nomorews6

iTrader: (7)

I was told I could get about 550rwhp n/a on a 402, and could add easily a 150 shot of spray. That is 700rwhp!! I was also told with a forged 346 and boost, the sky is the limit basically for hp. Which would you go with? What could I expect to spend? I know some boosted guys are shelling out like 20k for their projects. It seems to me the 402 route would be a lot cheaper and easier to maintain. What are your thoughts??

Race Car Driver

I don't believe you could make 550 rwhp on a 402 daily driver type of motor. But, anyway, I strongly recommend that you try to achieve your hp goals with cubes and try avoid either N2O or boost. An 11:1, LS1 427 will make around 550-560 rwhp, and you could probably go as high as 11.5:1 on a daily driver. (My FM 346 street car motor has 11.5:1) If you have use an adder, I would go with N2O.

nomorews6

iTrader: (7)

oh really? How high could you go on a 402? I was thinking 11.5:1, g5x4 or similar and afr225's.

SDB

iTrader: (7)

you can get 550 rwhp in a M6 with a 402, but it will have a big cam in it! For a daily driver, go with an aluminum 402, AFR 225 heads, FAST90/90, etc. and a modreately big cam (240 duration .600 lift) and then spray it with a 150 or 200 shot. You will be very very fast on the street. 346 boosted can be great, if you like dyno queens or can go to a prepped track with great suspension and tires. On the street, I would put money on the 408 with spray over a 346 with boost in my experience.

SDB

Race Car Driver

Well, with a F13 or similar street cam, a 11:1 402 would make around 500-525. You haven't said how much hp you want or how fast your want to go, but I would go with more cubes and less power adder.

An 11:1 to 11.5:1 c/r motor would work well with 91 octane U/L in most US locations. Mine is 11.5:1 but in Denver and on 100 octane u/l.

nomorews6

iTrader: (7)

N/A I want 550rwhp - with spray I want 700rwhp I am gonna make a new thread on this i think, but how much $$ do you think this could take? I heard the turbo folks are spending 20k easy to make this power.

Race Car Driver

Well, you should call the best engine builders and ask them for a price for such a motor, but just for the motor you are talking around $8,000 to $10,000 for a 402, and at least $15,000 for a 427. But the story only starts with the engine, you will have to buy a transmission, clutch and rearend to handle that power, along with some of the mandatory chassis stuff like a torque arm, LCA, etc. You're talking $20-25,000 if a shop does the work.

LC

On a side not.. What do you guys think a 347 N/A hp maxes out on a 11.5 CR?

I'm deciging between keeping the 347 or going 402, of course money is the deal, thats why i want to know if i can hit good hp with the 347...

nomorews6

iTrader: (7)

from what i understand it seems like for an a4 you'd be hard pressed to hit 450 rwhp n/a whereas a 408 may get you about 550rwhp. So in other words, perhaps the diff is 100rwhp.

SDB

iTrader: (7)

forged 402 short block is about $5000 with cam, gaskets, oil pump, ARP bolts...etc.
AFR 225 heads with upgraded springs is $2500
FAST intake and 90mm TB is about $1300
little stuff, like underdrive pulley, TB bypass, 85 mm MAF, etc. will be about $400
Kooks long tubes, Y pipe, cat back exhaust will be $1500-$2000
figure $2000 in suspension and chassis components (assuming your paying for some of the labor)
$550 for tuning
$279 for fuel injectors (Svo 42 lb)
Racetronix PNP kit for $259
$2500 for rear end
$1,000 on clutch and tranny work
$1700 on complete nitrous kit (not direct port, just a real nice MAF style kit with all the goodies)
so for about $ 15-16K you can do it.

nomorews6

iTrader: (7)

that is amazing ... how on earth do you all justify putting in that much moola?

JEB99TA

iTrader: (32)

How? 1. The dude who smiles at you and you know he's telling his chick how he blew your doors off a few weeks back and tells her to watch him own you again; 2. The feel of putting something into your car that you will always have if you need to use it, instead of throwing away $100.00 a month on lottery tickets like I see a lot of people do; 3. Finally having your dream car after 35 years of hard work, retiring from the Army and living through your 9 lives like a cat .. scathing past near death experiences and FINALLY having your dream car; 4. Last, but CERTAINLY not least, my chick digs it sooo much, she pays for half the mods.

I could go on and on, but, I think $20,000 will be the target to spend on a forged 346 cubed motor with supporting mods. I just love our LS1's with the original motor ... bragging rights are good when you beat a 408 or 427 ... IMO.

STROKER R/T

hi i have ls2 FTR 402 and love it i maid about 500 rwhp with manual z06 .. thats plenty of power!!!! ya more cam i'd have larger peak but i could spray if needed

SDB

iTrader: (7)

You asked what it would take to do a 408 with spray, that is what it takes. that is my setup except I have an aluminum 382 instead of a iron 408. I am putting my heads on this week and will break it in and then get it tuned. I would expect close to 500 rwhp through the auto with a 4000 stall unlocked Yank converter off the bottle. I have teh AFR 225 heads, spring upgrade, hand finished, FAST 90mm intake, NW 90mm TB, Kooks 1 7/8 to 2" stepped race headers, Kooks 3 1/2" Y pipe, Stainless Works cat back 3 1/2 exhaust, .611/.619 242/250 114 cam, Yank PT400, Rossler 4L60E, lots of suspension stuff, NX wet MAF kit with all the goodies, etc. If you want to play, you absolutely have to pay.

SDB

JEB99TA

iTrader: (32)

... well said SDB.

I washed my car and took it our for a drive this morning ... not near as strong a car as a lot of cars here, but, the adrenaline rush makes it well worth the money spent. 408's are strong and popular from the numbers I see on the board here. Good luck with your decision. I just prefer a 346/47 with power adder ... (probably 'cause I never owned a 408 CID motor ...LOL!).

NicD

iTrader: (7)

Kind of a hard question. Do you like loud and mean sounding or quiet with a whistle?

Nothing quite says I am going to stomp you in the mudhole like a big 408 on bottle. I think it sounds baddass, but personally I like a nice quiet unsuspecting setup like a 346 + turbo a bit more. Nobody knows what is coming and it will make just as much horsepower and torque, and it is always there.

Either way be prepared to spend some money.

Race Car Driver

My 11.5:1, 346 makes 453/406 on the motor, and I have a 150 dry shot on top of that. If I ever build another, I'll put a 11.5:1 427 in it, with a bit of juice on top.

LC

Well i want to make a bracket car, but my goal are the mid 10s..

MY PROBLEM.. Altitude.. 5200ft elevation with 8000DA+ this hot days

So.. being bracket i would like to stay N/A and maybe a 100/150 shot just for friday nights..

Would a N/A 347 hit mid 10s in my suck high place?

Race Car Driver

Where do you race at 5200 ft and 8000 DA?

No, an all motor 346 will not run 10s at 8000 ft.. In fact, an all motor 346 will have a hard time runnin 11s at 8000 DA.

LC

8000DA is just this hot days running at 12pm.. i hope it gets down soon.

Maybe 12s N/A and low 11s on a 150shot? just for the fun of it..