25thredrs

iTrader: (2)

I'm in the process of a T76 front mount build.....My local tuner will be doing a 3 bar Speed Density tune. What things can I get rid of??? MAF, intake air temp sensor? O 2 sensors? what all sensors wont I need.

Also, If I am only going to initially be running 6-8 lbs of boost, would it in any way hurt me to do a 3 bar instead of a 2 bar tune?

Thanks,
25thredrs

BOONE

iTrader: (4)

The tuner will def know what to do but, the maf goes. The remaining o2s go. The Iat stays!!! you need that. As far as doing the 3 bar instead of the 2 someone else may be able to help with that I do not know.

Assassin

iTrader: (3)

MAF goes in trash can... you can delete all o2's but good to have an incar wideband (the dynojet wideband commander is great)... you MUST keep the iat sensor, that is a crutal step for tuning a boosted car... I'm running 2bar map, there is no need for a 3bar unless you plan on going over 14.7 lbs of boost... (wich if you have an engine that can take that must boost will be in the 650-750 hp range at least.. (=100% of n/a power))

25thredrs

iTrader: (2)

so what exactly does the wideband do? does it read your A/F ratio? Couldn't I just monitor it with an A/F gauge?

As for 3 bar tune......My question is would it hurt to go ahead and get the 3 bar tune if I plan on going over 14 lbs of boost next year when I build the motor? Are their any disadvantages of doing it now vs. a 2 bar?

smokinHawk

iTrader: (48)

first off, i havent heard your suppose to remove the o2's you might but i thought the computer still used these for cruising readings, thought the 1,2 & 3 bar kept close loop calculations.
definalty keep the IAT sensor, only get rid of the maf.

next the only down side (presuming you have HPT) to running the 2 bar vrs the 3 bar, as for me my 99 PCM didnt have enough ram for 3 bar and the RTT, it had enough ram for the 1 or 2 bar with RTT. your PCM might have enough ram for the 3 bar and RTT i dont know.
since im going to be using some bigger injectors (96lbers) and have tuned for them yet i am going to start out with the 1 bar RTT and get my idle straight (1 bar so i dont have to buy another MAP sensor), after i get my idle good, ill copy the tables over to the 3 bar file and start tuning the boosted regions as i will be going over 14.5psi.
so if your PCM doesnt have enough RAM for the 3 bar and RTT you might just use the 2 bar and RTT feature, until you get past 14.5psi then switch over to 3 bar without RTT.

Country Boy

iTrader: (24)

A/F guages are NOT accurate. The WB monitors the A/F at part throttle and WOT and has its own O2 sensor The A/F guage just monitors WOT A/F since it piggy backs off a stock O2. You can get the 3 bar tune no problem, if wont affect anything.

WAHUSKER

iTrader: (4)

I think most systems need a wideband sensor to work right. I know Wideband Commander & Megasquirt do. And the PCM needs the front ones for driving, unless you eliminate it all together. Many systems still use the PCM to control timing & read the rest of the sensors.

I just installed Megasquirt on my car, and I plan to replace the stock MAF with an 85mm so 1) it gets more airflow, and 2) it has the IAT directly in the air stream. But you can just put a piece of pipe in there if you want.

25thredrs

iTrader: (2)

I have a 2000 pcm so it should be able to handle it...


I've done a swap into a 92 camaro so I only have the front 02 sensors...They rears are deleted on the pcm. So my question is can I just leave the front 02 sensors in and also run a wideband setup with another 02 bung in the exhaust? Can you tune using a wideband setup? is that better than tuning using the MAP sensor tune?

btw: thanks for the help so far

99SS-T

iTrader: (5)

There is another benefit to only using a 2 bar if u dont plan on goin over 14.7 psi. The MAP sensor reads teh same amount of voltage no matter the bar that it is. SO lets say u got a NA car. U put in a 1bar MAP sensor. It reads 0 volts for 25hg of vaccum(or whatever 0volts it set to as i dunno). It would read 5 volts for 0 vaccum and 0 psi. If u were to put a 3bar MAP sensor in tehre it would read 0volts for 25hg of vac and 1.66667 volts for 0 vac 0 psi. SO its wodl read it much less efficently. Makin it more numb to small changes.
I dunno if i explained it well enough for ya to understand but all in all u shodl get teh one that doesnt exceed waht u need. GL

John

Frost

iTrader: (45)

That's hitting it on the head. Those units per range are defined as resolution. The usable resolution of the INPUT (which could look like the sensor to you) goes down as we try to expand the range.

DanZ28

iTrader: (5)

With the SD tune, you won't need the stock O2's anymore, you can leave them in or pull them and cap the holes. You can put the WB in a new bung if you want, or just pull the stock O2 out and put in the WB in it's place. You should only tune using the WB setup and really has nothing to do with the MAF being there or not, it's just there to give you accurate AFR readings. Your tuner will/should use a WB to tune your car as well.

bowtieman81

iTrader: (35)

I am confused; maybe I don't understand the 2/3 bar setups.

When I tuned my car in SD naturally aspirated the O2 sensors stay on and function. The O2 sensors still functioned during cruising to keep the a/f at 14.7:1. If you go 2 bar SD and throw out the O2 sensors then what maintains the cruise a/f ratio?

smokinHawk

iTrader: (48)

thats hat i thought
sure the wideband is essential for full throttle runs and is more accurate in all the range, but i still think the o2's are being used for closed loop cruising calculations.

Frost

iTrader: (45)

Well what is the poster asking about here, OLSD or CLSD?

NA$TY-TA

iTrader: (21)

Thats the way mine is setup........
My stock O2's work for my cruise... im at 14.7:1 and my wideband is there for my WOT blasts and is set at 11.5:1
3 Bar MAP here.

Kyle

25thredrs

iTrader: (2)

I'm not sure what the difference between the OLSD and CLSD tunes are....
BTW....I will not have cruise control so that is no factor to me...

bowtieman81

iTrader: (35)

This is how I understood the 2/3 bar setups worked. I don't understand why somebody would want an open loop only setup on a street driven vehicle.

Assassin

iTrader: (3)

I'm running open loop and can tune the engine how I want, I get better mpg (30-32 on the highway), running just about 15:1afr(cruise/light load), and the throttle response w/olsd is awsome as well, I do play with the tune 2-3 times a year, and run a different tune for certain types of driving, race track, auto-x, and street... if your not going to tune your car or dont know/understand everything then its best to let the tuner give you a well rounded tune, I like to squeeze a little bit more, and couldnt be happier with the results...

btw, cruise controll is not effected... I use it all the time to keep my foot off the gas and not get anymore tickets...

bowtieman81

iTrader: (35)

What tuning program do you use out or curiousity? I might want to compare notes one of these days.

Assassin

iTrader: (3)

hptuners