You can definitely over think this stuff. I built a stock bottom 6.0 for my all steel 69 Nova. New rings and bearings, used BTR turbo cam, 317 heads with springs, VS s480, turbo 400, 9 inch with 3.70 gears. 80lb injectors, on 93 octane runs 9.71@140 in the quarter, in a 3700lb car. Safe afr, 14lbs and 15 degrees of timing. Scary fast! More than anyone needs on the street.
Would you be interested in doing a pump gas limitation video on something like a turbo ls. Timing vs adding boost to gain hp. Higher compression stock heads vs 317s. Keep up the amazing work and thank you for all the testing.
@@kyholm You'll need an adapter, but the CD009 Nissan transmission is reliable to 800 hp, shifts better than the T56 and costs $1500 brand new from Nissan, you can find them in the wrecking yards for $600. If the shifter is too far back, by a few inches there are shifter options. If it's way to far back then the Nissan Truck 6 speed has the exact same internals as the CD009 in terms of strength, the ratios may be different.
Yup, there really isn't an option that's very affordable if you aren't willing to just treat transmissions like wear items, pull timing/boost down low to help them live, etc. Been going through this as my nephew has a Fox project that we've been talking about BBF swapping(factory block 557" stroker w/ SR71 heads, 13:1 comp for E85/meth, and a turbo with very mild boost) and keeping a man trans in. With an engine you plan on being 4-digit capable, you end up in this hole in the market where your options are like
You can probably find a set of ls3 heads and intake for cheaper than buying a fast intake for the cathedral ports and still make more power with ls3 combination..
I agree with you, problem has become finding an intake. Truck rec port is more affordable but LS3 has become expensive. Maybe just get the Holley intake?
@@philsautobody I’ve seen new ls3 intakes go for a little over 300 on eBay, I’d imagine a holley intake would work, only some of us f body guys would have trouble fitting them under the cowl without having to chop it up and delete our wipers.. 😔
we're running 317 heads ported 225 intake CC with 2.05 valves and pack 650 Max Springs. Flow 305 or more. These things make big power. We're currently running about 1300 horsepower . Possibly an LS3 head would make more power at the same boost but I don't think we've come close to the limits of this current combination. Only 25 lbs of boost still have another 10 pounds left in it. 35 lb of boost should make big Power with the 317 heads
No, absolutely not, run what you brung for a turbo set up. Your factory LS cylinder head will give you what you want except for a spring replacement. If you want 750 street horsepower, any head with a decent cam is going to work... Sloppy(elgin), BTR, or Summit...just get your lift. Tried and True don't BS me builds terrorizing the street in that range all day long. If you need or have to have 1200 or better, it's far more complicated.
That is the final conclusion I thought you would come to...I’ll make as much power as I want, with my 317 heads....gonna be very careful not to over power the rest of the driveline and suspension.....Not going to start over, just plan to optimize the existing combination! Very grateful for the comparison!!
With stock heads that flow as well as the LS3, I think it comes down to economics. CNC ported LS3 heads from GM add 10% in peak flow and presumably a similar amount of power for $1200. I always think in terms of additional power added per dollar spent, because I'm always looking for the best value. If I have my NA LS3 up to 550 hp with a cam swap for $450, then want to add 50% more power (825 hp) with 7 lbs of boost with a $1200 turbo setup, that's a good value. But if I spend the same $1200 on CNC ported heads for 10% more power (605 hp), that's not as good a value. Say then that you have your 825 hp turbo LS3, and want to add another 10% power, you could spend the $1200 on ported heads, and get to 908 hp. Or you could just turn up the boost to 9.2 psi, and make the same amount of power, and not have to spend the $1200.
That’s what kills me about these Facebook groups and, to an extent, forums. Lots of people have one question, one answer they’re looking for but fail to realize that if you do the research you’ll learn a lot more in the process!
Man! This video really explains boost vs back pressure events. I'm going to share this video with one of the younger mechanics where I work. I've been trying to describe what may be going on in his turbo application but I've been unable to and I know I've been very unclear about it. This video showing back pressure, power output and boost required is freekin great... He either has to go to electronic waste gates or open up his exhaust (like a dump valve before the cat). Thank you again Richard, really useful data. Ed D EDIT: I would like to request information on an electronic controlled waste gate control that can be graphed on a laptop if someone can recommend one. One that can give data on all essential sensors including what is shown on a scanner. He has a lot of gauges including back pressure but in a graph it's much more likely to catch and diagnose an issue then trying to compare gauges. This would be on a Scion FR-S, not sure of the year or size turbo he is running.
For all us guys who purchased a wrecking yard LQ4 and were previously told that the 317 heads are not the go to head, this is great news. For the $$$ saving of finding a set of used LS3 rec ports, I can buy ARP bolts for the heads and mains and then make 800HP on 7 psi with 100 octane all day. In 1970 the famous LS7 454 with 12:1 compression was advertised to make 460HP ( made more like 525 HP). We've come a long long way.
You can get a pair of 823 and an intake for half the price of just the fast intake. Its well worth the swap. More power and far cheaper. Most guys wont have paid for a fast intake. If you buy a T6 hotside to start with, you can clear 1000+ at the wheels NP.
On an engine dyno, where you have unlimited cold water for the intercooler and race gas, it doesn't matter. however, on the street, when using 93 octane, and limited intercooling, it is always best to make the power at a lower boost level. This cuts down on AITs and makes the engine less knock sensitive.
@@richardholdener1727 Sure...why not? Less AIT allows more timing on pump gas. Why would that be a bad thing? Especially since LS3 heads are so plentiful and affordable.
Friggin love that you got a RU-vid now! Remember begging you on Facebook! Been a short year! Don’t see you do much posting on Facebook anymore though! Miss you in the community brother!
Nice! I just bought me a Silverado with a 6.0 not sure on if a lq9 or 4🤷🏻♂️🤦🏻♂️😂 but I’ve been watching this channel for a minute and lots of good info. How’s your truck run now with the mods you’ve done, I as well got the 317 heads but been thinking of swapping.
Great video and information as usual, Richard! I'm actually in the process of turning my LQ4 into a LY6. I was not a big fan of turbo charging, so I wanted to do the best I could afford NA. But might turbo charge in the future, so this video helped a lot. If I was going to turbo charge from the beginning, I would have saved my money on the heads and intake. Put that money towards the turbo and the conversion. The 30 - 60 hp/tq you gain between 823 vs 317 heads and intakes is not worth the money
I bought a lotto ticket because I want it all. LSX tall deck 461, LSX drag race heads. I want the LMR standing mile engine. That Camaro was a treacherous monster until the day it was totalled.
Agreed, there's more exaust backpressure because there's more exaust from the higher power production. Higher power production also implies higher intake flow. Maybe the lower boost on the LS3 head is a result of more airflow through the compressor. Compressor maps show that for a given turbo RPM, boost drops as airflow increases. The higher backpressure spins the turbo faster but not enough to make up for the lost boost from increased intake flow???
My 6.0 came with 823s on it, so I’ll keep them. When talking absolute numbers, there’s really quite a difference between the truck 6.0 and the car LS3. A bit over 3% in displacement means about 20 hp at the top. Dropping the compression a full point means another 20+. Suddenly your 584 hp peak is down to about 543, all other things being equal. If you drop back to a bit shorter cam, like 225° intake lobe instead of 231°, then you’re down to just over 500. My 6L90 should be able to handle that, but putting the turbo into the equation would make that a big question mark. I think it will move the old C10 down the road, but the rwhp number won’t be so impressive. We’ll just have to see if it demands a turbo later...
Depends on the compressor map of the turbo. You'd have to see where the air flow vs pressure ratio lands on the map and see if the turbo is more or less efficient for the given combo.
It's all about efficiency. Sure you can run a big turbo on a small headed engine and make 1000 hp. You are going to make the engine work harder and shorten the life. I would personally port the 317s (if running on the street and run a smaller turbo.) Texas Speed & Performance has a great program for cathedral port heads and it is only about $1100 and they flow as good as some aftermarket rec port heads (for about 1/2 the price.) The smaller turbo will spool up faster and you should get better acceleration. Just my personal opinion.
True that! I've seen many cars with less hp outrun more powerful cars just because the trans, converter, and chassis were spec'd correctly! I think many guys overlook that.
I was thinking from what I’ve heard 317s are not that good but this test changed my mind 🥴bet very little bowl work would even out this comparison.Loved this test as I have a 6.0 with the 317 heads.if 800 hp is not enough add a pound or 2 of the ole boost 😉
Just for fun I would really like to see what a set of 317 heads that have been ported with larger valves installed would do. When know the 225 cathedral trickflows can outperform the rec-port LS3 heads, but can the 317's with a little work do the same. Might not be worth the money for the machine work I don't know.
Good test as usual bud. If there are questions about the same cam ran on both heads being better for one or the other hes also tested that as well on RU-vid.
I have 317 heads. I do not wanna make incredible horsepower. I do plan to upgrade my maximum total power. I am going to put a cam (stage II probably) & intake manifold, headers/ entire exhaust.... It will be my daily driver as well as something I can sort of show off... Do I need new heads? It is more for show as my special needs daughter LOVES these things ( but I guess I am being a little selfish) but we bond this way. I just know that she loves the rough grumble & I love to see her smile
It’s all about the Benjamin’s. You’ve proven both heads can deliver serious hp. Each individual will have to answer that question. Some will be willing to pay more for the rectangular port heads some won’t. Both are correct. Neither is wrong. Just, to me, depends how many Benjamin’s you wish to spend.
From what I hear the cathedral port heads have a better casting and a thicker deck than the rec port stuff. That would make it a clear choice for anything boosted.
Unless you're building a max effort engine the smallest heads to make your power goal will provide the most area under the curve. I run 862 heads on my 370 lq9, and it makes the thing a torque monster.
There is a good size list of changes when switching to ls3 style head If more airflow IS needed a ported set of 317 heads is far less costly and much easier No ?
Up to a 1000hp, I really cant see the need to worry about a head change. On another note, you should run a 6.0 and a 6.2 in the same trim just to see the power difference.
So, let's go back to the 706 vs. 799 head video. That 6.0 made like 513hp with 706 heads, and something like 524hp with 799. In this video this 6.2 made like 560 something with 317's. As we can see these numbers are kinda strange, considering the loss in compression with the 317's vs either of the other heads. So, is .2 liters worth 10, 20, 30 hp. That's what I'm curious to see. Not to mention Mr. Holdner apparently loves testing. More content ideas, the more videos, and more questions get answers.
Can you run 20 degrees of timing at 7psi on 91 pump gas , race gas no problem , I think that’s the power potential ??? Richard start testing are good ole California pump gas and e85 , see what the most output is , throw in some high ambient temps , see what the low buck street runner gets , love the channel !
I had my 317 heads CNC ported which gave me another 71 cfm on a turbo 6.0 ls, I also increased my cam to your favorite comp cam, now it does run quite strong however it seems like I lost power. Those are the only thing that I changed other than valve springs.
Hey Richard, werent these tests run with a T4 exhaust sized turbo? What happens with the backpressure when you run a T6 exhaust with the 96mm turbine? Or do you have a video like this already?
Im in the camp that says smaller valves less valvetrain mass will live longer on a turbo engine. No need to waste the ls3 heads for the gain over a cat head.
Anytime you can make more power with less heat it is a gain. A better flowing hot side whether it be in piping or exhaust housing would allow for even more power at the same boost level. To match the power the less flowing head would need more boost and higher IAT’s.
If what you have can get you where you want to go, don’t change it🤷♂️. Budget friendly mind says, only change what needs changed to make the desired goal.
True the turbo makes the power you want but at what level do you loose reliability with boost I think over 15 psi your asking for trouble. So a ported set of 317 can make 800 hp at 14lbs non ported it takes 17lbs, porting heads has its place for sure
Is there a build combination for a LS engine for torque? Like a 6 liter built bottom with 4.8 heads, intake. Something where the power peaks between 2200-4500 rpm. Like 450 hp and almost 600 tq. Or is a big block the only way I'm getting those numbers at the rpm?
Naturally aspirated, no. But I would think with an undersized turbo it's possible. However, I think your engine would be happier with a more appropriately sized turbo that makes 600 hp to go along with that torque in the same way this engine is happier with the LS3 heads.
Keep in mind that LS is small block architecture and really are not great for torque as they require a fair bit of RPM for good torque. Gen 5/6 454 or a gen7 496 will blow every LS out of the water without even trying. From a prior test, an engine that made the most torque out of a ton of others run was a 6.0 with stock cam, 4.8/5.3 heads and truck intake manifold. More compression would make more power everywhere but theres definitely diminishing returns considering the rest of the combo is stock everything......
A turbo TPI small block would get him exactly what he's looking for - the Callaway twin turbo Vettes from the 80s put down right at 450 hp and 600 lb/ft of torque all before 5000 rpm. But he asked about doing it with an LS specifically.
Reason I'm asking for such a combo is because of the type of driving I do. I'm never in it long enough to see over 5000. I'm more interested in AutoX and Rallying than I am drifting and drag. Having enough torque to keep me sideways when it counts and to correct myself into another turn. I was hoping a cammed 4.8 would be able to see those numbers NA all motor.
You can trade peak hp for torque somewhat with cam choice (and vice versa), but not to the extent you're looking for and certainly not out of a 4.8. The newer intakes tend to make more power everywhere, so it's not a choice of torque with a dual plane or horsepower with a single plane like you used to see. Your exceptions to this would be the Holley Hi-Ram (less tq for more hp) or if you were to convert to a carbed dual plane intake (more torque for less hp).
My question is, if I was to run a 6.0 LS, na, carbureted, and dual plane intake, what would make the best power for the street and occasional track. What head, intake and carb combo. What cam do you recommend. I'm on probably the very lowest budget lol!!!
THE BEST (CHEAP) HEADS WOULD BE FACTORY REC-PORTS, BUT THE CHEAPESTEST WOULD BE THE HEADS YOU HAVE. A SLOPPY STAGE 2 FROM AMAZON WITH CHEAP SPRINGS, 750 BRAWLER
BYW, adding an airflow meter may be of interest. The 2.2+HP/CFM is the thing I've always thought was why the AFR heads seem to twist the dyno farther than the flowbench.
If your class limited to a certain turbo and need to squeeze every last bit of power out of what you have then yea port it. If you're running a stock turbo motor the thousand dollars you would put into porting the heads could get the same effect by adding 2 psi for free... Does it help, yes. Is it worth it, no.
Except that in cylinder pressure is what makes the power, so for a given engine configuration the stress seen by the pistons, rods, crank, and block are the same for a given power level regardless of if it took 20psi of boost or 70psi of boost to get there. Boost is only a measurement of intake restriction in that case. The caveat to that is of course when compressing air it makes heat so as boost pressure goes up so does the heat and that is detrimental to power and of course components.
@@bcbloc02 Stress on the bottom end is only the same/similar when you compare IDENTICAL bottom-ends at a given power level with different power adders or induction.....A bone stock 4.8 LS would need 8500RPM to make 600hp N/A and LS7 shits out 600hp at 6000RPM...VERY different bottom end stress levels. Stress on the bottom end is even WILDLY more different when comparing different engines (SBC-BBC-K24-2JZ, etc)
Hey Richard, do you have any videos about your process replacing or even just gapping rings for big power? If not, I’d certainly be very interested in an instructional video from you about how to gap rings properly and what works best for LS engines
Ok I need some opinions. I’ve got an iron 6.0 bored .030” over that I’m fixing to rebuild. I want some flat top forged pistons with valve reliefs, either summit or DSS, to go with stock rods. I’ll be running a S475 but I already have a set of 243’s ready to go. Will my compression be too high with this piston head setup for boost?
@@mctigmctiggy1475 you’ve got a point. I forgot to mention that it as forged pistons that I was looking at. Even my guy at the machine shop says if it was him, he run the 317’s. Because I have a set of those as well. But from watching Richards videos, if I can make more power with the 243’s N/A, then it’ll make more power under boost!
Non-decked 243's on a flat-top 6.0 will give you 10.5:1 compression. Personally I would go with 11:1 pistons (4cc dome will give 11.5:1 with 243 heads) so that youll still be in nominal compression range if you upgrade cylinder heads later on (most have 68cc chambers). Also more power with more compression. Compression is NEVER too high for boost, its only ever too high for your tuner.
I had been doing some thinking on Richards earlier video about optimizing the N/A setup and how it’ll carry the power into boost. I’ll be daily driving and using my truck for occasional towing and frequent hot doggin so I’m looking to keep my low rpm grunt. Thanks for your comment Richard and friends!!
Alright Richard, I'm just gonna have to admit it. Im soooo jealous of your job dude. Don't get me wrong as with any job , I'm sure it's it's got 1-2 parts of it that u hate. But to get to play on the dyno all the time testing new/oem parts on multiple engine types/makes etc,that right there is what I'd call my dream job. Just watched the rerun of engine masters you did "Big Bang gen 4 LS 6.0l",I think that'd be the only part i wouldn't be crazy about w your job. That's only cuz i hate being on camera though. Anyway,on that "Big Bang gen 4 LS 6.0" you ran outta map sensor at 29psi (1500+hp), whatever happened to that test? Did you finally get a 3-4 bar sensor and keep pushing it?
I was looking into doing an lsa and figured If I was going to get the dapeters why not just get ls3 heads so if you are testing lsa stuff one of these days I think that would be a cool comparison
The question is where did the 1/2 psi difference in pressure put you on the compressor efficiency curve????? I don't know if the intercooler could take all the extra heat out or not (if there was a difference). All we really know is which one had better MAF.
I don’t think you need to upgrade the heads until you’re over that 1000whp mark. I’ve seen plenty of stock head cars 4.8, 5.3, 5.7 make well over 1000whp without touching the heads (aside from springs)
Ok so to further the question. What happens to power/torque If we keep the intake and exhaust runners, valves, spring rate and compression (I realize that means different pistons) exactly the same and keep the shape of the chamber the same but use different chamber sizes will we see a greater overall effect on power by going to smaller chambers or a top end effect on large chamber heads Edit: Whilst under boost that is.
I suppose it depends on how much money you want to spend, as well as how detrimental the larger ports might be, regarding fuel efficiency and driveability at lower RPMs...
Richard: Dude, you made the 1000HP club! You: but, but, if I get LS3 heads & intake, I can get MORE Richard: SAVE the extra money, spend it on your gal.... You: the other more? Richard: class dismissed
If the engine is bone stock, put that money toward cam/lifters/springs/gaskets instead of boost. If the motor already has a decent cam, wait til you have $1000 set aside for it and get forged pistons/rods (dome with a point higher compression so that it makes more power N/A) so that down the road its 100% ready for boost. That's my opinion and pretty much what I did with my chevelle. I could've supercharged a stock+cam LQ4 and make good power til I turn the pistons into swiss cheese, but instead I installed wiseco pistons, SCAT rods, and LS3 top end (Roughly 5K all said and done) which costed less than the supercharger and still makes 600hp N/A for good fun. Its now perfectly ready for boost (literally install supercharger, tune and done) and will make 1000hp with ~10psi later on if I decide to (kind of pointless for an autocross car).
ok so I am watching every video you pretty much have doing my home work. I have 317 heads and shooting for 1000+ hp I have decided to utilize methanol injection for those special days when I want all I can get as those days will happen. I have said in numerous comments 408 stroker engine. your graph shows a pretty good power gain from 3500 to 5500 which is where this engine will be the majority of the time. and less boost pressure and more power will help with the limiting factor which will be the fuel 91 octane pump gas am I correct in this assumption. so 80% of the time will be at 7-10 psi on pump gas only the ls3 head puts out more power down low. even though I can just turn up the boost to get that extra power with the 317 heads I will run into my fuel being the limiting factor correct? so the wiser choice would be to up grade head in this situation. or am I off somewhere? I am slowly trying to learn all this from your videos. thank you so much for all you do.
Rich has said in prior videos (I've asked your exact question before) that the COMP 54-469-11 is really the largest that you SHOULD do for PTV clearance being nominal (in caps because you COULD go bigger and go less than nominal specs), that's 231/247@.050 .617/.624 113LSA. Dish LY6/LQ4 pistons have a similar depth to the valve reliefs on LS3/LQ9 so the PTV is similar. Cylinder heads won't change PTV UNLESS valve angle is different (some BPE, MAST, FED and TFS heads are 12 degree instead of stock 15 degree), or block and/or heads are decked. Speaking from experience and measuring PTV, a 12 degree LS3 head has roughly .050 more PTV than a stock LS3 head.
Does the exhaust before the turbo effect anything greatly? Would be cool to see the an actual turbo header vs the flip manifold and after we can ask do we actually need a 2k worth of exhaust or can we just get y pipe fabbed up
Thankyou for the awesome vid! What about upgrading the cylinder head for the extra thick deck surface? Because I’ve always heard once you get around 800 hp on a factory head then it’s close to push a head gasket because it starts distorting the head even with ls9 head gaskets and arp studs
