ZDOG

iTrader: (13)

i know theres no replacement for displacement but with a procharger d1sc is there any real benefit for going bigger cubes? say a 383 or 402? either way im shooting for between 9.1 to 9.5.1 compression. this is 98% street car. my 02 camaro is putting down 470 rwhp now on my stock block at 8psi. the l92 top end appeals to me but theres no performance data as of yet i can find in boosted applications. the l92 would help offset some of the 402's cost. thanks in advance for any info!

QSPres

iTrader: (15)

The more air you get in and burn, the more power you'll make. So, in theory, the bigger the bore/combustion chamber/valve relief/piston dish, the more air you'll get in.


Obviously, this is oversimplified, but for a street car, the basic concept will hold true.

JASON11WS6

iTrader: (7)

Unless you are going to be running an F1 or bigger I would just go with a forged 346. I was wondering the same questions for the past few weeks and have been mulling around the L92 402 idea. Since I am going to be doing the build by myself and on a budget, I am going with a 346. I don't see any 402's with prochargers out there with any special numbers. Not saying they can't make better power but for the cost and ease of the build it doesn't make any sense to me. Plus I hear running boost on a bigger motor usually creates more problems like belt slippage and what not. I beleive a D1sc at full boost maxes out on a 346, if you went any bigger it might run out of steam on the top end. Also another fear I have since I am going to be doing everything myself is that the LS2 blocks have enough differnces to create wiring problems. I know the cam sensor is on the other side of the motor, the knock sensors aren't compatiable and are also located in a different postions. Not to mention their are a handfull of guys on this site that make 700rwhp on a 346 with a D1SC. So in the end, to me anyway, it just seems like a waste of cash to do a bigger motor unless you are going to do a insane build up with a bigger blower or turbo. 700rwhp can easily take you into the 9's even with a pig as long as you have traction.

BoostedWS7

i agree with this guy...

BIG BAD BLACKSS

iTrader: (4)

Id stay with a 346-370. Bigger cubes build more torque and some people blame that for throwing belts. Your already gonna have traction problems onthe street with the power your gonna make, do you really want tons more torque down low to try to make hook?

JASON11WS6

iTrader: (7)

I wouldn't be opposed to going with a 370 as Big Black SS said which would be pretty easy with an LS2 or a truck block. You aren't really going crazy with the cubes but for me the extra cost and modifications required to build an LS2 doesn't seem worth it to me. The truck block should be cheap and sleesy but the weight Fbody's are pigs in the first place and I love my TA and don't want to strip the heck out of it. I would hate to devalue her any by ripping stuff out of it that I am sure to lose. Plus adding all the weight from the blower and other stuff. I already plan on running on a tubular K member so for me the extra weight is going to be a killer.

JASON11WS6

iTrader: (7)

I am only referring to forced induction set ups here. IMO the 402 LS2's are awsome naturally aspirated and a great deal from our sponsers.

QSPres

iTrader: (15)

Probably the reason why you don't see many is the added weight that the rotating assembly ads to the bottom end. It's tough on applications where you have to spin the snot out of a motor (most Procharger type units) to get it to make big HP.


But if you look around the fastest cars that run strictly drag racing (or max hp cars) are 400ci+.

ZDOG

iTrader: (13)

is a 383 within d1sc territory? thats a stroked 346 correct?

EPP

iTrader: (22)

Correct, it uses a 4.0" stroke crank. The 383 is still within the boundaries of a D-1SC. Bob

JASON11WS6

iTrader: (7)

You can also get a 383 with a resleeved block and a stock crank. Not to many people do that but its really a nice hi-revving combo.

lmt0705

iTrader: (7)

so are you guys saying that running the same combo of parts on a 347 or 370 versus a 402 is not worth much extra power for the money you would have to spend? I just spanked my swtock bottom end with 11 psi so im in need of some info on what to build

JASON11WS6

iTrader: (7)

I would say no, its not worth it but thats obviously just my two cents. Stroker motors aren't cheap and I have yet to see a big horse 400+ cubic inch D1SC car. 700rwhp is obtainable with a 346 if you need more then that more cubes would help but you would be pushing the limits of the D1 anyway. Then you would be swapping for a bigger blower or tossing the whole set up out the window for a huge turbo. All of which costs tons of money.

LSs1Power

iTrader: (5)

If you have a D-1SC then i would just stay with a forged LS1/LS6 346-348. Its true that a 402-408 will make slightly better area under the curve, but at the end the D-1SC will max out around 750rwhp (different RPMs) on a 348 or 408.
Now if you didnt buy the Procharger kit yet then i would start with a F1 or F1A if you plan to go over 750rwhp later on.

MyWs62FaST4u

iTrader: (2)

well said...

TS6

iTrader: (41)

Aside from Bob does anyone in this thread even have a running procharger car? Seems like alot of people talking out of their asses.

First, and always foremost: Bigger cubes= bigger power. If not, you fucked something up. That rule doesn't change.

Second, I highly doubt bottom end torque will cause belts problems. Most belt problems are usually caused by stupid things, like poor alignment, bad belts, or loose belts.

Third, the only difference between a 347 and a 383 is the crank, so unless you planned to use the stock crank you'd be a ******* tool not to go for the bigger displacement. It costs you exactly $0 more, unless your motor guy is ******* you over. BTW, stroker cranks=not expensive in the grand scheme of things. It cracks me up that you guys build motors and bitch about a $400-$500 crank but you'll spend $1000+ on intake that probably didn't do **** for you.

I've only seen one guy who claimed to have made more power on a D1SC (pump gas) than me, and he said it was a 346. I asked for a dyno sheet and he never produced one. I made 757 RWHP, and while he may have made a little more (no proof), I have ALOT of room left on mine. I have a smaller pulley I can run still, plus I have a safe tune.

If you're going to spend thousands and thousands of dollars on a build, why not go bigger and be prepared for more power in the future? I could strap a bigger blower to my car and be making more power in literally minutes. My motor will take it.

JASON11WS6

iTrader: (7)

I agree that a stroker crank isn't much more then a stock crank but that's not the whole issue. If you just want to run a 383 yeah that's fine but I am talking about a 427 or even a 402. The 427's are still pretty expesive considering the resleeving, the 402's are cheaper but still way more expensive then a 383. Like I said earlier, if you are going with a LS2 block everything isn't a direct bolt on. Which means extra wiring harnesses and more difficult tuning. If you are looking to make over 700rwhp go for more cubes, As TS6 said it makes sensce. But if 700rwhp sounds like a lot to you why spend an extra penny on the cubes.

TS6

iTrader: (41)

I have an iron block 408. It actually didn't cost me a thing to go with an iron block 408 because I sold my H/C stock motor for what the difference was. I would have had to do machine work either way, needed different heads either way, and wanted more durability. Theres an interesting read on iron block vs. aluminum going on in FI now. The ONLY disadvantage to the iron block is weight. Its like 80 lbs, and IMO is well worth it for the peace of mind.

ty_ty13

iTrader: (42)

also a 408 is not going to run out of steam up top... the only thing that will limit it is the procharger it self....

i also have a 408 with stock heads and a D1sc.... the reason you dont see alot of dyno slips from 400+ CI blown motors is cause they are race cars in a heads up class and they dont want to reveal info or they dont give a **** about a dyno cause its a race car any way...

the only thing i dont like about the iron block is that there is one bolt provision that is not there... i havent had problems yet but it just kinda makes me feel sick when i think about it...

all i know is im no where near done tuning my 408, stock 241 headed with home porting, 8:1CR, 224/236 .601/.602 , th350 car and all the gears are useless from a dig on street tires until my foot gets tired and i have to let up to turn or stop...

a bigger motor also gives the blower a bigger place to put all the air with out heating it up as much.....

i vote bigger cubes is always better....

but i vote for the aluminum block because it has all the right mouting holes for the blower... who cares if you can mount the knock sensors? how many BBC or SBC are ran with out knock sensors.... I've never installed them but im sure it cant be that hard...

QSPres

iTrader: (15)

Yup...


Again, the heavier the bottom end, the more you want to spin it, the more you'll break parts. So, you spend more on lighter parts...