i have an 88 iroc with a 91 350 in it. im not sure if the guy i bought it from had the 91 air induction system put in there with the block. whats the advantages of having the speed density system vs the maf system. i know the speed density system is less restrictive. how hard is it to convert from MAF to speed density? and how much would it cost? any other important information?

 

You need to do a search. It has been covered extensively and caused many arguments.

 

Thats just because some just can't get over MAP being better.

-- Joe

 

Also LMFAO....

 

Ive heard that if you use a MAF, it will allow bolt ons, minor mods fairly well without tuning. Althought SD is a little more finiky about mods, it can make a decent bit more power.

 

Once a MAF exceeds 255 gm/sec, then you must add fuel in the eprom.

In S/D, any thing you add to the engine that increases the VE of the engine, gotta tune the VE tables.

MAF does take an actual calculation, as it sees the additional air flow. S/D is a bit of a guesstimate.

Ive seen both make good power.

They both have their good points and bad points.

 

Right now I hate my Maf. Damn thing wont idle worth s*** so I gotta fix that. Either one will work great for performance, just depend on how you tune/what u do to your motor.

 

I'm not so sure I agree with a speed density intake being less restrictive. If you are referring to the MAF being a restriction, its not in comparison to the rest of the Tuned Port intake.

 

Took a ride in a MAP car... Great response from cruise to WOT... but my MAF car felt smoother once in WOT.

I have no plans to ditch my MAF... the real problem is the ECM, not the sensor itself. Either way, I'll take the slower less precise ECM if I gain true air metering.

Just my opinion.

 

I'd like you to explain this.

-- Joe

 

If you did not have the proper values in the VE tables, wouldnt the ECM just be fueling the engine by what the factory tables are?
Basically not knowing how much actual airflow is entering the engine? As compared to the MAF having the additional airflow calculated. Im not trying to debate between the two. I have S/D and I like it, and I am still learning about tuning it too. I dont dislike MAF either.

 

The MAF tables are preset too.

The airflow calc on a MAF system is just as unreliable as the airflow calc on a MAP system.

I think MAF can be a very nice setup, just not the '165s implementation of it. A lot of us have experimented with running a second ECM with a MAF for datalogging purposes on our MAP powered cars. The airflow calc in the maf setups are almost dead on with the MAP.

So after blowing out that theory, what remains is what BIN you enjoy tuning more, what the purpose of the car is.

-- Joe

 

I just have to know anesthes, do you sleep with a MAP under your pillow at night? You are truely obsessed with some personal life mission.

 

No, I sleep with a Glock under my pillow.

I'm not obsessed. I've just spent more time experimenting
with EFI than a lot of you folks.

-- Joe

 

Whats a "VE Table" and what causes it to be tuned?

 

A fueling table in a GM MAP application.

-- Joe

 

Than my PSA for the day will be to inform you of how unsafe that is......

... nobody should be experimenting that much

(actually, it is really unsafe to keep a weapon that close to you while in bed. 88% of accidental in-dwelling shootings could have been prevented had a weapon been less accesible under "Not fully awake" conditions in 1998. One of those dumb facts that will forever be lodged in my head.)

 

Brutal, I do not know anything about tuning. You are saying that the ecm guesses at a tune up and maf is reading the actual airflow and providing fuel based on the actual airflow? I am more confused now than ever. Are you suggesting that a guess at a tune up is better than one that matches fuel to airflow based on actual airflow? Please help me understand this. Also, what does my 87 tpi car have? Is it speed density or mass air flow? If I have the wrong one could you help me switch to the other? I certainly want what is best. I will do a search in the meantime to try to understand this whole thing a little better.

 

[B]

Maybe I should not have used the word "guesstimate".

 

[B]

Gee Floor...Now you got me confused too. You and I will never get this MAF, MAP thingy sorted out. I just wish you didnt confuse me more.

 

How does a VE table change?

 

It was a joke. My duty gun is in the safe while I'm asleep. (unless of course I'm in the cruiser parked under a tree)

But yeah, we learned that at the academy too.

I figure if your awake enough to run accross the room, unlock the safe, insert a mag, chamber a round - then your awake enough to shoot the intruder.

-- Joe

 

I think what was trying to be said above is the MAF reports airflow, SD reports airflow based on numerous inputs and a calculation. Neither is necessarily correct, but the MAF will be more accurate when thrown into an unknown situation. That will benefit those that dont make modifications to the code, but in either case you'd be better off making changes.

 

Do bolt ons change the VE tables?

 

speaking of tuning maf v sd: maf being a reading of air cooling down an element that is then translated to volts and sd being a calculation of manifold pressure vs. atmospheric pressure. anyone use an ls1 maf and/or ls1 ecu?

 

Rather than swap LS1 electronics onto a dated EFI manifold, take the whole engine while you are at it.

 

jus a tad bit expensive. besides, im not using a tpi manifold as much as id love to use the full ls1... its jus not pheasable.

 

Hey someone answer my question.. How do the VE tables change? from bolt ons?

 

[B]


They dont change from bolt ons, you would have to change them. If you added parts that increase the VE of the engine, your tables will be off.

The tables in $8d, (mask for 730 ECM), are seperated by "upper" and "lower" VE tables. Lower is from 400 RPM, to 1600, and upper, picks up where the lower left off, and goes to like 5600.

They both show the VE at different RPM and MAP ( in Kpas). MAP is the load of the engine.

MAF doesnt really got VE tables. Not really into the MAF thing right now, maybe someone can add to it.

Alot of this stuff is covered in the diy prom board, just read the stickies.

 

[B]

All joking aside, we will most likely convert to a $6E, when its time to tune your car. I already have a bin and all. You can even use your same ECM.

 

...or figure out it's your teenage daughter stublming around the house at 4 am because she "Needs" to have her cell phone attached to her head at alls times - sleep, awake, dead - like so whatever

 

[QUOTE]Originally posted by brutalform
[B][B]




MAF doesnt really got VE tables. Not really into the MAF thing right now, maybe someone can add to it.

This is why I don't really ever have any hope of being able to tune my own proms for my tpi setup. It's MAF. All the guys who know how to burn chips on this board only talk about MAP and the 730 ecm. I've basically come to the conclusion that not one member on this site knows how to burn a chip for a 165 MAF system. Someone please step in and correct me if this is a false statement. I've strolled the prom boards before and never found any info on burning 165 chips. So if burning chips is as easy as taking candy from a baby, like you guys always seem to hint at, how come nobody burns MAF chips? I'm not ashamed at all to admit that I need someone to give me some starting tips on burning chips either. I can rebuild engines, trannys, and rearends all day long, but when it comes to computer stuff, I just pound on the keyboard with my big hoofs! Not trying to stoke the fires here, but I've been dying to know the answer to this for a long time now. Does anyone know anything about burning MAF proms, or is it just a lost cause because the 165 ecm is supposedly so inferior?

 

I think I understand what you are getting at, but its not exactly what you are asking. Burning MAF proms is no more difficult than burning a MAP prom. It involves exactly the same procedure, and the same work. Tuning however, is where there is a difference.

The 165 is not inferior by any means (atleast I don't consider it). Its just a different way of doing things. It has its pros over MAP. You can throw a decent cam in the car, and run better right off the bat with a MAF setup than with Speed Density.

I have to admit that I do agree with you that the 730 is discussed and toyed with much more than the 165. Atleast it seems that way in regards to tuning /prom burning info.

There are some articles here regarding the 165, not sure if you've come across them before or not. Maybe they'll help though:

https://www.thirdgen.org/techbb2/sho...hreadid=288763

 

People know how to tune them, just that you have experts who say its a waste of time so it gets buried under arguments and ego. There are numerous people that had knowledge that flat out gave up because they likely got tired of the BS like I did. I find that most every statement made by so-called experts is false, they are more like statements showing lack of knowledge or thought.

You need to record the data from your car, and make adjustments from there. Inj # for global changes to rough it in, small changes to the MAF tables for some fine tuning, timing is the same as all the other stuff you may have read, and you will have to play with the AE if its lean, you run past 255 (unlikely, but possible) or you have a radical enough combo that what is there doesnt work.

 

Cool. Thanks for the link Angel. I could burn up several weeks of my life reading all the info in those posts. It'd probably take closer to a year to understand the majority of it, but at least I know where to find the info when I'm in the mood to study.

 

[QUOTE]Originally posted by Pat Hall
[B]A while back, we had a member, who was very very good at burning the MAF setup in his vette. At the time the vette ran low 11s, wich a punched out 400 block.

Anyway, for one reason or another, he ended up getting banned. I spoke with him about a year ago, off TGO about some things. (had a MAF question).. Well, anyway, end result of the conversation was, he had switched to MAP.

Did it perform better? I have no idea. We didnt discuss it that far.

Anyway. I'm glad this thread didnt turn into an argument. Woot woot!

-- Joe

 

Ya, you're talking about skidownit? Or similar...knocking on the 10's with MAF...find it hard to belive after him, that everyone got so hung up on "yeah dude, MAF can't calculate past 255g/s"....

Is the MAF even lokoed at at WOT for calculations? I dunno, but if a guy can run low 11's with MAF, I see no need to do a swap to be "better"...that said, if I had a non EFI car I wanted to cnvert to EFI, I'd go with SD...just to save the cost of buying a MAF.

 

If I recall, its a RPM multiplier which is part of the problem. heh

-- Joe

 

May be a problem, but maybe only if you're getting into the 10's...and I'd bet that only accounts for 2% (max) of those on this forum...ya think?

 

Anyway. I'm glad this thread didnt turn into an argument. Woot woot!

-- Joe [/B][/QUOTE] Me too. I want to know more about burning MAF proms purely for my own benefit! As we all know, the MAF vs. MAP issue has been beat to death worse than a hundred horses!

 

[QUOTE]Originally posted by 8Mike9
[B]Ya, you're talking about skidownit? Or similar...knocking on the 10's with MAF[B]

Now hes knocking on the 9s. The last time I saw him run was a 10.23.

 

I agree that with 98% of people on this board it isn't going to matter.

Regarding Ski_Dwn_It the last I heard about him he had tried switching to MAP but it did not improve his combination and went back to MAF. Now this was some time ago and maybe he has switched again.

I believe in his situation he would do better with a MAP system because the MAF is becomming a restriction in his intake system with the amount of air he is putting through his motor.

IMHO I believe the problem he was having is that he is very very familiar with the MAF software and not as familiar with the MAP software.

 

I believe you are right on that one. He still dimisses the MAF as being a restriction. He told me how guys SAY its a restriction, and he said "Well, I dont see it!"

This was over a year ago, when I spoke to him last a BSD.

 

Jesse ran his best et with mass air. Ran his best mph on speed density. Both pair of numbers were so close though. Et's were within 2 hundreths, speed was within 1/4 of a mph. I believe he has since switched to a FAST system for the 05 season. He has now run a best et for 05 according to a thread in the c-4 tech of the Corvette forum. I have not ssen the car run in a year or so though.

 

Fast eh? is it map or maf ?

-- Joe

 

I don't know. I presume it is map. Never heard of an aftermarket system that used mass air flow. What do I know though. I am just a floor guy.
I suspect you knew the answer before you asked the question.

 

Nope. I use GM stuff. It's cheap and works.

-- Joe