Well... I did it. In a moment of weakness, I bought one of these:
https://www.gohypermax.com/ProductDi...5-a3a12867ecce
They are advertized for use in beating California 'snap test' emissions.
I'm in a rural area with no emissions testing, so I didn't need it for that.
I bought it because it's an aneroid - a device which will limit IP fueling based on boost.
I thought it might help with off-idle smoking and require less-precise foot control.


What arrived was a small box with the few pieces shown in the above link, along with a set of instructions.
Here's a picture of the new aneroid+pump cover next to the old:

As you can see, the Hypermax pump cover has a new bulge at the 'back' side of it, where the new aneroid module attaches.

Also, you can see a lack of solenoids and stuff usually mounted inside of it.
You must use a small socket and remove all the screws, transplant the two solenoids and housing pressure regulator(black screw-in piece) into the new cover.

It's not a hard job; it took me perhaps 15 minutes to do the swap, even being extremely careful and never having taken one of the lids apart.

Installing the new cover on the truck is also simple, it's just a matter of making sure the FSS lever is in the right place, and the new "aneroid plate" which sticks down from the
cover to push against the governor assembly must be in "front" of a tab which sticks up.
http://arb.ca.gov/msprog/aftermkt/de...eo/D-175-4.pdf
Page 15 is a good diagram.

I followed the 'field install' instructions where you basically screw the aneroid in until idle speed is affected, then screw it out 1 turn. I ended up screwing it out 1 1/4 turns from that point on my pump(RD2-110).

Here's a picture of it installed:
p, li { white-space: pre-wrap; } http://robbiethe1st.afraid.org/image...160508_003.jpg
I just hooked the boost line up to the old wastegate port on my turbo, which I am not using.




After driving it for a couple of days... I am extremely happy with it. I end up with faster starts off the line, as I don't risk flooding it(With as much fuel as I have available, if you give it too much fuel near idle, the engine will choke and nearly die).


This aneroid is designed to "kick in" at around 5 PSI of boost; I've heard people changing the spring inside to reduce that to 2 PSI, but I'm happy with the stock spring. For me, with the limiting slightly over what it "should" be, it feels smooth up to and around when it kicks in, unless I'm really pushing it.
If I really push it lower in the revs, yes, you can definitely feel a surge of power when the aneroid moves(Insert joke about Vtech kicking in here).


It doesn't do any higher end limiting, so I have to watch my EGTs at higher RPM under load, but it's not designed to do that. I'm confident that it won't affect my peak HP at all, and should actually increase the area under the curve at the low end.


It's also increased lugability; I just had a friend of mine with a new learners permit out for a drive, and he hasn't gotten the hang of giving it throttle. Situations that would kill a gasser(like setting out in 2nd gear at idle) it doesn't even notice, and it even handled a 3rd gear start at idle without dying(it almost died, but recovered).

This is something that wasn't as available before the aneroid was installed; the pump would try to add too much fuel and the engine would basically stall(I say basically because when I was driving it before hand, I would always quickly put the clutch in before it happened.


Anyway... I think it was definitely worth the cost. Both for piece of mind(jumping out in traffic is less risky when you don't have to worry about giving it too much fuel and dying), and for reducing smoke to a tolerable level. Because I do care about the environment(and other people) enough to not want to deliberately cause more pollution than needed.


Questions, comments?

 

So its not liinear / progressive then huh? Once the boost reaches 5psi, its just as it was without the aneroid?

 

More or less.
The design(spring vs diaphram) should give some sort of linear response, but the problem is that the metering valve doesn't have a lot of travel between 'no smoke' and 'massive smoke'.
According to the manual, 1/4 turn of the adjustment will change smoke opacity by 10%. 1/4 turn of the adjustment is somewhere around .007" at the metering valve.

So once you hit that critical point, you quickly leave the "linear" area; I'm guessing it has some response in the 0-6 PSI range, but beyond that it's wide open.

With some adjustment and planning I bet you could change that PSI and rate, but it would also depend on the pump -- my 110cc pump is definitely higher strung than a normal one, with more fuel per .001 inch of metering valve travel.

 

Thats why i was interested in the aneriod, because of the governor sensitivity of the bigger pumps. But if all it does is delay thottle until 5psi... seems hard to pony up the cash for something so simple. Im sure with playing with springs and tweaking, a person could get a little more out of it, but not worth it to me. Ill see, havent even got the new engine together or all the parts. After driving it, might decide that its something i want.

Bottom line is, would you buy it again?

 

Thanks for this review and write up. This is definitely something I am interested in as well. Based on your experience I think I will probably buy one depending on how the 150cc behaves with the stage 2 turbo. If it has the touchy governor syndrome I will want it. That is the biggest reason I backed away from the 180cc pump. I don't want something that is a pain in the *** to drive. I get it... the Hypermax puff limiter does exactly what your foot can already do... but if it saves you from having to constantly watch your exhaust and feather your throttle then it's totally worth it. I may not need it but your evaluation of it is very helpful. My remaining question is whether it will still do anything with a stage 2 turbo which should hit 5psi pretty quick.

 

Yes.
The price is still kind of hard to swallow, but it /really/ helps starting out, getting onto a road in traffic. Especially when your first impulse is to give it more fuel to go faster, but it makes you go /slower/.
Now I can mat it if I wanted to, without killing the engine or over fueling. I don't generally, but giving it 1/4 pedal is a lot 'safer' than before.

The issue is one that all larger pumps will have, and the larger the pump the worst the problem: At low RPMs, you have too much fuel available. NA, the pump is tuned for a relatively constant fueling curve, with the fuel screw/plunger limit preventing over fueling, especially at low RPMs.
With a bigger pump and turbo, you have to leave the limit high enough to have proper fueling with boost pressure, which means far too much without boost.

This means the governor gets very touchy at low RPMs, because a tiny amount of metering valve travel will cause massive differences in engine fueling.
At higher RPMs and loading, it's not so much of an issue, due to the extra air available from the turbo, and using more of the metering valve's range.

Probably, yes. It's that idle-to-1400 RPM stop and go speed that this is really good for, and I don't think even Justin's turbos will really kick in down in that range.
So unless you launch your truck by revving past 2K when starting out, this will seriously help.

 

Thanks for the additional explanation. This definitely sounds like something I will want. Sounds simple and effective. Please keep us updated on how this works for you, especially if you upgrade your turbo.

 

That's very interesting, i was wondering if it would help with fuel ecconomy in city driving, i would think it would by keeping the pump essentially at NA settings until boost built up. I didnt realize it was 5psi on or off, i thought it was pressure/vs flow similar to how some gas turbo fuel pressure regulators work.

 

Yup, preventing clouds of smoke as well.
I think it has to do with the preload on the spring, meaning that it moves fairly quickly once it gets close to 5 PSI. It's still a spring-vs-diaphragm device, so it can be tuned the same way. I'm just saying that, with /my/ pump, there's a definite 'jump'/threshold at about the 5 PSI level.

 

While this is sort of a double post, I wanted to add some new information:
After doing some more driving today and messing with it, it appears more linear than I thought. I turned it down further than I had it, and while there seems to be a low end "jump" in it, beyond that it seems to still "follow" the boost somewhat - the (light) smoke cloud behind me as I accelerated with it matted stayed pretty constant... and a /lot/ thinner than without the aneroid.
I'm thinking that the spring /rate/ is probably good, but the "preload" needs to be a bit less. So shortening the spring slightly should do it.

 

How hard was the actual install, i've seen your videos and posts, and you are far beyond the average level of mechanical expertise, is this something i'd be better off having Conestoga do, or is it just remove some parts and swap them over? I've never had an injection pump open before.

 

Aw, thanks!
Remember, though, I've learned most of it here. If you don't try, you don't learn.
For a lot of things, the Chilton manual will guide you; also these forums are a good reference for easy ways of doing things. Also, making sure you have proper tools(and Harbor Freight is great for selling a wide variety of cheap-but-decent tools) makes life a /lot/ easier.
Pretty much just a direct swap. The only issue is that it is messy - when you remove the injection pump cover, you'll have half a cup of diesel splash out and down into the valley pan. Make sure the drain plug/bolt at the rear of the pan isn't plugged up, and that diesel will just flow down and out and drip off the bottom of the engine(so put a piece of cardboard under it)

On my pump, the cover is held in with torx screws, so make sure you have a set of torx bits(I think T20?) and a driver handle.

Once you've got the two covers next to each other, like in my picture, it's just removing two nuts from each screw, carefully keeping the pieces for each screw separate so you don't confuse yourself, and then sliding the parts out. When you see a particular grommet or rubber bushing in the piece you take out, replace it with a new one from the kit(Note that on mine, while the old rubber had been in there a long time, it was still flexible. I could have reused it all, but as the kit has a set in it I used the new pieces).

Then, just reinstall the new cover, Look at how the solenoid arm and aneroid arm are supposed to interface with what's below it and use that as a guide on how to get it down and in.
Once you've got it in, follow the instructions you have with the kit on tuning it. Don't be afraid to adjust it back and forth and see what happens.

 

All the turbo diesel pumps here have aneroids, do you think u can take a Picture what is underneath the cover behind the aneroid? Do you think the existing IP cover could be converted to fit some existing aneroid? Thanks Rob

 

I'd use the torque screw location myself; you've already got it on most newer pumps, and it goes right towards the metering valve and is designed to limit metering valve travel by default... the only difference is you'd need it to push /in/ with spring travel and /out/ with boost.

 

This, Except the only problem would be the potential of inducing air into the IP...

Cool you pulled the trigger on this, ive been interested in it for awhile, my focuses have just been elsewhere.