jayyyw

Of course that means I have to.

I will be parting out my (almost) 800whp all motor setup soon, to rebuild the car into a boost monster. The only thing I will be keeping is the shortblock.

Goal for this trip in my crazy head is 1200+ whp.

Shortblock is a 428ci, sleeved aluminum block
Stock crank and rods, with Wiseco pistons
Compression will be 12:1
Going through Cesar Tellez for his BR3 heads
Cam Motion LLSR cam
8000+ RPM

Now, the only thing I don't know, is the route I want to take to get there. I've done the turbo thing. I've done all motor and nitrous. I haven't done a supercharged setup.

I talk a lot of **** on the centri stuff, but they are definitely capable. A Kong 2650 is also an option but will likely need to be a custom install.

So basically, in order, my options are:
Twin Pulsar 73mm turbos
Kong 2650
F1X
Big single turbo

Car is a '08 Z06, 6spd, that is really light. So, don't need a ton of power to go fast. Traction is definitely going to be an obstacle but I think I can manage it.

I will most likely begin parting out the car towards the end of July.

TrendSetter

i think twin turbos is the best and im surprised how uncommon it is compared to big singles.

The BallSS

iTrader: (9)

My vote is for twins.
Will easily make the power, be much easier to manage said power and probably easier to package too.
I've always had a soft spot for Prochargers but it seems like they need more effort to make the same power as a turbo setup and they don't appear to be as reliable.
The Kong would be cool but that much instant torque with a six speed seems like it would be difficult to manage.
Is there a way to manage the power of the Kong effectively with say a traction control system or something because then it would be cool to do.

C5_Pete

iTrader: (8)

If I were to start my build over again, I would do twins.

Also, you should go 4-link/9” while you’re at it…

NicD

iTrader: (7)

Turbo, simply for the power control aspect of it. Turbos do suck to do on a Corvette from a packaging aspect though as there just isn't much room to work with unless you really start to cut or remove things.

The BallSS

iTrader: (9)

Love the build a guy did on here where he put the turbos in the fenders, think it was a C5 or C6 build.
Can't remember his name though, it was a silver vette, very clean install.

NicD

iTrader: (7)

I thought about doing the same with mine but then you would need a fender exit exhaust and have to relocate the sump tank, ECM, etc. Plus you also aren't fitting anything very large behind the fender either even with cutting.

TrendSetter

1200whp from twins wouldnt need that big of a turbo if you use something fancy like a pte or xona

BCNUL8R

iTrader: (2)

It would be boring if everyone agreed so for the sake of discussion...

I'd go F1x. My first question is what fuel? You say 12 to 1 static compression even on a 428 it's going to take a good amount of boost to make 1200 rwhp maybe around 20 psi with an efficient motor and possibly more. Are you running methanol?

The procharger install will be easier and quicker to complete than a custom twin turbo setup, but you may not care how long the car is down. Under hood temps will be lower with a procharger. Twelve hundred is easier to make with twins than it is a procharger. The procharger at 1200 rwhp will be easier to control wheel speed with due to its linear power delivery. You might not care about drag racing, but if you do all else equal 1200 rwhp procharged will be easier to manage and probably ET quicker than a 1200 rwhp turbo combo in the same car. Procharger doesn't need to build boost before bumping in. You can bump in and wait until both cars are fully staged before bringing up the rpm and you are ready.

Turbos have more power potential and definitely are the way to go in a streetcar above 1200 rwhp or what you can make with an F1x. Any higher than that or bigger of a blower and it gets harder to argue in favor of a procharger in a true streetcar.

jayyyw

I've done twin 6766s before. Made over 1400whp. Also had a single FI s476 that made 1050whp.

Very heavily leaning towards twins as it will also be cheaper in the end.

There's ways to control the 2650 with a Smooth Boost controller, or aftermarket ECU with traction control capabilities. Kinda similar to running a wastegate on a procharger to control boost.

Eventually, that's the end goal but thats a loooooooooooooong time down the road.

My engine bay is pretty gutted already. Fuse box is relocated to under the dash, etc... No creature comforts, which is why the car is so light.

I was thinking of doing this, but since I am keeping my shortblock, I don't want to relocate the dry sump tank. You can build it to run the exhaust out of the rear of the car, just takes more thought into the routing.

I'd be going with mirror image Garrett clones that are 73/75. Should spool quick and support my HP goal easily, with room to grow.

It'll be strictly E85 and most likely barrel E85 when I turn it up. Don't really care much about drag racing but will likely do some here and there. I just don't want to deal with belt issues, is the main reason pushing me from the supercharger stuff. But anything can have problems, so it's not the end of the world. I do consider my car a street car, but I don't have any extra amenities. No p/s, no a/c, fuel cell, drag brakes, etc...

I have seen a lot more people with Centri cars have traction issues than anything else. Once it starts to spin, it just keeps going since the boost rises with RPM. But once they work it out, they fly!

BCNUL8R

iTrader: (2)

I'm interested to see how it works out with 12 to 1 compression at 1200 rwhp on e85.

I'm at 10.6 to 1 on e85 and meth injection and planning a new 388 build with an f1x shooting for 1200 rwhp as well. I was thinking about trying to go with more compression on the new motor, but don't know that it really would gain much and may end up just making it timing limited on e85 and meth.

Everything I've seen at similar power levels the prochargers are quicker in the 1/8th, but the turbos mph higher. Everything streetcar and small tire is 1/8th mile now. My car is still daily capable although I don't drive it to work due to the risks of rush hour traffic and sitting in a parking lot all day.

jayyyw

The higher compression should make more power on less boost and make it more responsive overall. If I have to add meth, I will. As long as I don't get aggressive with the timing, it should work out. Guess we are going to find out! lol.

BCNUL8R

iTrader: (2)

Yes more compression will make more torque at lower rpm for better response, but if it’s too much for the fuel being used you will make less power because you will be too spark limited. I think 12 to 1 is a bit much for what you are doing in a street car on e85. I’d go 10.5 to 11 to 1 but I could be wrong. I also believe methanol as a primary fuel for a street car is silly as it’s too much hassle for something I want to be able to just jump in and drive any time I want, but most people running in street car classes these days claim methanol as a primary fuel is just fine for a daily street car lol.

jayyyw

I'm currently running pump E85 with 14.5 compression on my N/A setup. The fuel is capable, IMO. I want to run the shortblock as-is, since I know its good and built right. A 70cc head will put me at 12:1 with a .050" quench. I'll never run meth as a primary fuel on a street car. I'll add it as a secondary fuel to spray while in boost, if needed.

TrendSetter

you obviously have your **** together. im looking forward to the build.

BCNUL8R

iTrader: (2)

14.5 NA is no problem on e85, but 12 to 1 with 20 plus psi is a different ball game. Good luck sounds like you know more about this stuff then everyone else here. Maybe I will hit you up for advice when I start building my 388.

I think 1200 rwhp with a sleeved aluminum block with 4 bolt heads is pushing it so I was thinking dart or lsx block for my build, but I’m probably wrong again.

so you recommend a resleeved stock block for 1200 rwhp over a dart or lsx?

NicD

iTrader: (7)

This is a VERY generic comparison, but if you start out with a static compression ratio of 12:1 with 20 psi of boost that is similar to 10.5:1 compression with 25 psi of boost power wise. However one of those will be VERY susceptible to detonation/pre-ignition and will have a very large pressure spike during the ignition event (especially with Ethanol) and one will be a lot safer and easier on bearings and parts regardless of the "tune up". Also keep in mind that even though you are currently running 14.5:1 compression on E85, just adding 20 psi of boost to a 12:1 compression motor is essentially doubling the dynamic compression of your current setup, and that is certainly going to stress pump E85. Either way with enough timing pulled out of it I'm sure it will work for a while, just don't get it hot and beat on it.

NicD

iTrader: (7)

I'm intrigued, do you have any pictures of this? Did you chop/lengthen any wiring or how did you route it into the dash area? I've been thinking about doing something similar, just haven't had the time to investigate it. I would probably move the ECM, etc all at the same time too under the dash.

TrendSetter

send the heads out for softening. will drop a little bit of CR and open up the tuning window at the same time.

i did my ls3 heads myself and they came out pretty nice. havent stressed the combo yet but im far from the only person to believe in the value of the process.

BCNUL8R

iTrader: (2)

Obviously I’m not as experienced as everyone else here it just seems like for a street car with intentions of doing very little if any racing it’s not worth pushing the limits of compression here for very little if any power gain on this type of combination.

A 428 at 10.5 to 11 to 1 should have no issues with response or low rpm torque. I’ve obviously been proven wrong on everything else I’ve said in this thread so I’m probably about to be proven wrong on this as well. lol.