Fuel & Air

[jbolt]

From the VE pump threads I come away with the impression there are not many options to do to the VE pump. It sounds like the pump cam supply the fuel we need but at lower pressures???



So how do we tease the fuel out? I'm thinking more work needs to be done with the injectors????





So let's say we have all the fuel we need... . well enough to keep most of us content for a while. How about that air. The subject has been toyed with but I think it needs some more discussion.



With high volume low pressure fuel delivery what is the ideal air flow. High volume/ low pressure or high pressure????



Can there be an acceptable balance between low pressure drivabilty and high HP under these conditions? IE will low end suffer to the point that around town/ off the line drivability is unacceptable.



Areas of discussion-



Intake- filter, intake pipe (pre-turbo), Turbo(S), intercooler & piping, intake manifold



Cylinder head- Intake plenum, valves & ports



Exhaust- manifold, exhaust housing, exhaust piping



Jay

 

[PPeters]

I've been wondering similar things after reading the pump thread. Is there an aftermarket replacement for the air intake (pre-turbo) plumbing? I'm aware of the filter portion (K&N, AFE, BHAF, smokey mount), as well as the post turbo exhaust options. Anyone seen anything to replace the corregated air intake with a smooth wall pipe and perhaps silicone couplers? I would think that improving the flow to the turbo by reducing drag in the pipe would be consistent with all of the other mods. I can't be the first one to consider this, so who's got the solution to this component?



Pat

 

[Bob Beauchaine]

Not there yet but I'm working on it. I should have more on this in about a month. In theory if you are blowing black smoke you are pushing unburnt fuel out the tail pipe. I feel ideally that you should only see black smoke when you first put the pedal to the metal and overwhelm the engine with fuel. Then the smoke should all but disappear. Oh well time will tell and so will I.

It's all about efficiency

Bob

 

[JStoll]

Ill say this boost does not = power, CFM flow does. the people here running small turbine housings hitting over 25 lbs boost need to do porting bigger valves bigger exhaust & bigger turbine housings & anything else that will increase flow because thats where the power is. you can pack all the air you want but if you cant get rid of it, or if its hi pressure but are working beyond the point of highest volumetric eficiency you arent making more power, at least not as much I noticed with the saab that the change from 11 lbs boost stock to 16 or 17 resulted in a huge increase in power but I went from there to 26 lbs boost & I got more power but the increase wasent nearly as much. I know that backpressure before the turbine should be less then 1/2 the boost pressure if it gets close to or above half its time to step up to a bigger turbine housing. you cant have it all low rpm boost & big horsepower & drivability its all a trade off, all I think we can do is sort out the fuel & work to flow enough air to burn it like bob was saying

my 2 cents

JAK

rock stock 89 D350 fresh getrag

 

[cerberusiam]

Expanding on Jstoll's theory, its not neccessarily CFM but the density of the CFM that will be a large determinate in the amount of power produced. Denser air equals more oxygen which allows more fuel to be burnt in the allowable time. Black smoke will go down as wil EGT's and power will go up. The other inescapable fact is cylinder pressures go up. While it looks like the newer heads flow better the small percentage doesn't track with the horsepower jumps. It looks like the ISB engine had the compression ratio lowered to compensate for the increased fueling and air flow. Bigger turbo with the HX35 and bigger aftercoolers in conjunction with better air flow seems to be the way they were headed but the small hot side turbines didn't help the cause. There is no way the 3" outlet on these housings can handle the increased flow and higher fueling without hitting a plateau, no matter how large an exhaust system. An interesting test would be comparing boost pressure to exhaust back pressure on the smaller housings with big injectors. I would hazard a guess the relationship is way beyond 1/2 on the exhaust side under a load. Cooling down the incoming air charge would serve 2 purposes. You would get a much denser charge at lower boost pressures. Even without lowering compression ratios this should boost the power and not create an unmanageble amount of exhaust flow. Increasing the exhaust flow is the next trick that has already been solved. It is possible to have good throttle response, high end power, and driveability. The Japanese worked that problem out in 1996 and Cummins released it with their 2002 ISX series engines. The VGT (variable geometry turbo) was developed to address just the problem that is inherent in the gen 1 engine. It really burns me it has not been integrated and released on the newer trucks. It seems we get just enough technology and changes to keep the interest up but all the really cool things are released at a rate guaranteed to just meet emissions and consumer demands. The parts and technology is there to retrofit the older vehicles but it is not financially 'prudent' to sell $4000 of parts when you can sell $40,000 of a vehicle. There has to be parts to adapt the VGT turbos to the earlier engines but finding the right person that wants to answer that question could be a frustrating process.



How about water-cooling the after-cooler? That would improve efficiency without modifying the rest of the induction system. The next question is where to put it.

 

[Wayno]

I was looking at all the First Gens in the Member Rig Forms and one of the members is selling a intake air filter tube but it looks like he has that cone K&N filter on it that some of the Sec. Gens folks are using . I made one out of PVC that fit real good but I was afraid that it might break and get in the turbo . So I have got another ideal but cant (haven't) found all the things I need to build it yet .

 

[JLEONARD]

How about water-cooling the after-cooler? That would improve efficiency without modifying the rest of the induction system. The next question is where to put it.



The marine 270 has an antifreeze cooled aftercooler that mounts on top of the intake manifold. It might fit under our hoods, I'm not sure.

Sometime in the next few weeks I can measure the one on my boat engine if you are interested in that possibility.

I would still like to know if anyone has measured the temp of the air in the intake.

Jay

 

[jbolt]

Originally posted by JLEONARD

[BI would still like to know if anyone has measured the temp of the air in the intake.

Jay [/B]

I've thought about doing this but I wouldn't know what kind of temp sensor to use.





Do you have a picture of the marine engine with the cooler on it? Can't picture how this works.



Jay

 

[Bob Beauchaine]

Since I started using Old Smokey's BHAF with my K&N I have noticed a definite increase in power - no dyno #s - just seat of the pants. I will try a Green High Performance air filter to increase air flow. Then it's on to the next step. I adjusted my waste-gate and I still can only get 23psi of boost. Seat of the pants tells me that I am probably around 260 hp but I wont know for sure until I dyno. I will stay with my PW injectors and work on efficiency. Time will tell whether I am on the right track.

Bob

 

[JLEONARD]

West coast Jay,

If you look at this pic in the reader's rigs you will see a pic that shows the aftercooler. Look in the upper left... follow the turbo piping.





https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=2509&width=0



When I get into my boat next I'll take some good pics and measurements.



East coast Jay

 

[cerberusiam]

That marine cooler has some interesting possibilities. Mount that inline with a larger intercooler up front then mount a hood scoop to redirect air flow across it and that should provide some good results. You could also split the flow on the scoop to route part across the intercooler and route part to the fresh air intake system.



There is a business in Pocatello ID that makets a fiberglass hood with dual scoops and the ducting to put part of the air into the filter and uses the other part to cool the compressed charge. The only problem is the production pieces are for a gen 2. With some changes the idea should be adaptable to the gen 1 hood. I need to call them some time and see if they have done the gen 1 setup.



The smaller aircraft engines were all air cooled so finding an air temp sensor and gauge should not be hard. Westach or Autometer should make something like that.

 

[jbolt]

East Coaster Jay-



Interesting- is the antifreeze pumped to a small radiator somewhere or is some kind of seawater heat exchanger used?



The problem with modifications to the intake is the fuel lines cross a good portion of it. I have heard that some have been able to get the Banks twin intake to fit but I'm not sure how without having new lines made.



West Coast Jay

 

[JLEONARD]

Land lubber Jay,

In a marine engine, the antifreeze is cooled via a raw (sea) water heat exchanger, rather than via a radiator. The long tubular part on the right side of the engine is the heat exchanger.

This particular aftercooler is plumbed into the engine's antifreeze system. (You can see the small diameter hard pipe going into the front end of the aftercooler) So the exchange medium on this design is at 180 deg during normal operation.

The next higher horsepower marine Bs have raw water aftercoolers... . so the exchange medium is much colder, say in the 50 to 80 deg range depending on location.

Yes the raw water aftercooler will chill the air better, but sea water will corrode the insides... . so at least I won't have that maintenance to deal with.

Good point about the fuel lines... . I never paid any attention in that regard because I never considered doing this modification.

Fuel lines are doable, aren't they?

Sea farin' Jay

 

[JStoll]

in the saab community people have used the watter air coolers what you end up doing is to have a tank of cold watter a pump & the heat exchanger after prolonged boost pulls the watter heats up & is no longer useful

it is a novel idea but unless you can get a continuing supply of cold watter its not that useful although I drove a lotus esprit with a coolant to air the 180* type mentioned erlyer & that thing was impressive also the erlyer INT. DT466 used that type of intercooler I still feel

the air to air FMIC front mount intercooler is the way to go

the 1st gen IC is tiny Id use it on my 2 litre saab & it would work great Im gona look into a bigger one maybe a powerstroke IC people upgrade theres on furds leaving a surplus of better bigger ICs for us I havent measured inlet to outlet to see if its wide enough to fit around the radiator but Ill check it out & post the findings

back to what I was saying about flow when you compress air you make heat the more you compress it the more heat you make so flowing in CFM actually brings down temps

a free flowing intake makes it so the turbo doesn't have to work as hard to get air this also brings down intake temps

& its fairly obvious that bringing down intake temps packs a denser charge I just hate hearing I have a 12 CM2 wastegeted housing not hooked up & Im hitting over 35 lbs boost & my EGTs are getting way up there thats what I was talking about earlier I think this is a bad idea there is a way to know weather the exhaust side is too small which I outlined earlier with a tiny exhaust housing you are basically compressing against the exhaust housing it becomes the bottle neck & although boost is way up you aren't flowing eficiently which brings up intake temps & EGTs

I think what we will find in this discussion is that each of us has useful info that combined will let peoples knowledge of turbocharging expand Id say its not just flow its also cooling air, making sure you are burning all the fuel you put in (waste not want not) there is also allot about compressor maps that can be used not that I know how to read one but this knowledge allows us to run a turbo more in the range we want some of us are super heavy so we want not to make EGTs rise in prolonged pulls others like to hotrod around town & need the pull down there at the lower rpms & & not have EGTs rise there to be more efficient it is truely compromise or balance between all things discussed here

the variable geometry turbo would be cool I heard garrett was working on something like that it would be cool if it was available & affordable

enough of my rantings I need to leave room for others

Im a long winded fool

take care

JAK

 

[BushWakr - RIP]

One of the reasons for the water cooled system is that it really isn't practicle to mount an air style intercooler to the front of the wheelhouse, and hope you have enough airflow to be effective. .



There is an optimum temp for charge air too... . it can be too warm or too cold.

Variable geometry turbines are not being used because of two main reasons... . one is they are costly to apply and two is they are not yet being forced upon us by emmissions rules...

I understand that may change as early as 2004/2005. In fact, I think the TDR mag had something in it about this a while back.



One of the issues mentioned above, the hot side inlet, is a factor.

It is one of the reasons twins are being used. I think jbolt (??) did some testing relating to drive pressures. When the pressure at the inlet of the hot end is equal to or in excess of the boost pressure you have heat issues that climb fast. Hence the use of efficiency maps for various turbos/applications.



The VE pump has some room to work with. Nascar Mark is the most noteable example. He managed to tease 308 RWHP out of his.

If we all look really closely at the internals of our pumps you'll see a couple opportunities staring you in the face...

One or two possiblilities have already been mentioned elsewere on the board to.

Volume and pressure are two considerations. Injector matching is another.

We NEED other injector choices/designs/configurations in my opinion...

Our pump can hit high pressures of 8000 psi or slightly more in stock form (if the manual is to be believed). How many of us have injectors that have that kind of pop-off pressures????

Guys, look at the pics that have been posted on the VE... . what generates the pressure, what regulates it, and how can that be tuned up??? What is responsible for supply pressure within the pumps???



In our situation, assuming we want to get more out of a fully "original" VE setup, we need to find the 5 RWHP here, and the 10 RWHP there and so on... Like mark did...

Governor spring changes?? worth the cost/work?? and so on...



I'm surprised that the pump thread suddenly stopped... I thought there'd be more participants or thoughts... .



308 RWHP is the most notable number to beat at this point... .

That is with a VE pump and whatever nozzles/timing/turbo/exhaust/cam you care to use... .



BTW, in case I didn't mention it, there is some darn good stuff in this thread as well as the other pump thread. There are some hints that are being missed too... . trust me... . for example what did we modify and or adjust to increase the fueling? how can we speed up the fueling rate??

bob.