1970fbody

iTrader: (3)

What are the benefits of removing the MAF unit? And what has to be done besides simply unplugging and removing it?
I am building a custom CAI in my 70 so I have plenty of options with plumbing. My concern is setting up the ECM correctly to run without it. Do I need to add in a intake air temp sensor somewhere? If so, where?
Thanks for any pointers.

*02WS6TURK*

iTrader: (13)

I'm no professional on this topic, but I believe it would require a SD (Speed Density) tune. From what I hear you would need to adjust the tune every so often depending on the weather conditions. Being you are in Seattle, the weather is always changing. You should call Tom @ Wong's Performance in Vancouver. He's not to far from you and he's a top notch tuner. He does all my tuning along with several others in the NW.

1970fbody

iTrader: (3)

Thanks for the quick reply and local connection. I'll give them a call.

*02WS6TURK*

iTrader: (13)

No problem. IMHO I think you would be better off keeping the MAF. Talk with Tom though and see what he thinks. There is always Ellis out your way to and he tunes/builds as well. Good luck!

1970fbody

iTrader: (3)

I have a MAF unit but there is no screen in it (bought used, didn't know until I got it). And I may have a decent deal on a ECM and harness already tuned very close to what I need, but without MAF.
If it helps to keep it in the system I will. I want ease of use, good street manners and reliable running. I don't want to be stuck dragging my laptop on road trips just to keep the car in check.

redtan

iTrader: (5)

You don't have to do anything per-se, when the computer sees a lack of MAF input then it automatically defaults into speed density mode.

What you do need to do is tune for the fact that you're not going to have a MAF input anymore and get an external IAT sensor to talk to the computer as that's one of the key parameters a speed density tune uses.

1970fbody

iTrader: (3)

More good info, thanks! Is there any "rule of thumb" on IT placement? Say a set distance from intake bends, TB or air filter?

GoFastKid

It will drive like **** if you remove it w/o tuning it. Been there, tired it.

1970fbody

iTrader: (3)

It will be fully tuned for sure.

My questions are for two reasons. One is that I have a crappy MAF unit I may not want to use or replace. The other is because I may want to go turbo later and as I understand it speed density is the way to go with forced induction. Is that correct?

(this MAF unit works fine, but its been modified and I'm not sure I want to see how long it will last and have to deal with it later. May be easier to delete it now)

GoFastKid

I can understand if you are doing a turbo. If not I wouldn't bother. The gains are next to nothing.

1970fbody

iTrader: (3)

Ok thanks. Just the kind of info I'm looking for. If a turbo comes into play it will be way down the road. After the car is built and driving.

redtan

iTrader: (5)

Surely a 78mm screened MAF is going to impede airflow quite a bit. A bigger straight pipe is worth a good 5-7hp.

jlcustomz

Recently had someone at efi alchemy explain to me about this. Really does take away from the systems ability to adjust to environment changes. If you move to a different temperature/ altitude part of the country, you may need a retune.I,d stick to maf unless you,re into all out racing & constant retuning anyways.
Would not do it bacause you need a new maf.
It is my understanding ,through other's experience that a part such as maf, throttle body, or intake is far less of a restriction issue with air being forced through rather than having to pull it through.
Check out the book on ls1-7 dyno results.
Mid 80,s callaway 200 plus mph corvettes with stock tpi intakes are a good example of this theory.

GoFastKid

1-2rwh isn't worth having to mess with the tune all the time

1970fbody

iTrader: (3)

So with the different opinions (which I honestly appreciate) it looks like some more research is in order.

SweetS10V8

iTrader: (4)

People have argued this for years!!!! It will never come to a conclusion.

Keep your MAF, its an actual airflow meter. Your PCM uses speed density in the background in conjunction with your MAF.

Your plumbing your intake, make room for a MAF.

1970fbody

iTrader: (3)

Good point. Thanks for the input.

LS1-450

iTrader: (33)

^^^ This.

Although, will say that many times we will choose among, stock type fuel trims using MAF, o2's, MAP, temp..etc, Open loop MAF, or Speed Density. Each are effective & are chosen based on the owners preference. Each will effect "normal driving" performance differently. WOT tuning is basically, it's own tune.

Personally, I prefer Open loop MAF. This means that the MAF is used, but normal driving fueling is not trimmed by the 02 sensors.

If you have no room for the MAF, Speed density can work. Yes, w/ speed density, large temp swings can be an issue if it's driven year round.

redtan

iTrader: (5)

Who says you have to mess with your tune all the time if you don't have a MAF?

Why? That's why you have an IAT sensor to measure temps and have the PCM adjust accordingly? Never had an issue with the same tune in 0* weather in the winter vs. 90* weather in the summer?

LS1-450

iTrader: (33)

It says "can be"...not will be. Consider yourself fortuneate. IAT sensor is not a do all end all to temp related ignition issues. Log your tune in 0* & then 90* weather. The log will reveal how differently the tune is reacting to the difference in temp. Just 'cuz it's not felt doesn't mean it's not happening.