BOTTLE ROCKET

iTrader: (4)

I've asked a similar question concerning the MAF before, but since I havn't completed my FI tune and it would be a "do it now or not at all" situation should I toss my stock size (early style) MAF and go with a larger 85mm ZO6 MAF, a truck MAF, or maybe a Delphi MAF that actually came with the procharger.
If it was just a drop in, it would be a no brainer, but when you consider the purchase cost of a MAF (unless I use the Delphi) different hose adapters, and the cost of the wiring harness to seperate the IAT, I need to know that it's worth doing.Is the Delphi unit any good (I already have it)
I'm running a P1SC1 at around 9psi and 600+ hp
Thanks guys

onfire

iTrader: (17)

IMHO that if you're going to stay at 9psi or less, I'd leave the stock maf in it. I retuned a LPE TT a while back and rebuilt the VE table for 42's. Enabled the stock maf and it fell in line. RPM vs PE was dead on....but it was limited to 8psi and 540rwhp on an eddy current dyno...."should" be around 580-600 on a DynoJet.

That's my personal limit...beyond that throw the maf away and put a 2bar map/tune in it.

ls1290

iTrader: (20)

The best MAF improvement is to throw it in the trash and go Speed Density

BOTTLE ROCKET

iTrader: (4)

Thanks guys
I have thought hard and read a LOT of post about SD, but I think the only thing that makes me want to stay with the MAF, if possible, is the temp/humidity versatility. "Down here in GA" It may be in the 30s one day, and back in the 70s two days later. I want the car to be as low maintenance as possible (or as least as low as a boosted motor can be) and not have to swap out tunes for the seasons. If I was going for higher hp, then I might not have a choice.
If there's anything to gain from going to a LARGER MAF, then that's easy enough to do, but SD might have to wait until I get a lot better at tuning myself.

ls1290

iTrader: (20)

The whole point of SD is that ambient temperature, humidity, and other factors play a much less important role as MAF based tunes. If you want a tune that can compensate for changes in conditions, SD is the way to go.

BOTTLE ROCKET

iTrader: (4)

That's very interesting. I must confess I've probably read well over 100 post on SD vs MAF tunes, and although there have been major disagreements on everything from MAF limits to SD benefits, I have never heard anyone say that one of the benefits of SD tuning was it compensated well for different weather conditions. In fact, some of the biggest advocates of SD tunes, state that they simply have "several tunes" loaded so that they can simply "take a few mins. " and download a tune to fit major temp changes. One guy even stated that he had a winter and summer tune.
I'm not saying that ANY of this is fact, and it may simply be in the quality of the tune, but it's just what I've read for several months.
I would like nothing better than to drop my maf and go SD. It would even make my filter mounting easier since the corner of my filter hits my MAF; but the two tuners I deal with (One is a WELL known tuner) have both advised me (meaning they don't want to do it) against going SD until my MAF limits me.

JonCR96Z

iTrader: (33)

The MAF adjusts slightly better for weather changes but that's really the job of the O2s. Run it in OLMAF or OLSD and you'll be retuning often. Either of them in closed loop will be corrected just fine for the weather.

The real problem is the bias table the over adjusts for IAT temp.

NicD

iTrader: (7)

A MAF is always going to be more accurate than SD as long as you are not maxing out the MAF in the process. It's a device that actually measures the air flow/density unlike SD which is a calculated value. I usually only suggest people go SD when it's necessary ie maf is maxed out. You give up a few diagnostic functions that are helpful when you go SD. For your setup I would give the stock MAF a shot and as long as it isn't maxed out run that.

JonCR96Z

iTrader: (33)

Not always. MAF doesn't measure the airflow it measures the elecrtical frequency required to maintain the temp of the heated elements in the sensor. Then it takes that value and compares it to a table of airflow numbers that have been put in by the end user. Much the same as how the VE tables works.

Neither are going to completely compensate for weather changes, that's what the O2s are there for. There are some functions that you lose when going SD only but there are enhanced PCM operating systems from either HPTuners or EFIlive that give you back the features that you lose and offer some other benefits as well.

NicD

iTrader: (7)

Yea, I know how a MAF works and it reads air density to be exact so yes it does compensate the best for weather changes, etc. A MAF will ALWAYS be more accurate in fueling conditions as long as it isn't maxed out when compared to a calculated estimate (SD). You can't argue this, it's a fact.

Yea, I know that. However you lose misfire diagnostics which come in very handy at times, you don't get that back with a custom OS. Then there is the issue of some states emissions requirements...

Vetal

iTrader: (3)

Which HPT OSes drop misfire diagnosis feature??