fletchls1

iTrader: (10)

I have read a lot of post's where people said speed density tuning improves power. How much power are you guys talking? I dont know much about it though. You are able to get rid of the MAF sensor completly? Would this work with a turbo application? Is it safer to have the MAF or would it be equally safe with speed density?

NOTE: I was getting my car tuned at LS1Source and they unplugged my MAF (or forgot to plug it in) one or the other, and blew a head gasket

96lt1m6

iTrader: (31)

as long as you get it tuned for speed density it will be fine,although our cars are designed to run with both it needs to be addressed in the pcm

frcefed98

iTrader: (16)

Turbo with SD tune here, no maf at all.
From my limited understanding of tuning..
As long as you get your PCM set up with a SD 2-3 bar tune..offered by HPT or efilive you are good to go. The MAF will only be able to read so much airflow before its maxed out, on a boosted application thats usually in the mid 4000rpm range. Once the maf is maxed out it can no longer provide fuel for the incoming air. You can cheat your way around it in the PE table.

OR you can do a SD tune and run a 2 or 3 bar map sensor and unplug your maf, disable a few codes and be good to go. Your PCM will add fuel with boost, up to 14psi with a 2 bar map sensor or over 14 psi with a 3 bar map sensor.

Guess LS1source will be replacing your headgasket huh?
J

fletchls1

iTrader: (10)

Hah, I wish...After they did it they said they would fix it for $1000..Yeah right...The place went out of business a month or so later and there are several law suits with them to get peoples stuff back. Including peoples cars and heavliy modded engines!

Back to SD: With me only running a max of 10psi of boost right now I will be fine not running the 2-3 bar map sensor? Say I run 7 then want to turn it up to 10, does the computer have to be reprogrammed or is that what you were saying when it would add the appropriate fuel?

frcefed98

iTrader: (16)

Glad they went out of business, too bad they screwed up your car

Yeah you'll be "good" running with the MAF/stock Map sensor and cheating the fuel tables. I did this for a looonnnnggg time with my procharger set up. I ran 15psi with the MAF and added fuel manually after it was maxed out, but you still have to have HPT or EFI live to mess with these tables. Just get yourself a WBO2 and HPT if you don't have it and start learning how to tune
J

fletchls1

iTrader: (10)

A big thanks

NYSS Guy

iTrader: (1)

A speed density tune is much more involved, but it will be a little better than tricking the pcm using the PE table. If you use a 2 bar map, the pcm is tuned to add the correct amount of fuel based on the amount of boost. So, if you see 7 psi, the pcm knows how much fuel to add for that boost amount.

This is more important with a turbo which is load based. If the engine is seeing more of a load at a lower rpm than normal (going up a hill or something), the sd tune is the only way to be sure the fuel is correct at a certain rpm. If you trick the pcm to add fuel in the PE table, that is rpm based, and could cause you to run lean in the situation I explained above.

I hope that helps. By the way, I'm in the middle of my 2 bar sd tune, and it's pretty cool stuff!

fletchls1

iTrader: (10)

[QUOTE=NYSS Guy]A speed density tune is much more involved, but it will be a little better than tricking the pcm using the PE table. If you use a 2 bar map, the pcm is tuned to add the correct amount of fuel based on the amount of boost. So, if you see 7 psi, the pcm knows how much fuel to add for that boost amount.

What exactly is the 2 bar map?

OUTLAWZ RACING

iTrader: (9)

[QUOTE=fletchls1]
Its what the cobalt ss use because it has a super charger the map sensor plugs into the back of your intake buy the oil pressure sender unit im not to sure how to hook up a two bar map sensor but i have heard its fairly easy and you can buy them from GM granted you have the part number Because stealer ships are stupid But i havent got a clue on how to SD tune a car some say it take days some say dont do it on a dyno because of load issues got to tune it on the street Will some one please clear this up Last night i got a little tipsy out here and i went an hour later!!!

NYSS Guy

iTrader: (1)

The stock map sensor will only read pressure up to atmospere (105 kpa), which is no boost. So a 2 bar map sensor will read up to 14.7 psi (210 kpa). It is very easy to install, as long as you get the right one. Unfortunately I don't remember the part #, but it looks exactly like the stock one, just with a different part #. Only difference is the 2 bar map has an extra clip on it, you have to cut that off (it's just a plastic clip).

And yes, a sd tune has to be done on the street. If you devoted the time to it, and somewhat know what you're doing, you could probably get it done in 2 full days, 8 hours a day.

OUTLAWZ RACING

iTrader: (9)

Holy sht 2 days man i never knew it would take that much tunning so what will be the differance on a dyno loaded or on the street will u get a better tune on the street or is it play by the reactions of the car

JMBLOWNWS6

iTrader: (17)

I agree. Once you delete the MAF and set the mil to report as soon as the car starts that way it reverts to the low octane table. I like the fact that with the HP tuners 2 bar the resolution in the tables are there for you to tune on. Its takes a good while to dial it all in. We started off with just adding 7% of fuel and going from there. I rely on the wideband to make sure Im where I should be on the AFR. Im a rookie tuner The 2 bar will be right about what the max boost I will see with a 2.75 pulley with the T trim. Here are all the part #'s.

GM PN# 12223861 3bar MAP
GM PN# 16040609 2bar MAP
GM PN# 16137039 1bar MAP
GM PN# 15305891 - pigtail harness

hellbents10

iTrader: (10)

Doing a speed density setup is nice for safety purposes. I ahve heard of a handful of people who blow there stuff up from a single over boost. The nice think about a 2 bar setup is you can make your on fuel cut at a certain boost point and save yourself from certain failure of such a event.

NA$TY-TA

iTrader: (21)

Or go with a 3 Bar MAP (29psi)....... Thats what im using...... should be good to more boost then i plan on running.....

WestSide

iTrader: (6)

For the 98 PCM's...I hear of some doing a 2bar setup. Any details? Search wasn't working very well

JMBLOWNWS6

iTrader: (17)

29 psi

NA$TY-TA

iTrader: (21)

From what i Hear HP Tuners will never be doing a 2 or 3 Bar MAP setup for us...... i have a 98.....
Im using the MAF T Pro......

frcefed98

iTrader: (16)

2 days 8 hours a day I'm on day 30 and still tweaking it here and there to get it just right.

Rick@synergy helped me out with a custom 2 bar SD tune for those of you with 98's.

http://www.devilsownonline.com/alcoh...products_id=18

This is the 2 bar map sensor i'm using, just had to clip off one of the "ears" on it and it went right in.
J

fletchls1

iTrader: (10)

I talked to joel at gmr speed about tuning my car (SD) for me...he said he would but...... I would not go with a SD tune for a coulple of reasons. Your going to loose some of your drivabilty. You will have worse gas milage. Also you wont have any other fail safe if your MAP sensor goes bad. For what I mean about that..is when your running with the MAF and your MAf fails, your car goes into speed density mode and runs off the MAP then. If you run SD and your MAP fails...your cars dead. Also you will only need to run SD if your drag racing and have some serious HP

NYSS Guy

iTrader: (1)

Yeah, I hear ya. I've lost count how many days I have into mine. But, I was figuring if a professional tuner had the car, and devoted 2 full days to it, they should be able to get it pretty close. I am nowhere near a pro, which is why I have several days into mine.