6.0 Horsepower upgrades?

[COPPERHEAD42]

My dad is starting a build on a 2 seat ultra 4 style buggy. He is wanting to race in the SMORR outlaw series and KOH if he was to qualify. He has a 02 6.0. We pulled it out of the truck because oil pressure was low and it was knocking a little bit. He is going to rebuild it and is wanting to do cam and head work. Anyone have any idea what a good cam would be or if head work is worth the money or not on these engines?

 

[Juan_Hong_Loe]

Thats a very good motor to work with. IF you do head work, 92mm Intake and throttle body, Bigger injectors, and a cam, you push over 500hp easy out of it. Very good friend of mine has one in a RX7 and puts down 490hp to the rear wheels before the NOS. Runs perfect. No overwhelming cam or anything like that. LS1 Tech has good articles but will confuse the **** out of you if yo get too deep into it. Hinson Supercars in Bessemer, AL knows a lot about these motors if you need to call someone.

 

[COPPERHEAD42]

Thanks. Its a great motor for sure. He is just wantin to do it all while its apart

 

[hinton]

if you need someone to build the motor jeff burns out of tupelo performance built mine and it has been great. just pick the right cam and carry it to him, its all in the cam and heads on the power!!!! i have an ls1 with just a small 224 cam from thunder racing in my buggy and i love the power curve of it

 

[patooyee]

You shouldn't need a 92mm tb and intake to get 500. I'm no pro but PLENTY of guys are putting out 500 with 6.0's, stock intakes and TB's. If you're going to work on the engine the best bang for the buck in heads are L92 heads. You can find them for $500 - $800 all day long on LS1tech.com. You have to shave the block to maintain stock CR and you'll have to get a matching intake but the factory config with those heads put out like 505hp I think so 500+ with yours should easily be doable.

If you get into stroking them you are looking at MAJOR numbers. Of course, the tricky part to all of this is dyno-tuning or finding someone who can dyno tune for you.

J. J.

 

[InDaShop]

talk to John Zubach or Ben Minden, then work in a perf shop that specializes in making big HP from the GM platform's. MC Racing http://www.gomcracing.com/
Kelly has both their numbers, if you dont already have them. Or shoot me a pm, I have 'em as well.

500hp out of an 6.0 isnt hard as JJ said. Offroading it and solving your fuel problems will be though. LOL

 

[patooyee]

Offroading it and solving your fuel problems will be though. LOL

Please explain ...

J. J.

 

[InDaShop]

Please explain ...

J. J.

Everyone seemingly believes they can run a stock OEM fuel system after beefing their engine. I'm guilty as well. Add to that racing.
one the deadhead of the stock rails, two the heat of the fuel pump.

Hardly a racer out there hasnt fought fuel delivery issues on their LS's at one point or another. Or if you raced BITD the first couple times Ultra4 had a class everyone fought fuel problems.

Thats all I was alluding to.

 

[patooyee]

Oh, forgot this was going to be a race rig.

I think the main problem has been heat in the fuel system. Dead-head rails allow the fuel to sit relatively in place the entire length fo the HP line after the regulator in an OEM setup. Thus, if any of that line runs close to your exhaust or even in the rails at the engine it can soak up enough heat to turn into a gas which will cause the engine to run lean. There have been a lot of fuel system mods done and most of them have something to do with the heat. I think pass-through rails are a big thing because they allow the fuel system to circulate throughout and essentially use the passing fuel as a coolant. You can modify the stock rails to be pass-through or get aftermarket rails. If you run a truck intake it is difficult to find aftermarket rails that fit which is why I modified mine to be pass-through. (I just cut off both ends and had a -6an fitting welded to them.) Here's pics:

There are several reasons I modded my own instead of buying aftermarket. We can get into that if the discussion progresses.

J. J.

 

[Travis]

There are several reasons I modded my own instead of buying aftermarket. We can get into that if the discussion progresses.

J. J.

I plan to run L92 heads and intake, do you know what fuel rails are available? Or why did you choose to modify?

 

[patooyee]

I plan to run L92 heads and intake, do you know what fuel rails are available? Or why did you choose to modify?

I modded my own for these reasons:

1. I am running an SSR intake and no manufacturers knew if their rails would fit it. Not many manufacturers make aftermarket rails for the truck intakes.

2. The aftermarket aluminum ones presumably help heat transfer more efficiently out of the rails and act like little coolers. BUT aluminum isn't a magical metal. It transfers heat INTO the fuel just as efficiently as it transfers it out. Thus, if your issue is that your rails are absorbing heat from nearby components, the aluminum aftermarket rails will actually worsen your problem.

3. Fuel rails act like small little fuel accumulators so that when your big hp engine starts gulping down fuel it has a reserve and doesn't cause a drop in fuel pressure. The more power you have the faster it will deplete its reserve. All the aftermarket manufacturers brag about the internal dia. of their fuel rails because the bigger the bore the bigger the reserve. You will be hard-pressed to find an aftermarket rail with an ID larger than 5/8" though which equates to an internal fuel voume of 4.56cubic inches. Maybe compared to the small round car fuel rails that is a lot. (I don't know.) But if you consider the internal volume the rectangular truck fuel rails you will find that they have a much larger volume due to their shape. Do the math on those and you will find that the rectangular truck rails have an internal volume of over 7 cubic inches. That's A LOT. Now consider that a stock factory round car rail has been proven to be able to deliver enough fuel to feed a 750hp engine and it even further reduces the requirement for aftermarket rails. The important part for colling is that the fuel flows through the rails instead of dead-heads and that can be solved by a modded set of stock rails.

4. I am a cheap bastard and don't spend money on anything I don't have to. I have about $30 into these rails and aftermarket are $200+.

Oh, and if you need bigger injectors and are running a truck intake, consider the 8L injectors out of a big block. They fit the truck intakes but flow more fuel. Do some research as to how much more vs. the requirements of your build.

Also, the early truck intakes used round fuel rails, not rectangular like the new ones so the above math may not apply to all truck rails. But if you run an L92 intake with matching rails that was way after they switched to the rectangular rails.

J. J.

 

[InDaShop]

Best tech I've read in a long while. All sound assumptions. Thanks J.J.

 

[Blase]

Great tech J.J. thanks!

Did you have to cut the plastic covers off the those rails or was that how they came stock on your motor?

I ask because mine don't look like that. Might are round and plastic with what looks like a crimped or pressed on metal end. My motor is approx. 2002 so that may be the differance.

 

[patooyee]

I'm not familiar with all the rails that were available but mine had no plastic on them. Sorry I can't help you there. But I did not have to cut any plastic off. Those were how they looked with the exception of some additional fittings for the x-over pipe which I cut off and welded closed since I no longer needed it.

And I don't want it to sound like the aftermarket rails don't solve any problems. Most guys that convert from the OEM regulator setup to the aftermarket use the aftermarket rails simply as a way to get the flow-through design that they need to run the aftermarket components. IMO, the switch from dead-head to flow-through is what solves their problems, not the switch from stainless to aluminum. I don't think many people really think about it when they are doing it. I think they just say, "Hey, my fuel is overheating, I must need aftermarket components to fix it." But if you're heat-soaking from external engine to fuel rails, your rails are just going to heat up faster with aluminum. Its the cool fuel constantly flowing through them that keeps it from reaching the temperature point at which liquid fuel turns to gas vapor.

BUT if you want flow-through rails and don't need the aftermarket bling people will literally give these SS rectangular rails away.

J. J.

 

[BamaTJ]

Any mods you can make to stock car fuel rails to get make them flow through or just have to go aftermarket

 

[patooyee]

It depends on which car rails you have. Like I said, I'm not familiar with them all. Here's some pics of a guy who did it to his in his stock Corvette rails though:

Basically, if you can weld to them they can be modified. He maintained the stock crossover pipe which still dead-heads the back 4 cylinders. But he just did the mod so that he could use the aftermarket pumps / regulators, not for heat or performance. Nonetheless, he dynoed over 750 RWHP with those rails.

And before you ask, the thing inside the rail is a fuel dampener. It is a thin stainless "balloon" that sits in the fuel that expands and contracts slightly with spikes in fuel pressure. Not all fuel rails had them in there like that. Some had an external dampener that was just plumbed into the fuel rails. Others didn't have anything at all. It is widely believed that an aftermarket regulator setup regulates the pressure good enough not to have to need a dampener. Ultimately though, it probably won't make a huge difference if it doesn't.

J. J.

 

[kid rok]

I'm curious about the L92 heads and intake. What combo makes the most power, Ex: what, cam , intake, throttle body, etc. Also what internal upgrades need to be made.? such as springs rods and what nots. I was also told it was cheaper to run a drive by wire rather than a cable throttle body on the Corvette intakes. Is this true?
I've done a little research ,and have been talking to a local speed shop about the same thing, but I also would like to hear what the peanut gallery has to say.

 

[patooyee]

I'm curious about the L92 heads and intake. What combo makes the most power, Ex: what, cam , intake, throttle body, etc. Also what internal upgrades need to be made.? such as springs rods and what nots. I was also told it was cheaper to run a drive by wire rather than a cable throttle body on the Corvette intakes. Is this true?
I've done a little research ,and have been talking to a local speed shop about the same thing, but I also would like to hear what the peanut gallery has to say.

There’s too many combinations to say that any one makes the most power. However, if you look around ls1tech.com you will find a lot of l92 builds with dyno power specs. IIRC the most anyone has got out of a mild build (IE, heads, cam, headers, springs.) is about 460 RWHP. You can talk to different people and get different estimates on what that is at the flywheel but the generally accepted loss in those vehicles I think is about 25%. So 460 RWHP = ~575 at the flywheel. I’m pretty sure that was with a stock TB and intake. That guy did have a very flat torque curve that would be great for wheeling though.

Most do upgrade the valve springs when they change heads. This is because the stock springs are only good to about .5” of lift or so and most aftermarket cams will have more lift than that. If you’re JUST doing L92 heads and a cam though that’s about all that needs to get upgraded. The stock rods are generally considered to be reliable up to 700hp or so. If you put L92’s on a 6.0 without shaving the block your CR will drop by like .5 or so. Most people do shave their block or heads or both. Some don’t. The guy above didn't.

J. J.


EDIT: Here's the thread with the above vehicle: http://www.ls1tech.com/forums/dynamometer-results-comparisons/1123842-ls2-l92-heads-makes-460rwhp-446rwtq.html

 

[Cole]

So if you swap to the LS3 intake, do you need to get the LS3 injectors and fuel rail? Or will the LS1 stuff swap into the ls3 intake? What about the Throttle body?

 

[Travis]

So if you swap to the LS3 intake, do you need to get the LS3 injectors and fuel rail? Or will the LS1 stuff swap into the ls3 intake? What about the Throttle body?

I may have been confusing you texting, LS3 intake will only work for you if you add L92, or equivalent heads. Throttle body will be aftermarket if it needs to be cable.