why me

ok alot of people say after 500ish horse and for boost that speed density is the best way. but we have had **** stock mass air flow uints.

has anyone tried the new Abaco style mass air flow sensor. they are digital so i figure they can pick up air better.

please give my oyu opinions. let me know what you all think. i am hoping for 1000 plus on the dyno. but like 650-850 on the street with the change of boost.

thanks

calongo_SS

iTrader: (7)

for that power level go speed density without question.

why me

^^^ hard part is. that on the abaco website it says for tuning for 1000 horse. or 1300 horse. depending on the sixe you get. and it has to be good stuff right. i mean hellion does that twin turbo superchargeed kits. and uses it. so why everyone go speed density.

also how much does elevation matter? like if i get tuned at 500ft elevation. and i live at 1500ft elevation. how does that change my tune.

slow67

iTrader: (2)

With a good tune, elevation shouldn't affect your tune. The problem is not with the MAF, but with the 512g/sec MAF limit in most GM Operating systems. What kind of car is this for?

calongo_SS

iTrader: (7)

No personal experience with elevation changes here, so I won't comment on that.
As far as MAF vs. SD here's the basics:
The computers in these cars are hard coded to a maximum MAF airflow. Once you exceed that, the PCM can't tell what the actual airflow is. You then tweak the PE table until you get the fueling where you want it, meaning that your WOT fueling is based solely on RPM. It does not matter what MAF you put on the car your maximum measured airflow is the same (512 g/sec if I recall correctly).
With a 2 or 3 bar tune you're fueling on a calculated airflow from manifold pressure, temperature, etc... not RPM. You're only limited by the MAP sensor you are using, 2 bar or 3.

why me

so with speed density. if map sensor reads 12psi it will give X fuel at X rpm. and it it reads 15psi those fuel numbers will be different?

Super Slow SS

iTrader: (9)

Yes, the best thing about SD is you can change on the fly and it will automatically change fuel and such with the amount of boost, which really helps if you tune in july and drive in dec. because you can see a 3lb difference due to weather humidity air density etc.

OUTLAWZ RACING

iTrader: (9)

Yep so true. I dyno 760 in sanantino in Aug on 14 psi. and 813 in Ga in novmember no change in the tune no cool down. I think it was 80 degrees in sa that day and 67 degrees in GA. Speed density is godly IMHO.

dreamls1

iTrader: (25)

+1 SD. My buddy just had anderson ford put an Abaco on his TA, i think it did pretty good he is making close to 500whp. There will be an article in the upcoming GM high performance mag. they did here at Anderson ford motorsports.

slow67

iTrader: (2)

Close....sort of.....in MAF mode the PCM over 4000 rpm SOLELY uses the PE table and the MAF table....once the PCM reaches its hard limit of 512 g/sec in the MAF table of measured air, you only have the PE table left for additional fueling (read BAD). In SD mode, your pcm calculates the amount based upon the manifold air pressure and rpm and adds extra fuel with the PE table (you can also add more fuel with the BE table if you have a 2/3 bar OS from HPT, I'm sure EFILive has something similar). In these modes, your limit is only the amount of boost (either 2 or 3 bar).

why me

^^^^

so how does elevation play in?

also let say i tune in summer and run 14psi. why in december will there be more horse. (i know the colder the air the more oxgen in it. but is that the only reason)

Super Slow SS

iTrader: (9)

No thats not the only reason, thats part of it and im sure other ppl can explain it better but if you have ever driven a force induction car you will see an actual boost difference in colder climents thus more HP, this is very true and evident during april and may when its 85 during the day and 60's at night .. you can feel a difference in the car.

lt170chevelle

iTrader: (2)

I believe the cold weather (with more oxygen) actually leans it out a little equaling more power. Also i am sure the computer compensates to a point and adds more fuel so you have more fuel and air going into the motor..correct me if i am wrond on that

lt170chevelle

iTrader: (2)

and +2 on the forced induction on a cold day versus on a hot one- big difference in power...well ..very noticable rather..

slow67

iTrader: (2)

the computer calculates barometric pressure, so elevation changes are no big deal. Also, on 99-00 PCMs you can move timing around based on IATs, and with 01-02 OSs you can also add/subtract fuel when in PE mode with temps.

why me

slow67,

so going SD doesnt get rid of the ait sensor? cool

Frost

iTrader: (45)

We don't have Fords, all of our MAFs are 'digital'. The Ford MAF is relegated to 0-5VDC for it's output. Ours use a variable frequency output.



Again, that's Ford. Their systems are not VE/MAF hybrids like ours; it's their only option on the OEM hardware that I know of... AFAIK they have no underlying VE for air mass estimation, just the MAF.

Johnv

SD also gives much more control of timing in boost, with 2/3 bar EFI live COS (i'm sure HPT will have similar feature) you aren't limited to the resolution of the main spark tables and can manipulate timeing through your entire boost range.

OUTLAWZ RACING

iTrader: (9)

That is true I seen 10.6 in sa and 10.8-9 in cold weather ie, GA. and more boost lol

vaticano

iTrader: (8)

If tuned properly, altitude will have no effect on the tune. I have personally driven from 5200 ft., where I live and tuned for SD, to 14,000+ ft. and have had no issues at all.