Y2kforgedSS

Im in the market for a new motor and deciding on either a 402 or 408 is my question. I have a a4 and would like to make just at or over if possible 500rwhp on motor and about 725-750rwhp on spray. Does that sound about right or am i just dreaming? Let me know if you have a 402 or 408 and tell me what you have done to yours and what you would change if you had to do it again.

11SECDWS6

iTrader: (3)

I've heard the iron block 408's hold up better when using power adders like nitrous. But I'd rather have the aluminum 402.

Elite_Hot_Rod

408 CID 6.0 ltr iron block with all forged internals, Custom CNC heads, FAST 90-90, Kooks 1 7/8 stepped to 2" headers, 4000 RPM Neal Chance stall converter converter, Carl Rossler Terminater 4 Power Glide, Billingsley Fab 9" with 3:55 gears and lite weight steel spool. Makes 485 RWHP N/A and 725RWHP on the hose. The car runs low 9's in the 1/4.

Y2kforgedSS

Yep thats what im looking for, im going with a smaller stall (3500tci) but 4:10 gears. I want to do a set of long tubes more than likely 1 3/4 tho but is going threw true duals and sweet thunder so it will sound good. What size shot did u use elite_hot_rod? I was at most going to use a 250 but i was wondering it tsp's 402 will handle that.

Elite_Hot_Rod

At that time I had an NX dual staged MAF kit with a 150 shot on each stage making about 250 RWHP from the 300 shot which about maxes out the MAF kit. I'm sure that TSPs 402 can handle a pretty good sized shot, it depends alot on how much the heads have been milled on an LS1 based motor. The thicker the deck surface you have the better chances you will have at keeping the heads down and not pushing water. If you intend on going with a higher CR motor you will need the block and heads set up for O ring gaskets and larger diameter head studs. I take it this is a street car, if it is I would keep the CR somewhere around stock maybe slightly higher and you'll be fine. Make sure you talk to them about your expectations for the motor before you have them build it, Trevor and those guys definitely know what their doing.

Y2kforgedSS

Yea i was thinking i wanted some were around 11.2.1-11.5.1 compression, its a street car but is driven 4 miles to work then home and thats it so i dont care if the car is streetable or not i just want to get some power and dont care how i get it? I have a forged 347 right now but doesnt do much for me and i was never really impressed when i got it but payed out the *** for nothing really.

Elite_Hot_Rod

Well when I had the H/C 346 with the same MAF kit the car ran a 10.08@136MPH not bad for a 346. I was looking at TSP 402/408 packages in another thread and they offer all forged internals at a very reasonable price. I have the Callies 4" forged crank, Crower forged rods and Diamond forged pistons with everythig else I've already listed, the best it's run so far is a 9.23@149.1 MPH so yours ought to be able to handle a good sized shot and be pretty quick.

Nate_Taufer

iTrader: (1)

I would definitely go 402 alum block, Just because it's 93 lbs off the nose of the car by the block weight alone.

Only aluminum block failures i've seen have been from bad tunes. If you were stepping past 800rwhp i'd look into an iron block, but for a 2 stage or progressive shot you'll be fine at that power level.

Nate

Elite_Hot_Rod

I agree with that to some extent but when you really get these things hooking the extra weight up front helps keep the nose down and tranfers the weight to the rear better.

ArcticZ28

iTrader: (14)

I can't wait to have to worry about keeping my nose down on launches

btw, i went with the 408 for the added strength of the iron block.

Cyborg

iTrader: (8)

I have a LS2 402 w/ a Procharger. It's a daily driver. It's awesome. I'd recommend this setup to anyone FWIW IMO.

pewter 01 SS

iTrader: (5)

what kind of nitrous set up are you running.. i have a 408ci with all the goodies its not completly tuned so havent felt all the power but I only have the nx kit with the shark nozzle.. i know i want a direct port but that will come in the future

Y2kforgedSS

Dont get me wrong the 347 i have now isnt bad its just not what i really want as far as performance. I havent ran it for a number of reasons but now im stuck in between a rock and a hard spot trying to figure out if i want a 402 or 408. How much can a forged 402 handle with the aluminum block? Say it can handle just at 800rwhp and i make any were from 725-750rwhp wont this nock off days tell the end of this motor like crazy? Or say i go with a 408 forged internals i know this will last longer so i dont know what to do. I need some more opinions and shop talk on what you have and what you have heard on these motors. Member i want to get 500rwhp if possible in a auto and 725-750rwhp on spray and have about $7500 to spend.

pewter 01 SS

iTrader: (5)

i spend a little over 8k but for a 408ci callies crank, jessels rockers, afr 225's, timing chain and everything.. hopefully you can find a good deal that will work for you.. the only reason i went iron block is because of the longetivity of it when nitrous is put into it.. i know its heavier but with my bmr k member some of the difference was offset..

Mr_president

iTrader: (38)

wow you guys are doing my dream set up!! personally id go with the 408 and take 100 pounds out else were!! last way longer to be worried about 90 pounds..... be realistic

p.s hope i didnt offend anyone


dream prochager or turbo with a 408 stroker.........

pewter 01 SS

iTrader: (5)

mine was also a 408ci but after spending so much on rearend and all other goodies i didnt realy have another 5-7k to spend on a good turbo set up..

Mr_president

iTrader: (38)

ya thats real ill be getting all this in hopefully the next 6 months already got all the other stuff as you see supention 9 inch would anyone use this cam on the motor or bigger??

Mr_president

iTrader: (38)

what was your best time in the quater and what was the cost to do the motor swap?

pewter 01 SS

iTrader: (5)

i havent gone to the track b/c its not completely tuned, for the motor swap my friends and I do everything to the cars except tuning..

Y2kforgedSS

any one else???