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For those that delve into tuning (and tuners,) be sure you(r) tune is based upon cyl #7 as that cyl seems to run the leanest of the bunch.

If I were to supercharge my LS7, it would be centrifugally and 4.5PSI max.
 

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LS7 was not designed for boost as a add on and why GM in deciding to use boost such as LS9 came out with a forged beefed up LS3
GM makes it clear in selling the LS9 supercharger as a add on kit to not use it for LS2 or LS7.
You do not increase cylinder pressure with a engine that uses brittle sleeves instead of thick cylinder walls.

Lots of people want the big balls and have boost added but look at the life of car and you find 99% of engine life is part throttle cruising in the right lane.

Use boost daily and the end results are quite different,
add sealevel in hot weather areas and boost in a LS7 is a time bomb long term
 

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There's not a single link here, yet it provides a list of all the stuff I think will help folks with similar needs. Living within the rules isn't all that challenging for most folks.
 

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Sorry to dig up an old thread but I thought I would be able to answer this question fairly well.



This is my LS7 after pushing 7 psi for less than 1000 miles. The car only has 7000 original miles and the motor is out, sleeve and block are both cracked, #7 piston broken.
I would recommend 5 psi or less and a Conservative tune.
I have a forged short block going in next week
 

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Sorry to dig up an old thread but I thought I would be able to answer this question fairly well.



This is my LS7 after pushing 7 psi for less than 1000 miles. The car only has 7000 original miles and the motor is out, sleeve and block are both cracked, #7 piston broken.
I would recommend 5 psi or less and a Conservative tune.
I have a forged short block going in next week
Man, does that look familiar! I have almost identical pictures of my #7cylinder of my original H/C LS6 and it was N/A not supercharged. If GM would just buy good forged pistons instead of the hypereutectectic cast junk that they use this kind of $hit wouldn't happen. My sleeve and block in the LS6 are both cracked too, making the block worthless. I put in an LS3 stroker moter and have never looked back. Best of luck with your new build and I'm sure you'll go forged components from top to bottom! I sure did,,,,money well spent! :yeadog:

Doug, who is doing your short block? Someone here in CO or elsewhere?
 

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Man, does that look familiar! I have almost identical pictures of my #7cylinder of my original H/C LS6 and it was N/A not supercharged. If GM would just buy good forged pistons instead of the hypereutectectic cast junk that they use this kind of $hit wouldn't happen. My sleeve and block in the LS6 are both cracked too, making the block worthless. I put in an LS3 stroker moter and have never looked back. Best of luck with your new build and I'm sure you'll go forged components from top to bottom! I sure did,,,,money well spent! :yeadog:

Doug, who is doing your short block? Someone here in CO or elsewhere?
Yes, I have it at a shop here in the North Denver area
 

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I rebuilt the LS7 with forged rods and pistons using the stock crank and I am happy to say it runs great and has been trouble free for a few years now.
I left the stock cam in it and bumped the boost up to almost 10 psi
It put down 683HP on a Mustang dyno on a 96degree day and just passed emissions here in Colorado last month.

 

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Would it be safe to say must of the people with horror stories are trying to boost the 427 while stock? How many have fried their engine and have a forged bottom end?
 

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What I will admit is. Unless you're going higher then 5lbs,a bulletproof lower end ls7 needs Darton sleeves. Or unlimited time and money. ( Ls7 F1c darton sleeved )
 

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I know this is kind of an 'older' thread, but seeing as it's had some activity and I have some real world input on this, decided to add my two cents.

I think the fear of forced induction on the LS7 is either exaggerated or the product of misplaced blame.

Stock block, crankshaft, and rods w/ 14# of boost and making over 1,000 HP without any issue. Ethanol sure helps because of the higher compression, but everything runs smooth and it's street friendly.
 

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I know this is kind of an 'older' thread, but seeing as it's had some activity and I have some real world input on this, decided to add my two cents.

I think the fear of forced induction on the LS7 is either exaggerated or the product of misplaced blame.

Stock block, crankshaft, and rods w/ 14# of boost and making over 1,000 HP without any issue. Ethanol sure helps because of the higher compression, but everything runs smooth and it's street friendly.
Chris, I'm sure you've had good luck with this setup but based on our past experience, we usually take this type of info with a grain of salt when it comes from a vendor (especially a non supporting vendor like yourself). Might be true or it might be self-serving so it's hard to sort the wheat from the chaff sometimes.

Mike
 

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Chris, I'm sure you've had good luck with this setup but based on our past experience, we usually take this type of info with a grain of salt when it comes from a vendor (especially a non supporting vendor like yourself). Might be true or it might be self-serving so it's hard to sort the wheat from the chaff sometimes.

Mike
I'm not a vendor and have no reason to promote or advocate anything.

The engine has lasted two years full of racing and hard hits, and is going strong.

The LS7 has some strong components, just gotta build and maintain it correctly.
 
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