Tuning for power vs economy????

[Tony2ltr]

Hey folks, can someone give me some advice on injection pump and valve timing VS power or economy? I know with gassers advancing valve timing lowers the powerband RPM, but I don't know if it is the same with diesels. For Fuel economy we should be considering torque I would imagine, as Base Specific Fuel Consumption measured in pounds of fuel per horsepower/hour tends to be it's lowest near peak torque.
Anyone have any Dyno tuning experience with these?
 
Thanks,
Tony

[theman53]

Some may know better than I but I learned that if your cam timing is off more than a tooth and you run it you will bend all your valves. IP timing can be played with, but your looking at alot of trial and error. I dont have any dyno or know anyone here that is why I say trial and error. From what I know more air, more fuel, more power and if you keep you foot out of it should translate to more economy.

[Smokey Eddy]

Ditto.

With these pumps, done right, you can have good economy depending on how often you push the pedal down.

fueling is directly related to boost so if you want to save money - less boost
wanna go - fast more fuel more boost

[Tony2ltr]

I know that the cam timing offers some variability because if the lack of a keyway in the pulley. With a gasser, you can delay intake close to allow higher boost to more completly fill the cylinders before the intake closes, and generally, advance exhaust to prevent blowing fuel/boost from blowing right through during overlap. Of course overlap/LCA is fixed on these, being single overhead cam creatures, but how about injection pump timing advance? I remember reading something here a while back, but I can't find it now.  I get the governor mod, but how about the staked screw on the pump that points toward the driver's side?
-Tony

[arb]

Yeah, Ditto - don't touch the valve timing - the keyless chuck is to properly time a new belt as there are small differences in them. If you want to mess with valve timing, your only chance of not breaking a valve / head is to have a custom grind - understand there is more to valve timing than when the valve starts to open and closes all the way - the slope and height have profound affect.

on IP timing, get more push from an earlier injection event, you'll get more HP and efficiency, but it will get harder to start with a starter motor (fast spin-ups like a push start / big hill will not even require glow plugs if here is enough speed...

With the mechanical injection we have on our IDI engine, we can not dynamically change the injection event as much as they can on the TDI engine. That's why among other reasons, for a given displacement, they get more HP and MPG.

[Tony2ltr]

All right! Maybe I could add another battery in for a 24 volt start? I have a few good deep cycle batteries left over from the last pack on my electric car, hmmm, you say that power and econ is better with advanced pump, except for the cold start issue then...Does it make sense to drive around with the cold start pulled then, wait, doesn't that retard the timing?
Thanks, I have some thinking to do.
-Tony

[theman53]

cold start only advances a lilttle bit and that I believe is under 2,000RPM only once it goes above that the pumps own advance curve takes over. The best thing to do is port your head and manifolds and send your pump to Giles. Then see how much boost you can make and use for power vs economy.

[Tony2ltr]

the head is pocket ported, I have the early(84ish?) turbo with the 42 AR compressor. This is however running on an ecodiesel that I have outfitted for direct compressor meth/water misting. Made serious boost increase on the old engine. The 92 ecodiesel rattled the drain plug out on a steep mountain road and locked up.  It ran for three years after that, but used a lot of lube oil, which smelled bad. (I'm a veggie oiler, and not used  to my car smelling bad, even when it is boosting at 25 psi!). I had figured out the governor mod myself, long before I found you guys, and was glad to see I was not crazy once I found this forum. Is there a write up somwhere on any other mods people have figured out for the IP? I searched for it, and could not find a thread I remembered that had picks of some other mods.
How much HP will the Giles overhaul make? How much does it cost? He is in Canada right?

One of the things I am goiing to do is add a pusher pump from the tank.
Thanks for the advice...
-Tony

[Vincent Waldon]

I'd recommend you start with the FAQ sticky:

http://www.vwdiesel.net/phpBB/viewtopic.php?t=16687

Your best bet for information on Giles pumps is to talk to the man directly... his contact info is in the Vendor section.

[Tony2ltr]

Thank you so much for pointing me in the right direction! Boy there is alot goin on there! I read until my eyes were sore last night about pump internal pressure and the mean green spring tech. I only got about half way down the 14 pages on the other forum about thepump internal pressures. so far it seems like a good idea to make myself a gauge adapter for the pump body. I was having some trouble with the pump on the old engine before I took it apart, it wouldn't rev past about 2krpm, and it would REALLY suck wind going up hills.  I have the new engine swinging in the breeze in my fightfully chilly garage right now, I just set the tranny in place to do the pump timing. This morning I am going to pick up my 6 puck bronze clutch.

-Tony

[vwjunkie53]

Advancing your timing may net you some increase mileage, but it really depends on what your timing is to begin with.  If it is way off, you may see a sizeable difference.  On my '85, I tried advacing from within stock spec (I think at was around .90mm) to 1.05 mm.  I didn't notice any more mileage, and the car just idled rougher which I found pretty annoying!  About the only other "tuning" you going to get out of a diesel would be to make sure your injectors are in good working order.  Maybe have them pop tested.  If they have a ton of miles it also could be a good idea to buy some rebuilds or at least some rebuilt tips.

Jason

[Tony2ltr]

Hey guys, I set my IP timing today, at about .043", TDC crank. Cam is lined up, but then I checked full throw on the pump, it only came up with .082". I know the upper limit is about .0866" right? Do you think my pump has had it? Now the only monkey wrench is, I used a regular dial indicator with the injection lines removed, I used mechanics wire to hold it in tight, I suppose it could have moved, but I don't think so...I looked through FAQs, but only found a little of what I was looking for...
-Tony

[Tony2ltr]

It runs! It rips!
I had about 25 PSI of boost today running the new engine, but it makes a little bit too much smoke.  I have the NA pump's fuel screw turned in about 1-1/4 turns past the stock lock setting. If I go any further, I can't readjust the idle down any more
I fixed a few of the little things that are wrong.
I blocked off the blowoff port, because it was letting go at 15 PSI, I will probably get rid of the valve, maybe go back to the ecodiesel manifold that doesn't have it.
I am once again convinced that my water injection was a wonderful thing to do, I used about a 75% methanol to water, squirted into the inlet of the turbo compressor.  The volume is very low right now, but it helps the boost come up very fast.
Unfortunately, the injector pump leaks a bit out of the accelerator shaft seal, I didn't bother resealing the pump, I guess I should have, it was very old and had been sitting for a long time.

 I think I am going to put the turbo pump top on this NA pump like I had on the old engine.
I am also going to put a gauge on the pump body to check the internal pressure.
I have a question though, I think the engine seems louder at idle than it used to, It has great oil pressure, from 25-35 PSI at idle. Maybe my injection timing is too advanced???

Thanks for all your help in the past few weeks guys.
-Tony

[vanbcguy]

More advance will definitely make it louder at idle... But as long as it's not TOO MUCH advance (IE it's clattering like a PowerStroke) I'd let it be...

[Tony2ltr]

Hmmm, clattering like a powerstroke? What if I said that engine bay would be the last place I would want to be if I had a headache? It is real bad when it is cold, but quiets down a bit when it is warmed up.
-Tony