Podium

Going to the dyno this Saturday but already thinking for the winter build.

Going back and forth on a built Ls3 vs a Built ls6. Im going to keep the Vortech TI V3 and pulley down to at least a 3.4.

Motors will be forged so Im keeping that out of the pricing.

Ls6 would just need some nice heads. That would be between 2 and 3k

Ls3 block adds 1100

Ls3 build would use stock ls3 heads. 1k to 1.5k with rockers(I know they can be had for less but keeping a realistic budget)

Ls3 would also need at least ls3 intake(200-300)

Ls3 intake needs ls2 throttle body (250)

Whatever else is needed to swap to a ls3.


Goal is 750 to 800rwhp.


Thoughts?

FourG63 97GST

Keep it simple, you goal is conservative enough to just forge your shortblock and move on with your life. use the savings and perfect your fuel system and drivetrain.
The little things will add up and push another 1k+ over your budget

Podium

My fuel system is good. I planned ahead.


I should also think of what if I go with a YSI in a few years.

FourG63 97GST

there's no correct answer, and in reality, you'll reach the limit of everything else before the either shortblock gives up. the upside I see to the LS3 is the displacement will give you better low end on a centrifugal car. maybe that's worth it to you.

Podium

That was my thought to but the car already spins the tires in second if its under 70 degrees out so Id rather not have more low end.

neutron82

what tires do you have?

Podium

R888 305/35/18. Running 35 psi though. Sure they would hook better if I lowered the pressure. I am running shocks from 2001 though. 50k miles.
When I say spin, I mean If I go WOT around 4k. If I roll into it its great and manageable.

I also dont want to run softer tire so I have to buy a new set every summer.

neutron82

hmmm, I had the r888 and didn't like them all that much but some love them... to be fair I never did play around with the pressure much before I got rid of them (I ran them around 30psi), they were spinning when the car was n/a so I knew with boost it wasn't going to get any better... I have 305/35/19 mickey thompson et street s/s now and love them, when warm they will hook 2nd gear at any rpm... from digs they will break loose in 1st at the top end but I don't do much dig racing so I'm very happy with them... the r888 is pretty soft too and probably comparable to most other drag radials, if you don't drive the car a bunch or do burnouts you could probably get a couple of years out of them and that's worth it in my opinion vs having tires that will last 5 years but get sh*t for traction

NSFW

Related question - how much can you bore out an LS6?

I mean, can it be bored out enough that the extra displacement of an LS3 doesn't really matter anymore? It sounds like you're buying new pistons either way...
​​​​​

Podium

It would have to be resleeved. You only can bore a ls motor a couple thou due to the sleeves. You're better off buying a ls3 block at that point unless you're going to build a 427 or something like that

typeav

through all your savings and credit cards on it and make it right from the begining LS3 408ci stroker 4.00" with Mongoose heads and don't look back

Podium

If that was the case it would be a stroked ls7 all motor

C5 Pete

I have an LS7 block ready to go if you’re heading that way...

typeav

3 reason why you may not want a LS7 is because

1 - Much more expensive
2 - You have a supercharger
3 - You will need oil dry sump system

if you doing the labor yourself I would say go for it

silver408z

ls7 blocks are not known for holding big power. The sleeves are weak and crack. I would not build a ls7 with stock sleeves.

C5 Pete

When he referenced the LS7, he was talking an all motor build.

And there are plenty of wet sump LS7 builds out there. I have one I’m thinking of selling to build a turbo setup.

ysb02

corvet786c

Right now I have an procharged D1 stroked LS6 with patriot stage 3 heads and fast 102 lsxr pushing about 625 to the motor. I like the set up alot and if I was going to do it over again, I would keep everything I have but go into an LS2 block for larger displacement, not saying the LS6 could get to 800 cause it can, just pulley down. But I love my set up now.

Podium

0MVP @ TheRaceEngineShop