HOW TO: MAXIMIZE JUNKYARD 6.0L LS PERFORMANCE

foreign [Music] LS and you want to modify it either you already have a six liter in your truck or you have one that you're swapping in something else so the question is what should I do what mod should I perform what cylinder head should I use what intake should I use and most importantly what camshaft should I use how should I modify my 6 liter hmm maybe we should do a buildup how about a couple of different mods how about 10 6 liter combos in this video we're going to take a look at no less than 10 different combinations I'm going to show you a variety of different cylinder heads that we ran on a six liter a variety of different camshafts we ran on a 6 liter and even a variety of different intake manifolds that we ran on a six liter we ran Cathedral Port heads we ran record heads we ran Cathedral cams we ran wreckport camps we ran stock cams we ran all kinds of stuff so you can take a look at what you want to do to your six liter okay guys before we get to our testing I want to bring up something very important and that's the fact that we used an ly6 short block for all of our testing but all of this stuff applies equally well to an lq4 or an lq9 or heck even an LS3 short block you see all the six liter seven even the six liter stuff all of the modifications that we did on this ly6 6 liter short block apply to all of the other six liters now obviously the compression is going to be different on an lq4 versus an lq9 and even versus an lq six but the reality is that's not going to change the results sure more compression is going to add power but it adds power both on the Baseline number and on the modified number so the results of a cylinder head test are going to be the same on a lq9 because it has a little more compression I I want to point out something very important here a lot of guys think that compression works well with one specific kind of camshaft or one specific kind of cylinder head or intake manifold and it does not compression is a lot like boost it basically adds power everywhere and we always use a percentage to show how much it adds but the reality is that's just a an easy mathematical formula compression adds power everywhere no matter what camshaft you put in if I compare two different camshafts on one motor that has eight to one and the other motor that has 11 to one the camshaft change is going to be the same on both Motors it's just going to start out lower and end lower on the motor that has less compression and it's going to start out higher and higher Automotive has more compression so what I'm saying is we ran all these test on an ly six six liter but it applies equally well to an lq4 or an lq6 let's get to our results to get things started on our upgrades to the six liter we're going to start off with Cathedral Port heads and then for the next one we'll go into the rec Port headset because obviously the Record Head can be used on a six liter which the factory did on a number of combinations now as I indicated earlier in our discussion it doesn't matter whether you're starting off with an lp4 an lq9 or in this case an ly6 they're basically all the same you'll see a minor difference in compression ratio for each one that you start with but that will just improve both the starting power and the ending power of any of the modifications the changes from the modifications will basically stay consistent it just matters the starting point and the ending point so we're going to start off this six liter it's an ly6 short block and we have a cam in it because if you're going to modify a six liter the first thing that you should do with any six liter regardless of which one it is if you want to get the most bang for your buck is put a camshaft in it Cam and springs are the big upgrade for any LS that's what you should start with unless you're starting with a turbo which is also a good start even with a stock cam but we set up this ly6 short block with a comp 54-459-11 camshaft and it's it's not the the go-to 469 cam it's just it's the cathedral Port version of that which is a 617 624 lift split a 231 239 degree duration split at 114 degree lobe separation angle so basically it's the 469 cam but with less exhaust duration and don't worry I'm going to show you a comparison between this and the other Cam and it's not really very much different because they're both really kind of similar so what we did was we got things started by installing a set of 799 heads now the 799 hits for guys that don't know 799 243 basically the the go-to like high performance Factory Cathedral Port head these work really well and actually on a six liter and I'm going to show you the difference between a the 799 and the 706 head these might be as good or better choice than the smaller 706 head on this bigger six liter so we ran this thing with 799 heads and I put a Dorman LS2 intake manifold on which you've seen in any of my other videos or the stories I did on it the Dorman LS2 is basically the functional equivalent of a Trailblazer SS it's just a lower profile and it fits when I compare the two back to back the whole power curves are almost identical there's a little bit of wiggling here and there but basically they're the same kind of thing this Dorman LS2 works really well we had a 92 millimeter throttle body on it inch and 7 8 long tube headers and tuned all of this and all these combinations with the Holley HP management system so run run with the sock 7.99 head the only thing we did was put valve springs on it no Milling no bigger valves no porting no nothing just an azcast stock 799 head with valve springs on it run with those heads R6 liter produced 522 horsepower and 481 foot-pounds of torque so now I know what you guys are thinking okay well what about what if I had a six liter and I wanted to upgrade 317 heads which by the way we should address the elephant in the room 317 heads you should just get rid of unless you're running boosts and I'm sorry if I hurt the feelings of all the 317 guys out there but in terms of all the factory heads that's the low man on the totem pole because of the compression it makes the least amount of power of any of the factory heads and you can see that in any of my other videos so if you're going to upgrade that head the the easiest and least expensive choice is to put a set of 706 heads on from the 5.3 because though people will just give those away although maybe not after all the videos I've done but here's what happened when we put replace the 799 heads with 706 heads so the 706 had made more power than the 799 up to about 5000 RPM and out here at the top from about 5900 on out the 799 had made more power because on the 6 liter unlike the 5.3 which the 706 hit is a much better choice the on the six liter the bigger bore and this power output and that's very important this power output can take advantage of the extra airflow offered by the 799 243 hit they flow a little more than the 706 and they work well on the bigger bore so that combination allows them to make a little more Peak power although down low they didn't make as much as the 706 head and everybody points to compression but we were only talking about around three CC's difference between these two heads so this is not all compression people need to realize that that's also a combination of the smaller valve size and the port volume and the Chamber shape and there are other things that make this kind of head this 706 head want to make to enhance power in this RPM range so now let's take a look at the other modifications we did to our six liter after comparing the 706 and the 799 heads we'll get rid of our 706 so you're probably asking yourself hey Richard what happens if I want to upgrade the heads on my six liter what can I do to improve the power output compared to a set of 799 heads and obviously you could put more camshaft into this although there's a limit to how much camshaft you can put in with the available piston of valve clearance and something in the 231 or so degree intake duration which is usually the valve that's going to hit first depending on the lobe separation angle and the valve events you know you're getting up near you have a limited piston to valve clearance so there's not a lot more that you can get from the camshaft so what happens if you upgrade the cylinder head on this and the a natural upgrade for this would be to go to an aftermarket head and what we did was put a trick flow head on it so here's what happened when we put a TFS 225 head in place of the 799 head and you can see we picked up quite a bit of power power output jump from 522 up to 560 horsepower and in this case we ran the trick flow 225 head with the same Dorman LS2 intake at 92 millimeter throttle body but here's another interesting test and it shows you know the gains of an intake manifold when you're talking about this kind of power level the factory intakes obviously were not designed to work on a combination that was making over 550 horsepower although they're doing pretty well and the Dorman one the Dorman version actually is pretty good but here's what happened when we replaced the door the doorman intake with a fast intake and with these 225 heads and as you can see there were big gains starting at oh 4300 RPM or so so equipped with a fast the power output jumped to 576 horsepower and you can see it's carrying it fairly well even past 6 500 RPM we ran it all the way out to 6800 and it was still making the same power out there at 6800 so the fast intake on this combination is definitely worth some power I mean we're talking about gains of 40 53. you know we're talking about uh 15 to 16 horsepower over the other stuff so if you're looking for that last little bit the fast manifold I know it's more expensive than the Dorman but not it not so much anymore they I think they've raised the price on the Dorman and they're much more money so I might spend a little extra and just get the fast to begin with especially if I was going to upgrade the cylinder heads so now you're probably wondering hey Richard what about that you guys are all wondering stuff huh um what about that 469 cam so here's what happened when we ran the this is with the 799 heads in the dormant intake but here's what happened when I ran this combination with the 469 camera set of the 459 cam the only difference between the 469 cam is it just had a lot more exhaust duration but here's what happened it basically lost power down low and then picked up power in other parts on the curve so it like the added added exhaust duration it just doesn't like it as much down low the idle quality goes down a little bit from the extra exhaust duration it basically just wants to make power at a higher RPM so you know if that's what you want that's a good Cam and that's a recport cam on a cathedral Port head and it still works so now let's take a look and see what happened on our six liter if we step up to the rec Port hits It's the starting point for our rec Port modifications to our six liter head and again we started off with an ly6 short block but you could do this with an lq4 or an lq9 in fact we ran a stock lq4 camshaft in this thing we replaced the vbt stuff that comes in the ly6 so basically this would be the same thing as if you put Rec port ly6 or LS3 heads on your stock lq4 lq9 six liter with a sock camshaft in it so here's what happened when we started things out we still had the ly6 the truck version of the LS3 intake manifold which by the way produces identical power numbers to the factory LS3 intake so those two are the same even though they look different they made almost identical power curves every time I've tested them so fundamentally they're the same thing so this lq4 cammed ly6 our starting point produced 443 horsepower and 467 foot-pounds of torque so on the on these combinations what I want to do is show you what happens if we did a little bit milder stuff and then we can work our way up to a lot a lot more camshaft so the first thing I did was we put what happens if I wanted to put an upgrade with like one of the stock cams so what we did was put a factory LS3 camshaft in here let's see here we go so equipped with the LS3 cam the power output jumped to 475 horsepower but as you can see which is a you know a fairly good gain especially past 4500 RPM it picked up power but compared to the factory lp4 cam it lost power down low and we see that almost all the time when I compared the LS3 camshaft to like the lm7 camshaft we saw the same thing it loses power up to about this point and then gains power afterwards so your trading power so you guys have to decide is is that factory camshaft upgrade really what I want to do or do I want to go to an aftermarket Cam and here's what happened when we put the camshaft from trick flow and it basically it was the it was the sloppy stage 2 camshaft so it was like a 228 degree duration uh here we go so that was actually a good upgrade compared to that factory LS3 cam the peak power jumped up to 513 or 514 horsepower Peak torque was up to 493 foot-pounds and it gained power even over that mild stock cam even down as low as 3000 RPM so that's a fairly good upgrade if you want to pick up power everywhere it picked up the only good amount we're still we're over 500 horsepower 514 horsepower but here's what happened when we put the um you know something a little bit a little bit bigger cam like the 459 or 469 camshaft in here so here's the 459 camshaft and as you can see big gains pass 52 or 5300 compared to that um sloppy stage 2 cam uh basically big gains compared to the factory cam it kind of fell below the factory cam below 3 500 or 4 000 but picked up power from 4 000 on out and ended up making a power of 541 horsepower and here's what happened when we put the instead of the 459 Cam and put the 469 camshaft in and it just again it did kind of what it did in the last test on the on the cathedral board heads it lost power down low here in the 3000 range picked up power out here past 6500 everywhere else it was basically identical so there's fundamentally no difference unless you're revving the thing way out or care about the idle quality and the low speed stuff um than maybe the 459 cam is a better way to go but here's what happened when we ran so this is what happened if you ran the uh a factory ly6 or LS3 head upgrade on your cam to six liter whether it's an lg4 lq9 or in this case an ly6 which in that case it's just a cam upgrade but in the others it would be a cam and head upgrade so now you might be thinking well what what about and the by the way the peak power was 543 with a 469 cam but now you're probably wondering well hey Richard how does that compare to the trick flow headed Cathedral port well let's take a look at that and as you can see the ultimate combination with the cathedral Port stuff with the trick flow head and the fast intake manifold you know made 576 so it's still better than the than the factory Rec Port head and I know a lot of guys here's the comment I always get when I run this kind of test because I posted this before in another video um yeah but what about if I put a fast intake on the on the recport heads well unfortunately the fast intake on the rec Port head does not gain power like it does on the cathedral Port head in fact it probably would show no gain at this power level on these record heads so it would be the same curve the factory LS3 intake manifold or the ly6 intake manifold is really hard to beat as fast guys have found out and that fast LS3 just doesn't really add power there so this is still a good comparison um because actually the doorman intake of anything I think holds it back compared to the factory LS3 manifold on the other combination the trick flow 225 heads are just a better head than the factory LS3 hit is now maybe you could put a ported recport head on there and especially one that had um you know a milled head that had the right compression then you could get that up to the standard but I I'm not comparing those two things I'm not telling you which one is better I'm just showing you this is what they do and these are the kind of power gains that you can get if you run these combinations because they work very well there's obviously more power to be had from the factory head because we've made almost 700 horsepower I think with those combinations so you could definitely get a lot of power output of it on the right combination but here's what happens when you upgrade your six liter let's get to our conclusion okay guys what'd you think about all those test results on our 6 liter ly6 as I said you can apply that equally well to an lq4 or an lq9 but on the ly6 we did a lot of testing we compared a bunch of Cathedral Port heads and a bunch of rectangular Port heads and a bunch of camshafts and a bunch of intake manifolds did you guys get any ideas for the stuff that you want to do to your six liter is there something I miss is there something else I should attest now here's something important I know guys are going to want me to try oh I I wanted to try a camshaft that was between that sloppy stage two and the 459 or the 469 you can just draw a line in between those two and pretend that we did that because that's exactly what's going to happen same thing with the milder stock cams if you look at videos I did on all the stock cams on the 5.3 liter and you see the difference that's going to be the difference on the six liter it's just at the crossover point for some of these Wilder cams is going to be shifted back a little bit in the RPM range and by back I mean down a little bit in the RPM range it works a little bit better on the bigger motor and that's all that's going to happen so all of these modifications should give you a good idea what to do with yours sure if you want to put a specific camshaft in there like a Truck cam I know guys are going to talk about I want you to do a torque one I want you to do a six liter to maximize the torque and believe me I have that coming I'm definitely going to do that we'll do a little a small torque Cam and the 706 heads and we'll maybe milliman and do the do the chamber openings and all that stuff I so all that stuff is coming up but for right now this should give you a really good idea what to do with your six liter thanks for watching guys Richard holdner here like share subscribe ring the bell do all that stuff more tested coming up

Channel: Richard Holdener

Views: 923,709

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Id: YV32T04CFxw

Length: 18min 29sec (1109 seconds)

Published: Wed Aug 26 2020