Hey everyone,

I'm trying to read up on tuning to determine if this is something I want to get into. In my readings, I'm having trouble with a few terms that are thrown around so often it's impossible to search for definitions or answers to my questions...

1) What does VE stand for, and what does it mean?
2) What does PE stand for, and what does it mean?
3) When using a 2-bar or 3-bar MAP, do you have to use a different PCM?


TIA for any help.

 

I am kinda new also, but I will get you started:
1. VE = Volumetric Efficiency, from my basic understanding....(and anyone feel free to correct me) would be the percentage of air and fuel that actually enters a cylinder compared to what its actual capacity is. I am still shaky on how to exactly manipulate these numbers...
2. PE = Power enrichment, Total assumption here based on carburetors. Richens the Air fuel ratio under load?
3. As far as I know you use the same PCM for 1,2,3 BAR, but it must be set up for a 2 or 3 BAR sensor. I don't even think it will run if you plug in a 2 or 3 bar without a tune adjustment.
Hope this helps.........and remember I am new at this too....So if someone wants to critique my answer feel free

 

I'm usually the last guy you're gonna hear cry "Search!/Read the stickies!", but damn, read the stickies! Especially the highly conspicuous "*READ ME FIRST-- Tuning Docs,VE/MAF, SES Lights, FAQS!!!! + more! *01/31/07*" sticky. Horist put it there for a reason.

Seriously, the answers to questions 1 and 2 are in there all over the place, and are covered to great depth. If you're really interested in tuning, you need to spend time reading those stickies, and also the stickies at the HPTuners/EFILive forums. After that, pretty much anybody here will be more than happy to answer questions about VE/PE, but if you can't even be bothered to read the stickies to find out what those terms mean in the first place, many people here are not going to take you seriously.

As far as question 3 goes, no, you will not need a different PCM to run a 2 or 3 bar MAP sensor. Both HPTuner and EFILive offer custom OS's that enable the use of 2 or 3 bar MAP sensors for forced induction applications.

 

And the muthafuckin' smack down.

 

I hunted around on the stickies for a while, and I think I read about 20 pages worth of posts before I saw someone actually type out volumetric efficiency... I still haven't seen power enrichment yet. That's why I asked initally simply because no one ever uses anything but the abbreviations.

So, here's my situation...

I'm currently running around 400RWHP N/A. My plans are to go FI (Procharger) in the future. In the meantime I have to get the following: fuel upgrades, heads, Procharger. So, I was thinking that I could get HPT or EFI now, play with it a bit, get the fuel upgrades, retune myself, and then tune the car myself when I get the Procharger. Does this sound feasible? Or is that too little experience for tuning FI?

 

If you work and study a little and you are reasonably mechanicaly and computer literate you should be able to do it, however you may find a dyno is a realllyyy handy tool to have.

 

Computers are my profession... cars are my hobby... sounds like I might be in good shape.

 

Well, I'm glad you didn't take my post in the wrong way. The information is in there, but it's not going to jump out and smack you in the face, it's true. Going through the links in the sticky just now I see that many of the "Tuning 101, etc." type links are now dead. So, here's a freebie: Tuning VE via fuel trims

That's a link taken from the sticky to a brief writeup I did (wow, 2 years ago now and still not updated like I planned ) outlining one method of tuning the VE table, and also a bit about fuel trims and how they work. It's kinda dated now, but basically correct, though I gloss over VE for the most part. Both VE and PE (Performance Enrichment) are defined, among other basic terms.

At the point I'm at now, I couldn't imagine not having the ability to tune my own vehicle. It's pretty much a necessity if you want to squeeze the most driveability and best street manners out of your setup. It will also save you alot of money. The initial payout will pay for itself many times over.

My recommendation would be to hit the HPTuner/EFILive websites and gather as much info about the software packages as you can. Then decide which one will work best for you and has the features you want. Both are excellent tuning platforms. Purchase it, and start playing around with what you have now. I'd be willing to bet that there's a ton of things you could do to optimize your current tune, and that would be the best place to start.

The learning curve is pretty steep at first. The first time I launched HPTuner I thought, "WTF is all this ****?". Read the forums, play around, and eventually the pieces will start falling into place. This is one of those things that you have to pretty much learn by doing. After you have a handle on the basics, start tossing in the upgrades; injectors, heads, etc.- tuning after each one. By the time you hit the Procharger you should be comfortable enough to step up to a 2 or 3 bar system.