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This is the best part, YOU DON'T! No, just kiddin'. Play with your pump some, try backing off on your smoke screw so your not over fueling while the turbo is spooling up.

My 4bt is purdy smokey too, way more than my 6bt. And my 6bt has way more stuff done to the pump. ???
 

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I do not know what you would have to do specificly to your engine, but I if you understand basic diesel technology and itnernal combustion engines when more fuel is added to the combustion process it will require more air to give the proper air / fuel ratio and thus not producing lots of beautiful black smoke. So if you want to tweek your pump for inatant power gains without added air you must put up with the smoke up to a point, by playin w/ your smoke screw and adjusting it to better match your turbos spool charactristicts you can minimize the smoke but it will never go away until you increase the air charge to the engine with either cooler air or larger turbo, or both. My .02 hope it helps.

Kendall
 

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How do you increase power with out the smoking so damn bad?
Smoke is partially burned fuel. partially burned fuel means a few things:
1. Not enough air to support combustion (turbo is too small for the amount of fuel and/or not spooling quick enough)
2. Fuel is moving into & out of the engine so fast it doesn't have time to completely burn (truck pulls are a good example of this)

How to control the smoke depends on the conditions that make it smoke so bad. If you're talkign about a jackrabbit start from idle to full throttle, then you need to a) turn the pump down on the low end, or b) get a quicker spooling turbo.
If you're talking about smoke while towing on the highway, you need to a) downshift, b) not tow too much, or c) get a better matched turbo.
If you're talking about on the truck pulling track or dragstrip, you need better turbo(s).

Driving, towing, & occasional racing:
Fairly hard accelerations from a dead stop (stoplight) require a quick spooling turbo to clear the smoke.
High speeds (interstate) require a slower spooling turbo to minimize the turbo speed.
So, there are basically three choices:
1. small turbo to spool fast and use a wastegate to keep turbo speed down when on the highway
2. Larger turbo and turn the low speed end of the pump down to minimize smoke
3. Compound turbos. A small one that makes boost really quick and a larger one that makes boost at higher RPMs. A wastegate is required on the small charger for all but a very few applications.

Dedicated racing, truck pulling, and ricer killing:
1. A large turbo for maximum air flow, and nitrous to spool the turbo in the lower RPMs.
2. Compounds. For a serious truck puller/racer & towing machine, triples might be in order.

Also, an intercooler can help, especially when towing, and in the higher RPM range.
 

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Smoker

Just get more air through the engine or less fuel. I like more air and more fuel! :nuke: You should get an intercooler if you don't have one already. You can find them on Carpart.com, eBay, etc. The bigger the surface area the better.
 

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another thing that often is forgotten is timing. increasing your timing changes the burn time in the CC

less bottom end fueling adjustment.


lots of adjustments to make it better but with fuel comes smoke. hence why adjusting the stock caliberations is in violation of epa rules. they just dont seem to have a sense of humor nor the vision to see through the smoke
 

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what does timing do to smoke in general? increasing timing should reduce smoke somewhat, right? speaking of small increases in timing.
 

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I think a hop-up plan has to be vehicle specific. I look at my own and see that it's a different problem from others. First, it's a full sized truck, and when building I planned on a lot of towing. This means I want good bottom end power, but also need the higher rev's from a 3200 rpm governor spring, to get full use from my NV4500 5 speed trans.

Gears are everything, so pay closest attention to that. They'll make up for a marginal engine, and are all the difference in the world on a strong running one. You need the right final drive axles, and as many gears as possible in the tranny, 5 or 6 being best, unless you can get more!

Advancing timing tends to kill some bottom end power, so if you have wide spaced transmission gearing or a real heavy truck it may not be the best bet. However if your rear end gears are a little low [numerically higher] then that 3200 spring can give you the best of both worlds, along with some timing advance.

There's various screws to adjust on a VE pump. One reduces/increases smoke. If you adjust the full power screw to smoke, you can back off the smoke screw to clean it up some. As mentioned, you want not just fuel, but more air charge too. Many turbo upgrades are possible, and once you do that you can dump in more fuel without lots of smoke.

High EGT's Exhaust Gas Temperatures are death to a diesel, so you need a gauge. Then you can upgrade turbo and turn up the screws to max, with the extra air to protect the engine. Larger injectors will really wake it up, but again they have to be matched with more air pumped in. It's rare that a guy gets too much turbo if he's reasonable, so that's a good first move, then dial in the fuel to the turbo charge.

Exhaust DOES make a difference, so if you can hang a full 4" on there all the better. Larger turbo, like Hy35 or HX35, better exhaust, 3200 spring and pump mods can build a screamer that doesn't smoke too much. An intercooler / aftercooler makes for a more dense fuel mixture, increasing power.

Tell the guys what your exact planned vehicle, tranny and use are and they can get you dialed in. Enjoy yourself, whatever it is.
 

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JimmieD, you understand diesels. You make sense on all accounts. First of all, you are right, you need to know where you are trying to go. My 4bt is in a 4X4 work truck that I would like to make go as far on a gallon of fuel as it will without a power loss. As is now, it has more low end power than the 6.2 that it replaced. It is stock and gets down the road very well for what I do and is a pleasure to drive.
 

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Thanks, HC, and your last sentence says a mouthful:

"It is stock and gets down the road very well for what I do and is a pleasure to drive."

In the big picture here, that's what we all really want! "...a pleasure to drive..." Over the years I've had my share of hot engines & vehicles but in most cases a guy is narrowing his possibilities. With many increases in power a whole new world of problems can open up so that over the wide range of use it just gets narrower and narrower, and a whole lot more expensive regardless.

As in a gasser, sure, it'll hit 9 grand, roast the tires at 100 mph and blow the doors off of anything in the county but: it's a royal pain to drive in the other 95% of our ventures out on the streets! Therefore taking small or appropriate steps with a known goal is the best formula?

I was impressed when one of the other guys here threw up a question, something like, "Allright, what do I have to do to get 300 hp?" or somesuch thing. He had already researched what he truly needed & wanted, preventing him falling over the edge at the end of pouring out a whole bunch of money to end up with a 4 cylinder disaster. Toolman is in a different space, being a drag racer with a dedicated purpose vehicle: MAX EVERYTHING! Cool....:)
 

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Mine was a pleasure to drive until this trip.....

....50 MPH headwinds from Oklahoma all the way to North Dakota KILLED my mileage and the poor little 4BT was smoking the whole way trying to push the ol' '79 brick through that wind.
 

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Mine was a pleasure to drive until this trip.....

....50 MPH headwinds from Oklahoma all the way to North Dakota KILLED my mileage and the poor little 4BT was smoking the whole way trying to push the ol' '79 brick through that wind.


HaHa, no doubt Linc winds are a killer on these trucks. 22 miles one way to work every day has made me learn to live in the shadow of a semi truck. Even at a safe distance there is great benefit.
Carl
 

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Just a quit note, turbo mods don't need to be expensive either. I changed my turbine housing on my otherwise stock 91 12valve from a 21cm to a 16 cm housing. It fit on the turbo with no mods. Along with the housing I got from www.dieselinjection.net for $200.00 came instructions on how to turn up the pump as well. Did all the work myself in about 2 hrs and it's a different truck to drive. The turbo comes on at around 1400-1500 instead of 1750-1800 and there's just more power and torque everywhere. I use to run out of fuel at 3000 rpm's and now it climbs hard past 3250 but I don't know how much farther because I haven't gone there. Now I need a 4" exhaust because I can heat it up pretty easy. My fuel mileage hasn't changed, but I notice when I need a clean air filter because I will start leaving a plume of smoke when the turbo can't get enough air. The truck use to work a bit with my 30' 5th wheel behind, now it has no problems on hills or passing slower vehicles. A real cheap fix!
 

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I've found one of the best ways to control smoke is simply adjust the pump right. There are 4 adjustments. I found if you adjust it so the boost comes on early you get a little tuft of smoke as you accelerate, once, rather than a thick cloud. And the cloud only comes when you floor it (unnecessarily). Theory being to bring the spool up quickly and immediately so the turbo is screaming so you can actually consume the fuel rather than dump it out the tail pipe. Bombing is cool but is pretty much the last step in building power. You do not need a lot of smoke in fact I tune mine for as little as possible. The only downfall is if you have too much fuel at idle the noise can be unbearable at idle, sounds like the loudest 24 valves when they first came out...
 

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The only downfall is if you have too much fuel at idle the noise can be unbearable at idle,
How is that possible???

Too much fuel at idle just means the idle speed goes up.

The only time you can have too much fuel in a diesel engine is under load.
At idle, there is NO load.

More fuel just means more RPM's until it gets under load.
 

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Linc,

What kind of mileage are you getting?

I am contemplating dropping a 4BT into my 58 Wagon (reason for being on this board) but with 4.10 gears, and a granny four speed I am not totally confident it will want to run down the highway at 70 or 75 safely. Plus the reason for looking at a 4BT is for the mileage I have been hearing about. With a 70 mile one way commute mileage is playing a factor.
 
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