Roe VEC-2 & tuning software

[kverges]

I recently received my updated Roe VEC-2 and tuning software and after 3 days' use am very impressed! This is on the fringe of user-friendly in DIY way, but pretty easy if you pay attention. It is not of the caliber of AEM in terms of flexibility, but you won't lose OBDII compliance - my car passed inspection which required reading the computer.

What you can do with the VEC-2:

ADVANCE or retard timing at all rpms and based on MAP signal or "load"(e.g. you can retard timing for boost and advance timing for NA applications).

Change injector size overall (for bigger injectors) and change injector pulsewidth based on MAP and rpm (e.g. more fuel for boost and proper fuel for NA applications).

Change rev limits (you could even have a 3000 rpm valet mode)

You can change the injector pulsewidths by cylinder to help compensate for flow differences from cylinder to cylinder.

The whole thing is plug & play with no harness cutting and factory connectors (you do have to splice in for power and to add grounds).

With your laptop you make memory cards the size of a credit card that you can carry with you to change programming in seconds (so, at the track, you can have a race fuel program).

I do recommend tuning with diagnostic software to look at the computer function (e.g. long term fuel trim to make sure your injector sizing is done right) and with a wide band O2 sensor to make sure the mixture under load is right.

I would be willing to bet this is good for power in every application, even stock. It sure is helping me fine tune my SC application and driveability and power are the best yet.

Kudos to Sean for NOT abandoning the DIY crowd!

 

[Nightstalker]

What I like about the software is you can adjust:

With the programing software you can:

- set fuel, injector pulse offset
- set enrichment in milliseconds, based on manifold pressure
- set fuel enrichment percentage, based on engine RPM
- set spark timing change indegrees based on manifold pressure
- set percentage of spark timing change based on engine RPM
- set spark timing in degrees based on engine RPM
- set percentage of spark timing change based on manifold pressure
- set PWM signal in percenatge based on manifold pressure
- set PWM signal in percenatge based on engine RPM


At first when you are playing and learning it is.

I save all programs to the HD and back-up to a CD just in case of a crash.

You set the S/C to run in any environment with this software package.



The newer models of the VEC 2 that have been realsed have the Firmware Loader Program installed in them. This makes it so you no longer have to mail the box back to Sean


If you go to the Viperalley and look up the thread "A New Viper coming together"!!

You can view a new system coming together.

 

[Joe Dozzo]

Hello Keith,

A trio of us here in Denver are going down the same road, though none of us have the very latest VEC2 which allows fine tuning down to the individual cylinder level yet.

Which diagnostic software are you running to monitor fuel trims? EASE OBDII or something else? I'd be interested in seeing / hearing about what your SHRTFT1/SHRTFT2 vs LONGFT1/LONGFT2 look like over a 30 minute drive under varying conditions.

In my own case, I'm seeing some results I've yet to fully understand... The short term trims seem centered about +2 and yet the long term trims average closer to +9. (I'm referring to simple arithmetic average of all values.) Too bad I can't (or don't know how) to paste an Excel graph in here...

And if you can stand one more question, what wide-band O2 setup are you using? That's a tool we don't really have (except for the occaisional trip to the dyno shop).

Many thanks,

Joe

 

[Joe Dozzo]

Let's see if this works...


Long term fuel trim...
http://vca2.viperclub.org/gallery/data/500/233JAD_LONGFT.jpg?7715

Short term fuel trim...
http://vca2.viperclub.org/gallery/data/500/233JAD_SHRTFT-med.jpg?935

 

[kverges]

I use the OBD II explorer software - very inexpensive and works on all my vehicles:

http://www.obd-2.com/

Unfortunately, it does not seem to provide actual injector on-times, so I shoot in the dark a little bit in how many milliseconds to adjust injectors. It also has a slow data rate of just a few Hz.

I have only set the LONGFT at idle for right now, I have not done a log to see how they look running closed loop in light throttle on the road. I would more than likely address that by also looking at MAP values and LONGFT/SHORTFT and perhaps adjusting the fuel trim tables for higher vacuum and rpms under 2500, rather than overall injector factor or individual cylinder trim. In fact, the individual cylinder trim is more than I can fully use, as I can't do much more than read plugs to see if a cylinder is rich, and reading plugs in a modern fuel-injected car does not tell much about mixture IMO. I don't sweat this much, as my WB02 always reads about 14.7:1 when cruising anyway, so I know I have not exceeded the dynamic range of the adaptives for the stock computer.

But looking at your graphs, I now want to do a log, as your FTs go nutso! I wonder if a stock car does the same thing? Have you tried doing a log on a stock car? I can say I don't like to see the adaptives adding 30% fuel, that's for sure! Maybe you could enrich the fuel tables even under vaccum for 1000-3000 rpm and see if that settles the FT numbers down.

It does look like your FTs from 800-1200 secs on the logs looked pretty decent, under 10% anyway, so perhaps the engine strategy is just causing wild dynamic changes with throttle changes that are of no real concern. Are you experiencing any actual driveability problems?

At WOT, when the most important and risky tuning occurs, I use the Techedge unit:

http://techedge.com.au/vehicle/wbo2/default.htm

The whole works, including the 5-wire sensor, runs under $500, almost cheap enough to make it a permanent gauge in the car. I shoot for 11.5:1 at WOT, which is conservative and hopefully safe enough to give me some headroom for oxegenated fuels leaning things out.

I am a big believer in tuning on the road, not just dyno, as I consistently find a dyno tune is too lean on the road, so I have to enrichen after setting things on the dyno. I assume it is because the acceleration runs on a Dynojet are artificially quick through the RPMs due to the limited drum inertia and lack of air resistance.

The tough part is finding a strip of open road to do a 4th gear pull from 2500-6000 rpm without scaring the crap out of yourself, someone else, or getting arrested ;-)

FWIW

Now isn't this a better post than the perennial drivel like what do you do for a living? or what color stripes should I get? or, one of my favorites, what overpriced, massively heavy, 69" diameter wheels look best? Flame on!

 

[Joe Dozzo]

Appreciate the always thoughtful comments, thanks Keith.

First, after the engines warms up a little, no driveability problems at all.

While EASE OBD2 (www.obd2.com) has some plotting features, they are limited to data vs time. One of the nice features of the EASE OBD2 software is the ability to export data to Excel or some other tool for further analysis. Based on your comments, I plotted fuel trims with load, rpm, timing advance and open/closed loop operation. Strongest correlation (although not perfect) seems to be with fuel system status (open or closed loop).

http://vca2.viperclub.org/gallery/data/500/233LONGFT_vs_LOOP.jpg?3361

When Bank2 pegs at 30, the computer is very often in Open Loop. Your suggestion to add some fuel would seem pretty appropriate.

I need to correlate B1 and B2 with driver and passenger side... If B2 is, in fact, passenger, then maybe increasing the pulsewidth slightly for that side with the latest VEC2 software is the way to go. Would also suggest I change breather strategy and go with a catch can rather than dup back into the manifold (but only a hypothesis...)

No testing on a stock car... Maybe I can get one of the local guys to drag their car out this weekend (if it doesn't snow!).

I found the Techedge setup with a Google search. Glad to hear you like it and sounds like I need to step up and get a copy.

Have you experimented with the VEC2 and sharing programming. The 3 of us up here are using the rather cumbersome method of sharing serial numbers and codes. There may be a reason for this, but it definitely falls into the unfriendly realm...

"The tough part is finding a strip of open road to do a 4th gear pull from 2500-6000 rpm without scaring the crap out of yourself, someone else, or getting arrested ;-)"

Now THAT'S funny!


Silver with blue stripes! Isn't that the ONLY way to go!!!

 

[NDW]

Keith & Joe,

I am very interested in your posts, I enjoy learning about the engine management of the car. But without any personal knowledge of the hardware/software you are referring to or even what some of the acronyms stand for, I am at a loss as to what you are talking about. This is one of the posts that I will come back and reread after I understand more about the topic.

The post sure sounds good though, so I agree with whatever you two have said.

Keith, could I get your opinion on some new wheels?

 

[kverges]

Yo, Joe, you coulda clicked on the link for Techedge in my post! But I guess you like to do it the hard way.

I have not shared programs, no one here seems to have the software or use it, as best I can tell. And yes, the coding would seem to require me to insert box numbers and so on into my software to burn a card.

But to read a different card does not seem to require any codes. I was able to read my old cards (my original VEC-2 was lost in shipping back to Roe) without a problem, then just insert the codes into the software to burn new cards.

So I bet I could send you my .cbc files and you couodl read them, or vice-versa and I'll see if I can read yours.