Hi guys, noob here, but I will be buying my 1st vette this winter, or perhaps this year. And with that I have to make some decisions.

This will be for a built/forged TT setup, but it will not be immediately. So the 1st stage will be the car, plus TT, and some supporting hardware, like rear, trans/clutch, rollbar. Then in 1-2 yrs, building the forged motor, and turning up the boost, along with fueling upgrades.

I would rather not waste too much $$$ on the interim setup, so whatever I buy I want to keep my end goal in mind...900-1000whp TT.

1.I know enough to stay away from 05's, but do I buy an 06-07 LS2, or an LS3 08? I know the LS3's are better breathers, but ultimately wouldn't a built engine negate that?

2.The 08's had driveline improvements, but wouldn't a upgraded trans/diff also negate that?

3. Are there any PCM/tuning differences that favor one over the other?

4. What about the other chassis updates on the 08's, are they worth it?

5. Finally, I know traction will be an issue, but would going to a widebooty be worth it? OR could I just stuff 11" wheels, and leave it skinny?

I hope you guys can help a fellow car guy out, I am not new to power or going fast, but I have never done so with a vette.

 

First I would like to commend you on planning out the whole process in advance. Most people head down several roads before ending up at their final spot which costs a bunch.

'06 and up would be best, just get the best deal to leave a bigger budget for the mods. The LS2 can be taken to 1000rwhp with the proper internals without much issues. You can send it off to ERL and get the 6 bolt setup and be done with it for example.

Yes, you'll need a clutch, built trans, diff and even some torque tube bushing upgrades. It'll be far from stock and negate any upgrades from the factory.

2005 had the more difficult computer, everything after that is fine.

Not anything the money saved by not buying one can't cover. You'll be looking at something like coilovers for example and those are only $1800ish installed.

Widebooty isn't expensive for what you get. More traction and great looks, no downside. Being able to cram a 345 under the car is cheap insurance when comparing what can go wrong with no traction and 100+ mph. If you don't want to buy super expensive rims you can get 18" Z replicas in C6 sized for the front and Z sized for the rear from corvette-wheels.com. That's where I got my racing rims from.


Keep planning it out as you'll need the fuel system, gauges, boost controller, TT kit etc. Write it all down and run it by our vendors for prices and needs.

GL

 

Drewstein, thx Precise and to the point. You pretty much confirmed what I was thinking.

And yes, I have done the whole dog chasing its tail thing with mods on previous projects, only to change midstream and leave a pile of $$$ with each change....So this time I vowed it to be different.

I agree on the points you made, so with the widebooty, and Z06 wheels, I assume I can stuff a BBK or even oem Z06 brakes within the wheels? I'm not positive on the brakes, just yet, as so far I only see some caliper stiffness, as being gained with the BBK's, because it is almost always the pads, that make the difference, especially since I would be looking to do 1/4's, and the standing mile, with some occassional fun on the streets. These are short blasts, and not prolonged track oriented braking, so I would rather not spend $$$ on huge BBK's just to say I have them.

 

I'm not sure about the front with the regular C6 sized rims in 18" if they'll clear Z brakes, but the rear with the wide booty does clear my 14" Stoptech 4-pot calipers with plenty of room to spare. You can get the rims because you'll need them anyway and measure the front clearances. I think it'll fit but do not hold me to that.

You are right that a lot of it is in the pads though. Some decent Hawk pads work well.

 

To answer the LS2 vs LS3 question, the LS2 is the better short block imho for boost, I could have gone with either block as I bought a new block when I went with a forged setup, from data taken by my experience the LS2 has better cylinder spacing and thickness to keep head gaskets happy... So only for the "short block" my vote is LS2, now as far as T56 vs T6060 for different year model trannys, the 6060 wins hands down, so you can't really get a year model with the best of all worlds... If I were you, I'd look for an '07 in good shape, best bang for the overall buck... Good luck with your purchase and build...

 

Mr Big,

So even after rebuilding the T56, the TR6060 will still be that much better? I would think going with the 06-07, and the dough saved, I could buy a TR6060 outright, or used for that matter, and get the best of both if it really makes that much difference.

Interesting comment about the blocks, I wasn't aware that the LS3's was structurally any better. Why an '07, was there some change that year that wasn't in the '06? Not arguing, just wanting to know why...

Thanks for the helpful insights so far guys...keep them comin' I'm all ears!

 

08 LS3 blocks are ~20% stronger then the LS2 block. The 09 and later LS3 blocks are 18% stronger then the 08 LS3 blocks. GM beefed up the blocks for the 09 LS9 and then used the block casting for the 09 LS3.

 

What are you talking about? Blocks don't fail... things fail and take out the block.

In regards to the T6060, it's not that hard to pick one up instead of buying a car for it. Either way it has to be built.

 

The block casting it self your data is true Joe, with several big hp builds on LS2 blocks with zero issue with block integrity, my build is rather mild in comparison to some.... However the cylinder bore and spacing on the LS2, is better for keeping headgaskets intact in an F.I. application... I researched a ton of data before my build.

 

Just wait around and buy a car with all this on it to start with and save big bucks then go have fun.

 

best advice so far...

 

What is the stock bore cylinder wall thickness of the LS1/6, the LS2, the LS3 and the LS7? Nomally, when a auto company increases the cylinder bore diameter on their engines they maintain the wall thickness. They just lose some water jacket volume.


I didn't realise that there was a problem with head gaskets. I know the stock LS2 has a 3 layer, the LS3 has a 5 layer and the LS9 has a 7 layer head gasket. Aftermarket head gaskets too, I suppose, that could hold some serious boost on a street engine.

At the narrowest point(between bores), the LS2 is .400", the LS3 is .340" and the LSX454 is .215". Thomson Automotive Engines has put twin turbos on the LSx454 engine and has seen 2000+ horsepower without head gasket problems. Granted, the LSx series engines have the 6 bolt heads, but have the narrowest distance between the cylinder bores is .215". The LSx block can be taken out to a 4.250" bore and not have head gasket problems with the .150" distance between the cylinder bores. Somehow, I believe a LS3 with the LS9 7 layer head gasket(or equivalent aftermarket) would hold up just fine. If you're planning to take a LS2 up to a boost level that would be blowing head gaskets, then you will need the extra strength in the bottom end that the 2009 up LS3/LS9 block provides.

 

This was a great explanation of my point above. If you're building the motor you should have the proper head gaskets as well as studs etc. I recommended getting the 6 bolt conversion done for the OP's 1000rwhp needs which negates LS2/3 choices.

 

More to an engine then the top end. The LS7 was designed before the LS3 and changes they made to the block casting when designing the LS7 carried over into the LS3 block. As you know the engine is an air pump, but when the piston is moving downward, the air trapped below the piston has to go somewhere, easily, or it takes power to move it or compress it. In designing the LS7, besides increasing the main bearing web strength, to minimize crankshaft deflection, they also redesigned the windows so that the trapped air could move easier. On the LS7 they gained around 30 horsepower with the new window design and size of the window. The LS2 does not have the improved window arrangement that the LS3 does, as it was designed before the LS7 and the LS3.

Another little thing. Even though the LS2 and the LS3 have the same rods, the rod bolts are different. They changed the design of the LS3's rod bolt to make it stronger then the LS2's rod bolt, and they also changed the material to the same material as the LS7's rod bolt, again to increase the strength of the engine's bottom end. Less chance of spinning a rod bearing and creating a massive oil leak in the side of the engine.

 

Joe the above quote says it all, there are major head gasket issues when it comes to "higher" power LS F.I. setups. There is a ton of data to research, you could read about head gasket issues and "pushing water" for days once you start the search in the right places... LS engines have issues with pushing water once the boost gets cranked up enough to achieve 1000hp. There are ways to keep it from happening, and to prepare your setup against it... Too much already out there for me to retype it all. You may not have realized it before, but several of us have dealt with it and figured out ways to prevent it for years...

 

While I know it would add ~118 pounds to the front end of my Z06 and I would have to go with a wet sump instead of my dry sump, I think I would go with a LSx454 iron block with the six bolt heads if I wanted to make big power. They seem to have no problems with the head gaskets, even when pumping out over 2,000 HP.

 

Ls-3 better block and heads!

 

Good point on the window design but the rest of what you typed is moot. Built motor, remember?
I would also disagree with this. There are a few places that will do a 6-bolt aluminum motor and it doesn't have to be 454ci to hit the OP's 1000rwhp goal. What you missed with the LSX motors is I have seen a lot of them have issues with the water jackets. I would take an ERL superdeck motor over the LSX any day.

Wet sump or dry sump, I wouldn't bother changing from one to the other. If you have a dry, leave it, same with the wet.

Dude, once again it's a built motor... stock heads don't matter and blocks don't fail before other parts take them out.

At 1000rwhp a LS3 and LS2 will be near indistinguishable.

 

 

The reason I mentioned the rod bolts(and the stronger main bearing webs) is that the OP stated he wanted to go with a TT first, then a built motor later. I was stating a fact that the bottom end of a stock, non built, LS3 is stronger then a LS2.

Even later, when he wants to spend the money to take his motor and build it, starting with a LS3 block is a better starting point then a LS2. It would be nice if he had a block that didn't have a rod through the cylinder wall, to build.

You keep saying that the LS3 is a better engine because of the thicker cylinder walls, and I have asked what the difference is between the cylinder wall thickness between the two. Just because the LS3 has .060" larger bore , that does not mean it has .030" thinner walls, and proper selection of the head gasket will more then cover the .060" narrower space between the cylinder bores without blowing them out.

I mention the iron block LSx454 because it is much stronger then any aluminum block, and cost a lot less. The larger displacement means it would take less boost to reach the OP's horsepower goals which means less chance to have problems with high boost levels. It also has priority oiling. That means the crank gets the oil first, not last, like in a LS2/LS3.

I mentioned the change over to a wet sump oil system in my Z06, if I were to go with a iron block LSX454, because the LSx454's crankshaft is 1" shorter then the crankshaft in the LS7. Why, because a wet sump system doesn't need an extended snout on the crankshaft because it only has the single stage oil pump, unlike the two stage oil pump used with the LS7's dry sump. Keeping the dry sump system on my Z06 would require a custom crankshaft if I went with the LSx454, thus loosing the cost advantage the LSx454 has over the aftermarket engines. Since the OP dosen't have a Z06(as I do), the wet smp system that the LSx454 has, is not problem for him.

In addition, the LSx454 comes with a much better set of heads then any LS2. They don't have to be touched for 1000HP. Again less cost to build the engine. The LSx454 comes with a forged crank and forged main bearing caps. Again, less cost to build. The LSx454 comes with forged steel rods and pistons. Again, less cost to build. Even though the LSx454 has a high compression(which a stock LS2 has that the OP wants to throw a TT on first, before he goes into the engine), it would take some decent boost without a problem. If he wanted to really get serious and needed 9:1 pistons, he can add them at a reasonable cost with out spending more money on the rest of the engine.

$9300 for a LSx454 crate engine and he has horsepower from day one, plus he will have a "built" engine ready for when he wants to blow the doors off a "built" LS2. What does a "built" LS2 long block cost that will handle 1000 HP?