CHEAP EBAY BOOST SHOOTOUT-4.8L vs 6.0L (PROBLEMS)

[Music] hey guys richard holder here have you ever had one of those days when everything just goes perfect you walk in wave your magic wand the motor goes up on the dyno everything bolts right on it makes a million horsepower and everything runs perfect well this is not one of those days in this video we're going to install the not so low but cadillac sts supercharger on the larger 6 liter after already running this test on the smaller 4.8 liter the thing worked out great and made good power unfortunately after running that video the prices shot up on these superchargers so they're no longer a low buck option despite the fact that the guys at mcdaddy parts now offer adapters to install these on an ls but after running it on the 4.8 liter we decided hey i wonder if that supercharger has enough capacity to run on the larger more powerful six liter so that's the test for today we're gonna run the motor n a install the cadillac supercharger and unfortunately it did not work out great everything was not cooperating so here's what happened [Music] so [Music] okay guys now we got the na runs done it's time for some boost time to install the cadillac supercharger [Music] so getting started we ran our 6 liter naturally aspirated before installing the blower this was our original big bang motor the motor that made 1543 horsepower with twin turbos on it was running a little different configuration when we did that but it's still basically a stock bottom end ly66 leader with extra ring gap in it so stock block stock cranks duck rods stock pistons you know all that stuff we had trick flow 225 the gen x cnc ported heads on it it had a good size cam and decent for a six liter we could have obviously had quite a bit more camshaft than this but it was a centrifugal blower cam a 613 596 lift 227 244 degree duration split and 115 degree lsa now a lot of guys are going to be saying yeah but that's a centrifugal blower cam this is a positive displacement blower cam yeah that doesn't matter so we had that combination we did top it with a stock truck intake and throttle body which would be restrictive on this motor but we weren't really looking to try to maximize the n a power output we just wanted to get this thing up and running and working so we could install the blower on it we ran instead of inch and 7 8 long tube headers with the collector extensions and no mufflers on it we ran all this with the holley hp management system we dialed in the two and we ran 29 or 30 degrees of timing this was run on 91 pump gas this thing had 80 pound injectors in it and again you know pump gas 2 and this thing runs on pump gas because it's basically got stock compression it's not a problem and as we can see here this thing still makes good power it made 530 horsepower 528.6 so 529 horsepower and 499 foot-pounds of torque it has a good torque curve you know this thing's doing what it's supposed to we've run with a bigger cam shaft and a different intake manifold this thing will be up near you know 565 or 570 or so but here i did an interesting test when this thing was n a normally we have if we take a look at the timing curve on this thing we're starting out about 17 degrees and then ramping it up to 30 out of the power peak so down here below 3000 rpm it has 17 degrees of timing and then after we uh ramp up the timing curve we have 30 degrees of total timing out here at the power peak now i did something cool where we added a bunch of timing down here in this low rpm range and here's what happened so you can see we picked up torque here in the 3000 up to about 3 500 which is where we added the timing now we added three and a half degrees down here bringing this up to from 17 to 21 or so 22. the problem with that or the potential problem with that you know we have we're running this thing cold at about 150 degrees and we obviously have lots of airflow it's not in a heated engine compartment and we can get away with that stuff because we've got cold water we've got good air flow to it but in the car even though this ad even though it likes the extra timing here you might not be able to do that because in this area and then up to around the torque peak this is where you have to be concerned about detonation so even though we show that we've added power there by adding timing you might not be able to get away with that in the car especially running on pump gas so now that we've run the n a combination on our for our on our 6 liter let's find out what happened when we put the cadillac sts supercharger on there after running our naturally aspirated 6 liter we got excited and installed the blower as we showed in the video and everything was working out good we used the adapters from the guys at mac daddy parts and installed the cadillac sts blower hooked up the intercooler we have an air to water on this setup we ran dyno water through it just the way that we did in the 4.8 layer and all of that worked out just fine we had the same air inlet as we ran on the 4.8 liter there was one issue in the back on the on this because this is a gen 4 based motor it has a different valley cover on it that has the provision for the oil sensor and that's kind of in the way of the air inlet but we managed to get the air inlet tube back in there and it's the same big 102 millimeter throttle body and three and a half inch uh piece of tubing that we used to be the air back into the feed the supercharger we ran the same pulley assembly the same accessory drive everything basically was just taken off of the 4 8 and put on to the six liter but unfortunately here is what happened no matter what we tried to do this thing just did not want to make power now it's doing what we expect here maybe i can if this might be a little confusing so let's get rid of we'll get rid of the uh we'll get rid of the horsepower here so you can see so the red is the blower and the black is the n a motor so here on the load in at 3 500 and all the way up to almost 4 500 it's kind of doing what we expect it's making about 8 pounds of boost that's down from about 11 that we were running on the 4-8 and that's exactly what we would expect on the bigger motor it's making more power it has more displacement we would see a drop in boost exactly as we expected it went from 11 pounds down to about 8 pounds and it's adding a ton of torque here in this area so we're up from the n a motor from 455 to 620 so you're looking at a hundred and what's that 170 170 175 foot-pounds of torque so those are the kind of numbers that we were expecting but the problem is you can see here at 4 400 rpm or so everything is just falling off all of a sudden it just loses a ton of power now we we tried various things you know we didn't forget how to tune it all worked out perfectly on the 48 we were also running e85 we had more than enough injector more than a pump we're not dropping pressure none of those things are happening this was all at about we even tried i'll show you we tried running more timing in this thing and it does a little bit but we're having something happen here that's eerily not related to the tune the air fuel on the gas scale was about eleven and a half to one exactly the same as we ran on the four eight we know that this thing is doing or should be doing something differently what should be happening is this torque curve should be just above the n a torque curve basically everywhere it should just kind of railroad track over and be better than this all the way through possibly until we run out of capacity of the supercharger we don't need to spin this thing any faster something is happening that's causing this power to drop off like this and unfortunately right now i don't know what it is let's take a look at the at the booster and i'll show you that this thing is probably not losing capacity and that's why we think that there may be something going on with the motor we're gonna um do a because we ran out of time i'm gonna have to take this thing off and do a compression test and we'll do a leak down i don't think anything's wrong with the motor i mean it ran perfectly solid when running this thing n a so we're still scratching our heads a little bit about this but let's take a look at the boost curves and see if we can figure out something there so this is the boost curve supplied by the cadillac sts supercharger on our 6 liter you can see it's starting out at the load in about 8.2 pounds it's dropping down to at 4 000 rpm it's dropping down just below seven and a half i mean this sk on this scale that looks like it's a dramatic drop but you're talking about three quarters of a pound it's not it's not a ton um then it actually kind of climbs back up and gets back over eight eight eight pounds of boost eight point one out here at about six thousand rpm this is actually the kind of uh booster that i would expect on this size blower and this size motor unfortunately it's just not correlating to power and you know we ran a couple of different runs where we tried the tried you know different timing and things and the boost curve is kind of consistent and if anything out there at a higher rpm the boost curve is climbing up to eight and a half which is a you know it's kind of a good sign but i don't see anything here in the boost curve that shows me what would be happening and why power would be falling off so dramatically in this combination so if you guys have any if you guys have any things for us to try let me know like i said air fuel nice and steady at 11 and a half we've got a good timing curve in it it's not in the tune there's something else going on we thought maybe belt slippage we even as i showed you in the video we even took a video camera in and and had it aimed at the tensioner to see if maybe something was happening with belt slippage but we're not seeing that we tried to look at the inlet system to see if something was collapsing or you know with their aluminum tube so there was nothing there we're still we're still kind of scratching our head but the last thing i want to show you is a comparison between what's happening with the six liter and what happened with the 4.8 liter to illustrate the difference between the 6-0 and the 4.8 liter let's take a look at the n a stuff really quickly so this was our 4-8 it made 400 horsepower 401.7 and 368 foot-pounds of torque and here's what the n a power output in comparison looking at our 6.0 basically it made more power everywhere made 529 horsepower and 499 foot-pounds of torque and it basically did everything better as we would expect of a 6 liter compared to a 4.8 liter now let's take a look and see what happened after adding boost to both of those if we compare the 4.8 liter run with this cadillac sts supercharger it made 591 horsepower and 592 foot-pounds torque almost square there uh this area here below 4500 we could fill that in a little bit uh with another a couple of degrees of timing but as i said we just kind of wanted everything to be safe and not hurt either one of these motors but here's what happened in comparison to the so this is our six liter and it's doing what we kind of would expect um below 4000 or 4500 rpm you know it's making a lot more torque it's making 645 foot-pounds to 590 and actually i would kind of expect that mo that number to be a little bigger than that given the difference that we saw in torque production on the n a motor so this tells us that something's going on even in the area where it seemed like it was working okay down here you're still talking about a difference of 550 foot-pounds 625 so you're talking about 75 pounds there difference between the 4 8 and the 6 liter i don't think this is blower capacity i know if we sped the blower up obviously and we matched the boost we could pick some power up but i'm not concerned about that about those minor things what i'm concerned about is this thing just falling on its face after 4 500 rpm so we've got some looking to do when i say we i mean me i'm gonna have to do i'm gonna start i'm gonna do a compression test i'll do a leak down test um we'll obviously check the oil and make sure that there's nothing going on with the bearings and then maybe check for leaks and you know double check the inlet system i just don't really understand right now what's going on but unfortunately i ran out of dyna time so we're gonna have to take another day to figure this out okay guys what did we figure out running the cadillac supercharger on our six liter we found out that every dyno day does not go perfectly now i don't think that we showed that this supercharger is too small for a six liter i don't think we've actually figured that out yet i think we have a problem with either the motor or a boost leak or we have a coil pack going down or something like that i don't think that this combination would act like it is on the dyno if we just ran out of supercharger we've run plenty of other combinations with superchargers that are too small for that and what we see is the boost will start to fall off at the top where there's not enough capacity to support what the n a motor wants to do and we're not seeing that so we have some other kind of problem and unfortunately i don't have enough dyno time right now to figure that out on this combination the way that it is so i have to take this off but while i'm doing that we're also going to do a couple things we're going to do a compression test and a leak down and i'm going to check the oil to make sure that there's no bearing material i want to make sure that the motor is sound i think that it is based on what we did on the n a combination but i just want to verify that once we know that the n a motor is good then we can look at other things we can look at boost leaks so we can look at the air inlet system we can make sure that the blower is not seizing up we can look at all of these things and try to figure it out do we've got i tried changing spark plugs i don't think it's that i don't think it's if we tried changing coil packs we tried doing a variety of different things so i think we've eliminated some of those things but we haven't figured out exactly what it is but i will i'm richard older make sure to like share subscribe ring the bell do all that stuff more testing on the six liter coming up even if we have to do it on another motor

Channel: Richard Holdener

Views: 27,925

Keywords: LS, JUNKYARD, BOOST, SUPERCHARGER, 4.8L, 4.4L

Id: WGGf56pcG7M

Length: 16min 6sec (966 seconds)

Published: Sun Mar 21 2021