gtfoxy

If you have the room, Turbo 8.1 FTW.... 500cubes goes a long way.

1500HP would be like maybe 30psi on a slightly modded 8.1. Or 25psi on a slightly more modded 8.1. Or 20psi on a stroked & big cammed 8.1...

InsaneDomestics

iTrader: (28)

I've heard that there isn't alot of aftermarket support for the 8.1

ls1_chevelle

iTrader: (9)

Go back to sleep.

gtfoxy

Don't hate the messenger... If he wants over 416cubes it is the best way to go.

There is plenty of support out there for what he wants.

Raylar is supposedly the best place for 8.1L parts & they have mild 511 strokers making over 600HP N/A at a lowly 5,500RPM & 540 making almost 700HP N/A @ 6,000. It takes a heck of a 408 LS to do that at that RPM with proportionate cam sizes. & torque? Fogetaboutit.. Most 700HP 408-419LS's will take 7,000RPM & make in the 550lbft, these monsters make 600+ From 3,000RPM easy.

Take those combos, add 15psi of adequate turbo boost & there is 1200-1400HP... On a stock block.

Their head/ intake combos flow almost 400cfm... Over 400 on a 4.5" bore.

Google is easy to use, hey.

But if you are lazy...
http://www.raylarengineering.com/vor...nce-parts.html

Petraszewsky

iTrader: (28)

I'd take a look at RHS block, Dart, or a sleeved ERL block for the thicker cylinder walls with the big cubes. All very blocks and with the right power adder you'll hit your mark. I went with a ERL block.

gtfoxy

A $5k block there... Plus internals... + externals.

$10k kit+ machine work get you more, if he wants bigger why waste the time?

Plain & simple the deck height is going to limit you at that displacement.

Quick Carl

Here's a link to a Drag week build. Maybe more than you want, but "streetable" for a weekend toy. It doesn't take huge cubes to go fast.
http://www.enginelabs.com/news/clay-...rls-superdeck/

LASTLS1

iTrader: (7)

First gen LSX block. Six years old. Same block same heads, ET LS7.
Not filled. 430 ci.
Twin 76 mm over 2000 hp
4.39 @ 181 1/8th


Not sure why you needs more cubes for what your doing. When I build a new motor I'll use the same cubes.

Guard dog

...drops the mike.

gtfoxy

That proves nothing, comparatively.

It all depends if you want to run a high-RPM "Small-block" or a low RPM big block.

Torque advantage over a broader RPM range & more HP will always win out when you have the room under the hood. His Chevelle has the room.

Set up a stout BB to make max boost at 3,000RPM & 1200lb/ft @ 15psi will humble you quick.

LastLS1, do you make that at 15psi? I'd like to see the dyno sheet.

I still say BB if OP wants what he wants. He asked, I answered.

Live with it.

LASTLS1

iTrader: (7)

I wasn't on the dyno, I race. There's many reasons with the LS platform that not pushing the cubes pays off in longevity.

Also the fastest LS F body in the world runs a 427 ci. 4.21 @ 180

Just my opnion, I don't just type it I do it.

gtfoxy

Don't get me wrong, it's great you do what you do. Kudos.

The old adage applies, no replacement for displacement. That is, all things being equal. If the base HP & torque is greater as a baseline then adding the same PMP will result in a given scalar power curve. No way around it. It is what it is.

I know what a high-rpm LS power curve looks like & I know what a lower-rpm BB power curve looks like. It's apples & oranges & we can leave it at that.

If he is set on a LS then fine, no skin off my teeth. But if he wants cubes & bottom end torque the turbo BB is the way to go.

JoeNova

Who the hell is ever at 3000 RPM on the strip with a 1500+ HP car? And why does it matter how much boost its at? You run the boost to meet your goals. Saying "I make the same power as you on less boost" is irrelevant when both cars run the same times at the end of the day.

gtfoxy

There's a lot of reason to shoot for the same power with less PMP & less RPM.

You are going to honestly say a car that runs a big block with more torque on a tighter converter is going to accelerate the same as a higher rpm motor with a loser converter & less torque & that they feel the same on the street? If so, you've never been in a turbo BB car.

LASTLS1

iTrader: (7)

I'm just Trying to be informative. If it were NA cubes would be better. Also the op said cubes, NOT big block. A 500 ci LS is NOT a big block.

Also like the others said, when I'm on the 2 step at 4200 rpm and let go of the brake aNd the converter flashes to 5300 rpm. I'm not sure what 3000 rpm has to do with anything. Otherwise everyone I race with would have 500 ci small blocks.

Now if you want to talk about a 481x, 560 ci PLR BIG BLOCK with twin 94's then that's a different story. Those will last with big boost.

Now get those cars ready it's almost spring!!!!

IronBlocked

But that ricer math though, reminds me of the import scene

gtfoxy

I get what you're saying. Honestly I do & I agree to a point. The BB vs SB debate has been raging since they were both made. Everyone has their preferences & I prefer a SB, but I don't blindly discount the BB on its capabilities for certain applications.

He also asked for a "streetable" combo. On the street a faster responding low rpm motor is going to give a much more enjoyable drive, IMO. Just tap the throttle lightly at a 1500rpm cruise on the BB & it will take off faster than the other SB combo. It's all how you want it to feel. Out of curiosity how much street time do you put on your combo?

He asked for opinions & I gave mine. He can listen or not. Also, I said if you have room & want as much cubes & torque as possible, for the least amount of money, it is the way to go.

I also said if he is set on a LS then great, he can build what he wants.

LASTLS1

iTrader: (7)

I drove my car on the street up to 950 hp, which is useless IMO. It was fun for a while to blow the tires off at 70 mph at will but that got old. I got into racing and never looked back.

What kind of BB turbo cars do you own?

gtfoxy

Not sure what math you are talking about, but...

This is the other end of the spectrum & the roles are reversed. Would we want a 2.5L running 40psi to make the same HP vs a modded LS running 25psi & would we think the car would feel the same on the street? If so then why are people jumping ship there & coming to LS V8 power? Because it's easier, cheaper & more fun to drive.

gtfoxy

Never said I owned one but I have driven them. Good enough experience to feel what was what. Like I said I prefer a SB, but I am not blind to seeing the advantages of it.