problem.

supercharged and turbo'd cars can peg the maf at full boost but you usually don't see that sort of thing till 12psi or so. 10 is close enough for it to happen I guess. I've never seen it on less than 12 but I don't see a lot of 10psi cars...

While this topic might be true for pre S197 stangs, when it comes to the S197 stang its craptastic. The simple fact is that keeping the stock maf calibration will cost you HP. The CAI that use either the stock maf housing size or a reducer to meet the stock flow counts do not make the same HP as the ones that require a retune.

I know my C&L racer that has a large maf required a bit more tuning on the dyno to get the readings perfect thru out the rpm range since its so large (more then need on a stock car but with the heads/cams and more, it will help). They have proven the gains over keeping the stock unit.

Pegging the MAF and it size are two very diffrent things.
First the size matters depending on you use. If its a suck thru setup either N/A or S/Ced then size is critical. To small and you will be creating a major restriction.

On blow thru size is not as critical long as its size match the pipeing, to large or small and issue tuning it can come up.

now the maf pegging can easly be fixed with out using a new maf. The mafia will adjust it and all you do is change the table in your tune to work with the new readings. Going to a larger maf is not always the answer to a pegged maf reading. Maf size should be based on what you will be using it for and then the calibration can be done for that maf.

Cai
 

R3D N3CK stated that the "high flow converters and H pipes" do little to restrict air flow and nothing to power levels. So Sorry but you are completely incorrect. I base this statement on a trial that I did on my 06 GT. I drilled the pipe and installed some steel flex tubing which ran to an air pressure guage. In stock configuration I had 8.3 psi back pressure at WOT and after removing the High Flow Cats and stock H pipe and installing the off road X Pipe and Flowmaster mufflers the back pressure had dropped to 3.5 psi. I don't have a track or Dyno locally but that decrease in backpressure has got to help.

Since people installing just an O/R X are seeing around 10rwhp i would say that the stock H pipe with cats is restrictive

ok, first: way to bring it back from the dead wowzors... <5psi on a ~300hp pump. gosh... that's huge. not. Removing too much backpressure can be just as bad as adding it.

and vsop... cmon man. you got to pay attention. appearantly I was speaking of HIGH FLOW cats and pipes back in SEPTEMBER.

Mine pegged it at 8psi, but only over 5500rpm.

Around 400rwhp is usually where it happens.

all of you guys have valid points, but when my stock 2v goes from 9 teens when i first bought it to 8 thirtys with no more than an upr x and bbk fenderwell cai with a c&l 80 mm maf, I have to think they do some kind of good. Dont get me wrong thats not all i have done to my car, I have removed some weight, but everything else is just as i bought it.

making .8 seconds in the 8th mile requires a HELL of a lot more than any MAF change will do. You'd need like 70-100hp more for that kind of benefit to come off pure power increase.

not saying that was all i changed. ive taken alot of weight out of the car, 4.10s, went from heavy stock wheels to prostars, and of course put the x-pipe on. as far as the 70-100 more that has not happened. the car still has stock manifolds, stock plastic intake, stock throttle body,( upper plenum has been ported ) for what thats worth. just saying that all together as a whole they (the maf and the cai) had to help with what little stuff i have done.

Next time you go to the track, make a few runs with your current set up, then put the stock inlet tube and MAF back on your car and make a few runs. Make sure you log all the important factors too.