I have a 406w/miniram 30lb. injectors heads cam headers blah blah. I was wondering what you guys suggest for the MAF sensor.The person at Ed Wright didn't seem to think it was much of a concern but I heard they have low flow #'s. The motor is fairly stout so I don't want to restrict the induction after spending this much time and money. Thanks

 

Wells SU-145 MAF. The stock unit (un-hogged) is restrictive and somewhat unreliable. The Wells MAF not a heated wire style like the old Bosch unit. It does not have the heat sink in the way, and it has a larger ID than the Bosch unit. It is a direct replacement also. Dig in the old-old TPI forum, there was a discussion of this in there and even a picture of it. If you can't find the picture, I can email it to you.

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82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.

 

I have a page up on my site documenting some flow tests I did last year including the bosch "hot-wire" mass air meter for 1227165 TPI systems. Unscreened they will flow at about 658 CFM. I do NOT recommend removing the cooling fins from the unit. Doing this only nets you modest gains and can shorten the life of the sensor. You can check out the flow test page at: http://dtcc.cz28.com/flow/index.htm

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1987 Trans Am GTA WS6
5.7L SuperRam
4L60-E Trans
3.73 SRD

1987 Pontiac Fiero
3800 Series II
4T60-E Trans
3.33 Final Drive

1988 Pontiac Grand Am
3800 Series I
125-C Trans

1966 Plymouth Belvedere II
318 Semi-Hemi 2bbl
Torqueflite 727 Trans

Domestic Terrors Car Club Online

 

Why run one at all?.
Use a 90 SD ecm, and be done with it.
every 1% intake restriction, will cost you 2% HP.

You can play all kinds of screwy games with them, but they all destroy the linearity of the output. Once you do that the absolute best you can do is that it runs OK. OK is alot different then right in my book.

 

As great as the Wells replacement unit sounds, it is still Wells, and at least as far as their ignition components are concerned, they aren't too great. Is the MAF an exception?

 

There's a guy at the corvette forum who doesn't think too much of the Wells MAFs. His only lasted a short while. For as much as everyone talks about them around here, you sure don't hear much feedback about them, do you?

 

The Wells SU-145 is not a stock repalcement. It is an upgraded unit similar to the fourth gen MAFs and is more reliable, accurate, and flows more. It plugs directly in, and does not require recalibration. Wells also makes stock replacement units. I do not know about their track record as far as reliability is concerned.


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82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.

[This message has been edited by Greenshamrock77 (edited June 28, 2001).]

 

We've all heard the sales pitch. This is what I'm getting at:

 

Sounds like we need to take a poll, then! (but maybe not in the PROM board..) I'd like to know how many people have used the Wells MAF, and what their experiences are.

As for me, I've used Wells ignition components and am not too happy. I replaced one of the coil packs on my dad's 2.5L lumina a couple years ago, and last winter it started to miss again. The stupid Wells coil was full of cracks, which led to water getting in, rusting the core, enlarging the cracks, etc.. Given the fact that doing a coil R&R on this motor is a major, big-time PITA, i wasn't too happy. But, YMMV.

 

OK, so it flows more but you have to go back to the fact that the code will only recognize 255 g/sec. It's the code that becomes the factor, not the sensor itself.

 

From what I was told the computer goes into open loop at WOT. So the MAF sensor readings would have no effect.
What is involved in switching to a 90 ECM?
If the stock MAF sensor flows 658cfm. then there wasen't any point in me going to a 58mm throttle body, 230/238@.050 w.539/.558 roller cam. I should have looked into this closer before but I guess Hindsight is always 20/20.

[This message has been edited by 89406Iroc (edited June 28, 2001).]

[This message has been edited by 89406Iroc (edited June 28, 2001).]

 

[QUOTE][B]From what I was told the computer goes into open loop at WOT. So the MAF sensor readings would have no effect.

Open Loop just means ignoring the O2.

What is involved in switching to a 90 ECM?

Rewiring, and adding a MAP sensor, links to doing it are in the archives.

If the stock MAF sensor flows 658cfm.

Not even that.

then there wasen't any point in me going to a 58mm throttle body, 230/238@.050 w.539/.558 roller cam. I should have looked into this closer before but I guess Hindsight is always 20/20.

Yep.
You can run OK, but again that ain't to be confused with right.

 

Thanks alot I guess I will have to look into a 90 ECM and see if Ed wright will do me any favors on doing another prom.

 

Has anyone tried using a 98-00 SLP MAF in a third gen? I have a 1988 GTA, and am in desperate need of a MAF, but all i can find readily available is ones for fourth gen camaro's/TA's... take a look and tell me if u think it would work, or if you know someone who has tried.

http://www.proformance-motorsports.c...ors-98-00.html

thnx

 

I tried one in my Vette. I also replaced both relays. I had intermittent driveability problems (stumbled) and periodically threw a code 34 whenever the TC was locked up in 3rd and I put a load on the motor. (i.e. going uphill)

I put my old Bosch sensor back on and the problem went away.

 

Damn, well it was worth a try... guess im ordering the wells one then... thnx for the input

 

Drop the 165 dude. Even with a wells, thiers still the 255gm/sec limit.....

 

Yea go with SD. It is A LOT easier to tune also.

 

Would switching from MAF to SD really provide more HP???? I have a 383 cu. with the TPIS Miniram and Fast burn heads. I am willing to switch to SD if I will see noticable improvements in performance, if HP gains are only marginal, then why bother? What are your opinions on this? Also, A while back someone mentioned that MAP systems are not as throttle responsive as compared to MAF systems. Is that true? If someone can convince me that this switch is worth it, then I will do it.
Thanks

 

I too am considering switching to SD as one of my winter mods. I have read a lot of archived info on the advantages of SD over MAF and I am almost convinced to go ahead with the swap. I have no doubt that the SD can be tuned a lot better than MAF. The deciding factor for me will be if someone has actually gained power or bettered their ET's by going to SD from MAF. Does anyone have before and after timeslips or dynos from just this swap? I emailed Mike Davis awhile back and he said he thought that a high 12 sec car would probably see about a .15 reduction in ET. Does this sound about right? Anyone have some proof? Like I said, I am almost convinced, a .1 ET reduction or greater would sell me.

 

there is no need to switch so S/D. ill will have the maf flow issue worked out before winter. the goal is to have a 900cfm maf. you gonna use that much air ? i will also be posting the correctio that need to be made to the maf tables. as well as a multiplier for getting the fuel tune back on. give me some time i got projects brewing. the only way ill speed this up is if i get 50 emials asking for larger mafs and calbration tables.

 

How about gettign the 165 to RECOGNIZE and USE more then 255gm/sec. If you want a maf that flows 900cfm, make a giant pipe and drop your maf's internals int hier somehow. Dont mean the comp will ever see more then 255gm/sec

 

Well with a 383 you probably are maxing out a MAF. Technically if you were able to tune the MAF perfectly (which is very hard) the MAF would only be slightly behind the MAP system or possible be the same. In reality MAP is going to make you car run better with less effort. I have messed with both, I had MAF and had little luck tuning it well so I switched to Speed Density. I got the BLM’s very close to 128 in just a few tries thanks to VE Master. The rest I did by hand. I have noticed a performance difference with MAP because I was actually able to get MAP tuned right.

Whoever said that is very uninformed. MAP (Manifold Air Pressure) sensor has better throttle response. The reason why MAP gets better throttle response is MAP uses a sensor that is a diaphragm that moves in and out by engine vacuum. Changes in vacuum can be sensed instantaneously by measuring the position of the diaphragm. The diaphragm acts as a variable resistor with each measurement of vacuum having a resistance value. The ECM puts in 5V to the MAP by measuring the volts the MAP outputs it can tell the vacuum in the intake manifold.

MAF (Mass Air Flow) sensor measures airflow by measuring the temperature of very small heated wire. As air passes over this wire it cools. The amount of air that flows over this wire can be calculated from how much the wire cools in temperature.

By this point it should be apparent why MAP has better throttle response. MAP can measure vacuum instantaneously. It takes longer for the air to cool the small wire in the MAF sensor then it does to change a diaphragm in a MAP sensor.

More Pros of MAP:
- Map sensor is much cheaper then MAF
- No restriction of a MAF in the intake air flow.
- MAP is much easier to tune then MAP
- MAP does not have an intake flow limit

 

stop thinking of the maf air flow limit of 255 grams a sec. think of it as an output of 150 hz or 5.0 volts. this is were people get consed all the time. the ecm does not really need the resolution it gets form teh maf. also running a wild cam on a car with a map will really narrow down the useable VE table where as a larger maf will simply provide a slightly coarser reading but you wont lose the lower 30kpa of the tune. maf has a advantae over map but no body knows it just yet.

 

I know there is a way around the 255 limit but I am waiting to see how hard it is going to be to tune. Funstick, if you can find a way to make MAF as easily to tune as MAP that would be great for the whole DIY PROM community. For the time being MAP is much simpler to tune. You can start out by letting VE Master narrow the tables down for you and do the rest by hand which is much easier then MAF.

I am not trying to say MAF can’t be tuned effectively; it just is harder to tune.

 

Funstick and 89Irocz, thank you for your replies. I do agree, tuning MAF is very tedious. I have yet to tune my engine perfectly. Funstick, what constitutes a really wild cam? I am running a 230/236 I/E dur'n@0.050" and 536/555 lift w/ 1.6 rockers with 112deg lobe separation, so do you think I would have difficulties tuning at lower pressures?

 

i dont know if youve been reading my posts but read the Definitive $32 $32b maf tunning article on this very board. its not nearly as hard to tune maf as you beleive.

 

Neil, what's your car run? I have tuned mine using the ARAP 6E based bin with decent results, but I'm really considering dropping in a 32B bin and trying out Funstick's method. I just hate the thought of starting over.

 

the real advantage to using the PW tunning method is that you can make the MAF housing as large as you want and just spec the fuel any way you would like. give it a shot and just keep a copy of your current chip and start with a blank.

 

Steve,

Ihave been very unfortunate at the track the last few times so to be totally honest, i've been avoiding it. I have a torque arm to put on, so in a couple of weeks I will go out to the track and see what she'll do.

 

I haven't made it to the track yet either, but have been tuning with a Gtech. Your car should run low 12's or high 11's. What gear are you running? The Miniram and LT1 intakes like alot of gear and stall, especially with your cam. I really wish I had a 3200 stall.

I just got a Wide Band O2 monitor system all together this week. I see your in Houston, so if you need it to help with your tune, I'm about 2 hrs away. Just takes a bung welded in before the cat.

Steve

 

Ok, i'm back!
Man, 11's would be nice!!!! very nice!!!!
I am running a 3:73 gear and 3400 stall. Hopefully it will all stay together when I hit that skinny pedal on the right! I myself have been trying to tune my car and I could always use some input in this area, so whenever you have the time, let me know.
Hopefully in 2-3 weeks time I will have my car ready for the track, so keep in touch. Drop me an e-mail.

BTW, what is Gtech? You say it's a wide band O2 system, is that similar to the F.A.S.T. system (the newer version of the Fel-pro system)?

 

Gtech is an accelerometer that measures performance. I've been using the same flat stretch of road for the past year to verify my mods and chip tuning.

Wide band O2 is a unit that accurately measures air/fuel ratio in the exhaust. It's the same one that they hook up to your car at the dyno. It really takes the guess work out of tuning. You never have to wonder whether your rich or lean.