Okay guys, first time posting here so be gentle lol,

I'm currently overseas right now but looking to do a build so I can blow my deployment money lol this is gonna be my first big build and looking for some guidance.

I'm looking to do a LQ9/turbo build for my 2003 rcsb..

I want to build it from ground up, gonna be on a forged lq9, havent decided if I wanna get a block and have it machined or if I should just order a long block from TSP but my main questions are..

What size motor should I go with? 408/418 or a 421? I want this to be something I only have to build once lol

Compression? Best compression ratio for Boosted applications??

Cam? Keep in mind I'm still a kid so I really dream for that lopey sound lol but I still want something practical for the boost.

Heads? What would yall recommend?

As far as intakes go I was really thinking on a FAST 102mm with 102mm throttle body.

Oil and fuel? I'm not really knowledgeable on these systems so any info or tips would be appreciated.

Gonna ditch that 4l60e and get something from FLT, should I go with a 4l65e or 4l80e?

Really want a good rear end(thats what she said), right now I got open diff, Should I get a posi or LSD? Which is better and why? Any gear ratio recommendations? I'm definitely gonna get some caltracs, hopefully one day I'll be able to do a 4 link with coilovers

Now for the boost..

Twins or Single?? Sizes?? Brand? Best intercoolers? Pics of turbo set ups would be great!

Tuning? Not really experienced with tuning but I hope to have it tuned on a dyno, or who is recommended for mail order tuning? I want something that is fun on the streets and track but I can still get in it and drive it 16hrs back to Texas when I'm on leave.

Anything else I'm missing? Any tips, guidance, wisdom, or knowledge/input is all appreciated!

 

4l80e with lower first gear set(if its an option) better off with a locker,like a trutrac, probably either 4.20, 4.30 or 4.56 depending on tire size. Technically posi and lsd are same thing, going from a 4l60 to a 4l65 is really nothing but a couple gear sets and a couple beefier internals, other than that they are same design with same weak spots, 4l80 is in all reality the better option...heads either 799 or 243 or an aftermarket version of them, and as far as intake, you may want to look into either an nnbs intake or a fabricated metal intake.....

 

So say maybe a l92 intake?? I'm truly aiming for my first build to put anywhere from 950-1000hp to the ground, I know its a long shot for my first build but I can dream cant I? lol

 

L92 intake if youre gonna run 823 or 0821 rectangular port heads, need the cathedral port intake if youre gonna run 799, 317, or any other cathedral port head....sadly that hp with twins and a stroker isnt that far fetched......itsgetting drivetrain and traction to be able to handle it that is key....

 

Which combo do you think would yield the best results? Keep in mind I don't land back in the springs till November so I'm taking my time to plan all of this out so I don't have any hiccups when I do it lol

 

I wouldn't set a goal that high for horsepower on the street, it will never hook and you'll just be pissed that 900hp can't go anywhere on street tires.


Stock LQ9, 4L80, S480 turbo, fuel system, transmission and you'l have 600-700whp no problem and love it. I'd do it this way to keep it simple and not spend a wild amount of money on parts that you wouldn't need to make this power goal.

 

^^^ agreed, my goal was 425rwhp na..... If i decide to sc it later that will be a bonus..... But i need to get the 350ish i have now to hook up, before i even think about that!!!

 

If I went this route, what kind of mods would the stock motor need to hold up to the extra boost, last thing I wanna do is throw a rod..

 

The stock bottem end is known to handle that horsepower no problem. It wouldn't hurt to open up the ring gap and inspect the whole thing over before you drop it in.

The tune is the biggest thing to worry about when it comes to blowing a hole in a piston or sending a rod through the block at this horsepower.

If it still concerns you a little, you could buy some better rods and pistons if you wanted to. The displacement of the motor will still make great power with moderate boost levels.

 

There are a lot of 6-700hp trucks running on basically stock bottom ends..... My ch more and then youre probably going to want to start looking at upgraded rods pistons etc....