MOAR POWA

[alexgingles]

I am the guinea pig for a performance MOAR POWA fuel pin.  I am sharing my experience with it and maybe you guys can help.

Stats on the car.  '91 Ecodiesel Jetta.  Hydro MF block, turbo pump, governor mod, stock t3 turbo at 18psi, 2.5" mandrel downpipe and 2.25 exhaust.

We spent saturday morning fine tuning pump internal pressure, compression check and etc.  We then took the top of the pump off and set it up on the bench to measure the amount of travel the stock fuel pin places on the boost control lever.  We determined that the lever traveled a total of .040" using the most aggressive ramp on the stock pin.  We also plotted points with regulated air to determine how much travel happens with each change in boost.



We then removed the stock pin and installed the MOAR POWA pin and did the same tests.  We found that the new pin will allow the boost control lever to travel .140".

We then applied regulated air to the boost compensator housing and plotted points to determine how much travel happens with each pound of boost.




My car is on it's stock headgasket so I regulate my boost to 18psi.  On the highway I run about 3psi cruising 65-75mph.  I don't want added fuel at 3psi to limit smoke.

After plotting the points of boost to travel, we then adjusted the preload spring.  We backed the spring seat wheel out 2 turns from the bottom and plotted new points.  We continued to do so until we got 8 turns out.  8 Turns was pretty close to what we wanted but not exact so we went 9 turns but the wheel no longer made contact with the clicker to hold it in position so we then added a shim under it.



After careful measurement and some math, the shim used equated to 3.2 turns of the wheel.  After installing the shim we turned the wheel out almost 6 turns (9 turns in total). 

Mike filling his pie-hole with pie


We then preceded to again measure travel with boost but we ended maxing the spring out.  Remember our total travel with the pin is .140".  We got to a certain boost (I don't have the numbers with me) and travel stopped shy at about .120".  I increased the boost to about 30psi and it traveled about .002 more.

We then went to the barn and grabbed the preload spring and fuel pin from a Cummins 4BT.


MOAR POWA pin on the left, 4BT pin in the middle, and stock 1.6 pin on the right.

The 4BT pin has a more aggressive ramp than the stock 1.6 has.  Direct OEM bolt on upgrade?

The 4BT spring is a little larger and felt slightly stiffer (we don't have springs rates currently).

We pretty much acheived the same results with that spring.  We ended up removing it and backed the wheel out to a total of 8 turns from the bottom and installed the stock spring.

After putting the pump back together and going for a test drive, I find some extra power on the higher rpms.  Smoke is a little more than with the stock pin.  We came to the conclusion that maybe the rest of the pump does not support the MOAR POWA pin completely. 

For having over 3 times the travel on the boost control lever, it does not seem that fuel is increased by 3.5 times at full boost.  I guess the only way to really find out is to install this on a flow bench and determine what happens.  What are y'alls thoughts?

[alexgingles]

Clark sent me some numbers from Saturday..

Stock pin with wheel 4.25 turns from bottom (where it had been for months)

Travel       Boost
.005         2psi
.010         3
.015         4
.020         5
.025         6
.030         7
.035         8
.040         9
.040         10

Without looking at the pin, you can see that the stock pin is super linear.

Here is another set of numbers with the stock pin, this time with the wheel bottomed out.

Travel       Boost
.015         1psi
.015         2
.021         3
.027         4
.030         5
.034         6
.035         7
.035         8

According to these numbers, the the pin is already somewhat in travel before boost is applied.  Very little preload on the spring.

MOAR POWA with wheel bottomed out

Travel       Boost
.070         1psi
.070         2
.100         3
.120         4
.120         5

The same thing is happening here as the last results.  We checked the boost ramp and you could see where the pin was riding, riding in the ramp at 0 boost.

MOAR POWA with wheel 2 turns from bottom

Travel       Boost
.025         1psi
.090         4
.118         5
.135         6
.135         7

MOAR POWA with wheel turned 8 revs from bottom

Travel       Boost
.000         1psi
.000         2
.008         3
.015         4
.028         5
.040         6
.050         7
.070         8
.090         9
.110         10
.125         11
.138         12
.138         13

This looks good, no substantial additional fueling at 3psi.

MOAR POWA with wheel turned out 9 turns
.000         1psi
.000         2
.000         3
.002         4
.012         5
.026         6
.040         7
.050         8
.065         9
.086         10
.100         11
.110         12
.115         13
.115         14

Bound up spring.

[clarkrep]

Nice official name, Alex.   
Thanks for the pics and write up.
Btw do you have max egt numbers from the drive home?
I talked to "410" on here and he may chime in with his findings from lda tuning.

[RadoTD]

Very interesting, I'd like to see where you end up going with this! I'll be watching it for sure
That's awesome that you actually plotted pin travel vs boost pressure. I was thinking of doing that but I don't have a parts pump to tear apart

I made a 4BT blank boost pin for someone else on this forum and I remember it being significantly smaller diameter than the 1.6 pin, which is also slightly smaller than the AAZ pin, but in that picture, your 4BT looks the same size. Just a thing to keep in mind about swapping those pins directly


Here's what I've done regarding boost pins, but bear in mind I've got an AAZ pump, so it may all be different. I've got no turnwheel to play with anyway. Below when I refer to pin, it's the actual boost pin. When I say needle, it's the small pin inside the pump that actually rides on the pin. Just to clear up any possible confusion 

This past spring, I made some extra goodies for my pump, mostly for the LDA to get as much as possible out of my AAZ pump. I'll be running a fair bit of boost when I get the car back on the road; certainly over 30psi. I don't think I have a hope of getting the fuel/boost curve to match the air/boost curve, so I'm just trying to make the difference between off boost and full boost as much as possible and hope for some modulation in between.

The first thing I did was pull the top of the LDA off, pull the boost pin and find out how far the needle that rides on the pin can actually move without anything in the way. In order to keep my idle proper with the amount of fuel I was running, I had to turn my throttle lever back a few notches, so I removed the upper limit screw as well and rotated it as far as I could. To my surprise, it didn't actually move that far... less than half the diameter of the boost pin itself.
One thing that bothered me is that on all the stock boost pins, the point at rest was actually part of the way in. Meaning that with no extra pressure, you were already getting extra fuel, so the first thing I wanted on my pin was 0 boost = 0 extra fuel. I've even got a small amount of pin travel (1mm?) before the extra fuel gets added at all, because by the time I can get to full throttle in any gear, I'm surely already making some boost.
Next thing was that full pin travel should generally equal full needle travel, plus a little extra in case my measurement was off (it's actually pretty hard to measure how far that needle moves down in the pump!). I measured this out and fortunately, it was less than the radius of the pin which meant I could turn a cone on a lathe for it. Very close, but still not quite through.
Using a depth mic, I measured the distance between where the pin physically stops at the top and where it physically stops at the bottom of it's travel. Subtract the thickness of the rubber thing and metal plates on the pin and that gave me the full travel of the pin.
I then made a 3D model of that pin and the first thing I noticed was that the ramp was very steep. So, using the pump top as a template, I made a spacer, 5/16" thick to increase the travel of the pin and make that ramp slightly more shallow.

So, in my case, for my pump and running large volumes of boost, in theory, that should get me the most fuel possible out of the pump while hopefully retaining some sane levels off boost. I haven't installed any of it yet, but this late winter/early spring, the car should be back on the road, things will get installed and it will be glorious! 

Hopefully we can help each other out and design the ultimate modular boost pin! Looks like you've got a good start and I love the pin travel measuring. I may have to build myself a jig for it too!

Pics because, well, walls of text are boring. Pictures are not.


DSCF0580 by Pursuit_01, on Flickr


DSCF0546 by Pursuit_01, on Flickr


DSCF0549 by Pursuit_01, on Flickr


DSCF0550 by Pursuit_01, on Flickr


DSCF0551 by Pursuit_01, on Flickr

[clarkrep]

What I've found is that there are two(at least) different diameter fuel pins in bosch ve pumps. 11 and 12mm
Cummins pumps as far as I've seen are all 12mm.
Alex and I were discussing the possibility of making a new top cover to allow more travel. I see you've essentially done that. It took me a bit to realize that you were using a router haha(:
I can't think why you made a blank pin. Care to explain?
Have you ran yours with the modified pin yet?

[410]

I would check the travel of the pin (the one that is inside the pump that rides on the lda pin) with the lda on the pump.  This is the way I did it.
-Remove lda cover and remove the lda pin and spring.
-Looking down the bore of the lda move the throttle lever slowly to it's max travel.  
-Pull out your drill bit set and find the largest drill bit that can still fit in the lda bore while still holding the throttle lever in the max fuel position.
-Measure the drill bit and subtract it from the bore size of the lda.  This now gives you the max travel of the inner lda pin.  

Now pull the lda assembly off the pump and move the inner lda lever to its max fuel position and recheck to see how far the inner fuel pin moves and compare that to the measurement you got with the lda assembly on the pump.  If you get more travel then you can modify the lda lever by building up where the the lda lever touches the governor lever by welding it and grinding.  

I hope this doesn't sound too complicated but by checking this you can take full advantage of the lda.

I would also think about upgrading the camplate in the pump to the one found in the aaz.  Same profile as the 1.6td camplate but more lift.  It is possible that you are reaching the limit of the pump with the stock camplate.

[RadoTD]

What I've found is that there are two(at least) different diameter fuel pins in bosch ve pumps. 11 and 12mm
Cummins pumps as far as I've seen are all 12mm.
Alex and I were discussing the possibility of making a new top cover to allow more travel. I see you've essentially done that. It took me a bit to realize that you were using a router haha(:
I can't think why you made a blank pin. Care to explain?
Have you ran yours with the modified pin yet?

Haha yeah, the router actually worked pretty well! It chattered with that bit, but some cutting wax and cutting as close to the template as possible with an angle grinder helped minimize it. I'm just too cheap for a real aluminum bit!
I haven't put the spacer in yet, but it should work fine. I rounded the inside edge over so it wouldn't cut the rubber... I can get pics up of it finished soon

I didn't have access to a milling machine, so either way, the ramp was going to be cut with a dremel or die grinder or whatever. I turned the blank pin for him on a lathe so all he had to do was grind the ramp as he wanted it

No, I haven't run it with the modified pin yet. The car is off the road right now getting some more work done. I want to drive it for a while before I start playing with the pump as well to give me good baseline measurements and then I can change one thing at a time

I would check the travel of the pin (the one that is inside the pump that rides on the lda pin) with the lda on the pump.  This is the way I did it.

Good idea for measuring the needle's travel! Why didn't I think of that? I was sticking welding filler rod down there trying to eyeball as if it was a feeler gauge

Now pull the lda assembly off the pump and move the inner lda lever to its max fuel position and recheck to see how far the inner fuel pin moves and compare that to the measurement you got with the lda assembly on the pump.  If you get more travel then you can modify the lda lever by building up where the the lda lever touches the governor lever by welding it and grinding. 

I thought about trying something like this, but I never knew how it all works in there and was afraid I'd end up with a pile of parts in my lap. I might have to do that if I'm not happy with how it works once it's all together

[alexgingles]

410, this sounds like a good idea.  Clark and I were discussing this and thought about installing a small bolt instead of welding on more material.  This would make for easy change if necessary.  If I have some time this weekend I may try this. 

Clark and I also figured we may be reaching the mechanical limits of the pump via the camplate or intake slits on the plunger.

[92EcoDiesel Jetta]

Nice work alexgingles!

RadoTD, do you have a wood scroll saw? With a metal blade would have been easier to cut that aluminum than a router with a wood bit.

[410]

So, have you made any progress? 

[RadoTD]

Nice work alexgingles!

RadoTD, do you have a wood scroll saw? With a metal blade would have been easier to cut that aluminum than a router with a wood bit.

Unfortunately no scroll saw. That would be nice, although the router did quite well. I wouldn't hesitate to do it that way again

That would be great if someone found a way to either change how far the needle moves or how much it's movement affected fuel delivery. Maybe I'm just too chicken to pull my pump apart and be the first to figure that one out!

[regcheeseman]

Uk pumps can have two forms of max fuel limitation, I can see the lid and there isn't one there.

Maybe you have the limit pin in the lower pump half?

I've seen people cut great chunks out of their pins and not gain one extra gee gee because it's limited by the pin.


Interesting shape to the taper, why the step at the limit of travel - is there no chance it will hang up on that step?