So...my 2003 stock LS1 bottom end is being asked to do more than it was designed to do. Paxton SC, Methanol Injection, LS6 heads, Cam, 127 lb injectors, fuel system upgrades, and now a little bit of Nitrous. The rest of the drive train has been replaced and is rock solid. I am looking for info on what I should be paying currently for the upgrade. Most of the places I talked to locally are pushing me to go with a full swap and want upwards of $25K. I'm thinking no.

I want to keep the engine under 1000 HP, go with a good quality forged rotating assembly, and don't want it to take a year to complete. I would also want the requisite disassembly, machining, reassembly, and tuning. I expect to pay somewhere under $3,000 for the rotating assembly, but I have no clue what I should be paying for the rest of it.

Thoughts?

 

Well...

Firstly... I just have to say it.... for the money, there is no shame in pumping a 4.8 or 5.3 and having one or two on deck if you toast it. Gap the rings and go to town. Dollars ahead as long as you tune your power adders right.

For a build in the current market and in spirit of your concern for collecting parts I'd honestly recommend a prebuilt shortblock from a trusted builder. There are a dozen companies out there offering turn key forged setups. They might not be exactly the combo you want, but they're not lacking for parts or waiting on supply chain so you can get delivery, dump it in and be running it the same weekend. Then you can sell your WORKING LS-whatever to offset the cost.

Sounds like a fun car. What is the actual head unit, pulley, nitrous, cam, head combo there?

 

Thanks!
It's got a Novi 1500, I believe I have the smallest 6 rib pulley I can get - can't remember the actual size (it's making about 10 lbs), NX Proton Plus system (jetted to 50 shot currently), CAM - 600 lift intake and exhaust, 230-236 on a 115LSA, Texas Speed PRC LS6 Stage 2.5 CNC Heads w/ 68cc Chamber, Brian Tooley .660" lift dual spring kit w/titanium retainers, Katech C5R Timing Chain, Mellings High Volume Oil Pump,TFS 7.400" Pushrods, GM LS7 Spark Plug Wires, Meziere Electric Waterpump, ARP Head Bolt Kit for early LSx, GM Lifter Set, LS7.
Just put the nitrous on it and only had one shake down - not even fully tuned yet.

 

Every word Mr. Tusk typed rings with logic. How many episodes of Hot Rod garage had yet another 5.3 pumped and/or gassed into high three digit power?
I don’t see E85 on your list?

 

You are correct - I can barely spell 93 octane and don't do any of the tuning or engine work myself. Guilty of too many episodes of Street Outlaws, not enough knowledge, and too much time to think about it. To this point, 650 to the wheel and a low 10 sec quarter mile was fine. But I have been bitten - the only thing holding me back from doing something really insane is the lack of a job!! :-(

I'm looking to use all the stuff I have already invested in, with a better bottom end. Just need to know what type of investment I am getting into.

 

Wow. And when you say 10psi we all have to bear in mind that your heads and cam are able to vacate a lot more air than stock and produce less boost restriction. Methanol plus Nitrous.... you like to add your oxygen feeds!

What's your goal with the car, other than "900-ish" hp? As it is I bet you're fighting for traction.

Your heads and oil pump and parts combos are all stout enough. The only thing I might suggest changing with any new setup is going to Johnson lifters vs GM anything. LS9 head gasket should work, though that may change your pushrod lengths so measure/verify. And should you change CID, check and see if a different cam is worth changing to not only for flow concepts but to better meet your power goals.

All said, my current philosophy has shifted to being based on direct injection quality per cylinder vs injecting into the charge pipe. Bigger fuel system sure to provide flow and accurately meted fuel to each cylinder. I think a shot in the charge pipe is cool at 500w. At double that - and mind you I have no experience there yet, all I have is a combo which ought to be able to get in the ballpark if I push it - but nearing double the 500w I start to worry about the unequal meting of methanol and nitrous to each cylinder. Methanol particularly as it is sending droplets into the air stream which have been proven to pool near the back of the engine. #7 has always been the weak point, but now if you have more Methanol entering it and the same amount of fuel and air vs forward cylinders with less methanol you have unequal burn as well as what Doug Ring tested as being a 200*F variation in EGTs front to rear. So if you're going to keep the injection kits I'd say modify the intake for direct injection vs charge pipe.

Also, no need for giant cubes or the prices associated with giant cube short blocks. With boost, you have the great equalizer. Enjoy your cam or even go smaller if you like and just swap to a larger head unit. Done deal.

 

Thank you! Great info!

 

And yes - traction is a real issue. Street tires are completely unusable (unless the wife is in the car).

At the track I'm using M/T ET Street R (28.5" x 10.5"). Biggest small tire I could get to fit without modification. I invested in the NX Maximizer 5 so I have decent ramping ability and safety features for the spray. Couldn't invest in the direct port system - just too expensive right now.

Regarding Doug and company, I have a request out to them now - they've done all my engine work so far. Just want to see other's opinions on costs involved. But in the end, I always go back to ECS.