HOHN

Well I just installed my Van Aaken and I think it's interesting to compare/contrast it with a Catcher ECM.

When I installed the ECM, the power difference was obvious. With the VA, it's more subtle but it's definitely noticeable. I remember similar results with my EZ-- once you got used to driving without it, reconnecting it was kinda disappointing as the power seemed very slight.


When I tested the ECM with my Mach 4s, I could hit 38psi of boost. With the VA, I'm seeing about 34psi. Both were with wg blocked. The ECM seemed to clear up smoke better at WOT, as the VA leaves more smoke at 34psi than the ECM left at 38psi.

Smoke control with the VA is MUCH MUCH easier, and pedal response is very linear. With the VA, I can hold boost at a steady value at any point under 34psi. I could get into and see 29psi, then go WOT and watch the boost come up. With the ECM, I saw no difference in the last inch of pedal travel or so-- it would race to 38psi at about 3/4 pedal and stay there.

Overall power seems stronger with the ECM than the VA.

So, in short, the ECM compared to the VA seems to give:
-- more boost
-- much more response
-- much less control
-- much more smoke


But there's more to this than meets the eye. There's a FUEL variable that I'm suspicious may be skewing my "test" results.

When I tested the ECM it was summer. So there was no winterized fuel. I was running straight #2.

Now, with the VA I'm not only running winterized fuel (I *think* it is, anyway), but it's also B20! I'm quite certain that B20 has less energy content than straight #2 (in terms of BTUs). Moreover, if my B20 is WINTERIZED B20, then that's quite a bit less energy, no?

I've satisfied myself that I don't have any boost leaks (would a leak only bleed 4psi?), and I can't imagine that 4psi would be the difference in boost between two very similar mods (timing and fuel within ECM limitations).


I'm VERY suspicious that the difference in power (perceived) and the 4psi boost difference (observed) are due to fuel variance.


Am I off my rocker?


H

RowJ

Interesting comparisons.

May be too many variables to be totally useful?

Murphy Oil's General Mgr told me they switch to #1 diesel Oct 1st...from Tusla north. Assume this is done industry wide, so you probably are getting #1 diesel.

But is it mildly blended or a full dose of Kerosene mixed in?...Another variable.

Your also dealing with the better performance/less smoke scenario of lower outside temperatures. Does this variable offset the #1 diesel or is it not enough to do so? Could the colder/denser air account for the higher boost?
Since going to Mach 4's...I notice ABSOLUTELY NO smoke control problems below 80*.

If I follow all you said...it is safe to say the VA is stronger than the EZ and with no downside....correct?

RJ

Mike D

B20 will effect the power. Timinva saw this on one of his dyno runs while using bio, but I'm not sure of the blend.

I wonder how much difference if any there is with regards to timing advance?

hotdram

I have no idea (the smart money is probably on "yes"), but you have my vote for coolest avatar

~Rob

RowJ

I might agree, if could read it?

crobtex

All I can make out is "BS Meter".

HOHN

BS meter-- has three zones. I had to make it illegible to fit with our tiny avatar rules (hint, hint).

The zones are 1) put on boots 2) put on lifevest 3) man the lifeboats, IIRC

HOHN

That's the thing. I'm seeing LOWER boost in the colder, denser October air than I did in the thinner hotter July air I tested the Catcher with.

I called the local truckstop, and the lady was sure that their #2 was winterized already. But she couldn't tell me about their B20!! I've always read that bio has inferior cold weather properties (cloud point, etc), so I'm thinking that it HAS to be winterized in some way.

I highly doubt we are getting straight #1, as I don't know if anywhere that does that. It's usually just cut with X percent of #1, not straight #1.

Just so we're not confused, RJ-- I'm seeing LESS boost and LESS HP and MORE SMOKE (@WOT) in COLDER WEATHER.

I'm trying to figure out why I'm getting less boost by 4psi, and this is happening in COLDER weather (where I'd expect MORE boost!). I don't see any boost leaks, but I'm not positive.



The other thing that's interesting is that the Catcher had me over 1500° EGT. Today with the new VA I could BARELY kiss 1200!

If I had a boost leak, I'd expect HIGHER egt, right?-- not lower! So I don't think there's a boost leak.

I'd assume that 150hp injectors and a VA box would be enough to peg that pyro a little easier, so I'm puzzled. I'm getting plenty of fuel, as I have 10psi FP @ WOT.

So everything I can think of is pointing to less energy content in the fuel. If I was getting a bad burn, I'd see higher egt, not lower.
Same thing with a boost leak. Also, a leak would probably not only leak 4psi.


The final variable is that I'm now running a 5w40 oil instead of a 10w30-- so there might be more viscous friction for the turbo, which increase drag and reduces peak boost-- but I can't see it being 4psi worth.

H

Gotlift01

I think your problem is the fuel also. I have noticed over the last couple of weeks that my truck performs a tad bit sluggish compared to about a month or two ago............imagination maybe?? But the winterized fuel has always been know to cut down on power and also on mileage.

And as far as a boost leak, even if it was leaking so minimal, I still think you would see more than a 4 psi loss and higher EGTS for sure. Especially with your injectors you should be well above 1200*!

Bob Wagner

Marco programs the ecm to get all of the fuel out of the vp44 within its limit.

I would say the va is pushing less fuel

HOHN

I agree Bob. I think it's simply the case that the ECM is just "hotter" in terms of fueling.

Like the difference between a PM3 and a PMAX COMP


But I'm thinking back to when I ran an EZ and DD2s. Peak EGTs would barely kiss 1300.


Today, I finally got it to hit 1400 a bit, but this is in a lot cooler weather.

I'm thinking that this is going to be a great all around combo (VA+ M4s) Power is less than the ECM by a considerable amount (or at least the SOP power is), but the better smoke control and enhanced pedal modulation are a sacrifice I'm willing to make (especially for the cost savings).

I'm guessing that a PMAX (comp, of course) added to the mix will overcome any lack of fueling......

HOHN

Oh, and to answer RJs question-- yes, I feel that the VA is better than the EZ. Less rattle, more response.

j-dubya

thats kinda what ive been wanting to hear. any more observations on the van aaken?

jeremy

RowJ

Sorry, I misread you on that one. I think Bob W. is correct. Just not as much fuel with the VA.

I would discount the oil weight as a serious variable. I have circle track racing customers that get 4-6 more HP from a 30 wt oil (at operating temp) over a 50 wt (20w-50)....but that is at full power and 5000 rpm on a 600+ hp engine. That translates, in my mind, to no appreciable difference in our engines while driving on the street.

RJ

Ben

Hohn -

This is interesting. I am experiencing a similar situation at the moment. Except I haven't changed anything.

Normally I would peg 32lbs boost and egts wouldn't really be over 1100. Over the last 2-3 weeks I've noticed about a 4 lb boost drop and higher egts. I mean I have to work it to hit 30lbs and the egts are 1200. However it spikes to 28lbs yesterday.

I've noticed a 1-2 boost drop cruising and about 100 degrees hotter also.

I was leaning towards a boost leak at the intake horn BUT the fuel quality factor is interesting to say the least. Something I never really thought of. I still need to check for a leak tho......

Keep us posted on what you find.