Bink, last week I set about getting a list together but got busy. In LA there is Easy Street Motorsports, There is also another in Connecticut who has one the same Dynolog. There are plenty of Dyno Dynamics in the States too, they are good. Mustang also make load dyno’s.

I think most of the WRX boys are into this type of tuning.

Look at the options on this page and then move to the NEWS section, I think they list US locations in there. http://www.mainlineauto.com.au/products/awddyno/

 

Plan B - Thanks for the info and the link!!

gameover - personally, I think this thread morphed several times - I learned alot. It answered many questions. I wouldn't know what to do with a "hex editor" if I had one - I'm thankful that you guys have them,.... and more, and know how to use them!

NoGo - You are the MAN! - had to say it.

 

Pete, thats a great idea, im sure it will prove a point, i may be running the car up on the dyno this saturday, ill let you know.

 

Gameover, your a smart bloke, so you will hopefully understand where im coming from, if most people are tuning their ve table by monotoring a percentage , well they are simply wasting their time and will not get ahead. its basically this (sorry if i sound like a broken record but i want to make sure my point gets across, and ALL readers will understand) while you are logging, you should be constantly be montioring 'whats happening', so if there is a rich spot say for arguments sake @ map 100kpa 2000rpm, you should record that data and note down the air fuel ratio, (i use a pen and paper!) open up your ve table look at map 100 @ 2000 and decrease that value by entering a smaller number or using the percentage multiplication available in edit, flash that new program in and start monitoring again by repeating the process, its called trial and error my friend, this is the downfall of edit as 'real time' tuning is NOT available.

Now my understanding is that it will make tuning easier if you new what the ve values represent, true?
correct me if im wrong

Well you tell me what difference would it make if you had the ve table displayed in miliseconds?

You still have to increase or decrease the numbers to acheive the desired afr, true?

if the ve numbers represented say miligrams of fuel, and if done your calculations and come up with say 2123 miligrams of fuel which i would add to map 100 2000rpm, according to the calculations the afr should read 12.6:1. i just cant comprehend.

Remember Gameover, tuning is just that, tuning. an engine will make power and run smooth if its given what it needs, but if you give it what you think it needs it could all turn pear shaped.



Girch.

 

I think everyone gets it. Of course you're right, knowing the units doesn't make any difference to the tuning process. It just looks nicer.

BTW, putting 2 grams of fuel in each cylinder every time it fires your engine would run for about 5000 revolutions before the tank was empty

 

he he, if all we had were hex editors we would all be doomed

 

Just to get this thing back on track.

I have been logging on a few cars lately and have been making a point to reset the PCM prior to beginning.

Gameover's equation so far is ahead 2-1

I'll post up the results once I get everything in order.

 

Good some music to this madness. Keep up the good work. It is greatly appreciated

 

Open loop or Closed Loop??? Is there a difference closed loop??

 

These were closed loop cars with light mods (small cam and mild heads). I have been comparing WOT data to WOT data though, so it shouldn't matter..........I hope.

Just to clear things up.

When Binks and I did our test (thanks again Binks) we made a point to reset the computer as well, and it made a slight difference, but nothing dramatic. Gameover's equation was still sick lean.

 

Here's what I got using dimensional analysis (canceling units):

VE = 3444 * MAF * (273 + IAT)/(MAP * RPM *Displacement)

units:
VE = %
MAF = grams/second
T = Celsius
MAP = kPa
Displacement = liters

Seems to be pretty accurate with the data i've got but i think it'll be better when i switch my granitelli maf back to stock. I got excel to calculate VE for all the points in my log file, now i gotta figure out how to sort it into something useful.

 

My compliments to you all for the dynamite research. I'm an ME and a computer geek as well as a fairly knowledgable hot rodder, but this is gonna take me some time to absorb.

All I can say is "Great work" and "Thanks"!

 

I've gotten a headache every time I've tried to follow this thread

Does ChrisB's LFA perform these calculations correctly, or has someone else created an Excel/Access solution?

I just got a new engine and I need to re-tune it. Not sure if it's worth it to adjust the Main VE or just do it the old fashioned way.

 

I got a headache, too.
I think ChrisB's LFA provides a "close enough" calculated value to be useful. The main areas where VE changes seem to help are idle tuning for H/C setups and midrange/cruise tuning for drivability. You would still use the common techniques for tuning fuel trims and WOT.

 

OK, I got the LFA to work. I guess my question is, do I use the default scalar of 2500, or use the equation of 4096*(l/Cyl), which is 2900 in my case? I've got some whacked out numbers in MAP 5...VE%'s from 170-270% between 1200-3200RPM. Anywhere from 10-151 samples in the respective cells. I smoothed out the transitions between the new data and the old data until the rest is populated and loaded it into the PCM. I did not put the whacked values in the PCM.

What are the driving symptoms of a VE% which is too high or too low? If I've already tweaked IFR to get my LTFT's to 0 @ WOT, do I need to re-address the IFR table after altering Main VE?

 

Did you remove all the decel FTC (21). I usuall export my data into access run a quick query to delete FTC=21 and the export. The exported data is then used in LFA. Decel cell will skew your data

 

Yes, I removed all the FTC 21's, and FTC>23's (AutoTap throws them in for spite, it seems).

 

JimM, I also saw some "whacked" values for calculated %VE in the cruise range (1200-3000 rpms or so). Not sure the best way to smooth this area without a dyno.
I think you would be safe using 2900 = 100% VE based on data from NoGo and others. Many folks have been using 3000 for a while now with no reports of bad effects.

 

I would use 3000 then scale the table by 103.58 % to compensate for NoGo's findings in this thread. Remember, the MAF is inaccurate at low MAP and Low RPMs. FWIW.

joel

 

I don't recall the reference to the 3.58%. Can you briefly explain? Is the scalar formula EditVe=4096*(l/cyl) accurate? If yes, why use any other value? If not, how are we determing the alternate value?