1971ls1

iTrader: (4)

im doing a turbo ls1 and wondering what is better, a speed density setup or mass airflow sensor i know this is problably a common question but i havent been able to find an answer

ColtGT4g63

iTrader: (16)

Depends who you ask. I personally would rather use speed density.

yoshgixxer

iTrader: (74)

id love a answere to this question too..the guy i bought my turbo kit from was running speed density...the reasoning for him was cuz the guy who did his tuning recomended it...well i need more of a reason then that!

Jontall

Speed density is the best and I have no problems at all.

BLNLS1/RX7

iTrader: (2)

+1 for speed density.

crf538

iTrader: (3)

+1 for sd. even even if they are equivalent its just less BS to deal with.

denali_on_26's

iTrader: (26)

what about weather changes?? will SD be ok?
it might be 100* during the day and 40* at night here certain times of the year?

armintheman

iTrader: (31)

ya true that's what my tuner said. he said i should run sd if it's a track car but for street driving its not as efficiant

denali_on_26's

iTrader: (26)

thread jacking KINDA...lol

i will be running a 408ci and a gt-91 turbo and plan on about 15psi what would be the best for me... whats the pro's and con's of both
THIS WILL BE A STREET TRUCK!!!

RICE ETR

iTrader: (3)

I am still running a maf...gives me a good tune when I am just cruising around and I use it for a meth controller when in boost.

AFASTYZFR1

iTrader: (55)

Speed Density! Makes response better and is just the right way to tune forced induction (PCM can "see" boost).

yoshgixxer

iTrader: (74)

maybe its a stupid question but what all is need to convert a LS1 car to SD?

jomomma

iTrader: (39)

It will have to be tuned for it. And for forced induction you will need a different map sensor.

lordrazo

iTrader: (18)

Speed Density! and the higher the boost and power goals you might want to look into a stand alone ecu like fast and that will be speed density as well

conan

iTrader: (5)

+1

I've never found a detailed explanation on this. Some say its bad and others say not so much.

I have a SD tune and I live park city UT most of my driving is at 6,500- 7,200 ft/elevation, the temp can be 40 in the morning and 90 by after noon. I have never felt any differance in the way my car drives. I also see very little, if any change in my wide band gauge. So I've been happy since the MAF to SD tune.

elias_799

iTrader: (8)

what i have been told is that our computer does not read the maf past 500whp, so i after the 500whp it is a guessing game .

with speed density it is not, but does speed density correct for weather change ? i think you still keep the IAT sensor for SD, don't you ?

Jontall

The temperature has little effect/ no effect on the speed density tune, but altitude changes would cause big problems.

SS101

iTrader: (2)

just for reference (temps in Fahrenheit, density in (lbm/ft^3))

Air Density at Sea Level
20 = 0.0832
100 = 0.0705

@ 7000 feet elevation
20 = 0.0635
100 = 0.0544

onefastmx5

iTrader: (6)

You don't delete the IAT sensor, just the MAF.

The only way an altitude change would affect the tune is if the barometric reading wasn't updated with enough of an altitude change.

AFASTYZFR1

iTrader: (55)

Remove MAF and replace stock map sensor with 2 or 3 bar map sensor (and of course car has to be re-tuned).

Temperature changes do not affect speed density....my AFR is the same in the winter as it is in the summer