fuleinjection 460/514 Who

[Back in Black]

Why would I need more than 1000 cfm on a 600 to 650 horsepower motor? The 850 carb I have right now is more than enough.... ?

And Holley says the system I have, the pro jection with commander 950 computer module, is good for up to 600 horsepower.. ? (36 lb injectors.. although I may go with 45 or 65 lb'ers)

[James Baldwin]

Email David Kidwell (that is his screen name too)

He just built a really great 460 stroker with stack injection and so far, is really happy with it (dyno time only).

[Mr.Fixit]

Coyled,

Thanks for the offer, but I really don't work on cobras anymore as I left the industry a couple years ago. Kisler is the setup I worked with that had the speed pro CPU. I have done two of them. I got them to work fine, it just took a lot of time and data logging to get the airflow and fuel maps anywhere near reality. Yes, the injectors are near the intake valve, but that is of little consequence. The butterflies are very near the intake valve too, and the injectors need to be below them. On sprint cars with the non-CPU controlled version of the same injection, fuel makes it to the top of the tall stacks anyway. The air column pulses back and forth in a compression wave and the vaporized fuel migrates up the stack. I believe Kinsler gets their castings from Hilborn anyway, I may be mistaken. I found the carabine controller a lot more user friendly, it was easier to tune and made all the power of the speedpro. It also doesn't need an O2 sensor, crank trigger, or MAP sensor. Or a laptop CPU to tune it.

The low rpm throttle response improvement can be had on motors with big cams, due to their low rpm air velocity, booster signal is weak with a carb. FI shoots the gas out so that's not an issue, but this is not very important because it only happens at the rpm's that are too low for your cam to be making any power. You can get a wild motor to idle at a lower rpm with FI, but who cares? Individual stack FI gets a really touchy throttle, because they have 8 throttle blades which are much larger diameter than the 4 in a carb. So a small % of throttle opening has a much larger change in airflow. (It has nothing at all to do with the injector being nearer the intake valve)

BiB,
TBI injection often runs a throttle body much larger than the carb it replaces, so as to minimise the venturi effect of the throttle body. It is THE restriction on the induction. If you go to too big a carb, the velocity through the carb drops and so does booster signal, so the motor runs like crap until it has a bunch of RPM. Not an issue when the gas is shot out, only when it is sucked out. You may have the qrong floats in your demon becaus ethere are a wide variety of racing applications, and there is not one correct part for all of them, you need the road race floats according to the description of the problem you gave.

[coyled]

Mr. fix it, I care that you can get it to idle at low rpms with an efi and have throttle response below the power curve of the cam. You can have the best of all worlds. My motor pulled 660 hp at 7200 rpm flowing 750 cfm thru a 750cfm holley. My throttle body is 1050 cfm so I doubt I loose any top end versus individual runners. It's kind of the same reason roller cams make sense, lots of lift which helps everywhere with less duration so you don't kill your low end like the big cams of old used to do. The issue of the time it takes to tune an efi motor depends a lot on the resolution quality of the system. The more resolution you have, the longer it takes to tune the system. The other tricky part is the 02 sensor is behind the curve while you tune. Did you see that when you were tuneing? It took me a while to figure out that a few boxes earlier on the fuel map were the ones to alter when looking at a datalog graph. It was not as critical at WOT in 4th gear but was super critical on any tip in acceleration. Scott

[Mr.Fixit]

IR can help make more power by having the tall stacks that allow you to take advantage of Helmholtz resonance phenomema. The length of the stack has a fundamental frequncy (like an organ pipe) , get that frequency to be a multiple of the valve timing, and the column of air is allready moving towards the valve before it opens. This can get the volumetric efficiency of the motor over 100%, but you would have to have tall stacks, which would probubly be sticking out the hood of your car. Look how long the intake runners are on all new cars.

Low idle: same motor before and after. With the carb, 900-950 was a good idle speed. With the EFI, we could get it to idle all day long, at as low as 400 rpm, but still chose to have it at 850 anyhow. Low range torque was improved, but the improvement was all below 3000 rpm, which is not very important at the race track. Nice for cruising the street however, but this is pretty serious equipment for a street cruiser.

[coyled]

The volumetric efficiency of my motor peaks at 113 % allready. IR's sure look cool but the lack of room and air cleaner issues prevented me from considering that avenue. One more thing, you can run the efi leaner than the carb as you don't have the same distribution issue's even at high rpm. A carb has to be rich enough to cover the leanest cylinder. I am running my efi at 13.2 to 1 with no problems. scott

[cobrashoch]

Craig - Car coming along well, switched over to a shortie glide from Coan this season and a 9 inch converter. Just put 1700 big ones down for a air to water AFTERCOOLER from Vortec 3 days ago. Thats just for the box, the radiator, pumps and etc. cost more. Saving my pennies to buy a port injection setup this winter, most likely from Force. Going to look at Ron's fuel injection too.
Keepin' with my stated objective of making a wild STREET car, I.E.-the aftercooler, fuel injection and so on.

Yup, looked the idiots over, and not one of the 5.0 boys that are competitive use any cooling. Just a hose from the big pumps outlet to the top of the throttle body injection. Thats all I see, or all they admit to anyhow. If there was a better injection setup for blowers, believe me,,,,,,, it would be on them, regardless of cost. Some of those sheet metal manifolds cost upwards to 6 or 7k, so money is in theory not the issue.

Now to really poision the pot. On a naturally asperated engine no one, I repeat, NO ONE has ever shown me that injection will make more power than a carb. And believe me I've looked. I see tractability and emissions advantages for injection, and for me that's "nouf " for me to look that direction. We often metion how much better fuel injection is of late. What we haven't talked about is that the carbs have gotten better too. (and more costly)

Scott - If you have a slug running lean on a carb, what you have is a manifold problem. Trust me, its pretty easy to tune a intake so they will run even, on a natually asperated engine. Fact is, it can even be done with gaskets for a quick fix in the field.
cobrashock

[RICK LAKE]

Cobrashoch Okay Ron here we go. A carb will make more power in the top end than a FI system because the fuel and air start to mix sooner, in the intake and don't have to wait till the intake valve opens up. Port injection is close but the carb still wins. You have a better vaccum with the carb in the upper end than the throttle body because most throttle bodys flow min of 1000 cfm. You can run 75% of all motors on 750 cfm carbs and produce good lower and middle tork and hp power. The carb manufactoring has gotten alot better. How ever I can change my timing curve ,fuel pulse, lean or richer running without lifting the hood on my car. No gas spills, no fire worrys, just turnon check file and download. Weather changes from hour to hour at some tracks. I can adjust faster and at certain rpms points better. This is the same problem 2100 cfm of webers have the same problem. These carbs top out on a BB at 6500-6800 rpm they run out of flow. I am not good at explaining this but this is what happens. In the mid range FI will make 5-10 hp and 10-15 tork more that the carb but the fine tuning is why. Nascar and Drag racing are the only racing that still strictly uses carbs only. I am not counting the Salt flat racers. Ok Ron your turn Rick Lake

[RICK LAKE]

Back in Black You have the 950 kit witch is a nice basic kit. The max power with 36 lbs is about 480 -500 hp at 5500 rpm If you turn up the fuel pressure you may get another 20 hp. Rick Long back in 93 was running the same system as you but the computor was only 286 kb speed now they are 10 times faster That was rpm does your motor nose over?? I have a 452 FE with 50 lb injector and goes strong right to 6000 rpm when it hits the chiup in the MSD. When I up the super charger I am going to 72 lbs or 92 lb injectors. Rick had the 4 85 lbs injectors no his system and the car nosed over at 6700 rpm, out of flow for the injectors He put a dual system on the car with 8 65 lbs injectors and the motor pulled hard to 7500 rpm his red line. The only problem was the flooding of the motor when the dual throttle bodys are WOT. The cylinder where getting washed down and fuel was getting in the oil. They cut back the fuel pressure to min and it help with the wash and black smoke problems. He was one of the first to run the holley systems but had many calls to tech to fix the conditions. The 900 system you have has either 4 75lbs injectors for for 500 hp or 85 lbs good for 575 hp. If you are using the commander 950 mpi system, you have 1000 cfm or 2000 cfm throttle body and only 36 lbs injector. I would worry about a lean out on the upper end with small injectors. Better too have too much than being too small. My bother melted a 5.0 with too small injector with a blower 9 psi. Injectors run best at 80% of duty cycle. 100% with high pressure causes fuel flow trouble and pulsing fuel from the injectors at 100 % duty. Hope you understand my answers. I learned from the school of YEAH I KNOW IT ALL!!!! Got to go Rick Lake

[cobrashoch]

Rick - Reading your post I think you just confirmed what I posted earlier. After re-reading your post a couple of times I mostly agree with you too. The only thing I would add is that as the efficiency of a conventional carb drops off past its rating, it will still "flow" more than its rating, just not as well. And thats the problem with a tuned Webber system. If you get past the RPM's of a tuned system it REALLY drops off bigtime, because you lose the tuning in the manifold or the runners, not at the carb like on a holley.
Actually, in the real world a conventional carbs rolloff will match the rolloff of the efficiency of most engines if you over-rev the engine. This is both good and bad, dependent on how you look at it. But this does have bearing on the T.B. injection manifold you select vs. direct port injection or tuned port injection.
Again, the only reason l see to go to fuel injection is to make a car more streetable. And thats good enough for this hillbilly. So a Victor injection manifold will outflow a tuned system in my eyes. And the only other thing to figure out is your injector size when using this conventional manifold.
But I do understand that a carb can be tuned pretty dog gone good also. At considerably less cost I might add. Then there's the power thing. Later,,,,,,,,,

cobrashock

[RICK LAKE]

Cobrashoch Hi Ron I used a Dove single plane Med Riser for my manifold. It was the easiest to convert over to Port injection. You have to watch the flow ratings on these manifolds. The Dove is only good to 6800 rpm. The Victor will flow to 8000 rpm but doesn't come in until 3500-3800 rpm. You want the high velocity of air going into each cylinder. The bigger is not always better rule comes into play. You have a larger motor than mine so you may be right in the sweet spot when running. the injector sizing is ( estimated hp x .50 or .55 if NOX or supercharged) divided by 8 will give you the injector size. I add 10% for the fudge factor. This works with a 6000 rpm limit. As far as your Victor manifold, the tune port system will have a high flow reading in the mid range than your victor. The air velocity will be higher but the limited flow per cylinder is the same problem as the webers. Nascar runs a 390 holley that flows 118 to 120% over what it is rated for. It's a black science between cam, heads, intake manifold, and exhaust. I would like to see the number differents between the victor manifold and a torker2 manifold on the same motor. How much beyond 6500 rpm are you pushing that motor. Where is the limit on the cam? A 1 inch spacer will give you the differents if you are going to 6800 rpm. The torker is 70 bucks cheaper and the same design. Talk to you latter Ron Rick Lake

[David Kidwell]

Bill, I'm running the unit from Wayne Presley, verycoolparts.com
on a 514 crate. Have not got the car built yet but the engine was run on the dyno prior to installing it . E.T. Automotive in Garland Tex. did the dyno run and he was so impressed with the #'s and set up he is in the process of building another . The engine untuned produced 596 ftlbs. of torqe at 3,000 rpm and 575 hp @3900 rpms the red line on this engine is 6200 rpms. The final tune will be when the car is finished. If you email me I will send a pic of the set up. I did not want to post one.
David K.

[Wayne Presley]

Here's a shot of the set up that David has. EFI works very well on these engines and are not critical to the choice of cams like carbs are. The high lateral G loads do not typically pose any problems for the EFI equipped cars, especially if they are equipped with a surge tank.



And David's motor being installed



And here is a picture of the 460 manifold that is in a Superformance

[750hp]

Ron - We must be looking at different ewbsites, but I can't find a single PRO 5.0 car that ISN'T using an aftercooler.

In any case, when trying to push higher boost levels into any motor, I would always use a cooler for the added safety margin on today's poor quality pump gas, or to run a more aggressive tune-up for even more power.

For the same reasons as Rick and Ron have already mentioned, I'd always use EFI. To be able to individually tune cylinders is invaluable. Some engine designs always run lean on specific cylinders. With a better carb, you can try to jet that corner differently. This can mostly prevent the sylinder from running dangerously lean, but it then makes at least the next cylinder too rich -- less overall power produced. Also, to be able to tune depending on water temp / air temp / battery voltage, etc, etc is something that a plain ol' carb just can't try to compete with.



http://www.mustang50magazine.com/techarticles/29620/

http://www.musclemustangfastfords.co...Mlords19_z.jpg

http://www.wolferacecraft.com/images...silvanew07.jpg

[coyled]

Some one explain to me why a carb would make more power on the top end? Given the same intake(lets say a single plane), the air flow would be the same. With EFI you get better distribution and thus can run it a bit leaner(make more power). My throttle body looks like a 4 barrel holley with no float bowls, so what would the difference be in flow or power? With EFI, you can add cfm with out hurting the low end. I am not aware of a high dollar race class that does not use fuel injection. Certainly, if a carb made more power they would use it. Nascar builders would use efi in a heart beat if the rules would allow it. I have seen guys pick up mph at the drag strip when adding cfm, like going from 750 to 1050 cfm. The et might be lower, but clearly more top end power. Just like you guys, I have seen carbed motors that run really well and if I had a great running carbed motor, I would stay with it. Scott

[RICK LAKE]

coyled Scott it has to do with the distrubition of the air and fuel With port injection you have 1 injector dropping a controlled amount of fuel into that cylinder. the air is also limited into the cylinder by the runner in the intake and throttle body. You are trying to run wide open throttle and still get a good vaccum signal fromthe motor to get the most air,fuel combo in the cylinder. With a carb you can put more fuel and air in it at top end. The fuel and air mixin the intake and get sucked into each cylinder. You can get more fuel this way than with FI. Hot Rod and Car Craft did tests useing the same motor and similiar fuel induction systems a carb and a 1200 cfm throotle body with 36 lbs injectors. I didnot like this test because I do not think the injector where big enought to equal the carb. I did the injector sizing and 38-42lbs would be the correct size. I am running 50 lbs. with no problems no black smoke and this is without the supercharger. I will go to 72's or 83's when running the super. A 950 cfm carb will make more power than a set of 58 webers with 2160 cfm at top end The webers are flowed out at 7000 rpm. Pro stock in NHRA uses carbs only and thats high dollar. Scott it's all in the set up. Rick Lake

[coyled]

Rick, with the correct injectors you can also get the right amount of fuel in each and every cylinder. With webbers you are talking about a different intake when compared to a carb which changes the equation. I am running 48 pound injectors right at 80% duty cycle, 660hp application. scott

[RICK LAKE]

coyled Scott you are right if your system has individual timing and pulse throught the whole rpm range. The fast system is about 4 grand for this system. I have the sequential system. It still batch fires over 3500 rpm's I think I don't know what system you have but you would need EGT's for all the cylinder to get them all working the same. O2 wide sensor is better than the narrow one but it still limited. The gas checker for each cylinder is the only real way to know for sure. Electronic International sells an EGT gauge and sensors for $980 that reads each cylinder. Down the road I may add it to my car. It's good for 8 cylinder motors. I was taking into account that the manifolds where port matched to the heads. FFP has an article in their old catalog on a 427 build up. You did your homework on your injection system. Few people do this. Rick Lake 660 hp at the crank or rear wheels? I have 340 hp at the rear wheels.

[coyled]

I have the sequential fire all the way up in the rpm band. Also, the wide band o2 sensor. I have individual timing control per cylinder but have not used it. I agree that the ultimate setup would be o2 sensors in all exhaust runners. Its 660hp at the crank flowing 750 cfm thru a 750 cfm holley. It now has the 1050 cfm throttle body, should make more power according to the engine builder but who knows for sure. The fuel map adjusts at every 500 rpm and every 7% of throttle increase. I run it in alpha-n mode which is a throttle position versus rpm table, no map. My cam does not pull enough vaccum at idle or off idle to get good resolution in a map versus rpm table(speed density mode). Are you running speed density or alpha-n? Scott

[RICK LAKE]

Coyled Scott are you sure about the sequiantial on the injectors. Who's ECU? Speed pro said the same thing and I found out that over 3800 rpm it swapped over to batch fire. The 5 grand ECU with each cylinder was the only one that worked to Red line. I have speed density but can change 15 different tables for whatever I want, tps verse rpm, map verse rpm, coolant verse rpm, and list goes on. Timing tables, injector pulse, load, The ownly thing I wanted was a knock sensor. I think I can update the ECU to get one now. Thats a nice strong motor. There is a test with finding out what the best throttle body to use with a motor. I will have to look in my books to see if I can find it. You have a larger motor than mine and I do think that a 1200cfm or 1400 cfm would be the better body for your motor. I have the small intake holley base not the larger dominator one. It's all about flow and velosity of the air fuel charge. Rick Lake