Thanks for the time you took to do these tests and explain the results in easy to understand lingo.

I would love to see results if you could find about 10k to tow up a hill to see how they compare in heat production. I think quicker turbo spooling after each shift is a good thing, gets things cleared out and cooled off as soon as possible. Do you have any SWAGs (scienetific wild a$$ guesses) on that?

Would you expect the DVs to maintain the same characteristics you described, as I make other changes to the engine like bigger injectors or re-adjusting the AFC to reduce smoke?

 

Well for a SWAG I would say for strictly towing on grades with heavy weights that the smaller DV the better honestly. A 181 would keep the heat down because of the short Injection pulse. Look at it like this, a short burst of fuel that comes on and goes off really fast (open and close of the injector) would allow the fuel to be burned fast say by the time the engine hits +5* of crank position as an EXAMPLE if all the fuel is burned by that point then the resulted pressure would force the piston down faster because the explosion has hit its peak pressure on the beginning of the down stroke. All the spent energy that wasn't lost by heat is pushing the piston and rod down ward. This can also be compensated with timing though, You could use a very wide and a little more messy injection such as a 191 or 024 would give vs the 181 because the longer injection may have very small pressure fluctuation but the delay in injector closing time could mean that the injector didn't close still +20* of crank position and fuel didn't burn off till 35* as an EXAMPLE this means the peak cyl pressure off all the burnt fuel will be lower because the piston was further from the deck meaning less pressure was exerted on the piston itself. Now the heat energy is being lost into the exhaust (EGT) BUT that's the purpose of turbos, regain that energy lost in boost pressure to then allow even more fuel to be burned... Its a viscous cycle... another but though is the compensation with timing, if enough timing was introduced to the burn then the injector closing could be moved to where the 181 was on the old timing setting.

With all this said and easier to understand terms, think of the DV as the injection pulse controller and the injector is the max fuel flow limiter. Programmers on electronic trucks work in the same sense, The wider the pulse the more response the truck receives but at a cost of EGT rise, again it can be compensated for though with air and timing. The injector limits the fuel allowed in X amount of time so with a small DV and large injector you can have a very clean burn but a lot of top end power along with on demand fuel where the DV the fuel is always there so smoke is easier to come by resulting in EGT. Understand?? Im complicated I know

My thoughts on towing 10k on a grade would be along this line, max aggressiveness I would choose would be the 052, there wasn't enough of a heat change to make me nervous, I would pull with just the DV swap and not really monitor temps since the change was so minor. The throttle and turbo response was probably what made up for the EGT to stay relatively the same, meaning the turbo lit fast enough to over come the length in injection pulse heat produced. This would have created a good balanced injection even. Now my personal fav for strict towing was a 131/181, the injection was short and cool but the down side was slower turbo response which means heat early in boost but cooler later, a smaller turbo or timing change can help with this. Its all about the setup, my personal preference, short injection with a larger injector. Big short bang means cool and fast, lower EGT=more efficient bang.

I hope that kinda helps share the view on that. Larger then the 052 she would have gotten hot and I would back right out of the throttle, which on long pulls EGT and power output need a balance, the added EGT makes you back out of the throttle and in turn this throttle reduction could mean less actual power output for the same EGT. 1200* making 248hp isn't as great as the cleaner 1200* making 350hp to move the same load to try and maintain the same speed. Ill take a lower EGT for towing but with racing I would be all over an aggressive DV since the duty cycle of that power would be less and less prone to damage.

And finally a change in injector size seems to keep the same characteristic from my experience, it just makes the driving feel and temps more noticeable on how the truck responds.

 

This is good to know ,I just purchased a set od 181's to replace my 131's, now I'm thinking about doing the 131/181 hybrid mix.
Should made a good combination to go with the 5x12's and Super b turbo in my tow rig.

 

I would agree, the top end power will feel a touch more broad specially with a larger then stock injector and turbo package. EGT shouldn't change much. I experienced a 100* jump in EGT but only up in the higher rpm like 2700-3000 where the turbo chokes and drive pressure sky rockets, this indicates to me there was more flow but the injection pulse remained the same because of the 181 seat design. Throw it together and I'm pretty sure you will like the result and probably better then I did being that you have a turbo that wont choke like the factory ones do.

 

Maybe a new DV added to this mix coming up soon!!! The rating will be placed in this thread when testing has begun and completed. Ill be as informational as I can. Ill keep everyone posted. Im also going to try and explain the relationship between DV and injector and how they change fueling and response after the new mystery DV arrives

 

da da da dun opcorn:

its like the end of a season cliff hanger, keeping us wanting more


can you tell me what DVs my '97 180hp pump have stock? is it the 181?

 

I somehow missed this until now. Awesome read!

I'm gonna have to read this a couple more times and sleep on it.

 

I am running a 11mm 190hp p pump on one truck with 5x12 injectors. any thoughts on how your test would apply to my setup.

 

I'd like to know also as that's what I'll be running on my new engine. A 190 pump has 179 dv's that I was told where an industrial version of the 131's. I was going to pull the 131's out of my 160 pump and do a 131/181 hybrid setup in the 190 pump along with 5x12's.

 

Ive got a 180 p pump and I love my 024s. I havn't compared them to anything but stock, but with AFC Live, 024s and 5x12s I can tow 8500 lb trailer up some good hills all day long without getting crazy hot. Usually around 1200 at 60+. And that is with 35in tires.

 

The AFC live is what helps you out a lot and the aggressive DV keeps you on the turbo easier but if you went back to a 052 or equivalent valve you would notice an EGT drop under the same conditions though. The short injection keeps the heat in the cyl instead of throwing it into the exhaust or turbo during towing. Heat being energy means more loss if EGT is high, lower that temp and you find your able to add more fuel under the same EGT limitations.

I tow 25k up 6% grades with the hybrid DV, pump work and a tuned stock 5x9vco injector and 4th gear (I can do 5th but don't wanna stress it) I can pull 55-60mph @1100* and 25psi of boost around 2300rpm. I don't feel im really laying into it either, now would a DV help yes I would make more power but then Im adding heat which I would have to back out of the throttle again for.

This same situation I could swap in say a 5x14 injector vco or sac and keep the EGT but top end power would be there if I commanded it. With parts testing and building diesels of the years, bottom line Injector before a DV.

You may wanna throw in your stocks if you still have it, wont be as fun but go back and pull that same hill and you should see a cooler truck.

 

All dodge cummins p-pump's have 12mm plungers. No performance application will benefit from an 11mm pump.

 

If you mean plunger size vs flow then I agree but if im not mistaken the 11mm had an aggressive cam profile which modified flows a great amount of CC's even with the slightly smaller plunger. The 190 pump was an AG pump I believe which emissions wasn't an issue so some parts were more aggressive like the marine 370 for example was a haze monster with 24* of timing out of the box but it had reasons and with lack of emissions cummins could produce it. The truck was tamed by the EPA, if not we would have had 400hp/800ft trucks back in the 90's easy. Im getting off track though...

 

I like the 024 as well. Easy to tune smoke away with or without AFC live and make good power.

 

Ok now Im gonna try and explain the injector DV relationship, we all know these go hand in hand, the most basic way to explain it is the injector is the over all fuel limitation (like a fuel plate), the DV has 2 main jobs, determine how long to keep that injector open by the shoulder width and to act as a 1 way check valve to keep the pressure in the injector line up between injection cycles, if not the line pressure would return to 0 between events and the injection pump would have to build pressure all over again from 0 which takes much longer and more energy then holding that pressure for those few miliseconds between injection events.

Now the DV shoulder, smaller obviously is more aggressive meaning it holds the injection event longer, also shapes how the beginning and ending of the injection is shaped. This means the injection could have an instant pop open in the injector with a nice sharp stop to keep dribbling and haze down, or have a slow some what messy end which in cases of competition and large turbos this haze and heat created will help get the turbo lit and stay lit just as the shoulder width itself controls the heat in the same type of premise.

Now DV changes also change actual timing since the injection is now larger and the shoulder is smaller this means the injector opens faster but with a softer smoother injection line pressure curve. If looked at on a graph there is less of a pressure spike to the injector. If you swap from say a stock to 191 or any large jump like that, grab the injection line at idle with each valve, you will physically feel less of a pulse inside from the smoother lesser spike in pressure during the event. These aren't common rail trucks here, the pressure isn't constant threw the event, you have little spikes and fluctuations in those few milliseconds the injector popped open. Part throttle this is particularly true because you end up with a shorter event at the injector nozzle because there is less fuel going past the DV and into the line which in turn raises pressure, the injector pops open but the lesser fuel means the spike is shorter and the injector closes faster again VS full throttle full rack situations.

This timing change is no set number, too many factors come into play to put a number on it, pop pressures, injector size, type, pump cam ect ect. The pump cam is another large contributor to shaping the injection event spikes and how it opens and closes the injector.

That being said....and aggressive DV can be compensated for with higher timing assuming the head will hold the abuse BUT then your closer to the point where you start to spray outside the bowl and wash the cyl walls down, haze, and general inefficient fuel burn begins to kill power IE full cuts. Full cuts are messy injections with very very little control except to act as a check valve. This valve is so aggressive that it actually causes 2 injection events per plunger stroke.

So high timing and large wide injection can mean a boat load of fun and power but a working or weekend warrior would want a top end power but not have the harsh effects or high timing an aggressive valve would give.

Another simple way to think of how the fueling of each changes is
DV=mainly low-mid range power with some top end power unless you get into taper cut valves which is a totally different situation and ill save the details on that
INJECTOR=fuel across board but most of what the size shows is up top where massive amounts of fuel are injected fast causing power increases under high load and rpm

The injector itself, from my test stand results and customer truck builds have yielded me this:

VCO micro blinds (usual stock and aftermarket injector nozzle) offer a stream like fuel injection into the cyl which is good in a few ways, penetration of the compressed cyl air or during high boost situations, this offers a stronger top end with the cost of a slightly dirtier bottom end due to less atomization. A VCO generally uses a nozzle design that the end of the pintle contacts the seat while the injector is closed, this causes wear over many many miles of use. Some designs have the bottom of the nozzle dug out to keep this contact from occurring. Another fault is a small amount of needle steer which is a small flex of the pintle as it lifts off its seat which can cause some holes to open before others causing a slightly offset injection, this isn't as large of a deal as it seams since the injection and burn are violent anyways.

VCO cylindrical blind is pretty much the same as above but this uses a oval looking hole in the nozzle vs microblinds circular. Nozzle shape is the same as well as internals and seat shape. The oval pattern on the test stand works well for even distribution of fuel but atomization still wasn't very good as the center of the hole would have a very thick stream of fuel that makes for a dirty burn.

SAC as we all know and love is the current cream of the crop, there is debate on wither the sac at the bottom of the nozzle would cause a "dribble" at the end of the injection event but in my testing I have yet to find this happen, I blame a large injector line, pop pressure, and DV setup on that dribble some have reported. Now sac characteristics are much cleaner burn from better atomization of fuel which in turn lowers EGT and smoke in comparable sizes to the vco but this injection doesn't have as much of a high end power under high boost/pressure situations because the penetration is reduced along with a faster flame rate which means the fuel cant get as far into the bowl/away from the injector as the stream shot of the vco. Needle steer appears to be gone with this style as well.

As always theres always a trade off between injector types and styles but there is always an application they shine in. Competition trucks run massive sizes usually in a vco style some where in the 5x30-5x40+ sizes and some run dual feed injectors to match full cut DV's and such...

Purpose of this was to inform those who haven't poked around much on the subjects, there are other old posts from years back with photos for visual learners but be careful ive found some that people got info backwards like 'vco burns cleaner and cooler' one of which was from Weston I believe, idk if that was a typo or for whatever reason the inside of cummins is an alternate universe and im totally wrong. He is a top injection specialist not me but I base info on facts and results of extensive testing. Againg IM NO INJECTION SPECIALLIST THIS IS ALL SPECULATION FROM TESTING AND MODELS.

Ill try and help with questions the best I can, there is more to all this to the point where I can go on for hours but this covers the large majority.

MY OPINION if your looking for fueling upgrades after the general pump upgrades have been done then get INJECTORS FIRST, DV's for competition or if you need assistance in low-midrange fueling/heat to light turbos and such. If Im wrong about any of this and a full design specialist wants to beat my please I bring this on and will admit to being stood corrected:S:

Thanks for reading and happy thanksgiving to everyone

 

This is a great thread and a lot of people could learn from it. Mods need to sticky this thread or at least imbed the 1st post in the newbie stickies.

 

I'll second that :thumbsup:

 

Part 2!

UPDATE__UPDATE__UPDATE__ Part 2:

Ok so to add on to part one of this testing process, Im now ending the cliff hanger from the previous post! The mystery DV is a 7mm From BigBlue24 of Power Driven Diesel! BigBlue contacted me after the initial write-up and offered me/my business/write up here a tester set of DV's. Im extremely grateful as I wanted to test these also but funds limited me from purchasing a set and also with 7mm there are many different cuts, taper, straight cut, multiple shoulder and cc changes. SO that being said this will be specifically Power Driven Diesels valves, after a few questions he gave me this information to use in testing. "These 7mm give about 80cc over stock and are said to be between a full cut and 191 (50cc)." That's not exactly word for word but that is what was conveyed. So that said they still aren't here because of thanksgivings back up and the huge mass of shipping delays from black Friday and cyber Monday orders. That being said the next few days they should arrive!

Now for this round 2 of testing some things have changed a little so Ill be running the test as follows:

AFC changes have been made, the AFC travel has been extended as per the basic mods a lot of people do (its something I had been meaning to do) From driving after the modification I'm fueling no different then before the travel change according to Boost and EGT numbers along with the butt dyno. Honestly I didn't expect anything because Im running a maxed pump WITHOUT the rack plug or shimmed rack plug. In my case it would give me no extra fueling what so ever to get the extra 2mm of travel.

The other AFC change is on my control DV which is the 131/181 hybrids, the star wheel setting has changed, in part 1 I ran my pure clean towing setup which is 0 smoke threw the entire rpm range under load or even reving. Now ive set the AFC to a more "normal" setting I would call Tow/Race if I had to name it. The star wheel is 3/4 forward where there is no tension on the spring but no room for slack movement of the spring. This gives a light smoke until about 2000 rpm where it gets to a mild thickness till 2200 then totally clears. This is a setting I associate a general tune to be with the mass public. Meaning its about what everyone sets there truck to for street use. There is no real lag now on the control DV, this added fuel should help to determine low end power capability! This will also help to relate to most peoples setup as they read this.

So the range of testing has lessened, sorry I wanted to test the entire field but I sold part of my stock to customers trucks during performance modifications at my shop. So that being said this is the testing field at this AFC setting:

131/181hybrid (control) (no 131 and 181 separation this time)
052
191
and the new 7mm DV that I will post specifics on when it arrives!

The 052 is still a mild DV I still stand by, the 191 is a general and popular performance DV that I still say is the under dog and I don't understand why people dislike it so much...its a wonderful performance setup with a great duration and characteristic to do almost everything with except for heavy heavy towing which I would recommend the hybrid or 052 as a MAX for that situation.

So these common DV's vs the 7MM is gonna be the main focus of this part 2. Im going to go more indepth with the hybrid, 052, 191, and 7MM. This testing procedure is going to be extended also, past was a 2 hour course and test procedure in the same day. This time 48hours of testing is going to be commenced for a better feel and understanding between these valves on a more performance oriented AFC setting. So starting tomorrow I begin testing and I may make video drive and smoke shows and post them on my youtube channel so everyone can see the changes in real time for a better understanding.

Only variable differences will be weather and temperature changes. The truck will be at full operating temperature in all components by running a warm up lap of approx. 10 miles at high way speeds with about 8 traffic lights in that length.

Finally Ill collect data and post when available probably next Friday or the following week of the 14th. Lets beginarty018:

 

Another vote for sticky.

 

Very well done, sir! One of the best write ups I have seen.

 

Home-Built 12valve,
If you have the time, and while we wait for the new batch of test results, will you please give us/me some basics on DVs?

What I think I know about our fuel system is . . .
the injection pump has a barrel and plunger for each cylinder. The helical cut on the piston/plunger rotates to change the amount of fuel that gets pushed out of the injection pump for each stroke.

The timing of the injection pump sets the time (relative to TDC of the engine piston) the plunger pushes the fuel through the DV, through the injection fuel lines, this overcomes the pop pressure of the injector and sprays the metered amount of fuel into the cylinder.

I think it is the job of the DV to keep the injection lines pressurized (at least on the pump side, and the pop pressure valve in the injector on the injector end of the line) but obviously there is much more to DVs than just being a check valve to keep the lines pressurized.

can you post a picture of the different parts of a DV?

you mentioned different "cuts" what part is cut?

In the different sizes like 181, 191, 052 what part does that measurement come from?

How can a 052 deliver almost as much fuel as a 191 which in size measurment makes me think a 191 is almost 4 times bigger?

How do the DVs change the duration of the injection event? Do they open sooner? if so, does that in effect advance the timing of the injection event? How can they make an injection event go longer later in the combustion event (which I believe you said makes the EGTs go up)?

and on to the new 7mm, what part is now 7mm and what size is the comparable part on the previously tested DVs?

Your info on the end results of the different DVs is very valuable but it has made me more curious to know what "magic" or science goes on inside them.
thanks!

 

Ok first with the plungers, your correct to a point, its not really a hecticle cut that rotates and opens up the fuel port. Its more of a 45* cut and a spill port and the plunger rotates to open up the spill port. The hecticle cut your talking about is on the 215 pump and slows the plunger travel, effectively reducing timing, the cam profile keeps the same but it acts like the cam lift is lessened which reduces timing. Atleast from what I've seen... I don't have a flow bench to watch things in action or rebuild pumps...yet...

As you said there is 2 jobs to the DV, a check valve, and to control the injections duration and how the beginning and ending of the injection event itself is done. So duration, the shoulder is the main controller of the DV, the holder, base area (I forget the technical term...) and above the shoulder that seals back against the seat as the one way valve seal. Im having a crummy day ill post the technical terms later on... Anyways the shoulder cuts are in a million different forms. The edge of the shoulder is usually really sharp so the injection and stop of injection happens very quickly as the DV lifts and falls back into its seat. So larger the shoulder the shorter the injection because the valve is open for less physical time. I don't have the actual physical times the valve is open and closed because the cam profiles control this and since each is different there is no set time but the differences in valve CC are usually with-in 5cc of each other as there switched between pumps. In the photo attached you can see the differences. Now there are also tapered shoulders usually on custom cut valves but 7mm are usually found with a taper cut. Now there are many taper cut and non taper cut 7mm, in this test they aren't. The taper cut fuels harder on top, its more for competition like racing or pulling but you tend to find true competition valves above 8mm but that's hush hush stuff. (Ive seen a 12mm DV before that had been taper cut and the pump moved north of 1000cc of fuel per revolution....) Now the 7mm base is shown in the photo, from the upper seat down is where the diameter changes. The 7mm is said to move less fuel down low for EGT control but up high it throws fuel like there is no tomorrow. This is my first time with a 7mm personally so that we will all know together, but Ive talked to people who have run them and they said it was there favorite, even over a full cut comp valve. Mind you the full cut can have 2 full injection cycles so to me that's pretty cool.

Now right at the top in the photo you can barely see the 7mm at the very top is taper cut, because the shoulder is so so small that the taper helps top end fuel flow at high velocity even though the shoulder is between the top of the valve and the valve seat. Again they all play into each other.

Now the base of the valve itself is also tapered, this again helps fuel flow by lessoning turbulence in the flow. Same as air its less of a restriction.

Finally the duration does change the timing at the piston. .080 (131) and a .033 (191) change duration a lot! a 191 is usually near the full travel of the pumps stroke, but again depending on pump cam and size. I have read a 191 is like 70% of the stroke on a factory 180 pump from a dodge application. There is no way to know what final timing is and there is 2 real ways to measure the injection timing, a spark on a gas vehicle is like 1-2ms where the injector on diesel can range. So injection is longer then that, this gives us 2 measurments like when the injector first pops open and when it closes, ending the event. We measure from the start, so the DV aggressiveness means it does open sooner BUT closes later. Example: So 131 could be 4ms, opens at 20*, closes at 8*. A 191 could be 10ms, opens at 28*, closes at 0*. Something along that line. The pop pressure also changes overall timing, a marked balancer and a timing light with pulse adapter can determine this. Every 10 bar is said to be 1* I believe but that would again depend on cam profile so we cant rely on that information and we don't know how much pressure is being held in the line between injections.

There is a lot of math involved, Im sure there are math equations a mile long to know but trigonometry is a little above my pay grade

That's all I can think of at the moment though. As for testing things have changed a little the 191 is in right now then Saturday the 7mm will be, this is giving me 5 full days of testing between the 191 and 7mm. From the cuts I would expect the low end to be like a 191 and upper be like a full cut comp on the 7mm valve. Only time will tell.

For notes I will say the 191 is still one hot valve, I can beg my 1600* gauge FAST where the hybrids lugging trying everything to get it hot, I couldn't pass 1400* no matter how hard I tryied. Plus its a slow climb with the hybrid. Smoke on the 191 is heavy across the board, a lot more then I expected. Under full boost the hybrid was 36psi now Im at 42 because of the increased drive pressure over coming the internal waistgate. This could be tuned but I don't want to mess with results, smoke also still exists under full boost where the hybrid did not, it was clean at 36psi. Ill say one thing she is fast butt dyno is saying 50hp on the top end so on paper 350 to the tire is where I should be which is the MAX a stock hx35 or wh1c can take. A hogged out WG would do more by keeping drive pressure in check more. Its fun yes but too dirty for my taste. There is a lot of haze, ever time I leave a light there is a small haze/poof like a cigarette smoker puts out. Nothing serious but Im proud of my truck being 100% smoke free power. Its more low key and keeps people from getting pissy with you over stupid stuff. The law around here is also big on smoke because Im near the state capitol so they take emissions kinda seriously even though diesels don't get tested, if the smoke is visible for more then 3 seconds then they can pull you over.

 

I tried to find the answers to some of my questions out there in the interwebs

A=holder
B=delivery valve
C=seat

This seems to be the "shoulder" and its the thickness of the shoulder that the size measurement comes from.

although the bigger number seems to show a narrower shoulder in this picture. So does the measurement come from the gap between the fluted cut and the top ring?

 

My understanding is the numbers come from the last 3 digits of the original Bosch part number in the 131 181 292 024 and 022 case. Some of the aftermarket has named some new ones by shoulder height 025, so there is no real measurement that is used except in the case of the 7mm valves. Stock valves are 8mm but the 7mm has very different top end flow so it idles well but outflows on the top.

 

Ok the numbers are just the last digits of the original part number. That makes more sense than trying to give a measurment to what I'm seeing. And I think I remember hearing/reading that is where DDP came up with their 042s they just reversed the number of the 024s.

Is the purpose of the "shoulder" on the DV just to take up space which means the biggger the shoulder the less room there is for fuel in that cavity?

 

View attachment 455258

View attachment 455266

Sorry my hand writing sucks I broke my hand and it never set correctly...

 

Sorry my hand writing sucks I broke my hand and it never set correctly...

Its not the prettyness of the hand writing but the content that counts! :thumbsup:

I really do apprieciate the time you have taken to help me understand these DVs.

I added a set of .052 DVs to my Christmas wish list. Probably won't get them, she gets nervous about buying bike & truck parts for me in case they are not quite the right part I had in mind.

my left handed scribble is not any better and I don't even have an excuse like braking my hand.

 

I vote for sticky as well...also want to thank you for spending the time and greenbacks to do this testing, just awesome dude. Looking forward to hearing what you have to say when your're all said and done with each set.

 

So the 7mm valves have been tested! And my mind is blown. FIRST IMPRESSIONS: you would think going from 8mm to 7mm would reduce flow a lot but the cut is much more important. This being said the 7mm is now my new "hot rod" valve of choice, previously the 191 was a personal fav and still is for mild street and race machines but if anyone is really serious about performance with good street manors then look no further then the 7mm! They come in multiple cuts, these from power driven diesel (im not affiliated with them!) these specific valves are .022 shoulder (not to be confused with the 022 DV that's totally different) but the top "mushroom" as some call it that contacts the valve seat is taper cut allowing much smoother faster fuel flow. The smaller diameter increases velocity of the fuel flow per plunger stroke, this coupled with the tapered edge creates a lot of CC's increase. They pull 90cc according to the company and boy do they!

Testing and driving:
Smoke is HEAVY, like that of a full cut but the strange part is the 7mm body actually keeps throttle sensitivity very very calm down low. Meaning they actually feel like a stock valve under 0-50% throttle but from 50-100% they act as if you threw in a set of full cuts and are just mean!arty018: This makes for a very smooth drive on the street with power on command. The spool itself acts like a 131 stock would, the 191 spool was instant where this doesn't feel as instant just stock like. Throttle response though is equal to the 191 or full cut, instant response because of the small shoulder=long and wide injection pulse width. So you get the good feeling of an aggressive valve on demand but the refinement of the stock valve when you don't wanna be a jerk and spin tires or black out the highway all the time. Now with the lessened spool feel, its not that it feels totally stock, it does respond well just not as well as the 191 or full cut. My theory is there is less volume of fuel per throttle position hence the soft/smooth throttle feel as if it was stock. Back on the smoke though, its so heavy! I feel on my stock injector/turbo as if I just put a set of 5x14's in! At this moment in time Im actually fueling so hard that I've totally overfueled the turbo under 38psi of boost up from 34 adjusted on the 191's, Im currently blowing a huge thick cloud at max boost. I need air to really find the true top power output of the valve. That being said if you have a street truck that you wanna race or pull with on the weekends, the 7mm is #1 on my list of parts choices. Not just the CC it produces but the added feel and way the fuel is delivered make this valve so smooth and refined that your 600hp monster pump street beast can retain its DD or street truck elegance for traffic or general driving without a huge haze. Now idle haze is there as well as under load like pulling away from a light, at night with cars behind me I can see a small haze all the time BUT the actual SMOKE at low rpm and low throttle makes you feel your running less power then you are, that is until you wanna really rockarty018: step on the throttle, the smoke poors, the turbo comes alive and buddy hold on!!! Its almost like you changed tunes in a common rail from a 40hp tune to a full on 200hp race tune! Now at idle there is a small lope effect, my truck always lopes some because of my pump settings and a very small leaky injector. But this valve brings the lope out a little more BUT less then the 191, the 191 was rough for idle lope. The 7mm also has a knock of a marble in a cement mixer, 18* sounds like 26* right now, exhaust tone is awesome! The 191 was super super loud in the exhaust since fuel was injected late and wide, the 7mm wasn't as aggressive and was slightly quieter. A plus in my book, but on high rpm swings say 2600+ it got loud and fueled harder as RPM rose due to the taper cut edge.

Summary:
191: good general street truck valve for the performance enthusiast. Good for almost any setup except for towing. Timing change is needed to feel the potential of the valve. I wouldn't hesitate to put them in every performance oriented truck that comes threw my door, since the fueling is great specially for large turbos or even stocks that just want the instant spool or throttle response. Tuning is key!!!

7mm: A dual acting valve, down low and light throttle its almost stock feeling, no major fuel or smoke if your not stepping on it or running a dirty AFC setting. I believe with careful tuning this could be tuned almost totally clean till high rpm conditions like 2500+ where your working the engine. Heavy throttle unleashes the animal within, this valve is a MUST for race vehicles that don't want the horrible effects full cuts give. If you want a clean injection and characteristic for streetable use then this is you valve of choice. Now yes the street feel is better then the 191 BUT at a cost of spool up speed. Turbo lag returns as if stock valves are in place, even at heavy throttle the smoke and heat still don't make up for the 191's turbo characteristics.

Stock is well stock. Great for towing, DD, MPG, light racing, small turbos etc etc. If you want performance on any injector the 191 is great, but when your ready to step up the game 7mm is now top of my list on street performance!

MY RATINGS IN DIFFERENT CLASSES UPDATED****

Performance list: starting in #1 place going down
7mm-Balanced, smooth, controlled
022-hot ready to race, fast throttle and spool
191-not as hot but throttle and spool is just as fast
024-slightly cooler if EGT is an issue spool is still quick but just a touch slower
052-towing valve that can race when duty calls, EGT almost identical to stock. The perfect balance valve for all trucks that work play and to take the wife on a date without looking like a prick


Towing list:
052-winner in the towing world, helps throttle response, clean, EGT very very managed but can flow fuel if that mustang wants to play at a light. No sweating over heat under load I.E. you don't have to hover over the gauge worried that you need to back off
131or181-small change between valves, you would gain maybe 3-10hp depending on the truck by going 181 to a 131. So these are equal, great towing and EGT control, leader in MPG because of small injection, coupled with a large injector they can make very very clean power for anti-smoke types or 5th wheel haulers that don't like black on there RV and are willing to wait that extra .5 seconds in spool time. honestly no real concern they are the universal valve since heat is controlled.
**any other valve would be too aggressive for large towing** but to this note loads up to 8000lbs could be done with a 7MM, 191, 024 or 042(not tested) without EGT problems. I wouldn't want too but if you must then be careful cause your gonna melt a piston if your careless

This will near conclude testing of DV's, I hope this helps the community in choices on DV's. Persoanlly I would rather run a weak DV say a 181 with a large injector, I can have power up top with the injector but keep haze free and clean driving on normal drives to get ice cream. If your on the fence of DV or injector first: SAVE YOUR MONEY AND GET INJECTOR FIRST. This will keep EGT in check per power output. 1400*egt can =430hp with injectors vs 1400*egt =310hp with an aggressive DV. Get a large injection of fuel THEN shape the injection event the way you need it, in the end you will be happier with the outcome. Good luck to all in your choices!

 

Would your thought process change w/ a compound turbo setup? I'm currently running 21° of timing w/ 5x.014 vco's, Colt stg 3 cam(181?/210?) 62/70 over a475/96-1.32

 

I feel that with compounds you could get away with a more aggressive setup because your able to light both turbos faster and the combined CFM could over come the heat generated better then a single turbo could. That said, drop the vco's, there good on the top end with really high boost but efficiency is less then a SAC. 5x14 sac would give you more power all around. As for a DV, assuming your a street truck that may occasionally race, I would honestly say the 7mm you cant go wrong, I really was impressed by its street manors. If you want more spool down low though, 191's really do a great job or a 024/022 as there so close to the 191 I just don't bother with them as an option because the 191 is much more cost effective to get.

The 191 had a great low and mid range with a mild upper end, meaning it still fueled hard but as RPM would rise you could feel it wasn't as strong.

The 7mm was the opposite, they act stock but as RPM would rise you could feel fuel progressively come along. Mostly because of the taper cut I think, the higher velocity of fluid at higher rpm meant that more could pass the DV. That said if you need good street manors but you want to rip hard up top then this is that great balance.

I wouldn't consider a full/laser cut on really anything honestly. Even a full on sled puller I doubt I would even want to use it on unless I was turning 6000rpm each time all the time.

The 052 would be fine if you tow but with twins that may still be a little weak for the effort. Don't get me wrong gains will be noticed but when you have the air there why not use it??? Twins and the tow valve....ehh not worth doing.

So really it comes to a 191/022/024 or 7mm for performance. The 7mm even blew the 022 away, now I cant give perfect results in that direct comparison but for over all feel the 7mm did better as far as not being so violent. Being my testing was with stock injectors though your injector could fill the top end fueling need so the DV could be more focused on getting the primary lit. That said a 191 or 024 for your personal setup sounds like it would be best. The 7mm would work better for smoke control but if your more performance driven a 191 style cant go wrong!

 

Hi HB12V.... Are the 052's you've been referring to the same or nearly the same as the 055's listed on PDD's site? I can't seem to find the 052's listed on retailer's site for some reason.

I'm running stock 131's still on my '95 with 5x12's......so been contemplating making the move to these 052's or 055's.... just not 100% sure they're right for me yet.

Thanks man...and appreciate all the work you've done on the writeups and testing.

 

Sorry for the late response some how I overlooked this... My 052's were from a local pump shop I had ground for this. It was a 131 based valve just with a .052 shoulder. Anywhere in the .050-.060 is gonna be nearly identical, as the test data showed me on the street EGT was great with a small bump in power. If your gonna spend money though 131's and a 5x14 would do great, strong top end and more bang for the buck. Spending $200-500 on DV's to me isn't worth the gains unless your running at least a 66mm turbo where you need the pulse width to get on top of the charger. Even with that said, if you keep the 5x12's a 191 with proper timing on that injector size makes for a fun ride, if you tow and are dead set on a DV change then .052 will show some power but it's not gonna be roasting tires left and right for street performance. It's a valve that if I found for $100 I would do but dollar to power ratio wasn't there enough to justify in reality. That's my opinion though... I would rather step up an injector size and keep a stock type DV to keep EGT way way down but still have power up top when I wanna play

 

If the 052s are from PDD, it's not surprising they're not on the site. Will has experimented with probably hundreds of different DV cuts by now, and my understanding is the process to get new products on the site is cumbersome. If you call them, they'll accept orders for stuff not on the site. He can also advise you of any differences between the 052 and 055s

 

Thanks for the help HB12v! Only thing is, before you had a chance to post, I assumed they were a good choice, without really knowing for sure. Should I hold off on putting them on and just swap in 5x14's later and keep my 131's? I always thought from my reading here that 5x14's is where the mileage starts to drop some.

I tow under 10k from time to time now, timing now at 16, with the 60-68-14 with IG, setup as FYI.

 

Let me add this: aggressive DV's lower MPG plain and simple but the .052 shouldn't effect it at all because it's such a mild pulse width change. Now what's your primary use of the truck? If you already ordered them then put them in and I would bump timing to 17* to compensate and you should be fine, the timing bump will gain back the .5mpg estimated loss due to longer pulse width. But each truck is also different, your setup should be tuned to what you do with the truck.

If it was me though, put the .052's in and save the 131's. Later when/if you go to 5x14 later on then you may wanna go back to the 131 valve for heat control of you have problems. For tuning I would go to 17* and tune the AFC to give as little smoke as possible without being sluggish or laggy. From there you should be good.

As for 5x14+ from customer work I haven't seen a drop in MPG with large injectors unless they were VCO nozzles. SAC seem to keep good mileage till about 5x18ish from. What I've seen, but again each truck is different. A good 5x14 SAC I wouldn't worry about at all honestly! Make sure pop pressure is around 270-290 bar and you will be golden. Now even SAC injectors when you do pass 5x14 they start to become touchy and dirty which may be what people complain about for loss of MPG.

So like said above put them in and tune it, later do the 14 injector and go back to a 131 if heat gets to be way too much.

 

This is some good info!