I am looking to put a single turbo on my 2000 Corvette. I am looking for 800 - 850rwhp on pump gas. Meth is not out of the question, but e85 is as it does not have the availability needed. Here is what I have so far:

402 LS2
- Callies Compstar crank/rods, Wiseco pistons, 11.5:1 compression ratio
- GMPP CNC LS3 heads, milled .036. Comp Cams 921 spring kit
- Comp Cam 235/250 .621/.596 115+4
- ARP main/head studs
- ARP2000 rod bolts
- Cometic MLS head gasket
- return style fuel system
- 450 walbro in-tank pump
- Holley billet rails
- Aeromotive A13101 fuel pressure regulator
- Deka 60# (69# at 58 psi) injectors


Here is what I am looking at getting:
- S480 turbo
- Turbosmart Big Bubba Plumb Back BOV $380
- Turbosmart WG45 Hypergate 45 wastegate $470
- Treadstone TRST Single Turbo Intercooler, Chevy, Corvette, GM, Viper 968HP intercooler $450
- truck exhaust manifolds

The conundrum I am in is I had been wanting to keep it NA, but making power NA is getting waaay too costly. The headers I need are going to set me back $2300 alone. I figure I can sell my current headers for $800 - $1000, my nitrous set up for $1500. That would put $2300 in my pocket and I am trying to keep the cost of the turbo system under $3500. I will be doing all the labor and any fabrication necessary myself. If there are components other than what is listed above that would work better and are more affordable, I am more than open to suggestions. I also have no idea where to look for the S480, assuming that would be a good turbo for my build.

 

You also have to consider the cost of lower that CR ..11.5 is waaay to high at least you need to keep it down to 9 or 9.5 also that cam looks to big the S480 easily can reach that 800 mark you want but that CR will demant C16 or e85 plus some meth and to much timing pull ..just my 2 cents

 

Atreet car? Truck/c6 will work with V bands. I don't have accesoroes so my pics may not help.

 

Having raced LS stuff well past your HP goals and being an owner of a c5 myself I think you're going about it all wrong. If you already built that monster 402, sell it. Its way too much engine for what your trying to do and not cost effective.

If you want an alum block get a gen4 5.3. If block weight isn't a big issue (80lb difference) I would get a basic gen4 6.0 engine. Leave the bottom end and heads alone, including the hardware. It is more than capable of 800hp. Run ARP head studs and a good MLS head gasket. (LS9 gm gaskets work great) Run a small low lift turbo cam that utilizes the factory valve train. Upgrade the springs to match the cam. That is literally all you need engine wise for your power goals. Factory intake and exhaust manifolds are more than adequate. Don't over complicate it.

Your fuel system sounds good. I would suggest 80lb injectors. They cost no more, idle just as good and will allow for more power in the future if you want it.

Turbo system will be difficult to package IMO unless you go with a rear mount setup. The S400 frame turbo is HUGE. Twin small frame 60-67mm turbos would be much easier to package up front and easily handle your 800hp goal. If you do go S400 frame go with a custom T4 1.25 housing with a larger 92 or 96mm exh wheel and a billet 76mm comp wheel. It is more than enough turbo to reach your goals an S480 is not needed and will just slow spool.

The entire turbo kit could easily be done for under $3500 if your using factory manifolds and doing the work yourself. Use 2.25' piping off factory manifolds for the hotside. Its easier to package and flows more than you'll ever need.

 

I disagree completely on a few points, and completey agree on others. If he built the engine already, he will most likely lose money by selling it now. The extra cubic inches and cylinder head flow will allow him to reach his goal and have a more streetable car. I agree that the compression and cam need to be changed. Two of my friends built an iron 408 for a customer's 1999 C5 That already had an STS kit on it. The 408 utilized 9.0:1 compression, Trick Flow heads and a ZR-1 cam and head gaskets. I believe it was the stock intake, but can't say for sure. After upgrading the turbos to twin 67's, the car made 925rwhp on 13 psi of boost. My tuner friend also likes to use LU80 injectors because they are relatively inexpensive and have good idle characteristics. The OP stated that he wanted 800-850 RWHP, to which a t4 based 76mm turbo would be maxed out. It may make the power, but it won't be very efficient in doing so. The better quality parts will increase the engines longevity due to the increased strength over stock parts, and the engines ability to make the power at a lower stress level. Less boost and less rpm will allow the engine to live longer. Of course the stock long block will make it as well, but with a lot more boost.

 

800-850rwhp equates to about 120hp per hole. The #60 injectors can cover this at 55psi base pressure. If it were mine I'd go with larger injectors though. Then again with the motor you described I'd forget the turbo and put a good plate kit on it and spray it until it runs the number you want.

 

Leave everything you've got - instead of a single turbo try a pair T3 based turbos with Ptrim turbines in good housings and a good 5Xmm or bigger compressor. These turbos would probably package way better than any single capable of 850+ rwhp on a well done 400+ cube LS engine in my opinion AND the twins will work much better with the large split of your current cam. Outside of that - yes, bigger injectors. At least 80lbs as anything less is pushing it IMHO cause you are only going to end up wanting more or at least "knowing you can". Another bonus of twins would be two small pownpipes package very neatly in the room already there for exhaust manifolds and x pipe, etc. You can build right off a pair of factory manifolds of your choosing and cost would likely only increase due to the extra wastegate. Don't think I'd bother with BB T3's as it's not so important on a bigger motor.

I think it's all really doable. There are a lot of turbos to choose from as well.... TONS of T3 options really. Plan on spending between $1200-1800 range for a pair and you can have some really nice turbos capable of over 1000rwhp which would allow for good flow through the hotside/turbine/turbine housings....

 

I guess you may want to plan on some meth as well to aid in detonation due to compression since E85 is out of the question.

I've run high comp and boost on my last setup with no issue using E85 and feel like you could achieve the same with meth injection and 91 or race gas alone. Probably even run perfect at lower boost levels without meth since the vehicle weight is so low too! Do it up. I'll bet it makes great power on pump fuel and low boost without being aggressive.... One thing to remember is that higher compression motors have a cooler exhaust gas temp due to their more thoroughly burning the fuel during combustion. So sure there will be more of a "hit" from each cylinder due to the CR but the heat will be less. Just something more to consider....