LS1 CARBS vs EFI-WHO WINS?

what makes more power on an ls carburetors or fuel injection in this video we're finally going to decide what makes more power on your ls carburetors or fuel injection this is the last test i'm going to do and this is finally going to decide it which one makes more power this is it are we really going to decide that probably not and here's why if you go to the internet and talk about carburation versus fuel injection they're basically two camps there are guys that think that fuel injection is the only way to go and there are guys that think that carburation is the only way to go the reality is that there's a third camp and that's the one that i belong to and anybody that's done any real testing fuel injection works well carburetion works well they both work well one doesn't have to be better than the other they both work well in fact how we deliver the fuel to the motor has much less of an effect on power than the intake manifold design that we use to eject the fuel too let me give you an example a lot of guys think that fuel injection versus carburation just means this we go to the wrecking yard we pick up a 5.3 we run it on the dyno we take off the fuel injection which is the truck intake and fuel injectors and fuel rails take that off and replace it with a carburetor and to them that means any intake manifold that has a carburetor on it so we run that and we compare them that's the universal thing fuel injection versus carburation but the reality is the intake manifold that we choose to run that test on has a much bigger effect than how we're supplying fuel if we compare the truck manifold to a dual plane it's a different test than comparing the truck manifold to a single plane or comparing either one of those intakes to a fast manifold or a high ram or a sniper you see how we deliver the fuel whether it's through fuel injectors or carburetors has much less of an effect than where we deliver the fuel and that's what we're going to show in this test i ran a test on actual ls1 a 5.7 liter ls1 with the high ram now the high ram allowed me to run port injection versus carburation on the same intake manifold and we ran a few different lids on it so it's really cool stuff let's check it out to run this very last ultimate comparison on carburation versus fuel injection i'm sure that there's going to be more i ran this was a actually a 5.7 liter ls1 started out as a an ls1 crate motor way back in the day this is one of the first ones that the guys from west tech had they had to land around for a couple of years before i finally tom and i actually got these things running but this one was upgraded we put four drops and pistons in it because it had a little uh adventure on the dyno during one of the tests so they replaced the rods and pistons with forged pistons it's a forged flat top piston with valve release which allowed us to run enough camshaft in this thing so we put a healthy comp cam in it it was a 54-46 see i didn't even run a 469-11 that was a 624 lift a 239 255 degree duration split and 114 degree lobe separation and the reason i did that is because i was trying to make some fairly good power with this 5.7 liter um just by itself and then we ended up doing this high ram carburetion versus fuel injection test but we had the healthy cabinet we had obviously hardened push rods in it we had good cylinder heads on they were rhs cnc heads and it looks to me these are real early ones it looks to me like maybe the guys from rhs and let me know if you guys out there know anything about this because i certainly don't i don't have any firsthand experience or any information but these rhs heads that we have look an awful lot like mastheads i don't know if mass maybe did heads for them early on but these heads these cathedral port heads work really well and they like i said they they look a lot like the math stuff which we know has worked well in the past so anyway they had good heads on it and obviously we had the high ram on there we were controlling this with the fast if or the uh holley hp management system it had a set of inch and 7 8 headers on it and to get things started we ran this 5.7 liter ls1 with the high ram and the lid with the single front throttle body with 102 millimeter throttle body on it we had i think we had 80 pound injectors or 83 pound holley injectors if i remember right on this thing and so we had more than enough fuel to do what we were doing but as you can see this thing made some pretty healthy power for a 5.7 liter equipped as such with that single throttle body opening on the holley high ram this thing made 568 horsepower out here at 7 200 rpm and peak torque checked in at 449.5 so 450 foot pounds of torque and peak occurred at 6100 rpm so the combination of this displacement and that much camshaft we had plenty of head flow and the high ram which is a relatively short runner compared to like a fast or obviously a truck manifold it's making peak power out fairly high so the first test that we did was to compare this lid to a dual quad lid with 2 000 cfm throttle bodies on so two four hole 4150 000 cfm throttle bodies we were still had the injectors down in the port where they are on the high ram when you're running efi so this had the lid with the dual quad you know more flow 2000 cfm throttle bodies more than enough air flow and i don't know let me know what you guys think does just changing the lid to that dual quad high ram lid change power we didn't see a big change in power when i put the kegelidon on the high ram so i don't know if the platinum actually was responsible for any of this so let me know what you guys think in the comments but changing to the dual quad definitely changed the power and both you know air fuel is optimized timing was optimized all that stuff so equipped with the dual quad lid this thing and the two 4150 throttle bodies this thing made 574 horsepower peak torque was up to 456 foot-pounds of torque so basically it helped everywhere from let's say 46 or 700 rpm all the way out um you know it was a good gain and and a sizable change given the fact that all we did was change the lid now i don't know how restrictive a 102 millimeter throttle body is on the high ram with that single opening but when we did this test here's what happened let's get to our next test after running our comparison between the high ram with the single throttle opening with 102 millimeter throttle body versus the dual quad opening with the two 4150 throttle bodies we decided to put carburetors on in place of the throttle body so we took the 4150 000 cfm throttle bodies off and replaced them with two holley 650 xp carburetors and ran those in place of the throttle body so here's a comparison between the single hole front entry 102 millimeter throttle opening on the high ram versus the carburetors here are the carburetors and equipped with the two 650 carburetors this thing made 579 horsepower peak torque was up to 462 horsepower remember this is a comparison between the front throttle body opening the single 102 millimeter and versus carburation on the dual quad so you might be asking yourself okay well how does it compare to the two thousand cfm you know 4150 throttle bodies so here's that that's the green so the carburetors made more power than both the single front mount 102 millimeter throttle body on the high ram they made more than the two dual quad 1000 cfm 4-hole throttle bodies they made more power than either one of them and so now here's another interesting test after running this and and before i get to that by the way the reason for this doesn't have anything to do with flow it's not the fact that and i'm going to show you why in a minute that the these two 650 carburetors don't flow obviously more than the 2000 cfm4 health throttle bodies it has everything to do with charge cooling when we introduce fuel at the top of the carburetor on a tunnel ram we cool the charge air and if the charge air is cooler the motor makes more power and this doesn't do this just this time or sometimes it does it every time this is the same reason that you move fuel injectors if you have port fuel injection or that you run multiple injectors you move the fuel injectors up higher in the port away from the cylinder head because the earlier you inject that fuel in the intake port on of the cylinder of the intake manifold the more power you're going to make because it cools the charger there's more time for charge cooling to happen the farther away that is from the combustion chamber so there's more time because all this is happening very very quickly if you do the math on this you'll see what i'm talking about you'll see how how much time it takes for that air and fuel to travel from its injection point into the combustion chamber at 6000 rpm you know you're talking about almost no time at all so you want anything that you can do to add more time for that charge cooling to take place because it takes time for the fuel and the air to absorb heat so it takes time for that to happen if you inject the fuel up at the top where the carburetor does there's more time for that to happen and it makes more power we show that time and time again so now let's take a look and see what happened when we ran basically what i did was for the last test we replaced the we kept the carburetors but ran the motor fuel injected running just air through the carburetors and supplying the fuel through the injectors to show that the carburetors themselves were not adding power because they flow more which obviously they don't so now let's take a look at that so here's what happened and basically the carburetors when we were injecting fuel down the port made almost exactly the same power as the throttle body the two the two 4150 throttle bodies and the reason for that is even though the thousand cfm throttle bites flow more than the carburetors the combination doesn't need more airflow probably one of those thousand cfm throttle bodies is probably enough but two 650 carbs even with the venturis the way that they are and with the boosters and stuff they flow enough air to support this power level so injecting the fuel down at the port still has the same effect it still has minimal charge cooling compared to the carburetion at the top of the intake manifold so all that's what all this is about it's not about the intake design it's not about carburation versus fuel injection it's just where you inject the fuel and on the carburetor we're putting the fuel at the top of the intake manifold there's more time for charge cooling to take place and we make more power let's get to our conclusion okay guys this is it here's your time make comments right now stop what you're doing make the comments ask me this question richard why didn't you run throttle body injection where you run the fuel at the top where the carburetor enters the fuel so we can get charge cooling and have complete control and have better atomization and better fuel and make more power and have it be the ultimate fuel injection here's the problem with throttle body ejection first of all i didn't test it because i didn't have them but here's the problem with throttle body injection it's not the same as port ejection you are at the mercy of the intake manifold design which is going to determine distribution in the intake you see throttle body injection doesn't improve fuel distribution port injection we can adjust all the cylinders individually and optimize that which is a good thing about port injection and allows you especially if we have 802s we can go in and do fuel trim and not so much because i've already shown that in another video it's not so much for power production but it's definitely for safety if you have one cylinder that's running at 14 1 at wide open throttle and you can adjust that and put that into the safe zone it's going to save the motor port injection does that throttle body injection much less so but throttle body injection would probably make as much power as the carburetor because it's supplying the fuel at the top we have the charge cooling which we know is the big thing and it definitely adds power so there's the answer to your comment that shouldn't stop you from making the comment go and tell me i don't know what i'm doing because everybody does i'm used to it armature holder guys thanks for watching like share subscribe ring the bell make the comment about the throttle body injection more testing coming up

Channel: Richard Holdener

Views: 43,747

Rating: 4.9698763 out of 5

Keywords: CARBS, EFI, HI RAM, LS, TUNNEL RAM, 650 HOLLEY, 1000 CFM, THROTTLE BODY, 102MM

Id: EBalrpY73Jc

Length: 12min 32sec (752 seconds)

Published: Sun Aug 02 2020