mass airflow sensor (jet store)389.99 (summit racing online)299.95 (knowing where the **** to go and how to use a forum to find out how to fabricate my own for FREE .... Priceless.. BIATCH.... lol sorry this is my first post guys and i love forums... for this exact reason...

i mean shoot pretty much anyone on here that is serious at all about doing anything to there truck is going to get there shii done up with a power programmer of some sort so the extra chipping you get in an aftermarket MAS is null since the prog. is going to make upp for that shii anyways... .why not just nock out that friggin screen..... SAME DAMN THING AS WHAT YOU BUY..... with only one partition wich i feel help direct airflow and create better suction without restriction it with tht friggin huge honey comb in there..... DAMN thats gonna free up some air flow.....

n theres been a fellow who ive allready read many posts kinda dogging on the ebay style CAI out there and blabbin up the fact that the stack has better feed anyways since it feed right out the back of the headlight...... WEELL not as good ad you think buddy.... at least with my 1998 Ls vortec 2 dr 4x4 that shii is BLOCKED MAN look where your precious tube is actually feeding from and youll see you ssuccking through a 1 inch slot to fill that 2.5in (o whateva) tube running into the stock box ..... duck and look from the front to behind the head light and there is a giant waffle plastic lamp support strapped right across the opening.... someone should take theres out cut it fabricate a mold and sell after market lamp supports that feed the air through to its fullest potential.... ill be cutting mine for free... but hey i was thinkking that if you got the top protion of metal tubing from an ebay thing for say 27 bucks then did your MAS to that and then fashion the same shape or even make the old box top to fit between with a rubber connector (im sure there made of somethin else and il be corrected but thats welcome) and then with the extra flow from the compartment you actually thought you were getting air from and the less restriction from HUGE ASS AIR DAMN RIDGES from the stock tubing youd prob have the most effective system.... i think...

hmm, i wouldnt just start chopping pieces out of your MAF, you might need that

and if you really want to suck in lots of air, just pull out your headlight extend the intake tube and put a filter in its place, ram air effect! :eek:

LOL You make me laugh. I know you're talking about me so why not just say it.

I'm not even going to get into a pissing match with you. You think that your stuff works. Well, have at it.

You also might want to take some grammar classes too... Your ramblings barely pass as readable.

Ditch the entire air cleaner. Cut a hole in the hood above the throttle body. It give you 3.1465768 HP.

Can anyone show my how to gap my Bosch +4's?!!!!!

oo, even better, use a 4" throttle body spacer, run it up through the hole in the hood, and put a huge round K&N on top. That would be uh, 3.14+2 HP.

we're just joking with ya, nothing personal, we just like to joke around sometimes. I dont have the same year, so I cant really help. My stock intake is different.

allright maybe i didnt point you out either specifically casue i dont like e-fights either so if you truley dont then just dont mention it bro and let things be and no insults man..... thanks for pointing it out now.... could you at least offer you advice/opinion/experience with what it is youve done with your set up to adress the problem i mentioned or seen others do to make it the most free flowing??? .. im sure you have way more experience man since i just started lookin into modifying my car a lil more then my exhaust and am excited bout what im reading ???

and then all you guys joking about 3 hp well listen here i got that 3 hp for free..... what now? dotn be jerks and flame instead share insight and help me figure out other cool new things you guys have seen like i have here with the headlight mount bracket..... i even took pics with sectionals and showing where to cut and would put them on here gladly to show what i did.... thanks for the welcome guys.... now you wanna help me out instead please?

Just pullin' your doors bud. Welcome to the Blazer forum.

My first intake mod ever, was gutting up the stock airbox and installing a K&N. I removed the MAF sensor screen w/ a screw driver too.
After a few saved bucks, I purchased a K&N FIPK. Later that year I purchased a Granatelli MAF sensor. I paid $329.00+ for it. The vehicle needs a MAF sensor, But you already know that.

I'm interested in what you did. It may give others here an idea to do it too. I enjoy reading peoples' posts about their mods and how they liked them. If you have any pics on your mod post em up!

*rant*
Ok, so you come here and, without naming names, say that, in no uncertain terms, I don't know what I'm talking about. Yo Yo Yo, that shii is wack yo... Geez. I'm "blabbin up" all this crap yo. OMG!!! LMAO!
*/rant*

So here's the facts.

The MAF screen is there for a reason. The purpose is to smooth out the air flow through the MAF to give it a consistent, average reading of the air flow into the engine. With out a consistent reading, you could cause a very problematic lean condition in your engine (ie - engine go boom or atleast significantly shorten the life of the engine). When you get right down to it, if you look at the cross-sectional area of the MAF, it is much larger where the screen is than it is down in the throat where the sensor is. I don't know by exactly how much different it is in diameter, but (hypothetically) if the inside bore is 2.75" and the outside bore is 3", you have 7.07sqin of flow area vs 5.94sqin of flow area in the throat. You'd have to have a mighty large mesh to choke out over 1sqin of area. IIRC, the screen is made up of a VERY fine honeycomb and should not result in that much of a restriction.

I have seen it many times (albeit not in blazers, but other GM vehicles). Every engine is different and there have been a few (very few) that have been fine without the screen. With track and dyno testing on 3800 powered cars, the screen has been proven not to hinder performance, but promote it. The averages that I have read about certainly fall in the realm of dyno tolerancing (+/- 5hp), but if you can't see a gain, then is it really worth it to have your MAF frequencies bouncing all over the place? Is it also worth it to potentially harm your engine???

I removed my screen from my Bonneville and the car idled like absolute crap. It also didn't run correctly and when scanned, my STFT / LTFT were up and my MAF freq was bouncing all over the place due to the lack of consistent laminar flow over the sensor. Overtime, your computer will adapt and undo much of the performance gains that you thought you had when removing the screen. It is in that time where the computer is 'fooled' that you may have a problem.

Scott, about your Granetelli MAF... Did they calibrate that to the exact specs of the original MAF? If not, how does your engine know that it is getting more air? MAF sensors are delicate and typically, they cannot just be swapped around without proper modification to either the MAF sensor (to match that of the stock sensor) or to the PCM to account for the differences in rising/falling rates of the sensor. There is a MAF frequency table in the PCM that supplements the STFT/LTFT and timing based on TPS, MAF freq, calculated engine load, and a host of other sensor data. So long as the Granetelli MAF has the same frequency range and rising/falling rates, you should be fine.

Now onto the eBay air intake. By putting a filter in the hot engine compartment without a heat sheild to isolate it from engine heat, you are actually defeating the purpose of the intake. The stock intake with a k&n drop in filter will flow very close to the same as an eBay unit with their crappy filters (unless specifically purchased with a k&n cone filter). Now, the reasoning behind why less restrictive hot air is worse than stock cold air... The IAT (intake air temperature) sensor reads the temperature of the incoming air charge. The PCM then takes this reading and modifies the timing curve to suit this temperature. The warmer (hotter) the air charge, the more timing is pulled (retarded) and the lower the power output potential of the motor (all other things being equal). Now, if the intake temp charge is hot enough, you could get some pre-ignition or knock. The knock sensors will see this and in turn will KR (knock retard) the timing even further, decreasing the power output even more.

While we're on the theme of disproving things... Lets talk IAT mods... Many

Scott, about your Granetelli MAF... Did they calibrate that to the exact specs of the original MAF? If not, how does your engine know that it is getting more air? MAF sensors are delicate and typically, they cannot just be swapped around without proper modification to either the MAF sensor (to match that of the stock sensor) or to the PCM to account for the differences in rising/falling rates of the sensor. There is a MAF frequency table in the PCM that supplements the STFT/LTFT and timing based on TPS, MAF freq, calculated engine load, and a host of other sensor data. So long as the Granetelli MAF has the same frequency range and rising/falling rates, you should be fine.


Therer is no way for me to prove Granatelli programmed, calibrated to any performance specs at all. I could have "stock OEM" MAF sensor programming" on there now! I no longer have the stock MAF (dumb move on my part) and cannot compare the differences. Since it has been installed it's never caused thrown codes or fail emissions. I've averaged 18.1 MPG all winter so far.

The MAF and the combined intake mods on there helped me achieve this, for I averaged 16+/- MPG when I first purchased this Blazer.

It is very possible that they have the same frequency range and rising/falling rates. I just know that when switching to other MAF sensors on 3800 engines, you have to recalibrate the PCM to make use of the larger (or just different style) MAF sensors.

I guess I should get the PCM reflashed on the Impala to take advantage of the aftermarket MAF.

Ok so here's the pictures and some information for you.

The snorkel out the front of the filter box necks down to ~2-3/8" ID. This has a cross-sectional area of ~4.43sqin, but due to its venturi design, it will flow more than a 2-3/8" ID tube.
http://i11.photobucket.com/albums/a187/swartlkk/filterbox8.jpg

As far as the restriction by the headlight bracket, the picture below will show that there is 1" of clearance on 3 sides of the headlight bracket. So 1" by 1" times 2 + 1" by 3" = 5sqin of flow area for air to go through. Still larger than the MAF and snorkel. That is assuming that the headlight bracket covers all of the opening, which it barely covers 1/2 of the 3" opening (see second picture below).
http://i11.photobucket.com/albums/a187/swartlkk/filterbox6.jpg
http://i11.photobucket.com/albums/a187/swartlkk/filterbox3.jpg

The MAF sensor has a starting diameter of 3" ID, but necks down to 2-5/8" ID with a 15/32" wide band through the center as seen in the picture below:
http://i11.photobucket.com/albums/a187/swartlkk/MAF2.jpg
This results in a CSA of 5.41sqin minus the bar (2.625*0.47=~1.23sqin) or ~4.2sqin (being generous).

Going through the intake track further, the throttle blade is a 75mm blade (same for the SCFI 350 v8 and 4.3L v6). The Vortec 350 has a little bit smaller deflector on the throttle blade. I do not know exactly what the smallest bore size is in the throttle body, but going with the throttle blade size and throttle shaft size, the flow area around the throttle blade is a maximum of ~5.7sqin. Now this is not taking into account the restrictor due to the obvisous increase in calculation complication.

About that restrictor... Here is a good explaination that I found on S-Series.org:
Draw your own conclusions.

Some say its because GM wanted to save money by using the same sized throttle body from the 4.3 through the 8.1. The 8.1 has no plate and the 5.7 is smaller, but still has one like the 4.3. The 8.1 and 5.7 however have coolant running through theres and also use the side port the 4.3 is left blank on. Those while maybe the same size must use a different casting and also different maching, so that throws that ideal right out the window, the save money part. It would be much more cost effective if all the did was bore each out different off the same exact casting then go through the other motions. What do they then share exactly the same, the base throttle plate and shaft.

All the motor share the same problem if you want to call it that. Forward sitting throttle bodies to give room to the SFI injector pack. The reason is shorter in height verus the front is to create more air speed to the rears having it smaller since they are the furthest away from the bore. The reason they rear open it is to ramp air toward this area to also aid in its air delivery. Its like electricity air is, shortest distance is where it wants to go unless something steers it away. The plate does restrict , thats one of its jobs, allow a higher amount of air flowing toward the cylinders that will under vacuum have the largest problem drawing air versus ones sitting right under the bore. Engineers knew they had the plate hence the reason they dump the EGR and tank purge line into that area. Set it in motion in the dead calm and allow vacuum to pull it as needed. Without the plate in place you will lean the front cylinders out in a 2 fold scenerio. One you'll disrupt the balance the plate was designed for, so under WOT or when EGR is shut down, the air balance will be lost and the rears will fight for air while the fronts have no problem drawing it in. Second during EGR you'll also lean it out. EGR is known as lean burn technology, so EGR gases will be cut off by the air entering down the backside of the plate cutting off the dead air space to distribute from. If that wasnt a planned event, someone explain why they did add EGR to the intake tract like on other V-8s that dont use this type intake!

Take it out completely, no. Modify it , yes. Since the V-8 uses the same style yet smaller and feeds 4 cylinder off the front bore and 4 off the rear, copy that, half the plate. Still has its dead spot for EGR and purge, but allows more air in IF needed. Taking the whole thing out just takes away the pedal is all. By 60% or so open you'll have now allowed the max air flow the motor will ever use, but at a lower TPS reading to which the 02's now have to try to compensate for since its off skewed on its maps. Then you can listen to all the others tell you how alive it is at WOT, when at WOT all it did is rebalance the cylinders out, got the TPS now to read to air draw etc, which does feel like it came alive since it was part dead at lower RPMS!

I have cut down my throttle blade deflector and will be returning it to stock. I don't feel that it did ANYTHING to WOT performance, but it did make it 'snappier' off idle. That is not worth the potential side effects listed in my previous post. I will be attempting to find a v8 throttle blade and another v6 throttle blade to try out. Should be able to grab them from the local PnP for ~$5.

Scott, what MAF are you running in your Impala?

It's a Granatelli motorsports MAF. It's very similiar to the Blazers. I left the factroy MAF alone. If I remove it. I would have to fabricate a cover for the hole.

http://img.photobucket.com/albums/v403/photobot121/2001%20Impala%20LS/th_P3070004.jpg (http://img.photobucket.com/albums/v403/photobot121/2001%20Impala%20LS/P3070004.jpg)

Wow man that was cool and very informative.... dont you think youll still get better air flow by removing the blocking section nonetheless? Either way all your calculation had me quite lost although lol... but i understood altogether which means that i can gain more by changing diff parts..... the only thing i noticed you didnt mention is the mad amount of ridges in the stock tubing that has to have a tremendous amount of drag on the passing air would it not? i think that the best possible set up where someone could gain more airflow in an intake would be;

[>:]replacing stock tubing with straight (ie see if top section pipe off $15 ebay exhaust will reach stock box top.)

[>:]get a larger diameter (= less restrictive) MAS as you pointed out

[>:]get a thinner TBD as you pointed out (3/8" as appossed to 7/8" right?)

[>:]cut the bottom and front of the box and a portion of the drivers side of the box and remove headlamp section to allow most flow (maybe capturing/ramming more air?)

[>:]putting in a K&N free'er (?) flowing air filter

...... Dunno you think youd accomplish as much air flow on a stock box system as cutting it???? What about altogether what else do you thikn you could do to make it better???? Know that im speaking something everyone can do to their ride to mod it cause i know the best thing would be a custom made induction but we cant all fabricate our own parts.... unless you know how to mcguyver something else???? lol

and just some random questions i had since all my reading is what would you guys suggest as far as a cheap set o headers and y-pipes??? i have a 3" 40 series flomaster from midas (lol i got the whole thing for around 225... aint that pretty good??? he had to bend a pipe himself for it too.... gotta love utah man he was just as happy to see it on there as i was.... lol) but i know my system is getting a mean choke hold from the stock headers and pipes and need to let that puppy breath.....

... and ive read what you said on TBS but what is your personal opinion on the lower RPM power arch you achive??? are there any dynos showing ther approx. diff in the peak power range??? or do you have any from the few you fashioned for the 3800 series??? and how come i feel my old 94 3800 HO transport would beat the pants off my 98 blazer manual 2 door 4.3???? is it all the diff in gears and tranny or what??? is it maybe just a perception of going faster in that car since its a friggin space ship ( lol inside joke about the windsheild from my highschool freinds when i had to drive moms van..... lets just say there were many wide eyes seeing that van constantly smoke emm out the highschool driveway LOL ) i still cant get mine to really even break loose and spin on dry???? pulleys??? better clutch??? just feel my low end is reall podgy and then my power drops off round 4100 even though i should be taching out around 5500??? whats the deal there?

and last but not least would you guys suggest something like getting a pcm flash (and who would you suggest... please dont name off random places... i wanna hear testamonials on personal flashes LOL) or a power programmer for my truck ( wich i dont know how to use but if i learned i could always adjust for new mods)


haha sorry for all the questions just been reading alot and had alot of things to be answered or just discussed lol

Please know my tone here is inqusitive and speculative im not trying to be a smart ass at all in this post just trying to see what you think. The biggest problem with e-talking is no sense of tone or more then one tone can be percieved from someone. So i hope we are at an understanding im here to learn and have fun and im not wanting any e-fights :o) Cool?

Realize anytime you draw fresh air from inside the engine compartment you are drawing in hotter air then the factory location of behind the headlight. Also realize that anytime you go to a K&N style air filter you are allowing more dirt into the combustion chamber of your engine, where it will either burn and/or get trapped in your oil, which might scratch your piston walls, rings, or numerous other parts of the engine on its journey to the oil filter.

Running a K&N filter on a race engine is one thing, running it on a DD is another. One of them gets rebuilt frequently.

Ever wonder how K&N can offer a million mile warrenty?
The warrenty isn't on the engine, its on the filter. Sure it will last a million miles, but all that dirt it let through will eat your engine long before you ever even dream of reaching one million miles.

ok cool that is something i understand and am willing to sacrifice for power when needed.... but i will most likely use a standard high flow fram filter or some crap cheap that i can just frequently replace.....

but do you have any tips on headers ypipes or pcm flashes and powerprogrammers? thats what id really like to hear about, i currently have a 98 4x4 2dr SFI and cant find hardly any parts for this thing to upgrade... everything is for cpi and tbi .... where does my 98 get to have fun?????

Edit: any tips on a good cam too more for power then mileage...

actually, there is a lot more stuff out there for your year, and 96-04 in general compared to the CPI, theres almost nothing for the CPI, kinda sucks

try sites like Truck Performance (http://www.truckperformance.com) and others that sell aftermarket parts. There are programmers, headers, all sorts of stuff for your year.

tight thanks man

youre welcome, also try Summit Racing (http://store.summitracing.com)

nice ya ill def check summit but still cant find y-pipes as of right now..... they have headers but no connector ypipes

as far as I know nobody makes y-pipes for Blazers, youll have to get them custom made at a muffler shop