tobb14

I have a LS3 GS Corvette with the following mods:

A&A supercharger
Methanol Injection
1 7/8 Longtube Headers

My question to this forum is what would it take to get my car up to 700rwhp and what add-ons will i need to make 800rwhp. I've been talking to a few of my friends and seems that 700 is the breaking point to just shoot for 800+ because dollar wise i would be out the same amount of dollars. Either way i would like to know what people have been using to achieve these numbers.

Patriot Six

Make sure you have enough fuel pump and injectors and then turn up the boost. A blower cam will also help. Plenty of LS3s running around at 800whp.

_zebra

cam, heads, 102 throttle body, fuel injectors/pump, trans build - particularly if auto
big power = big $$

Unreal

Don't need a cam but it will help. Heads don't have to be touched. TB doesn't need to be touched. Need fuel system and a smaller pulley is all you really need. It also depends on auto/manual and what A&A supercharger you have. T/Ti trim will make 800 no problem. The s/si trim will not and would need a large blower.

_zebra

but doing it with the rest of those supporting mods will yield a much more efficient setup on less boost with lower temps, making it more reliable & way easier to tune. not to mention, plenty of guys start pulling vacuum behind the 90/92mm TBs once they start pushing 700+
i'm making mid500s with just a PD blower on a stock LS1. sure, i could pulley down for a few more pounds of boost & be over 600, but it'd also be a time bomb... just like any unmodified GM automatic transmission when you double the engine power output.

Unreal

It isn't a pd blower so that is completely irrelavant. With an AA kit he just needs enough fuel and right pulley. Done.

tobb14

To all thanks for the advice. I think I will just change the pulley wheel for now, re-tune, upgrade injectors, purchase valve springs, lifter rods and cam separately. after i purchase all the remaining components I will add them later this year. Right now fuel and pulleys are a good temporary fix.

russ472

you are going to need more fuel to the bigger injectors

_zebra

i never said he couldn't do it that way; i said using the extra components would be more reliable & efficient. that becomes a little more important when you start talking an 800hp build vs 600.

explanation spoiler: i'd recommend pulleying for mid-700s then adding the other top-end parts listed earlier to bust past the 800 mark.

PD vs centri makes no difference regarding the point i was trying to convey. horsepower is purely the math of an amount of torque at an rpm, and torque is determined by how much air & fuel you can move through a given amount of time & space. different builds (n/a, nitrous, pd, centri, turbo) do that in different ways - each with its strengths, weaknesses, and regions of better/worse efficiency than the other.
a centrifugal blower is just a belt-limited turbo, which of course flows better on the top end than a PD - true... meaning easier to make big HP numbers.

my point is this:
you reach a power goal by moving a specific amount of air/fuel through the engine. a supercharger moves more air than the engine can (that excess air movement is measured as boost). thermodynamics says that compressed gases heat up, and hotter air/fuel mixtures are more prone to igniting early during the compression stroke. that can lead to a bad day for an engine.
how can we combat this? make the whole setup more efficient by increasing its natural air flow capacity. that way, the supercharger still moves that same amount of air, but since the engine can now move more on its own, there's less backlogged air (boost), which leads to a cooler intake charge temp and allows the computer to continue taking advantage of the prescribed ignition timing (as opposed to retarding it to prevent detonation). this is even more important when you've got almost 11:1 CR because high-compression engines also have a lower margin for boost & high IATs than a FI build does (typically between 9 & 10:1).

as for the throttle body, have you ever tried to drink a coke through a coffee stirrer? the same principle applies to an engine trying to move a crap-ton of air. or maybe a water analogy would be better: you can use the hose-pipe on your house to easily douse out a campfire in the back yard, but let's say your entire garage is ablaze, you're gonna want the fire department's 4" hose connected to the high-pressure hydrant to keep it from evaporating before ever having any effect on the fire. the stock 90mm is fine up to high-600s before it starts becoming an intake restriction. some guys've seen as much as 25-30hp when you start talking 700-800hp builds just by swapping to the 102 because it stopped choking the engine on the top end. the alternative is to turn the blower faster to force that extra air through, but then again... heat/knock or efficiency.

and good luck actually using that much power for very long through the stock clutch or a stock automatic. i've seen tons of dudes talk about having to replace the trans after the tuning dyno pulls... not saying that'll necessarily happen to him, mind you, but i ain't out to lunch on that statement. when you're making (and actually using) that much power, it ain't a question of 'if', it's a matter of 'when'.

any of that make sense?

_zebra

i'd recommend the in-tank replacement over a boost-a-pump.
either should work, but the replacement is actually engineered to move fuel more fuel whereas the boost-a-pump simply supplies extra voltage to the existing one to make it run faster & pump more than designed.

russ472

i would suggest listening to Unreal. He has an 1100 rwhp daily driver and has been around the block a time or two. 800 hp is a different animal than 550.

I run the ECS stage 1 fuel system. At the power level you are looking to run, this is much easier than dropping your fuel tanks to do an in tank setup.

Unreal

PD vs centri has a huge effect on getting to 800. One does it with ease, the other needs all the little tip/tricks/etc.

There are plenty of super basic 800+rwhp centri setups. Just need octane, enough fuel, and the right size pulley. Sure you can do a cam/heads/etc etc and spend a TON of money, but it is absolutely not needed.

Bone stock TB on my car, well over 1100rwhp. You are pushing air through it, not sucking like a PD. Not an issue and almost no gain.

xBoostx

Just a quick one here all, when changing pulley is best to change for a larger lower pulley sense you can keep a larger top to stay away from belt slippage in my 402 GTO I use a 9 inch lower and a 4 inch top though not for every body sense power comes in early but a 8 inch lower is sweeet.

Detoxx03

Follow these guidelines

7SECONDS

Exactly what these guys said. Overdoing it with the Fuel System is Key! Lean will burn it Up.

tobb14

Yes I'm in agreement with UNREAL not because it's the cheapest option but simply because that seems to be what everyone is saying on different forums. I won't ignore the safety the additional mods but my prime focus right now is make sure the right injectors and the pump to feed the beast so that's where i will start. From there I change out the 3.8 wheel to what others are running to make this setup work. Again thanks to everyone who has provided feedback it has really helped me to understand the pros and cons to this build.

7SECONDS

I am at 750RWHP on a Mustang Dyno. I am using 850 Injectors and a Fore Triple Fuel System. Yes, 3 pumps is a little overkill but it has been reliable. My build also includes a ECS Novi 1500 kit @ 14 psi Boost (No Restrictor), Big Blower Cam, Alky Control Dual Nozzle, 1 7/8 Kooks headers, 3" Offroad X Pipe, Corsa 2 1/2 Extreme mufflers, Mantic 9000 Twin Disc, Carbon Driveshaft, ECS Transmission Brace and Drag Radials. All on a Stock LS3 Cam Only. It has been very reliable for the last 3 years.

MRSUPRA

Interesting topic. Are you all saying you can get 800rwhp with a stock cam and stock valvetrain with a T trim blower?

Unreal

Easy, if the rest of the stuff is properly setup. Is it easier with a small cam, sure, is it needed, absolutely not.

MRSUPRA

/\thanks. Didn't realize that.