what all is involved to make a 2 bar map work on a factory 1 bar system? what are the advantages of doing this upgrade?

 

I would like to know also.Because I am doing a 408 with a t88 with less than 15lbs of boost.What do I need to use.Not trying to hijack your thread but ive done a search and still confused.

Thanks
Brad

 

2 bar can be a more accurate tune based on the temp and barimetric pressure its being tuned in, and you dont have to trick the MAF. the problem is when you have any kind of a temp change it will affect your tune because theres no sensors being used to adapt to air flow, temp and pressure changes AKA your MAF. I prefer a MAF tune because there is no part throttle hesitation with temp changes, it seems like its easier to set fuel trims at idle and I dont have to worry about beating on my car in really cold wheather. just my.02

 

All you do to make it work is remove the 1-bar, lose the MAF, and install the 2-bar. After that, get it tuned (It won't run without a tune).

Advantages: better throttle response, no dealing with the MAF.

Disadvantages: you're probably going to either want to buy HPTuners, or knock over a bank to cover tuning costs when the weather changes.

 

???????? Not true, the main reason to going to a 2 bar set up is because a 1 bar measures from 0-14 inches of vacum and a 2 bar measures from 0-14 lbs of Boost, If you are running low boost like 5-7 lbs a 1 bar is fine, if you are going up to the 14-15 lb range then go 2 bar, over 15llbs 3 bar. This makes the timing tables linear to the KPA range of RPM vs TPS so you don't have to calculate these areas with a 1 bar running 14lbs of boost...I have 2 bar running 14 lbs of boost, no tip in problems in any weather condition....

 

Wow, several people in here who don't know what they're talking about giving advice.
You need of course the actual 2 or 3 bar map sensor, then you will need a custom OS from either HPTuners or EFI Live. I think it is better than a MAF tune, but it's really a matter of opinion. You will not need to change the tune when the weather changes, perhaps in extreme cases like driving from sea level to the rockies you would have some problems. A 2 bar tune is more time consuming to get dialed in, but once it is there it is a better tune IMO.

My car is running 2 bar OL, and I haven't had to mess with it in months, that's with no O2 sensors...

 

Am I missing something or are you talking about a SD tune?

 

I assume you're flagging me with your statement, since I had one of the posts responding.

I pretty much said the same thing as you, only in much simpler terms.

He asked what you needed and advantages:

2-bar map sensor? yep
removal of old unit? yep
HPT (or similar piggyback EFI tuning tool): yep

retuning to find a sweet spot? yep, said that too.

I must be a freaking idiot...yeah. I should never give advice...especially since I'm running a 2-bar in my car on HPT.

Go on, genius.

 

No, not you, calm down a little. I should have said one person, lmt705 who said:
"the problem is when you have any kind of a temp change it will affect your tune because theres no sensors being used to adapt to air flow, temp and pressure changes AKA your MAF"

Which is totally untrue. You do lose the MAF which actually measures airflow, but there are still sensors that measure temp (IAT) and pressure (MAP) which are used to calculate airflow.

 

No worries...lol. I read lots of people and saw two replies, of which I was one...

I'm just edgy because I really am not all too bright

 

So for like my application a 408 with a t88 on 10 to 15lbs of boost I would be better off with a 2bar and sd tune.Also if you go to a 2bar you have to get rid of the maf and do a sd tune.Also what is a custom os.


Thanks
Brad

 

2 bar tune is a SD tune. The custom OS is a change in the OS (Operating System) running in the PCM. It extends your VE table into the boost region instead of stopping at atmosphere and adds a BE (Boost Enrichment) table and I'm sure a few other things that are escaping me right now. Basically it allows you to actually use the 2 or 3 bar capabilities you gain from changing to a 2 or 3 bar sensor.

 

Thanks for the explanation calongo ss It Is greatly appreciated.

 

dont mean to but in, but as long as your low boost...like 1-8psi kinda deal. you are fine with the stocl MAP sensor. and from like 10-14/15 psi the 2 bar SD is the way to go???

just makin sure im reading all this right

 

Well now I am confused I am going to maf tune may car after I get my turbo on (LPE MAF) .I thought I was going to still need to change the map sensor am I wrong.

 

if you are for sure doing a maf tune, then keep your stock1bar in there, it would be a compleat and utter waist of time to remap you VE to work with the two bar sensor. unless you ever planned on more boost and a future SD tune.

 

I would like ot do a SD tune but my car just wont let me . I am thinking its cause its a 98 ,maybe its me I am new to tunning . I think I will be fine with the maf

 

ok that clears alot up for . so now answer me this...how much boost is a maf good for?

 

From my understanding after talking to a local tuner, my 98 PCM will support a SD 2 bar tune (14.7 lbs of boost), the 99+ PCMs will support a SD 3 bar (22 lbs).
The stock MAF is only good to manage up to 14 lbs of boost, this being it's threshold of an accurate reading. He recommended not going over 13 lbs of boost on a MAF tune. It costs nearly twice as much to do the SD tune on my car, and I'm not going to be boosting over 13 lbs for a while so I'm planning on tuning the car with a MAF to start with due to cost and my puny converter/tranny that's in the car currently. I'm going for about 8 lbs of boost to start so a MAF tune will be fine. When I get a th-400 in the car and a 9" or 12 bolt rear and I'm ready to go all out with it, I'm going to max the MAF, see how it does, then possibly go SD with it.

 

how much boost you going to run? the 98 does lack alot that the other ecm's have, 01-02 having the most tables to work with for more extreem situations, but the 98 is cabible of a 2bar SD OS. or you have the option of testing your patients and get the pinout, and repin your connector for a 99 up ecm