402 LS1?

[RedHeartbeat]

You can run the engine without a turbo without any problems. You can also run additional timing with the low compression engine to gain some of the lost performance caused by the lower compression. Most LS1 type engines can't handle but about 24 degrees of timing before they ping but with the low compression you'll easily be able to pull about 28 degree or more. I don't think Calico will coat your pistons for you but you can ask them. You can do a little research on the net to find places that will coat the pistons for you. You may be even able to get the company that supplies the pistons to you to have them coated before shipping them out. Speed Pro and Mahle both sell a coated piston. Do some research and don't be afraid to call or email the manufacturers for more information.

[gmcguy11111]

Sounds good i will do those things. How many horse is the engine going to put out do you think in the low compression form? If its a significant drop couldnt i buy normal not dished pistons for the buildup and use the stock heads and then later put on the 6.0 heads? Which is better, dished pistons with stock heads or stock pistons with 6.0 heads? Thanks

[RedHeartbeat]

You could use the stock heads with flat top pistons and then when you go turbo you can swap the 317 casting heads and then put the turbo on it. For what it's worth, there are guys running the stock compression LS1 heads and pistons with turbo but they have to limit the amount of boost to about 5 lbs max.

[gmcguy11111]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 04&#58;23 PM) [snapback]77925[/snapback]</div>

You could use the stock heads with flat top pistons and then when you go turbo you can swap the 317 casting heads and then put the turbo on it. For what it&#39;s worth, there are guys running the stock compression LS1 heads and pistons with turbo but they have to limit the amount of boost to about 5 lbs max.
[/b]

I may have to do that. If im gonna spend 3-4 thousand for a turbo im gonna use most of the boost it can make. You can set it on two modes and i think i will run 7psi and 12psi but i may change my mind. What would the hp numbers be on the low comp engine if i had the dished pistons until the turbo? If its not very much i will do that and save the money of having someone have to swap the heads and buy the different heads when i install the turbo.

[RedHeartbeat]

I would build it with the dished pistons and not worry about the power loss. Once you start worrying about it, that means it&#39;s time to go turbo and 317 heads. The lower the compression you start with, the higher boost numbers you can build safely once you put the turbo on it. I&#39;ve seen guys run 8:1 compression and run 30 lbs of boost. More boost means more combustible fuel/air combination and more HP potential. Look at the power numbers they get out of a turbo&#39;d Honda or Toyota, that is possible only by building huge amounts of safe boost. That is possible by running low static compression, boosting it to the max and supplying a steady safe amount of fuel. Don&#39;t forget you will need some big injectors to replace the stock units. Budget money for that, a speed density tune and a good fuel system(one fuel pump per fuel rail, you&#39;ll need aftermarket fuel rails for that, or something like one of Aeromotive&#39;s A1000 pumps).

[gmcguy11111]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 04&#58;51 PM) [snapback]77927[/snapback]</div>

I would build it with the dished pistons and not worry about the power loss. Once you start worrying about it, that means it&#39;s time to go turbo and 317 heads. The lower the compression you start with, the higher boost numbers you can build safely once you put the turbo on it. I&#39;ve seen guys run 8:1 compression and run 30 lbs of boost. More boost means more combustible fuel/air combination and more HP potential. Look at the power numbers they get out of a turbo&#39;d Honda or Toyota, that is possible only by building huge amounts of safe boost. That is possible by running low static compression, boosting it to the max and supplying a steady safe amount of fuel. Don&#39;t forget you will need some big injectors to replace the stock units. Budget money for that, a speed density tune and a good fuel system(one fuel pump per fuel rail, you&#39;ll need aftermarket fuel rails for that, or something like one of Aeromotive&#39;s A1000 pumps).
[/b]

30 Psi, good lord thats a lot of boost. So with the bigger injectors and the new fuel pump am i going to have any gas mileage at 5-7 psi of boost?

[RedHeartbeat]

I have heard of some of these guys on here picking up fuel mileage once they went turbo from stock. The larger injectors are really only going to make a difference at power levels greater than stock. The O2 sensors will keep the fuel mixture appropriate for normal driving times. You&#39;ll only lose mileage if you can&#39;t help but have your foot buried to the floor all the time just to hear the turbo whine. You need the injectors and pump to supply more fuel when boosting it. You don&#39;t want to put too much air and not enough fuel, major lean condition and soon a dead engine.

[gmcguy11111]

Yeah i know to upgrade the injectors and fuel pump but i didnt know about the fuel rails. Ill probably install some 42 pound injectors for it. That should supply enough fuel. I know this build isnt for fuel mileage but hopefully under normal driving conditions when everything is done i will get 15 mpg. If not oh well but 15 mpg would be good. Another question i have is regarding the transmission. I have the 4wd version of the 4l60e and was thinking about having it rebuilt to hold the new horsepower. My question is if the camaro 4l60e already stronger and easier to build up. If this is so i could just get that with the ls1 and have the output shaft switched with my 4wd one. I just dont know if there is a difference between the two?

[RedHeartbeat]

I am not 100% sure but the internals of the 4wd 4L60E should be the same as the 2wd version. The only diff should be the output shaft. I would take your tranny down and have it rebuilt while you have the engine out. Get billet 1-2 and 3-4 apply pistons from Superior, they will help keep power applied solid to the band while applied. Tell the builder NOT to add frictions or plates to the 3-4 clutch pack, have him install the 3-4 clutch pack from a 4L65E transmission(BorgWarner preferably).

[gmcguy11111]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 07&#58;14 PM) [snapback]77943[/snapback]</div>

I am not 100% sure but the internals of the 4wd 4L60E should be the same as the 2wd version. The only diff should be the output shaft. I would take your tranny down and have it rebuilt while you have the engine out. Get billet 1-2 and 3-4 apply pistons from Superior, they will help keep power applied solid to the band while applied. Tell the builder NOT to add frictions or plates to the 3-4 clutch pack, have him install the 3-4 clutch pack from a 4L65E transmission(BorgWarner preferably).
[/b]

Ok that sounds good. How many horse do you think this is going to hold safely?