thinking of rebuilding an lt1, help!

[gunter96ws6]

for those of you who have rebuild your lt1's, where did you get your kits from? summit has 2:

forged.................10.40:1........58cc for 539.95
hyperuetectic........9.90:1........58cc for 449.95

i want to build a lt1 to take some boost (like 12-15 lbs.) will ethier of these be a good idea? if not what would? thanks~gunter

[Joe 1320]

Here's the rub.....
Hypers don't tolerate lots of boost.
Forged are the way to go, but.....
Lower compression is more friendly for high boost.

[gunter96ws6]

so what do i do joe? is there a better answer?~gunter

[markd79ta]

Basically, you need to figure out what your plan is for this motor before you buy a anything. After you decide what you want it to do such as hp range, nitrous, blower, or naturally aspired, you can plug in the pieces that will get you there. First, make a concrete game plan, and move from there. There are a lot of people on here that can help you choose the pieces to achieve what you want.

[gunter96ws6]

i want my lt1 to make 550-600 hp, with boost but no nitrous, i want it to be streetable, i want it to have a nasty cam, now what do i do?

[4THGEN Z]

There is a person in our local f-bod club here that has a turbocharged LS1 making about 580 RWHP at approx 8lbs of boost. The motor build-up IS very important for that amount of power, his list of parts specific to this application is long and expensive...

Be warned that he has also redone the tranny (T56), Carbon fibre driveshaft and 12-bolt rear to take it......BTW so far his best ET is 11.39 on ET streets...he need slicks and some traction still.

[Joe 1320]

Originally posted by gunter96ws6
i want my lt1 to make 550-600 hp, with boost but no nitrous, i want it to be streetable, i want it to have a nasty cam, now what do i do?

A normally aspirated stock bore with good heads, intake and cam can be tuned for 400-425 HP. A supercharger can up that by 125-150 HP, in my opinion that is living on the ragged edge of parts carnage. If I were going to build a reliable motor to generate that kind of power, I would start from scratch on the internals. I would definately go with a forged crank (maybe a stroker of 389 cid) , forged pistons with a compression ratio of around 9 to 9.5 max, really good flowing LT4 heads and intake, or an aftermarket matched head and intake combo, with a custom blower grind cam. The problem is that I see this combo running you $10K minumum for just the engine if you do alot of the work yourself. Then you have to address the trans because the stocker ain't gonna live, the same goes for the rear end. All total, expect to pay $15-$18K. Also expect to run high octane gas, not the 93 pump stuff either.

That being said, It's going to take a a LOAD OF CASH. Speed costs $$$$$, how fast do you want to spend for?

[markd79ta]

Originally posted by gunter96ws6
i want my lt1 to make 550-600 hp, with boost but no nitrous, i want it to be streetable, i want it to have a nasty cam, now what do i do?

Sounds great, Now...what is your budget for building this monster? And, what do you plan to do with it...dragstrip or road?

[Joe 1320]

Also, just to give you an idea.......

The 231 V6 that I am building for my Grand National with forged internals, block girdle, balancing, blueprinting, roller cam, and so on has already gone over the $4000 mark for the short block alone. That is with me doing all the work except the machine work, that also doesn't include the headwork (done by me), intake porting, headers, larger turbo, intercooler, injectors, fuel pump, computer, and so on ad nausium. This "little" motor will be somewhere in the $7500 range with me doing the work.

[markd79ta]

Originally posted by Joe 1320
I would start from scratch on the internals. I would definately go with a forged crank (maybe a stroker of 389 cid) , forged pistons with a compression ratio of around 9 to 9.5 max, really good flowing LT4 heads and intake, or an aftermarket matched head and intake combo, with a custom blower grind cam. The problem is that I see this combo running you $10K minumum for just the engine if you do alot of the work yourself. Then you have to address the trans because the stocker ain't gonna live, the same goes for the rear end. All total, expect to pay $15-$18K. Also expect to run high octane gas, not the 93 pump stuff either.

You are talking about some serious cash. You are looking at a forged crank, rod, piston combo with some moderately expensive machining and balancing work on the bottom end (piston compression varies between 8.5-9.5 depending on the psi of boost you plan to deliver). If you are putting it together yourself, you are looking at about 4-6K(you could use a cast crank and stock rods, but be really leery of any high RPM use or too much boost in the 5,000 RPM + range). Your top end needs work whether you port and polish your LT1 heads and intake or go with an LT4 setup, you are looking at 2-3K. Match the cam duration/lift to the intake, head, blower combo...you will need to do a little reasearch on this. The blower will run you 5-6K...I would go with a twin intercooled ATI or a Aftercooled Vortech. Incidentals, pumps, pulleys, sensors, coil, opti, etc. should be replaced, you are looking at another 1-1.5K. The exhaust, long tubes, y-pipe, and catback will run around 1-1.5K. Don't forget the fuel management and PCM, injectors, retuning, etc. $$$ Now, you need to harden the T56, you are looking at 1-1.5K. Finally, you need to replace the 10 bolt, unless you have stock in a gear company and you don't mind changing them out every quarter; you are looking at 2-3K. Now that the powertrain is finished, you need to look at the suspension that will actually put this on the ground. If you have all of this work done...double the cost.

You could cut corners and put this together for a lot less, and get into the 500hp range, but the motor won't hold together nor the rest of the power train...if you plan to use it that is.

[gunter96ws6]

who makes a sick @$$ 6 speed that can take this kind of torture?~gunter

[markd79ta]

Originally posted by gunter96ws6
who makes a sick @$$ 6 speed that can take this kind of torture?~gunter

The T56 is not bad it is just that it needs to be hardened after you move into the 500+hp range....just rebuilt with the hardened synchros and such similar to the version put in the Viper. The stock version put in the f-body will take it for awhile until it comes appart which would s*ck. The days of the bullet proof Muncies put into the car stock are long gone.

[N20LT4Bird]

I've been running a stock T56 with a stage 3 SPEC clutch and a pro 5.0 shifter on my bird for a year now. The motor alone is putting out 400 hp and then another 100 - 125 with the N2O. It's holding up great. It was originally a 4L60E car, but I could pop those once a month if I wasn't careful - so I swapped in the T56 and it has been great.

[markd79ta]

Actually Gunter, I plan to build my LT1 that will put out around 500ish that is blown with an aftercooled strim and a 10psi pulley.

I am buying a Vertech strim to install on the T/A as it sits stock. It should be good for around 360ish hp at my altitude and mileage. Later (probably 3 years or so), I am going to add the LT4 heads, intake, and cam package with a forged 383 stroker bottom end with 9.5:1 pistons, shorty headers, and loudmouth catback. I will change out all of the sensors, injectors, coil, opti, etc. at that time. Even with this mild setup, I am looking at a custom program job that hopefully, I will do myself. My car will have around 150,000 miles so I will have the T56 rebuilt with the hardened components. I am going to focus my energy on getting the front k-member and a-arms replaced with BMR components as well as the BMR adjustable trailing arms, panhard rod, and torque arm. If I get ambitious, I may get a strange 12 bolt rear-end; if I leave the 10 bolt, I know that I will be chewing up my 410 gears fairly often. I am also looking at a different oil pan and oiling system to provide better protection when I take it out on the course. I am budgeting $13,000 to do it, and that doesn't include the supercharger that I am buying in the next few weeks. I have toyed with a custom PCM, opti delete coil packs, 18psi blower, custom worked heads, a blower friendly cam, and a wild ride into the 700-800hp range, but the really goes way up in cost especially with machine work...but you really need to build it that same way when you get past 500+ range to ensure some measure of longevity. Also, it becomes increasingly difficult fuel-wise as well as emissions compliance.