Turbo 5.3 or 6.0 - ?'s

You don't need big bores, big cams, big cubes, or crazy flowing heads on a turbo motor. Thats kinda the point!

Also don't have to worry about the smaller bores shrouding the valves when it's all under pressure. Your boost knob dictates how much is flowing through the head (to a point). If your going stock for stock the 6.0 will fail before the 4.8 will power wise. OEM 243 heads will support over 1000whp. So unless your aiming for over 1000whp and plan on spending alot of money, why go with a 6.0 or $1000 intake manifolds?

The bigger is better mentality doesn't always apply.

I wouldn't classify the bore or cubes of the 6.0L to be very big. I'm not after any of that really. I'm not trying to set any records, I just want a fun toy that will be able to hang with nearly anything it meets.
I'm fully aware of how high the 243's can take you, but I'm also aware the prices of them vs. the Ls3/L92's. I actually just sold a pair of BRAND NEW 243's and only got $500 out of them (but I only paid $375 :p). If there was an affordable, cathedral-port head that flowed comparable to the Ls3 for the same price, I'd go with that. But there isn't.
And I won't be going with a $1000 intake any time soon. One of my reasons for going with Ls3 heads: The Ls3 intake is just plain AWESOME!
 
Sure you dont need them but why build it twice, you could use the ls3 intake and you probably will never need any more, just crank the boost, But FOR MY money Id build it right the first time, The better the heads and intake flow the less the turbo has to work to move the air AROUND SHROUDED valves and unsmooth intake passages. But I guess that your POINT! is do it cheap and do it numerous times. To each his own I guess.

"money". About that...I'm 21 and go to an automotive tech school full-time and work part-time so MONEY is not something I have a vast amount of. This will be a "budget" (to an extent) build. As someone else has mentioned already and you're probably full aware of this, in a FI application, high $ heads and intake aren't "necessary". Hence, Ls3 heads/intake. Neither will break the bank for the level of performance received.
For the record, I'm not looking to do this build numerous times. More than once? Maybe. But I hope to do that on my own terms when I decide to crank up the boost just to see what the breaking point may or may not be.
 
The OP is talking about using an OEM motor. We don’t all have bottomless wallets to build things to the hilt. I’d go that way too if money wasn’t a concern.

Ding! Ding! Ding!


My point is (if you know what your doing) you can make 600-700hp+ without aftermarket/LS3 parts or the larger cube 6.0 engine. That is a fact. To many guys out there over building engines when the factory equipment is more than adequate. (…and sometimes better). Shrouded valves aren't an issue with boosted LS motor at the 600-700hp range. Many folks (me included) run a 317 head on a small bore motor.
It’s not a matter of doing it the “right way” or the “wrong way”. It’s all about total HP vs $$ invested. If I you can reach your goals with factory equipment why spend more? An intake manifold, heads, and a bigger motor/cam aren’t going to last any longer that the factory 5.3/4.8 equipment. The countless guys out there making 600-700 reliably on a bone stock lsx series engine speaks for itself. It is more cost effective to run a $300 engine hard for a season (or more) and just replace it than it is to build some forged “super motor”.Longevity is an issue with any performance motor. I don’t care if you have a fully built motor or not. Chances are you’re going to hurt it at some point. I’d much rather blow up a $300 short block than a $5000 one anyday.
Turbos are made to “WORK” that is more my point. They operate at a specific range. Size your turbo correctly to your engine on a compressor map the first time and you aren’t causing extra wear and tear on the unit. Semi turbos operate at 25-30psi for 300k+. Turbo longevity is the least of your worries on a turbo build. The whole point of a turbo build is to use the turbo to make power, not the other way around.


You honestly think if the the TR guys running stage motors could make the kind of power they are putting out on factory parts that they wouldn't do it? Over building is moronic, period. If you can reach your goals with factory equipment then there's no reason to run anything else.

I agree with most of this. But I'm not looking for the turbo to make the power for me. I'm, more or less, trying to max out what N/A power I can make and use the turbo to get me to my goal power level. I believe that doing so will prolong the life of the motor and turbo. Let's say I can get the "budget" setup I'm wanting to last 5 years...that's money well spent in my book.
 
you guys both have good points, I will agree that I feel like the $1000 FAST manifold, while nice, isn't necessary since you are forcing air past it at. I'm sure it would make more power at less boost, but I wouldn't even consider buying one unless I was rich as hell and had nothing better to do with my 1 grand.

^This.
 
yeah don't run anything bigger than 2.5. 2.5" crossovers and 1.75 (or 1 5/8) primaries have made way over 1000 rwhp before. If it's big piping before the turbo, it kills your velocity and will not spool worth a damn.
 
yeah don't run anything bigger than 2.5. 2.5" crossovers and 1.75 (or 1 5/8) primaries have made way over 1000 rwhp before. If it's big piping before the turbo, it kills your velocity and will not spool worth a damn.

No bigger than 2.5" crossovers. Got it. I'm not worried about the primaries. I'll be using my truck manifolds which I don't think are anywhere near 1.75". I'm just gonna' have a good coating put on the bastards after all the fab work and maybe even add some header wrap because I like the look.
 
yeah that would be perfect, I'm using truck manifolds and the primaries are small, you can cut the flange off and get a 2.25 or 2.5 pipe welded on there pretty easily. I'm wrapping mine as well, downpipe is already done, I'll fire the car up and check for leaks before wrapping the crossover pipes.
 
yeah that would be perfect, I'm using truck manifolds and the primaries are small, you can cut the flange off and get a 2.25 or 2.5 pipe welded on there pretty easily. I'm wrapping mine as well, downpipe is already done, I'll fire the car up and check for leaks before wrapping the crossover pipes.

I like your style. :cool: Smart idea to wrap after the initial start-up. That's probably something I would have done differently. Haven't checked out your thread in a while: How close are you to getting that bad boy on the road?
 
This seems like as good a place as any to ask as my other thread hasn't gotten near this feedback...Can the factory gauges be made to work with the Ls swap? I'm looking to make some modifications to the car, but there are some things I'd like to keep "GN" appearing if that makes sense.
 
No bigger than 2.5" crossovers. Got it. I'm not worried about the primaries. I'll be using my truck manifolds which I don't think are anywhere near 1.75". I'm just gonna' have a good coating put on the bastards after all the fab work and maybe even add some header wrap because I like the look.

Truck manifolds and 2.5" primaries here. Those "tiny" truck manifolds have flowed enough to make over 1400whp so don't worry about it, they will be just fine. I can spool 12 psi on the brake in 1.4 secs. Check out my build thread in my Sig, might be helpful for some ideas. Good luck man, you will love it when your done.
 
Truck manifolds and 2.5" primaries here. Those "tiny" truck manifolds have flowed enough to make over 1400whp so don't worry about it, they will be just fine. I can spool 12 psi on the brake in 1.4 secs. Check out my build thread in my Sig, might be helpful for some ideas. Good luck man, you will love it when your done.

Yes, they're definitely capable of supporting all of the power that I'll ever even dream about. No worries there.
I'll definitely have to check out your thread.
Thanks.
 
I like your style. :cool: Smart idea to wrap after the initial start-up. That's probably something I would have done differently. Haven't checked out your thread in a while: How close are you to getting that bad boy on the road?

I should have it running this fall, or winter if I keep getting my evenings wasted like they have been lately with work crap...lol.

Factory style gauges are not worth a crap, and they won't really mesh with the ls engine management stuff. I pulled my gauge cluster out and I'll build one with some autometers that show actual figures, instead of the gay dummy lights like the factory gauges have. I'd advise the same on a turbo car, for anybody building one. Too much stuff going on not to know where your batt, temp, oil psi, etc. are at when you are driving.
 
I should have it running this fall, or winter if I keep getting my evenings wasted like they have been lately with work crap...lol.

Factory style gauges are not worth a crap, and they won't really mesh with the ls engine management stuff. I pulled my gauge cluster out and I'll build one with some autometers that show actual figures, instead of the gay dummy lights like the factory gauges have. I'd advise the same on a turbo car, for anybody building one. Too much stuff going on not to know where your batt, temp, oil psi, etc. are at when you are driving.

Shweet! I look forward to seeing the completed work. Are you planning on putter 'er on the rollers to see what she'll do?
I figured this much. If I could get them to work I was just gonna' swap to the 145moh speedo and use the Aeroforce Interceptor gauge to monitor some of the rest of that. It'll monitor all the stuff like battery, temp., oil pressure, knock, etc. And of course I'd have a boost gauge and I guess a wideband. I'm just looking to keep the interior fairly clean and not full of gauges.
 
I doubt I'll dyno it yet. I am going to load in a tune from Frost, then modify it myself to correct with lean/rich conditions. Once I get it nailed down I might dyno it, but who knows. I'm just ready to get it to where it can move itself, lol.
 
I doubt I'll dyno it yet. I am going to load in a tune from Frost, then modify it myself to correct with lean/rich conditions. Once I get it nailed down I might dyno it, but who knows. I'm just ready to get it to where it can move itself, lol.

Frost? What will you change it with? I have HPT, but I haven't trusted mysel to touch my bolt-on, Ls1 GTO, much less a H/C, turbocharged, 6.0 spraying meth. I need the professionals for this one. I gonna' see if I can get a safe, cruising tune on it and then take it to Heintz in Mooresville, NC for the rest. Or I'll just have to trailer it there. But it would be nice to do the break in on the way there.
I hear ya' on wanting it to move under its own power. Until earlier this week, mine didn't even have a rear end underneath it. It's just a 7.5" 10-bolt so we can roll it around, but Gpa thinks he may have actually found a rear for me. For $750, we'll get it, the '78 Malibu it's been installed in, and a full set of 22" wheels. Point being, it's a steal of a price for just the rear, and we'll be able to make money back yet. And Gpa will use the front of the Malibu's frame in his '33 Buick PU so we can toss the TB motor in.
 
sweet. Yeah I have EFI Live, so I'll fiddle around with it if it's not dead on. It won't be a DD, so I can just tune it going down the track next season for WOT stuff. I'll probably have him load a fat tune into it so I won't have to worry about it going lean and torching something right off the bat. The good thing is if it does torch something, it's a $700 engine and my dad owns a machine shop so I won't be hurting too bad.
 
sweet. Yeah I have EFI Live, so I'll fiddle around with it if it's not dead on. It won't be a DD, so I can just tune it going down the track next season for WOT stuff. I'll probably have him load a fat tune into it so I won't have to worry about it going lean and torching something right off the bat. The good thing is if it does torch something, it's a $700 engine and my dad owns a machine shop so I won't be hurting too bad.

Right on. This won't be my DD, either. I have a gorgeous, white, 4-door, '98 Mazda 626 complete with Mp3 player and remote start for my DD duty. *Hint. Hint. Total sarcasm* Keeps miles and the normal DD dings off my GTO. Gotta' love how easy these iron blocks are to replace. I've got multiple other candidates to toss in if mine blows, and I go to an automotive tech school so I have the machine shop covered. It's too bad we don't really cover tuning until 5th semester. Hopefully I have my other 6.0 block forged by then. Might even try to find an aluminum Ls2 block for the forged assembly...
 
If it blows up and sends compressor wheel pieces into your engine you'll be out a lot more than you think. Don't buy a cheap turbo...
B4 you go that route, look over on LS1tech.... LOTS of reasons to NOT buy that crap....

Not a problem anymore. I've decided to be less "fickle" with the build, although, it means taking longer than I want. I've talked with John @ Huron Speed and he's offered me the ball bearing Turbonetics TC78 "Benita" for a pretty fair price. Thinking I'll end up with that when I order my turbo, but we'll see if something bigger/better finds me.
Since, I've decided to do this build once, and do it right, my Lq will make the transformation into a 370. Another student at school will do the machining and boring (4.005" to 4.03") for free. So why not? I'll be keeping the stock 3.62" stroke crank and adding forged Compstar H-beam rods and forged pistons. I've seen both popping up on ls1tech recently. I'm gonna' see if I can snag either one brand new for a good price. If not, I'll order from Texas Speed sometime after the holidays. I'm looking to make 700whp/wtq now, but will build the fuel system to support far more. 120lb injectors ain't cheap! Still plan on doing e85 and meth. Guess I ought to start looking into beefing up my 4L80...
Can't wait! I should probably start tearing apart yet another 6.0.
 
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