Blown 408?
Blown 408? I have a 2000 WS6 NBM M6 and am trying to figure out the best way for 700 RWHP. I am new to Ls1 performance and am trying to figure a few things out. I have recently purchased a LQ9 block with the 317 heads from an 03 denali for $400 (good deal i thought?). I want to build a 408 with a DISC procharger. I already know what i am going to do for the driveline but have no idea what the best products for the motor are (crank, pistons, rods, etc.). I am definitely going to go with a D1SC from procharger since i can get them at distributor prices, I am just not sure what compression or cam specs would be best for my power goals (700 RWHP). I was also thinking about having patriot performance port the heads to their stage 3 specs. Any suggestions would be very helpful since i have no idea what would be the best combination. I also want the car to be streetable (pump gas), or as streetable as 700 RWHP can be! I have searched the site quite a bit and there seems to be a ton of people who know what they are talking about. And if anyone has a procharged 408 let me know would love to get some tips. Thank you in advance.
are you building it yourself? If not any sponsor would know what you need to get your goals.
Most FI guys prefer a 370 LQ9 block to keep the cylinder walls thicker and stronger, the stock crank is more than strong enough for 700WHP, alot of guys are using the compstar rods, and diamond, je, wiseco pistons is really kind of a prefference thing.
Patrick G could spec you a cam from thunder racing, i have talked with him through pms and seen a few post on turbo cams, he said a typical turbo cam he would spec for a 346 would be 224/230 113LSA +2 for a 370 or 408 it would be slightly larger and the lift would depend on springs and other variables
compression you will hear anything from 8.0-9.5 and some people are now saying 10+, for my TA i want first and foremost a high HP STREET car but I still wanted a low compression build (I've seen the hype with the high CR builds but I would need to see more before I spend my money on a setup like that) so I am shooting for 9.0:1
But once again if your having a shop do this they should be more than able to answer your questions, and if not find a new place to have the work done
Most FI guys prefer a 370 LQ9 block to keep the cylinder walls thicker and stronger, the stock crank is more than strong enough for 700WHP, alot of guys are using the compstar rods, and diamond, je, wiseco pistons is really kind of a prefference thing.
Patrick G could spec you a cam from thunder racing, i have talked with him through pms and seen a few post on turbo cams, he said a typical turbo cam he would spec for a 346 would be 224/230 113LSA +2 for a 370 or 408 it would be slightly larger and the lift would depend on springs and other variables
compression you will hear anything from 8.0-9.5 and some people are now saying 10+, for my TA i want first and foremost a high HP STREET car but I still wanted a low compression build (I've seen the hype with the high CR builds but I would need to see more before I spend my money on a setup like that) so I am shooting for 9.0:1
But once again if your having a shop do this they should be more than able to answer your questions, and if not find a new place to have the work done
+1 for what is said above. Stock crank has been able to handle 1000rwhp and is fairly reliable so you shouldnt have to replace that unless you want to go larger CI. Also, a lot of people seem to use the compstar connecting rods with a lot of success. As stated above some people prefer diamond pistons, other mahle, others wisco so its whatever you choose to go with as all are fairly reliable. The 317 heads should be fine with upgraded springs and porting them wouldnt be a bad idea, especially since you already have the heads. Cam should be in the 23X to 24X duration depending on how close you want to keep the idle to stock. If you want a very smooth idle then go smaller but it will cost you some hp. Compression is another variable that is open to opinion. Some want higher compression but with higher compress comes the need for race fuel or alky/meth injection. You should run meth regardless IMO when going for 700 rwhp as you want to make sure your engine stays healthy, but I would say to aim between 8.5-9.0:1 compression IMO. There are quite a few procharged 408's on the board so hopefully they will chime in but IMO your best bet is to build the shortblock with the best components available and if need be stick with the stock LQ9 heads with upgraded springs, LS6 intake, and a solid turbo cam if money needs to be alocated eslewhere (IE drivetrain, rear end, fuel system, suspension, etc). Good luck and keep us updated on the build!
Check out this build using a D-1SC.
http://www.exoticperformanceplus.com...Car.php?car=40
For a 402 you should consider an F-1A, such as what we used on my '99 Z28.
http://www.exoticperformanceplus.com...Car.php?car=12
The F-1A won't be worked as hard as the D-1SC. We upgraded one customer's car that already had a 402 and a D-1SC by adding our front mount intercooler kit, and a new fuel system. You can check it out here. http://www.exoticperformanceplus.com...Car.php?car=42 Bob
http://www.exoticperformanceplus.com...Car.php?car=40
For a 402 you should consider an F-1A, such as what we used on my '99 Z28.
http://www.exoticperformanceplus.com...Car.php?car=12
The F-1A won't be worked as hard as the D-1SC. We upgraded one customer's car that already had a 402 and a D-1SC by adding our front mount intercooler kit, and a new fuel system. You can check it out here. http://www.exoticperformanceplus.com...Car.php?car=42 Bob
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Joined: Sep 2002
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TECH Regular
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Posts: 444
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From: San Jose,CA
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I should probably just go with a 370 ci block instead of a 408 then. If EPP made more than 700 at the wheels with a stock displacement vette, a 370 should easily be able to do it in my WS6. And i can still use the D1SC. It will make to much power to hook up on the street with a 370 anyway so going with a 408 and an F1A might be a little much for a car that will rarely see a track. I can see you have tons of experience to EPP I have already thought prett hard about bringing it to you to have it built, maybe even work something out with the procharger ( I can get them damn cheap though). I would definitely go with you guys for the build though. Thanks for all the suggestions to guys!
With better Fule system and good flowing exhaust your car should have the same numbers as SVC707 IMO.
my pet peeve on these build ups i see is that people half *** too much here and there. just do it right the first time. go big on your fuel cuz you can always turn it down so it wont be rich. but you cant make up for being lean unless you go meth. f that. im not trying to fill another bottle. reason being i went FI and go rid of the bottle. as everyone says, i too built this car for the street and it rarely goes out to the track. hell i dont even take it out on the street much either. traction is bad but i run it on mt drag radials. and i must say these are the best tires if your having that dreaded traction problem lol.
