stacked VA boxes on a 305!

[OT-OF-HERE!!]

Originally posted by DLeno

probably "best gain" -- do you know what the peak gain is?

Probably a dumb question,. . but when you stack boxes I suppose they are in series? Soooo if you are not using the duration box, as you stated, do you have to take it out of the series to utilize the other box or can you just shut either one off and it still workon the box that is on??

 

[CIverson]

Originally posted by OT-OF-HERE!!

Probably a dumb question,. . but when you stack boxes I suppose they are in series? Soooo if you are not using the duration box, as you stated, do you have to take it out of the series to utilize the other box or can you just shut either one off and it still workon the box that is on??

The 2 boxes control different functions. One duration, and one fuel pressure. They work independently of each other, which allows you to not use the duration and only the pressure. You can't really stack boxes that do the same function as far as I'm aware.

 

[bpenrod]

The duration box plugs into the ecm connector and the pressure boxes are usuall MAP and Fuel pressure sensor. Turning the duration box off still allows the pressure box to do the boost fooling and hp / torque increases. I have been driving on my Edge EZ only most of the time and turn on the duration for a little fun now and then!!

 

[DLeno]

OT-OF-HERE: Both of the VA boxes are built to attach to the same physical point on the engine -- The ECM connector. It turns out that the boxes themselves utilize different pins on the same connector, so "stacking" them is really a mis-nomer. they really operate in parallel in the sense that the pressure box does its thing with the analog ECM inputs, and the duration box does its thing with the digital bus. There is no interaction between the two boxes.



Because there is no "stacking" harness that connects both boxes to the same ECM connector (which would be the best thing to do), we have to insert the boxes in "series" (mechanically). But electrically they are not in series and operate on different pins within that large ECM connector. the only exception to this is the fact that box boxes do "boost fooling" on the same wire. this means that one of the stacked boxes boost fools the 2nd box which in turn boost fools the ECM. But, by virtue of the way boost fooling is accomplished, stacking has no affect on boost fooling and order is not important.



I have both boxes hooked up and adjust them independantly, including turning one or the other off. This is all possible from in the cab without opening the hood.



CIverson: you are absolutely correct with this clarification: you can't stack two boxes that perform the same function in the same way. I say that because it is actually possible to stack the VA duration box and the TST duration/timing box. Without commenting on the results of such a combination, this is interesting because the VA adjusts duration at the ECM level, and then the TST box comes along and manually adds additional duration by connecting directly to the injector solenoid. whether or not thats a good idea or not I don't know -- but its interesting

 

[bpenrod]

Dleno,

Thanx for the clarification, I was thinking of the Edge I stacked when posting above. So how much room do the two ecm conectors take up next to the engine?

 

[DLeno]

thats kind of hard to describe. I'll try an ASCII pic

Basically, imagine a wire harness with two ECM connectors on it -- one female and one male, and 50 or whatever wires (about 6 inches long) connecting the two:



***---------------------***

***---------------------***

***---------------------***

***---------------------***

***---------------------***



basically, the VA install goes like this: remove the factory ECM connector from the engine block, insert the above harness in its place, and then re-connect the factory ECM connector to the new harness.



for the two box install, you have to hook up two of those wire harnesses back to back:



***---------------------******---------------------***

***---------------------******---------------------***

***---------------------******---------------------***

***---------------------******---------------------***

***---------------------******---------------------***



Stacking the Edge with the VA duration would actually be a cleaner, even though more complex, install. You're right: the edge would connect to the pressure port and the MAP sensor, and the VA doesn't touch those. no 2nd wiring harness.



I've mentioned before that VA needs to (and I believe they will) come out with a stacking harness that will eliminate the 2nd harness

 

[bpenrod]

Great ASCII pic! I agree the Edge stack is cleaner but your stuck running on whatever your set at under the hood, no in cab pressure adjustment. Other than that little downfall they work well together, no codes or conflicts that I can tell after 5 days running around on all sorts of different settings. Currently have the Edge on level 2 but might get gutsy and bump it up to level 3.....

 

[OT-OF-HERE!!]

Originally posted by bpenrod

Great ASCII pic! I agree the Edge stack is cleaner but your stuck running on whatever your set at under the hood, no in cab pressure adjustment. Other than that little downfall they work well together, no codes or conflicts that I can tell after 5 days running around on all sorts of different settings. Currently have the Edge on level 2 but might get gutsy and bump it up to level 3.....

As I understand,. . the Edge is more of a top-end box. Would it then stacked with the VA duration box provide a better result than the two VA boxes together? Is the Edge also a timing box?

 

[DLeno]

I hear ya. love the adjustabilty. learned one thing though -- the VA pressure box doesn't come with the adjustment switch. it is built for one, but its not in the box! so I'm working on that...



I'm currently on:



VA pressure: all the way up:



VA duration: level 1 of 2.



wonderful drivability. the (VA) pressure box alone is just not enough. both all the way up is just too much for a conservative analytic without an EGT gauge

 

[DLeno]

Originally posted by OT-OF-HERE!!

As I understand,. . the Edge is more of a top-end box. Would it then stacked with the VA duration box provide a better result than the two VA boxes together? Is the Edge also a timing box?

Indeed, the Edge is more of a dyno-day box -- top-end RPM wise. So depending on your goals yes: it would certainly provide more fuel at the top end than the VA pressure box would, and less fuel at the bottom end. The Edge is NOT a timing box -- pressure only.



I'd love to test an EZ in place of the VA pressure box, but at the end of the day, I'm impressed with the connection simplicity of the VA box, and the low-end drivability of the combination the way they are now. and the VA pressure box has the advantage that I actually know what its maximum pressure is. If you dial up the EZ to a 30-40 HP setting, you'll be about the same

 

[Greg Boardman-RIP]

Originally posted by DLeno



I haven't gone past 1/2 throttle at low speeds and 75 mph top speed under cruise.

Then how can you give a honest report of how these new boxes work? If you cannot goto WOT and give us a seat of the pants feel you shouldn't be praising something. Alot of people are following the threads you write and will believe you know what you are talking about. I for one think that the EZ is stronger than the VA L2 by itself. I may be wrong but it seems to drop off after about 1/2 throttle... .

 

[Matt400]

Originally posted by DLeno

learned one thing though -- the VA pressure box doesn't come with the adjustment switch. it is built for one, but its not in the box! so I'm working on that...

Mine did and the instructions show it so they should send you one.

 

[bpenrod]

I've have ran mine like I stole since installing the VA box, including several full throttle runs to 100+ mph. Judging by egt the VA box is still fueling since my temps change with the VA setting and really get warm at the 100% setting and a sustained foot to the floor run. I saw a brief 1450* on the pyro before taking my foot out of it. It was only that high for a minute as I did a top gear passing run from 65 mph to over 100.

 

[Gypsyman]

Originally posted by DLeno

I hear ya. love the adjustabilty. learned one thing though -- the VA pressure box doesn't come with the adjustment switch. it is built for one, but its not in the box! so I'm working on that...

The pressure box that I tested and the install literature that I have show the rotary switch. Also, Ted Janetty said that they should be in the box. Wonder why yours wasn't there?

 

[DLeno]

Originally posted by Greg Boardman

Then how can you give a honest report of how these new boxes work? If you cannot goto WOT and give us a seat of the pants feel you shouldn't be praising something. Alot of people are following the threads you write and will believe you know what you are talking about. I for one think that the EZ is stronger than the VA L2 by itself. I may be wrong but it seems to drop off after about 1/2 throttle... .

I haven't meant to praise anything except the concept (duration, no pressure, no injector connection) and the connections (simplicity), and driveabilty. I've been very careful to report exactly what I find (including the engine code upon install) and I'm being completely honest, not only about what I report but about the completeness (or lack thereoff) of my results. I don't have an opinion yet on the SOP feel except for light city driving because I don't have air or gauges yet. and above all, no dyno run, so I can't comment on peak HP. Please dont interpret what I have written so far as comprehensive and complete because it isn't. I report what I know in the order that I learn it.

 

[Gypsyman]

Well put Doug. At least your taking the time to test and report.

Originally posted by Greg Boardman

I may be wrong but it seems to drop off after about 1/2 throttle... .

I do have gauge, do make WOT runs and have reported on this box. Look at the dyno charts. It's MAPPED to pull less at higher RPM's. Completely different fuel map than the Edge EZ. I think both have thier place and that might even be in unison.

 

[OT-OF-HERE!!]

Originally posted by Gypsyman

Well put Doug. At least your taking the time to test and report.







I do have gauge, do make WOT runs and have reported on this box. Look at the dyno charts. It's MAPPED to pull less at higher RPM's. Completely different fuel map than the Edge EZ. I think both have thier place and that might even be in unison.

You state that it's mapped to pull less at higher rpms. Could that be as a result of VA not having removed the top speed limiter? Danny told me they left that feature alone? Also if you stacked a VA duration and the Edge would the Edge eliminate the limiter and if so, ... would that let the VA assist at higher rpms more than in it's present form??

 

[bpenrod]

I know my egt's are higher with the VA box turned on than just running the Edge EZ at full throttle runs so I believe it (the VA) box is still adding something even near redline. JMHO

Bill

 

[Gypsyman]

I'm just saying that the additional amount of fuel is gradually decreased as the RPM goes up to help with high RPM EGT's. Just my opinion...

 

[Blakers]

Originally posted by bpenrod

I know my egt's are higher with the VA box turned on than just running the Edge EZ at full throttle runs so I believe it (the VA) box is still adding something even near redline. JMHO

Bill

Which VA box are you running? You just keep say "VA Box", but which one? Thanks.