t3/t4 Garrett advice

[tkoforpresident]

The difference is in the programming and how the ECM converts the voltage output to an actual PSI reading.

Which I'm guessing is what a mask like $59 will do by default?

[bszopi]

Yes, it is the same. The difference is in the programming and how the ECM converts the voltage output to an actual PSI reading.

[pocket-rocket]

Physically it's plug and play. As far as the way it reads, the PCM has to know if it's a 1, 2 or 3 bar sensor. So yes and no. I don't believe it sounds like you are disrespecting people here. Asking questions is the only way to learn besides going out there and doing it and blowing up a few engines and learn what you did wrong.

[tkoforpresident]

This is a picture of a 3 bar map sensor.


It looks almost EXACTLY like the one I have now with the single vacuum port and even the sensor connector looks the same.

Is it really then, just a matter of buying a 3 bar map sensor and replacing the old one with the new?

[tkoforpresident]

I hope I don't sound like I'm disrespecting those who know infinitely more than I do about boost than I do but since I don't know the answers, I have to ask silly questions. I picked up Maximum Boost but I just started reading it. Even then, that doesn't make me an expert on turbos or even help me much for my own particular setup, especially since you mention that technology has greatly changed since that book was written.

I also have a book titled Engine Management Advanced Tuning that Bob (60dgrzbelow) sent me. It has a section on tuning for turbo applications so I will have to look into that as well.


But for now, what is involved with swapping to a 2 or 3 bar map sensor? Is it as simple as cutting/splicing the new sensor into the harness and running the same vacuum line to it? Or is it more elaborate?

Also, who knows for sure what kind of map the $59 mask runs? It sounds highly reccomended.

I should probably be talking to Ben about this too, since he will most likely have a heavy hand in the tuning side of things.

[pocket-rocket]

Your car from the factory has a 1 bar. One bar reads 1 atmosphere or 14.7 lbs of pressure at sea level. Since you are adding 9 psi of boost on top of that 14.7 psi of available pressure, that is why you need a 2 or 3 bar, depending on if you go with $59 or not. Like Brad, I've heard good things about $59. Also, I would listen to Josephs opinions, he is very knowledgeable when it comes to boost. That and his comment about head bolts got me to lol. Also the quote of Robert in my sig comes to mind as well. Besides, technology has come a good way since that book was written. Why not use that to your advantage to get more out of your car than you would have 10-15 years ago?

[bszopi]

What kind of map do i have right now?

1-bar, ie it reads from -14.7 (vacuum) to 0psi.

[tkoforpresident]

What kind of map do i have right now?

[ghrarhg]

I'm pretty sure $59 requires a 3 bar map.

[bszopi]

You really only need a 2-bar MAP, since you won't be going over 14.7psi (1 bar = 14.7psi). As far as code base, check out code 59 : http://www.code59.org/ I have heard MANY good things about it, and I'm sure Joseph will vouch for it as well.

[tkoforpresident]

Allright, then let's figure out for my current setup what will be best.

I wish someone would just tell me what to do, rather than my asking a bunch of dumb questions to get to the same conclusion.

I will buy a wideband because I don't want to half ass this.

I'm running $a1 right now. Which code mask should I use? Isn't there a turbo based mask out there?

Do i need different sensors based off of the answer to the above question?

I'm going to buy 42# injectors and a walhbro 255 because they will suffice my fueling needs.

I plan on running 9 psi so that I don't have to get into all of the water/meth injection stuff.


Basically, how is the best way to tune a turbo with obd-1? Someone lay it out for me

Questions:
Is it a MUST that I tune with a wideband?

Do I have to switch to a 3 bar MAP sensor?

Interesting notes from Corky Bell's Maximum Boost Chapter 1:

- A turbo can double the power without doubling the load.
- Turbo's do not increase fuel economy while not under boost.
- Boost threshold is the rpm in which the turbo has enough exhaust gasses to create boost.

Now, more questions about tuning.

I still don't know if I have to use a wideband and 3 bar map sensor to tune with my obd-1 setup but I was kind of thinking to myself about how you can tune for boost by using the "boost threshhold" By knowing the boost threshold (let's pretend 1600 rpm) you can setup the VE tables in a manner that starts dumping fuel from 1600 and up. Now this is a crude depiction but i'm sure it's not too far off.

Also, I found a deal on 6 42# lucas injectors (brand new) and a Walhbro 255 pump (also brand new) for around 300$

Should I bite?

The cylinder heads have bolts that can be unscrewed holding them on, so you don't have to blow them off the motor by trying to tune boost without a wideband O2 sensor.

Honestly it can be done to a degree, but you are asking too many of the right kind of questions to suggest you'd better not try it. Even back years ago when I was boosting engines without the ability to modify code, I had a gauge that worked off of my stock O2 sensor to give me some idea of what my AFRs were.

If you are starting with a tune that is from an entirely different engine a WBO2 is mandatory. If you change your injector size considerably a WBO2 is mandatory to help you reestablish your base pulse constant. I would purchase the necessary items to properly tune the engine first, then look into assessories. You'll always find a deal on Ebay. You should have at least a 2 Bar MAP system but ultimately the code you run will determine which one you need, so don't buy one until you decide what that will be.

You can't tune your engine using theoretical formulas alone unless you have some seriously exact data regarding the fueling efficiency of your engine liking to what the manufacturer would have and that would only get you close.

[tkoforpresident]

Questions:

Is it a MUST that I tune with a wideband?

Do I have to switch to a 3 bar MAP sensor?



Interesting notes from Corky Bell's Maximum Boost Chapter 1:

- A turbo can double the power without doubling the load.
- Turbo's do not increase fuel economy while not under boost.
- Boost threshold is the rpm in which the turbo has enough exhaust gasses to create boost.


Now, more questions about tuning.

I still don't know if I have to use a wideband and 3 bar map sensor to tune with my obd-1 setup but I was kind of thinking to myself about how you can tune for boost by using the "boost threshhold" By knowing the boost threshold (let's pretend 1600 rpm) you can setup the VE tables in a manner that starts dumping fuel from 1600 and up. Now this is a crude depiction but i'm sure it's not too far off.

Also, I found a deal on 6 42# lucas injectors (brand new) and a Walhbro 255 pump (also brand new) for around 300$

Should I bite?

Here is a more appropriate question...

How succesful has tuning turbo's been with obd-1? Especially without a wideband.

Surely it's not optimal but it's probably been done alot with obd-1 setups.

I know that there are some masks that are more appropriate than $A1 for a turbo'd motor.

Generally you'd buy a stand alone wideband controller to tune, Zeitronix, PLX, AEM, etc.

[tkoforpresident]

42.5 lb/hr injectors should be enough. For a pushrod 3.4, 36 lb/hr injectors from a GTP might even work.

Water/meth injection isn't necessary for 7-9 psi.

Generally:
New Power = Stock Power * (1 + Your Boost Level / 14.7 psi)

Tim

Ok, so using this formula with the *educated guess* that my motor produces 200 hp (at the crank), which if anyone would like to go attain knowledge of my current setup, will probably agree that is either a very reasonable guess or if anything a little less than what it actually is, I have come out to a nice round # of 322.448979 HP @ 9psi (my intended amount).

Using the injector calculator I have determined that 33.5 lb/hr injectors are necessary to satisfy this amount of power (@43.5psi). It looks like I have but one option then when it comes to injectors. The ford mustang 5.0 "green top" 42 lb/hr injectors should fit the bill by giving plenty of room to tune, with the chance also of needing slightly more than 33.5# injectors if my bhp estimations are in fact higher than I suggest. Also, they are relatively easy to find on ebay/message boards.

Anyone agree/disagree?