170412

Hi,

I'm trying to decide wether to leave the MAF screens in or out. The fins are already removed. I've done alot of reading and am under the impression that the screens help with tuneability / driveability. However this is for a 383ci motor with 400+hp potential and I am concerened that the MAF may not flow enough cfm to support the motor with screens in. Maybe not even with the sceens out?

I am paying good money to have a prom burned for my particular configuration so need to decide wich way to go.

I guess what I'm really asking is will a MAF with fins removed and screens in place have adequate flow for 400+hp?

Anyone out there know? And no, at this point I really don't want to go to SD.

THanks,
Jim

Stock 88 ECM with modded prom
stock 88 MAF fins removed
Accel superram base plenum runners, port matched
1 3/4" slp headers, 3" cat / exhaust
longblock dynoed at 430hp / 470ft/lb with carbuerator

c4boom

dont want to kill your dreems but imo the maf will not flow enough no mater what i think you are going to have to swap to a SD setup sorry man

breathment

ya the screens have nothign to do with ur problem. its the fact that ur maf can't support\read that high of air flow... so yup ur gonna need SD

170412

Thanks for the input guys. I guess I may have to consider SD. I now somewhat understand that although the stock maf may be able to flow enough for my needs but it can only report up to a certain airflow to the ecm.

At this point I am wondering if there are any aftermarket MAF's that will flow more cfm, but more importantly be able to report the higher flow rates to the ecm?

breathment

i think the stock maf flows up to 350 HP.. or somewhere around there. so far i haven't seen any aftermarket mafs for TPI. i believe the reason why isn't cause there is no MAF's that can support a higher flow, but that the ECM's wont support any higher flow rate.

Bort62

The 165 ECM can only interprate up to 255 g/s airflow. Not to mention the flow of the MAF itself is also a potential restriction.

SD is really the answer. There is no easy MAF solution.

Jim, I see you are local to me in the BA.

If you need help converting to speed density, shoot me an Email. It would be an afternoon job.

Guest

If you dont want to go to SD, dont. There are plenty of fast MAF powered cars out there. Cut out the fins, and retune the chip.

Bort62

Don't listen to Madmax

LOL

Sure you can get **close** Using early PE engagement and BPW Vrs RPM...

But with SD you can Do it Right... At part throttle.

Plus you won't have the physical restriction of the MAF, or its 300$ liability.

Its like the rebuild a 305 thing... Unless you are an enthusiast with something to prove, don't waste your time

86IROCNJ

Hey guys, when would the MAF be too restrictive? Is there a tech article on this or how to switch? The post above said around 350hp, that has me a litle worried! I could give you my motor specs if you would like. I am just wondering if it would be a good idea to switch now or soon! Thanks for any help-Bryan

DannyT

Well we'll find out soon enough. My Iroc is putting 283HP to the wheels with an auto tranny so with the 20% drivetrain loss that's about 353HP. I'll soon be adding the SuperRam plenum and runners along with a 58mm TB and 26# injectors. My MAF has the screens removed but the fins are still intact. According to the naysayers my car will not gain any more power. I'll let you know

88 350 tpi formula

iTrader: (9)

hey to day I got this car in at work 99 3.4 and it had a lean code p0171 ! so I went through the flow chart to diagnose the code and the step was to check the mass air flow for blockage or debre, when I pulled it it looked great all except a few small bugs and a couple crumbs of a leaf, well I figured hey it doesn't take much so I lightly blew it out installed it again and guess what that small little bit went made a hug differance the ST was 0% and LT was 21% after reinstalling they both were 0% right on the money! now if that little bit does that emagin what removing your screens do! holly cow you ecm must think it is super lean and just dumps the fuel

Guest

At least you could be correct about how much one costs.

SD guys

DannyT

New MAF was $175 for me over 5 years ago

86IROCNJ

Well, here is why i am worried. My setup is similar to that of TPIS' only i am using the hot cam instead of their cam, which is a little smaller than the hot cam. They claim that they made ~460hp and ~435lbs/ft. I am hoping for similar numbers with proper tuning. I am running the zz4 with fastburn heads, hot cam, and miniram. Along with other little stuff like upgraded ignition. Should i be worried? I mean, i already have the chip from fastchip and they said that i should be alright. Also, TPIS knows that i am running a MAF and they did not say anything! I think i will call them up and see what they "say" or "recommend". I knew that they were restrictive but i did not think that it was this bad. This is truely the first i have heard of this. I was planning on "modding" the MAF but i might as well keep it stock if i might have to switch to a SD setup. What do you guys think? Should i be worried or no? Thanks for your time-Bryan

Guest

I wouldnt be worried.

BadSS

Me either. Gut the MAF and if it doesn't run as well as expected,,, chances are something else will be wrong.

86IROCNJ

Oh yeah, i am planning on it running good enough to get it somewhere so they can check my work and to tune it properly! I am sure it will run well, just not perfect at first. I am definately getting it looked over once its running though. Thanks

Bort62

Id like to see the Look On the Part's guys Face when you try to Turn in your Descreened, Fins Removed Ported MAF for a Core...

Besides, Your right MAF costs arent much of a concern to me. MAP sensors cost 20 bucks and they Don't Fail when Drop them.

MAF guys w/ Modded Motors Barely Faster than My 305




Danny T, When you Want to really see what your Combo Can Do, Email me and we will set up a Day

DannyT

Well you probably have a modded to hell 305. My point was that they said that 350 HP was the limit for MAF cars. Since I'm at that now then I guess adding the SuperRam plenum and runners with larger injectors will not make me any faster right? I'm waiting on the parts as we speak. This DOES NOT mean that I'm saying MAFs are better/worse, just going with what I have....for now.

Guest

Dont need a core for a Wells. Besides that, most parts guys dont know whats supposed to be there anyway, they can hardly order the right part let alone know what its supposed to look like. You're giving them too much credit.

170412

Well... there sure are some varying opinions here. I am going to see what I can get with MAF, screens out, fins removed. I've already paid the money so what the heck. If I can't get it running correctly according to the scanner or can't get a calculated 400hp at the crank I guess I'll go to SD at that point.

Any problems with passing smog test in CA with a MAF system converted to SD?

Mkos1980

iTrader: (8)

I know my car maxes out the MAF 4200 rpm . Then from crusing to a hard downshift the MAF will messup causing a spike of 90Degrees of ignition timing causing massive detonation to the full 50 degrees retard in the chip leaving me nowhere.

86IROCNJ

Can you guys give me a straight answer please? I feel like i am not getting one since there is some conflict in this thread! From what you are talking about i am "guessing" that i should switch to SD. Anyone want to give me a legit answer? Please, so that i can "see what my combo can do"! thanks

Mkos1980

iTrader: (8)

you can tune a maf system + leave the screans in

Bort62

Okay, Here is as strait of an answer as I Can Give...

The MAF is a good system. It directly measures airflow and delivers fuel accordingly.

The Problem is, our Particular MAF system is limited to a max measurement of 255G/s of Air, All Physical CFM limitations aside.

Mkos' says his MAF Maxes out measurement wise at 4200 RPM... thats Not very High.

The More Power you Make ( the More Air you draw at a Given RPM ) The earlier and earlier the MAF will Max out.

Now, there are ways to get around this, Primarily Engaging PE Mode earlier and using the '88 Mask and PE BPW vrs RPM Table to get your PE fuel close. Thats what Madmax will tell you, anyway.

And Supposedly it works fairly well... I can't say I havent tried it.

Lets Not forget however, that the older 165 ECM as compared to the 7730, In both hardware and Software sense is More primative, and Slower - an added caviat.

Granted you Can make the MAF system work with alot of Fudging, Fiddling, and Band-aid Type Changes. And sometimes that is what needs to be done in light of no other options.

But Hark! There is another Option. The Speed Density setup has none of these problems, and is SO readily avaliable and easily installed that there is really no reason to Work too hard on getting the MAF to work.

So realisitcally, While you can probrably get the MAF Setup to work (disregarding CFM limitations) its probrably not worth it. Might as well Swap to Speed Density and Do it "right" (Accurate, Non Fudged Early PE ect Part throttle Fueling.) Not to mention, as hard as you work on the MAF setup, If you know what your doing the SD setup will always be more accurate.


Thats My take on it, Anyway. Im Sure some will argue that the MAF Setup is better, but I would really like to see their reasons why.

rockind78

Well I WAS gonna vote for an LT1 sticky, but I am changing my vote to a PROPER MAF versus Speed Density Sticky. I swear we have this discussion once a week! Oh, and on the screens bit, maybe this will help:
http://www.gmtips.com/3rd-degree/dox...maf-screen.htm

Guest

You have to fudge and fiddle with SD to get it to work right too, just they are in one table instead of 3.

Want the answer? Theres at least 2 people who post/ed here in the 11's with a MAF setup. I think thats past 350hp at the flywheel. I know my car is past 350 at the flywheel. Look at Mike Davis' site. Notice all the major difference from MAF to SD. What you should do first is try it. Nothing will stop you from changing it later, but if it accomplishes what you need it to, what are you out? You arent out the time and the $100+ it cost you to do the swap, just because a bunch of 'experts' here told you MAF doesnt work and you have to run SD. If you want to take some opinions of people you dont know, and shell out $100 or more, well then be my guest. I wont stop you, and I wont say SD is worse, but I will say you might have just burned 100 bucks or more.

BTW, GN's are MAF cars. There are some that have been changed to other systems, but the basics are the same on the factory setup as the TPI's. I know all of those are real slow cars that dont run worth a damn.

86IROCNJ

Well, with that being said,(all of the above), i think i should see how it runs for me. Once i get some more cash flow i will be getting into prom burning and i might as well convert to a SD setup. We'll just have to see what the MAF does for me now! I am a type of person to do things right the first time, as long as i have the right info that is. So, i am not even going to ask how to switch to SD, i have seen info before and i am pretty positive there is even a tech article on it. For now i will just play it by ear and i am sure i will be moddifying my modds, so to speak! Thanks for the input guys, all of you! Hopefully there will be some updates in a couple of weeks here so i am sure i'll be posting more about my progress. By the way, on a side note, how many of you think i will have a bad running motor with the MAF as it sits now? As far as tuning goes, i went with an Ed Wright chip. Thanks again-Bryan

Bort62

An interesting peice of circumstantial evidence to note is that ALL aftermarket Fuel injection systems ( Motec, Speedpro, Haltech, Eletromotive, Accel gen VII DFI, FAST, ect) Are Speed Density.

Megasquirt is Speed Density.

True, LS1's Lt1's GN's and alot of other fast cars are Mass Air, But that really doesnt mean Much. If I had a GN or Ls1 and Didnt have a cost effective Easily obtainable Speed Density Solution, I would fudge around and trick the computer into tuning my MAF, too.

But Why ? The easy answer is so right at your fingertips.

Madmax is right, Do what you like. Fiddle around with the MAF till you decide it won't work for you, then Jump on the SD bandwagon.

I just firmly belive, from everything that I have seen and personal experiance, that SD is a better way to go.

I don't think there is any real need to make a sticky. The sort of people who are too Lazy to do a search on the topic Shouldnt be attempting such a Cognatively demanding swap, anyway.

Bort62

Well I don't nessicarily subscribe to the whole Physical intake restriction thing to that extent. I mean, were not talking about an inherantly flawed, Uncircumnavigateable Fuel delivery system with a Very real and Static Maximum Horsepower Limit here.

If we were, We would be on the TBI board.

BadSS

Do I think you will have a bad running motor with the MAF? No - not if everything else is right. Mine runs just fine with a gutted MAF, a stock 1988 350 GM chip with 24# SVO injectors, with TFS heads, and 218/228 - 110 cam. Go figure.

Personally I think this MAF vs SD "war" is silly. I have no "loyalty" or anything to prove by sticking with it. If I didn't have the MAF set up I would choose SD. When or if the MAF goes out,,, I'll convert,, but not until then - I've got too many other things to do (not car related) than to swap over for no real reason (not in my mind anyway).

Guest

Interesting to note almost all factory stuff is MAF.

If you are fiddling anyway, SD is a better setup because it can read transitional changes better. Thats why the aftermarket uses it. It doesnt mean you should change to it, if what you are using is working fine. Doesnt make sense. Its also quite sensitive to changes, so when you make changes you have to mess with it. At least if you want the perfection everyone is claiming that it has over a MAF setup.

Bort62

Yup, haha.