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  #1  
Old 04-29-2003, 09:33 PM
turbotim23 turbotim23 is offline
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Default how to setup manifold for multiport injection?

Hi I need advice on how to setup a Holley intake for mutiport injection. The best way to have it machined,Welded?Type of injector bungs,How they should be mounted etc. One setup I seen had to mount the throttle body on a three inch spacer beause the throttle would hit the fuel rail otherwize.This isn't normally needed is it? How about it anybody got any expert advice? Thanks Tim
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Old 04-29-2003, 09:44 PM
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Quote:
One setup I seen had to mount the throttle body on a three inch spacer beause the throttle would hit the fuel rail
They sure didn't do that right!!!

Buy a book at your local speed shop. I know there are those as I've seen them, just haven't bought one yet. Then wait for the engineer from Edelbrock to come here and tell you the finer things. What was his name, John?

The book will give you ideas on the angle, position, ect. The size will be determined by the motor componets, ie. horspower potential.
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Old 04-29-2003, 09:47 PM
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If Roger H answers, pay attention to his advice, that's all I can add
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Old 04-29-2003, 10:00 PM
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That's the guy, Roger.
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Old 04-30-2003, 12:11 AM
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one of the mopar mags (mopar muscle I think) built their own efi setup on a 4door coronet (maybe) with a 383. I will look for the article, I know I have it somewhere. I remember they had a drawing for where to drill the holes and other info on the bungs for the injectors. Even have instructions on how they built their own throttle body, adapted an IAC from some gm pos, etc.... good stuff. I will look for it.....
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Old 04-30-2003, 12:52 AM
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If you want to do a port EFI intake it is not that difficult. Speed-Pro and other companies sell injector bungs that need to be welded into the intake. All you need to do is measure the exact center of the runners and transfer the center with a combination square to the top surface and make a center line. Measure up from the head surface of the intake enough to keep the port flange intact (approx 1.5") and center punch a mark on all 8.
To drill the holes you need to angle the hole from 15 to 20 degrees away from the centerline of the engine. This aims the injector towards the head (intake valve). I have done a few intakes but I have access to a machine shop and milling machines. I have some friends that have done it in a small drill press and some wooden fixtures to give you the angle. Either way the correct hole size would be determined by the bung size. Once the holes are drilled have someone weld them in. Also you will need to have some rail mounting tabs welded on to retain the fuel rail. Take a die grinder and remove all the extra bung from inside the runners. The fuel rail will need to be drilled the same distance apart as the runners. This is a ROUGH description to the process. There are books out there on the subject that would make the idea less scary sounding. Its not that hard to do.
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Old 04-30-2003, 03:50 PM
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Default Just Cheat

If you can afford it Edelbrock has a bolt on set up for both LA and RB engines.

http://www.edelbrock.com/automotive/mpfi_chrysler.html

Blygy
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Old 04-30-2003, 05:05 PM
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I recently modified an Edelbrock LD4B intake for MPFI.

Injector bungs: Ideally all 8 injector bungs should point so they spray toward the compression chambers. Make sure all angles on each bank are equal or you will have a heck of a time getting the fuel rail to line up correctly and then one or more of the injector o-rings will not seal correctly causing fuel to leak onto the manifold. Sometimes with a custom, this is not possible due to space constraints. Get them as close as you can. Edelbrock, Holley, Electromotive, and Accel all sell these. A little pricey, though. I paid $200 for a set of 8.

Mounting: I mounted mine using the bolts on the intake manifold and some 1/8 steel brackets that I fabbed by drilling a hole for the bolt then hand bending them up and around where I wanted the fuel rails to be. I spared the cost of clips here, too because when done correctly, the bracket holds the injectors in place.

Fuel rail: I used 1/2 male/male pipe nipple and just dremel'd the inner diameter to create a good o-ring seal. Then I tapped the fuel rail and threaded the other end in at the proper horizontal distances. This is a little tricky and takes some patience to get it right. (I used 14 pieces to get 8 good ones.)

When finished AIR PRESSURE TEST the entire assembled manifold to 45 lbs. pressure. It should hold pressure indefinitely. If it does not, find the leak with soapy water or something and repeat until it doesn't.

I realize this is the hack way to do it, but I don't have a lot of tools or any machinist/car guy friends. So I had to make due. It actually doesn't look too bad. I will try to include a picture tomorrow.

The total cost was:
Injector bungs $200
Injectors $220
Pipe nipples $20
Fuel rails $75
Manifold (used) $75
Brackets $8

Total $598. Works great with no leaks. Hope this helps.
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Old 04-30-2003, 07:58 PM
turbotim23 turbotim23 is offline
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Default how to setup manifold for multiport injection?

Thanks that doesn't sound too hard.I have a drill press at work,might try it my self.I take it the bungs are alumium?Are there any different types of bungs[thin or thick wall,different lengths etc] or different types of fuel rails or fittings to pick from? Anther thing I have is a multiport nitrous kit. The injectors for this kit are very small.Would like to mount them Hidden underneath.Think this would be too much to mount on each port?
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Old 04-30-2003, 08:41 PM
turbotim23 turbotim23 is offline
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Default How to setup manifold for multiport injection?

Edebrock system looks like a good system. very easy to tune anyway.I need a system that can handle boost and multiple stages of nitrous.Not sure Edebrock system is right for me, been leaning to the Accel system.I have a Linkenfelter 1200 cfm throttle body already so I'm not looking for a complete system. Hey pictures would be great!
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Old 05-01-2003, 08:21 AM
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i am currently doing this setup. i am modifying mopar big block intake manifolds. i will hopefully have a prototype by the end of the week. i am also in micigan. if anyone wants more info email me at jczub@hotmail.com
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Old 05-01-2003, 08:56 AM
turbododge turbododge is offline
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Lots of good info already given, but here is my $.02. You can save a bunch by making your own bungs. They do not need the flange that the purchased ones have (used for some mountings, I guess) and can be made of 3/4" diameter aluminum for about $5, and could be done in a drill press, if no lathe is available.

As for tilting the injector towards the port, I have heard several theories on this. The most common one that I have seen is that you should tilt to spray at the back of the valve with a sequential system, but not for a batch fire system. It has to do with air movement, fuel puddling on the back of the valve, etc. Many of the factory system do seem to follow this rule (TPI etc.)

It is also very hard to tilt the injector much if you use a dual plane manifold, which I prefer to do.

I will be doing a Performer for the new TT340 in a few weeks, and am going to experiment with aluminum brazing in the bungs, which would make a cleaner and easier home job.
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Old 05-01-2003, 09:14 AM
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aiming the injectors towards the valves is good to do whether batch or sequential. the difference in runnig the straight come in with very high flow injectors where you need to mix the air with the fuel better. the aluminum brazing is porous and therefore will cause a vacuum leak. i have been experimeting with it as well and cannot get a 100% good seal. in the runner this could cause a lean spot that can't be compensated for. the bungs cost about 7.50 to make since i just made a set. which is roughly the same price as you can buy from the suppliers. the hard part of drilling them on a drill press is getting the .541 diameter where the o-ring seals. this will have to be reamed.
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Old 05-01-2003, 09:46 AM
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Yes, you do have to ream if you are going to make bungs in the drill press, but you will also need to ream the fuel rails the same size, so you need the reamer anyway. You definitely need to build a fixture to hold the bungs in line for welding, just a bar and bolts thru the bungs works well.

Runner, where did you find your info on the sequential/batch fire setups. Almost everything that I have seen says to point straight in (vertical)for batch fire, which is also how most of the aftermarket setups are. Because of the angle of the head and ports, you are actually going into the largest volume of air in the port (when you are vertical), but not at the valve. Sequentials are able to atomize at the valve (opening) low pressure area, without puddling, as they can time the fuel to get there as the valve opens. I have seen some high flow setups that actually point the injector upstream to increase atomization.

There is also a question of whether or not to center the injector in the intake runner, or on the port. Many ports have a pushrod bulge at the inlet to the port (302's bulges are huge) which comes from one side of the port. Should you offset the injector to miss the bulge and point into the open port, or take advantage of the low pressure area created at the bulge to help in atomization of the fuel?

One of the biggest misconceptions is that fuel injectors atomize fuel well. Carburators do a much better job of atomization, but a much worse job of metering and fuel control.

Good info on the aluminum brazing. Luckily, I have an old manifold that I planned to practice on, so I will be able to check for porosity.
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Old 05-01-2003, 10:24 AM
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hey turbododge, i'm a mech engineer and am currently working on my masters in engineering in engine design and fuel distribution. much of the info is proprietary and i know that no one has done studies on where or how to place injectors.

the reason the shoot at the back of the valve is because its hot and will atomize the fuel on its own. realistically on a modified intake that won't happen so the next best thing. try and keep it off the walls and get as close to the valve as possible.

like i said, i designed a fixture for modding the bb mopar intake. i centered the injectors on the port opening in the head. i'm not worried about where that falls in the intake runner since its not flowing in there.

the more fuel you deliver at a time the less it atomizes because the droplets are larger. there are ways to increase atomization like boosting fuel pressure. and decreasing the pulse width but thats another topic.

anyother questions let me kow
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Old 05-01-2003, 10:48 AM
turbododge turbododge is offline
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Mechanical engineer here also. Engines as a hobby only. The primary info that I saw a few years ago (like 10) on this was from a detonation testing project at a University, I wish I remembered where. Their big concern was fuel puddling at the back of the valve, and then evaporating, as you have said. What they found, was that the higher volatility components of the fuel could come out early in the evaparation process and cause a stratification of components into the chamber. Since the components have different octane and anti-knock properties, they found a higher probability of knock if the the fuel of a batch fire system was put right on the valve. The implication was that keeping the fuel off of anything that would catch it (like the walls) or puddle it (like the valve) was what you should do. Their goal was to minimize evaporation, and maximize atomization. If I remember right, their testing did not include any efficiency or power testing comparisons, and was based on detonation, with the theory expanded to other areas thoretically. The best results they got (with batch fire)were when they moved the injector away from the head a bit, with a very straight intake runner, and put the injector at a very low angle to the runner, so it was spraying almost in line with the airflow down the runner. Make any sense when compared to what you have seen?

Also, have you seen any of the long runner EFI manifolds where the actually spray into a venturi to get better atomization. Really cool, and used on high efficiency setups for max mileage.
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Old 05-01-2003, 10:51 AM
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turbotim23,
Sorry I forgot the pix. Your setup sounds very similar to mine as I used a Lingenfelter TB as well. I'm very happy with it. The bungs I bought from Electromotive were aluminum as was my intake. I used the Holley universal fuel rail P/N 534-79, but you should be able to get them from anyone who sells aftermarket MPFI stuff.
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Old 05-01-2003, 11:35 AM
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even in efi you want to keep your fuel cold and your air warm. this decreases chances for detonation. puddling does heat the fuel. realistically you can't avoid puddling, except in the case you mentioned where you have a long runner for good fuel mixing.

however, the long runner has to maintain a high velocity ortherwise the fuel will fall out of suspension and then puddle. there needs to be a good balance. what the long dry runners do in efi setups is generate turbulence. i could get into the equations but its not important. turbulence is what mixes your air and fuel. lots of turbulence plus fuel equals good mixing equals more uniform combustion.

for the big block setup the optimum runner length is about 13 inches which includes the head. so you need about 10 inches in the intake. most single planes give you about 6-7 with the taller ones giving 8 inches. i don't like using dual planes because the runner diameter is too small for a good performance engine.
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Old 05-01-2003, 06:37 PM
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Hey turbododge,

You mention you're building the NEW TT340. Is this a rebuild of the current one, or a completely new engine? Was the old one just tired, or are you going for a new combination? Details please, your setup is sweet!
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Old 05-01-2003, 07:29 PM
turbotim23 turbotim23 is offline
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Default how to setup manifold for multiport injection?

Well buying the bungs sounds a lot easier.The bung fixure tool is just a 1/4" flat peice of metal with bolts through Holes drilled over bungs? That sounds easy enough to make. Runner4404spd I'm coming close to you on way to Ohio swapmeet. Might be interested to see what it would take to have someone just set it up for me. I think aiming injector at back of valve sounds best if it can be done and have everything fit right.
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Old 05-01-2003, 09:48 PM
turbododge turbododge is offline
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Runner: I hear what you say about runner length, but I have actually found that many of the dual planes have plenty of cross sectional size, and even too much for my application (5500 rpm twin turbo 340). I currently am running an M1 dual plane on the existing engine, and when combined with the 2.02 valve, 190cc intake port, X heads, I lose too much velocity to run efficiently at cruise and mid rpm speeds. I prefer the dual planes primarily because the ones that I use have very closely matched runner length and section area. This allows them to give good distribution at all conditions from cruise to WOT full rpm, as all the runners react the same to the changes. Single planes never have the same length or crossection runners, and if you tune them for WOT full rpm, you will have poor distribution at cruise and lower rpm, and vice-versa. I can pull my plugs after a full throttle run, and they will match perfectly, and will also match perfectly after long periods of cruising. I have never found a single plane that would give close to a good match at both conditions. Even though most OEM EFI manifolds would be considered single planes, they are definitely isolated runner, matched length and cross section pieces.

As you said, you cannot eliminate puddling completely, the point of the article I saw was that if you are going to put fuel on the valve backside, you should only do it when the valve is open, e.g. sequential. A puddle on the valve is much more likely to vaporize and stratify, when compared to a puddle in the intake or port, because the temp is much higher at the valve head.

72: The "new" engine that I refer to will be an all new long block, but use the same turbo and EFI. The old engine has over 40K on it and still runs very well, but I wanted to try some newer tech, and some kinds of different ideas. Here is what it will be, compared to the existing engine.

X race block with 4 bolts at standard bore-current is stock 340 +.040 with 4 bolts added

Solid pin truck forged crank-standard sized, nitrided-current is stock 340 at -.020 nitrided

.0015 clearance on all bearings on both

JE quench/dish pistons without any valve cuts, .038 quench height, 8.25 to 1--current is JE pistons, flattop 7.8 to 1

Eagle h-beam rods--current is stock 340 with ARP

Same super hi volume oil pump

Cam will be Crower 208/201 at .050, 110 LCA, .441/.421 lift--current is 210/220 at .050, 114LCA, .470/.440 lift

Heads will be 302 castings with 1.88/1.6 valves, ported to flow 185 at .500 (165 at my .441)--current is X heads that flow over 240 at .500--the big benefit will be the swirl configuration and the tiny ports of 127cc on the 302s vs the 190cc on the existing heads. Should generate very good velocity and turbulence.

Intake will be a smoothed out standard Performer dual plane--the existing is an M1 dual plane

The engine specs were decided on when I looked at how the engine would be run, and the mimimum it would need to run there. We are talking about a 5500 rpm engine, that in N/A form would only need to make about 320 hp out of 340 CID. The turbos come in at 2500. all in by 2850, but the old engine is stone below 2500 and will not run lean (14.7 to 1) below 2100 rpm.

The goal was to build a high intake velocity, high swirl, high quench with just enough flow to make the power I want, so the velocity stays up. Shortening the cam should also help the bottom end, along with the small runners and ports, and widen the torque curve over the entire range. Economy and detonation control should also be improved. I think that the old engine is a bit too hot for its turbo size and rpm range. If I put on bigger turbos, and went to 6500 rpm, it would probably make more peak power, but not be much fun on the street, as it would be dead below 3500 rpm.

I am hoping for 600ft/lbs somewhere in the upper 3000/low 4000 range, with close to that from 3000 to 5000 rpm. Also hope to gain some economy up from the current 19mpg to above 20.

The engine was scheduled to be done by now, but job loss delayed it. Now have a new job and am ready to go back at it. It should be a grand experiment to see how it goes. At least the Spreedpro gives me a very good tool for tuning and data collection.
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Old 05-01-2003, 11:42 PM
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hey turbo, i think the difference in our setups is that mine is naturally aspirated and yours is forced induction. in forced induction the runner cross section isn't as critical as it pressurized. however in a naturally aspirated setup the dual plane does not give my 440 enough volume.
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Old 05-03-2003, 08:11 AM
turbotim23 turbotim23 is offline
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Default how to setup manifold for multiport injection?

Turbododge you should look at the Holley street dominator intake.It's a single plane,got equal lenghth runners,and lower powerband than most single plane intakes. The motor I'm setting up is a 383 with single T04B turbo. Haven't worked everything out yet but to get it together fast and keep the power band low for the street[at least at first] I'm going to use cast iron motorhome turbo manifold.Stock this manifold would limit power to below 4400 rpm. I plan to port it and change the bottom inlet from 2" to 3".With luck getting a 5000-5200 powerband.This should be right in middle of powerband of intake and mild cam I have. Getting back to setting up intake.Still think it would be better to mill top of intake runner under bungs.I know welding fixture tool holds them the same,but it would help to drill them all the same angle.Once you know all milled surfaces are exactly flat level,same height,a simple wood block drill angle guide would help you drill each the same angle. If you don't drill them all the same how could you expect fixture tool to hold them all the same!
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Old 05-03-2003, 10:01 AM
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thats what my fixture does. it holds the drill so everythign is level and then there is a second jig for welding everything together.
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Old 05-04-2003, 03:32 PM
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Tim: I have done extensive testing with the Street Dominator, as it was the only single plane I could find that was setup for the lower rpms. The runners of a SD are not equal in length, or cross section, and are quite short do to the low rise design. I found the SD to be really quite good for power. Decent on top with good mid and low response. The problem that I had was with distribution. If I tuned the flow for power (which I did), I got very poor distribution at cruise. The plugs would read way different after cruising (I run very cold plugs) and I would get about 2 mpg less mileage, when compared to a good dual plane. I ran the SD with a carb and with both EFI systems, with the same results.

Concerning the fixtures for welding bungs. True, if the holes are grossly out of square with the top of the bung, you will not weld straight, but even drill press square should be close enough if you are careful. Spotfacing the tops of the runners of the manifold is usually not practical, as the runner slopes and you will break through before you cleanup all the way around. Here is how I do my own manifolds, which takes more time, but is the very best in accuracy.

I make bungs with a 3/8" tapped hole in them.

Bore the manifold to a press fit on the outside of the bung.

Press in the bungs to the manifold and bolt a bar to bungs to hold them in a plane and at the correct spacing.

Weld the bungs.

Remove the fixture.

Face the bung tops to uniform height.

Drill out and bore the bungs to the finish diameter and location.

Drill and bore fuel rails to the same dimenisions as the bungs.

This will give you exact locations and sizes with perfect alignment, even if you are putting the bungs in angled toward the valve.
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Old 05-05-2003, 10:00 PM
turbotim23 turbotim23 is offline
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Default how to setup manifold for multiport injection/

Well I was told that holley SD had equal length runners,but maybe that was just closer to equal length than other intakes. Maybe holley tech knows some porting trick to help distribution. I don't know if I could make my own bungs like you do.I can see that drilling and tapping the center of your bungs would give a much more accurate way to locate placement on fixture. I was thinking of using bolt through fixture and bung with washer and nut on bottom of bung.That looks like a sloppy way to hold them in place though. Anyway wanted to thank you guys, I know much more what's involved now! Thanks
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Old 05-06-2003, 08:16 AM
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hey turbotim, drop me a line. i just did the conversion on my edelbrock torker intake with my fixture and it came out great.
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Old 05-07-2003, 12:04 PM
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Wow....lots of good info on here! Dang, I have fallen by the wayside since I have been swamped with work! That's what happens when you have a normal job and then get tied up building a showcar at the same time!

Building a multi-port intake manifold isn't too difficult, but for it to turn out nice you need to know how to machine, and maybe weld. And of course, being good with a grinder helps too when you need to cleanup the ports afterwards.

From what I have done, I think the most difficult part is not machining the bungs in place, but the whole package. How you attach the fuel rail, the angle of the injectors, etc. From the tests we have done here at Edelbrock, we have shown about 5 horsepower increase with targeting the injectors at the intake valve vs. standing them straight up, on a 400 horsepower engine. When you put the injectors at an angle, it makes the whole package more difficult to fit, especially if you use a low rise intake manifold. That's why we like to use our pico injectors, they are a lot shorter than the standard Bosch style, but they are not offered in large flow rates.

As far as what Edelbrock offers, the Pro-Flo EFI units are still not available for sale. Its just taking forever to get the calibration work done, just a lack of manpower with all the work that is going on here at the moment! We do use single plane manifolds for our EFI setups, and that because of the packaging, with a carburator style manifold, its too difficult to have long runners (dual plane style) and nicely package everything. We are slowly coming out with a line of Victor EFI manifolds, that are exactly the same manifolds we already offer, but have fuel injector bosses on them and machined for Bosch style injectors. Each manifold is also offered with a fuel rail package, and we also have a square bore and dominator EFI throttle bodys. To date, there are no Mopar manifolds converted to EFI, but they are on the list and we will get to them soon. As always, for us to get things done sooner, calling our tech department and requesting it insures that it stays higher on the priority list.

The Pro-Flo EFI systems work well by themselves, but are not really meant to be used with forced induction or nitrous. We do have a nitrous kit that works with the Pro-Flo EFI systems, but for advanced drag racing setups, you really need a more programable ECU. As with all EFI systems, the most important part, besides packaging is tuning!!! Tuning makes all the difference in whether you will be happy with your EFI setup or not.
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Old 05-08-2003, 08:42 PM
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Well can some of you enineering people help with one problem setting it up. That is I don't know how to predict exactly how much horse power to count in chosing the injectors. I called a supercharger company, said my motor would make 462 h.p.,577lbs torque at 6000 rpm [at 6lbs boost I think] with their supercharger on it. Boost is boost so can I count on close to the same top horse power with a turbo at that same boost?I doubt I'll have max h.p. at first My turbo system will be compromised by a few things at first,Later once on road I'll improve them. How can I Plan for this in injector sizing? Will a injector sized for max power work good on a motor with less h.p. Can increased fuel pressure help in too small a injector size? Thanks for a the posts Tim
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Old 05-09-2003, 10:20 AM
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tsteiner61 tsteiner61 is offline
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My Electromotive fuel injection software has an injector size calculator. I plugged in your numbers and it calculated you would need a minimum of 33 lb./hr injectors if your max is 6000 rpm. 34 lb./hr minimum if you want to turn to 7000 rpm.

If the injector is too large, you will run into idling problems as the minimum turn on time for the injector will provide more fuel than you need for idle speed.

Increasing fuel pressure to an undersized injector is really not a good idea as they are designed to work optimally at certain psi, usually between 35-50psi.

One factor that really affects your injector needs is your BSFC (Brake Specific Fuel Consumption), which I have attached a small explanation below. I used .5 in the calculations above to be on the safe side as far as fuel delivery is concerned.

I would recommend a 36 lb./hr injector. Any thoughts on this guys???


***********************

UNDERSTANDING BSFC:

BRAKE SPECIFIC FUEL CONSUMPTION
--------------------------------------------------------------------------------

BSFC is a frequently misunderstood term that rates an engine’s efficiency in terms of fuel usage. More specifically, it is the measured fuel flow in pounds per hour divided by the horsepower. On the engine dyno, this calculation applies to observed power numbers, not corrected power. If you look at a dyno sheet and try to compare corrected power numbers to brake numbers it won't compute. Many people believe BSFC indicates a rich/lean condition, but that is incorrect. The brake specific rule of thumb says that a typical engine will burn one half pound of fuel per horsepower per hour, or .5 BSFC. This is based on the efficiency of a relatively good combustion chamber and reasonably well matched intake and exhaust components capable of maintaining good dynamic energy across the engine. Most rough fuel requirement calculations are based on a .5 brake number, but this is only an estimated number indicating relatively good efficiency. It means that an engine of average efficiency generally burns about .5 pounds of fuel per horsepower per hour. The best (lowest) brake number always occurs at peak torque where the engine is most efficient.

Racing engines and many modern high efficiency production engines are capable of generating maximum efficiency with less that one half pound of fuel per horsepower per hour, or .4 BSFC for example. Today’s high performance engines operate comfortably in the .42 to .48 range, even on ordinary pump gas. Contrary to popular opinion, this is primarily due to the widespread availability of good quality unleaded fuel, active, efficient combustion chambers and superior fuel atomization provided by electronic fuel injection or the newer breed of performance carburetors offered by Demon.

A Pro Stock drag racing engine operating within a very narrow power band may show brake numbers as low as .35. These numbers are achieved by optimizing combustion efficiency across the engine’s primary operating range. And because efficiency varies above and below the torque peak, brake numbers will vary at low and high engine speeds. That’s why engine builders target specific operating ranges to optimize component compatibil
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