cp3 info

[lord_verminaard]

Well, the next question, is how would you go about actually tuning it on a dyno?  For example, with MS, you can use the "megatune" software, which analyzes logs of a dyno run, then will automatically tweak the map for your desired a/f ratio.  I'm not so sure how you'd do that on a diesel other than guessing.

Brendan

[MikkiJayne]

Well how do the pros do it with edc15 etc? Tuning with MS should be exactly the same as that - pick your timing, iq, and fuel pressure by rpm and load, program it in, and see what it does Instead of an O2 sensor for AFR presumably you just tune for minimum smoke?

Megatune doesn't necessarily use the O2 sensor to map the ecu. It can be done manually - it's just easier letting Megatune do it for you with a wideband O2. Aren't there diesel O2 sensors available though? I'm sure I read something about VW using them...?

If someone came up with something like megatune for the OE ecus then that would be fab, but most apps like that cost many thousands of ££s rendering impractical for the tinkerers.

[gigaz2]

the same way the mtdi guys do it: EGT and smoke

I have a spare MS but wouldn't use it, too complicated. I would even make it M-CR if possible LOL

[lord_verminaard]

Well I did a bit of reading and Mikki you are right- you can pretty much use a wideband o2 to measure lambda in a Diesel the same as you can a gasser.  Diesels can see around 15:1 or so for good power before smoke/EGT can get excessive, so plotting a graph of AFR vs. RPM would show right away where fuel would need to be added/removed.  Under idle/part throttle conditions, it probably wouldn't help much as diesels go lean enough to be unreadable on most widebands- in which case you would just tune to minimize smoke/egt with acceptable power. 

Now Timing, on the other hand, is a completely different thing.  I'm not sure how much effect injection timing would have on lambda- my guess is probably not much- but EGT I think would probably change a bit.  That's something I still don't know much about. 

Brendan

[MikkiJayne]

Now that is interesting - I knew there was an O2 sensor for diesels, but I didn't know a wideband would do it! It would be easy to tune with megatune then. Is info on the timing available in any of the technical data? Could it be extracted from the existing ecu maps?

I was thinking while in the car earlier - this would allow us to do transplants & conversions with engines other than the 4-cylinders, for example the V6s and V8s  4.2TDI Corrado anyone? 

[lord_verminaard]

Crikey!  The VR6 is enough trouble! 

Brendan

[MikkiJayne]

VR6? Meh!



 

I reckon a 3.0TDI would work pretty well in there running on MegaCommonRailDieselSquirt! 

[lord_verminaard]

 

I've read your thread, trust me.    That's nuts.

Brendan

[lord_verminaard]

Bump. 

Brendan

[lord_verminaard]

Back up.  Found a good post on TDI club about A/F ratios on a diesel.  Yeah, a good post on TDI club.  Go figure. 

You have 3 zone, before the turbo spool, at spool and after spool.
-Before turbo spool, engine run like NA, 15:1 to 17:1 is good, 14:1 between 1000 to 1400rpm for better torq if little smoke is ok.
-At turbo spool, very narrow zone of rpm (200 to 600rpm zone), very hard to adjust A/F, 14:1 to 15:1 is better for fast spool, 15:1 to 17:1 for low cloud of smoke, many chip car are too rich in this zone but is very narrow zone!.
-After turbo spool, 15.5:1 to 16:1 is good target, gray haze and good power, 17:1 to 17.5:1 is low smoke ajustement, more than 18:1 power drop fast but no smoke in most case.

In exel, just divide air by fuel for A/F!
But chip are not calibrate for quantity of fuel, if nozzle, head or voltage map are change, ecu report wrong quantity of fuel.

Add O2 wide band on your down pipe and see what happen, i have and is very usefull for good tune.


Dieseleux

Brendan

[gigaz2]

crikey.. good info outside of vwdiesel or "the other good forum" 

that is very interesting, I always thought that a lambda probe on a diesel system would only work for a few minutes, then it would get fouled up in soot.
the lambda range used for power is also interesting as it is lower than a gasser.

I guess EGT is also a indirect way to measure lambda no?

[lord_verminaard]

I've also found out that Bosch Motorsports sells a complete standalone CRD ECU, they have two versions, a "sport" version for the small sum of $3500, and a "competition" version for $6000!!!!  Even the sport version has more inputs and datalogging than most of us would ever need.  I wish they made an "economy" version. 

Brendan

[lbreton]

I havn't been on this list for awhile..found and read through this thread with great interest.  I recently bought a DMAX CP3 pump Part #CR/CP3/S3/R110/30-7895.

I previously did not know what the yxx stood for.  Are you sure it is mm^3 per stroke? I ask this because it is common for a DMAX to run up to 600+HP on the OEM CP3 pump with the right tune, injectors & turbo.  After this, people start swapping in modified CP3's and double CP3 set-ups.  To produce 600HP (and about 1100ft-lbs), considering 2 combustion events at one time, or 550ft-lbs/cyl, fueling would need to be about 140mg/stroke.  Since the sg of fuel is around .95(?), that would mean the pump is delivering up to at least 147mm^3/stroke.  What am I seeing wrong on this guys?

Also, what direction would R be..clock wise looking at the pulley, or ccw?  

I read through the site link on the "Specialist Componants" CRD ECU, pretty nice looking unit.  However, I really cant imagine how one would build the correct tune starting from scratch. Perhaps they provide base tunes for different application to help get one started?..or even a built in autotune system, similar to the G3 system, to help get started?  An EDC15C or EDC16_ seems like the easiest route.

thanks for the good read guys.

How are you making out on this project anyway?  


EDIT  - answered my own question here.  The VW pump is designed for one injector event at a time, the DMAX is design for two injector events at a time so:
VW = 70mm^3/stroke x 1 injector
DMAX = 110mm^3/stroke x 2 injectors = 220mm^3/stroke if all the fuel goes to just one injector.  That is a lot of fuel!

[gigaz2]

I've thought about that, the cp3 has 3 plungers, could it be that its capacity is rated "per stroke" ?
would make sense, as it has to have at least twice the capacity than the fuel system can deliver in order to keep the pressure

the project is a loong running one, as the final goal of this would be to restore dignity to a originally good diesel that was was converted to a gasser before hitting the assembly line

a good gasser btw, but with DI, CR and a good vnt turbo it has potential to deliver

[lord_verminaard]

I guess you can't really have too much, since excess fuel is just sent back to the tank, correct?

With the tuning and Standalone, I would imagine it's pretty much the same as megasquirt- you go through a "wizard" answering questions about displacement, cylinders, firing order, crank/cam timing points and position sensor type, etc... and the software calculates what to do.  I've seen someone set up MS on a VW 8valve cold, IE. no base map, in about 10 minutes it was running.  The tweaking and fine-tuning is what takes so much time.  I'd think that with a diesel, it would be even more simple since there is no spark map to worry about.

Brendan