# 800hp on stock ls2



## Bluegoat05 (Mar 22, 2010)

hey does any one know just how much power the stock ls2 bottom end can handle? i understand its a kind of luck of the draw thing but how much hp can you acheive and remain reliable. i want to acheive around 650 hp to the ground.


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## RJ_05GTO (Jul 6, 2008)

I dont really know for sure but I think the rule of thumb is dont go over 40% of stock hp on a v8 but every engine is different so....


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## GM4life (Mar 18, 2007)

Pistons, rods, and ARP stuff is what you need.

I may have read stock bottom end LS2 taking that much. I would just spend a coulple grand or so and have insurance.


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## 740tank (Mar 23, 2009)

my car is the shop right now its going to have 650 whp with stock pistons, lifters, rocker arms, push rods Ill let you know how it goes:rofl: its a ls1


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## batmans (Aug 16, 2007)

When I spent nearly $15k on forging engine (including machine, blue printed, balanced, ceramic coating) I was told by over 5 unrelated guys that have over 800HP LSx engines that they all left the crank stock since it supported 1000HP.

http://www.gtoforum.com/f37/somethings-wrong-my-ls2-23923/

The rods are sinter powder forged from GKN and will take 850HP before they start to bend and stretch. Pistons are the weakess part of the engine, but I suspect that as long as ur not detonating it should be OK although I'm not completely sure about that.


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## GM4life (Mar 18, 2007)

$15k seems way too much, just motor work and parts. You must be adding in labor to build/tare down of the motor, R&R the motor, tuning, parts, ect. I that couldn't been just the motor alone. I would have bought a crate motor.

You can get a stroker assy for $2k and change. Throw in bearings, hardware, hone, and labor shouldn't add up to that much for the short block. You can save yourself some coin doing your own R&R.


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## batmans (Aug 16, 2007)

I don't wrench anyone these days. I rather pay others and spend my time doing something else.

Must be an age thing where I feel like I never have enough time to start and complete a variety of projects.

Yes, the $15k was parts and labor..... no short cuts and much of it was over engineered for my current HP goal and what the Maggie 112 can deliver.


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## GM4life (Mar 18, 2007)

batmans said:


> I don't wrench anyone these days. I rather pay others and spend my time doing something else.
> 
> Must be an age thing where I feel like I never have enough time to start and complete a variety of projects.
> 
> Yes, the $15k was parts and labor..... no short cuts and much of it was over engineered for my current HP goal and what the Maggie 112 can deliver.


I can understand that. I wish I had deep pockets like you.


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## Bluegoat05 (Mar 22, 2010)

so you think that pistons is the main thing i will need i like the idea of forged for the added insurance but if i do that i would do a stroker kit. and not to mention after i did all that im gonna be out a lot of money, maybe batmans could borrow me some lol because plans for the future include
l92 heads, l76 intake, livernoise cam stage two l92 cam, procharger, drive shaft, half shafts, and axle stubs so im gonna be into it around 9000 by the time im done so if i add a stroker to that its gonna be 2000 more. by the way these upgrades are gonna be way in the future. im just dreamin for now. but like someone said somewhere i read it may be worth it to get forged and have the power and still last 200,000 miles.. but ya any input you can give is great:cheers


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## batmans (Aug 16, 2007)

Definitely the pistons are the weak link and need to be upgraded for forced induction applications where detonation occur more easily.

There are two common alloys used in forged pistons, 4032 and 2618. Silicon-aluminum alloys, such as 4032, have great wear characteristics because the silicon particulate hardens the alloy and reduces the thermal coefficient of expansion. However, silicon-aluminum alloys can turn brittle and become prone to fracturing when subjected to extreme stress. With a piston made of a silicon alloy once a crack starts, it doesn't stop until the piston suffers a catastrophic failure. Low- or no-silicon alloys, such as 2618, may wear a bit faster but provide better strength and durability. In the rare case of a crack in a 2618 piston, the crack will migrate to an area of lower stress and stop. 2618-alloy pistons keep their shape under extreme pressures and high RPM's. 

The "4032" performance piston alloy has a silicon content of approximately 11%. This means that it expands less than a piston with no silicon, but since the silicon is fully alloyed on a molecular level (eutectic), the alloy is less brittle and more flexible than a stock hypereutectic piston that I believe the GTO has. These pistons can survive mild detonation with less damage than stock pistons. I think that most cars with factory turbos and superchargers uses the 4032 since the boost are not normally very high and that the cars have been tested and tuned so that detonation is not really a factor. Furthmore, the 4032 pistons should wear better than the 2618 pistons (there has been disputes whether or not the 2618 do have any appreciable wear than the 4032).

The "2618" performance piston alloy has less than 2% silicon, and could be described as hypo (under) eutectic. This alloy is capable of experiencing the most detonation and abuse while suffering the least amount of damage. Pistons made of this alloy are also typically made thicker and heavier because of their most common applications in commercial diesel engines. Both because of the higher than normal temperatures that these pistons experience in their usual application, and the low-silicon content causing the extra heat-expansion, these pistons have their cylinders bored to a very loose cold-fit. This leads to a condition known as "piston slap" which is when the piston rocks in the cylinder and it causes an audible tapping noise that continues until the engine has warmed to operational temperatures. These engines should not be revved when cold, or excessive scuffing can occur. 

Some owners have considered hypereutectic cast pistons as an alternative to forged pistons. Hypereutectic cast pistons could be an upgrade for normally-aspirated engines. However, A.Graham Bell in his recent book "Forced Induction Performance Tuning" (published in 2002 by Haynes) says they are a poor choice for turbocharged engines. Hypereutectic cast pistons have about twice as much silicon in the aluminum alloy as regular cast pistons (15-20% instead of only 7-8%). According to Bell, the added silicon leaves them "quite brittle and, as such, prone to breaking when subjected to detonation." 

I looked at Mahle, Manley, etc. and went with the Wiseco Powersports Forged Pistons - Wiseco Piston Inc. since a few of my friends with 1000HP boosted LSx haven't had any failures with them.


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## batmans (Aug 16, 2007)

GM4life said:


> I can understand that. I wish I had deep pockets like you.


My pockets are not that deep. Just average.

I have friends with very deep pockets like this blonde single mom of 3 boys:


























She managed her $$$ well and did good as a wall street lawyer (she likes to play the dumb blonde and people fall for it and try to walk all over her).

She's got 2 airport hangers that you can eat off the floor.

Mansion in Woodside (next door to her neighbor, Larry Elison, another NSX owner and CEO of Oracle). 

There are 20 vehicles, planes helicopters registered to her name. She's been known to take her good friends on a private jet flight to Paris on the weekend.

She bought this when she saw them pull it out to have it cleaned at a dealership for $380k:










Then she heard about a GTR and bought a white one to learn how to race her Ferrari with the paddle shifter. 

She's got a white hummer H1, votes republican, likes to shoot guns (has a lot of them).

I met her at a NSX meet since she has a red one and was looking at another one (ideally white). She likes mines and at one point almost bought mine when I was toying with the idea of a Z06.

There are people that I know that are further up than her.

I'm just a regular guy in Silicon valley.......


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## batmans (Aug 16, 2007)

Bluegoat05 said:


> so you think that pistons is the main thing i will need i like the idea of forged for the added insurance but if i do that i would do a stroker kit. and not to mention after i did all that im gonna be out a lot of money, maybe batmans could borrow me some lol because plans for the future include
> l92 heads, l76 intake, livernoise cam stage two l92 cam, procharger, drive shaft, half shafts, and axle stubs so im gonna be into it around 9000 by the time im done so if i add a stroker to that its gonna be 2000 more. by the way these upgrades are gonna be way in the future. im just dreamin for now. but like someone said somewhere i read it may be worth it to get forged and have the power and still last 200,000 miles.. but ya any input you can give is great:cheers


What are you HP goals?

Is this a daily driven GTO? race only? pump gas?

I like the L92 heads and would have done that if I knew about it before finishing up the engine


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## Bluegoat05 (Mar 22, 2010)

my horse power goals are right around seven hundred to the crank i think that is pretty much what ill have with the parts listed. im just gonna run that stock procharger psi of.. i think its about 6-8, i was readin on high performance gm and saw a build that they did with an ls2 with l92 heads and a pretty mild cam and got around 550 to the crank.


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## GM4life (Mar 18, 2007)

Bluegoat05 said:


> so you think that pistons is the main thing i will need i like the idea of forged for the added insurance but if i do that i would do a stroker kit. and not to mention after i did all that im gonna be out a lot of money, maybe batmans could borrow me some lol because plans for the future include
> l92 heads, l76 intake, livernoise cam stage two l92 cam, procharger, drive shaft, half shafts, and axle stubs so im gonna be into it around 9000 by the time im done so if i add a stroker to that its gonna be 2000 more. by the way these upgrades are gonna be way in the future. im just dreamin for now. but like someone said somewhere i read it may be worth it to get forged and have the power and still last 200,000 miles.. but ya any input you can give is great:cheers


If you're going to upgrade the pistions do the rods too. Do it while your in there, don't do a half ass job. Most what kills rods is RPM, to make more HP you need more RPM.


batmans said:


> My pockets are not that deep. Just average.
> 
> .


Come on... Ok then your pockets are above average..


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## batmans (Aug 16, 2007)

GM4life said:


> If you're going to upgrade the pistions do the rods too. Do it while your in there, don't do a half ass job. Most what kills rods is RPM, to make more HP you need more RPM.....


My engine builder said that the common reason of the rods failing from over revving was not using upgraded ARP2000 or higher bolts to prevent them from stretching.


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## Bluegoat05 (Mar 22, 2010)

batmans im kind of confused by your last post.. what do you think i should use for rods?


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## batmans (Aug 16, 2007)

Based on you HP goals, I would use the stock rods and upgrade all of the bolts in the engine, including the ones for the rods to ARP 2000 or higher.

If you want to go to 800HP+ then you will need to consider upgrading the rods.

The LS2 already has forged rods.


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## Bluegoat05 (Mar 22, 2010)

ok cool thanks! :cheers


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## GM4life (Mar 18, 2007)

batmans said:


> My engine builder said that the common reason of the rods failing from over revving was not using upgraded ARP2000 or higher bolts to prevent them from stretching.


That means something else becomes the weakest link. 

So what that said if I didn't "over-rev" a 1000hp engine the stock rods/bolts it will be fine.

Rods stretch too and they also take the abuse.


Bluegoat05 said:


> what do you think i should use for rods?


I would spend the extra money and go with aftermarket rods. I don't hear too many people and with your HP goals expecally with FI stick with stock rods. It's better to over build the motor than to short cut it. There are reasons why GM upgraded the rods in the LS9 at 638HP, insted of using stock LS3 rods. You can forge any metal, forging is just a process. Some metals/grades are more stonger than others.


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## Bluegoat05 (Mar 22, 2010)

ya i agree that it is better to over build than half ass.. so what ill probably do is do the heads/cam first. then get drive line and half shafts. then save and do rods pistons and new barrings. then do procharger.. sound like a pretty safe plan?


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## GM4life (Mar 18, 2007)

Sounds like a good plan to me. I'm just looking out for you. I seen too many people throw rods thru the sides of their block. How the saying go: "Pay a little now or a whole lot later." I live by that statement most of the time 

The drivetrain is defantly a good thing to mod before goin big power expecially if you drag race. I've talked to a few guys that have over 700rwhp through the stock stuff. As long as you keep the wheel hop at bay.


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## Bluegoat05 (Mar 22, 2010)

awesome! ha ha now all i got to do is come up with a bunch of money ha ha


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## batmans (Aug 16, 2007)

Bluegoat05 said:


> ya i agree that it is better to over build than half ass.. so what ill probably do is do the heads/cam first. then get drive line and half shafts. then save and do rods pistons and new barrings. then do procharger.. sound like a pretty safe plan?


Make sure ur knock sensor wire is in good working condition and not melted on some aftermarket headers, which is what happened to me.

Couple that and bad gasoline and my "safe" maggie factory tune was useless.

for your HP goal, I think you should be safe with a 11.5 A/F tune.

My tuner also did something with the timing once the AIT went up from the Maggie being run constantly. I think he pulled timing.


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## batmans (Aug 16, 2007)

Dun forget to add this to your list:

http://www.gtoforum.com/f37/may-best-water-alcohol-injection-system-yet-27497/#post229746


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## Bluegoat05 (Mar 22, 2010)

wow. so you can use windshield washer fuid and up your horse power by 10-15% that is pretty crazy!! so what is water alcohol? what else can you put in this


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## 87GN06GTO07IRL (Aug 10, 2009)

Bluegoat05 said:


> wow. so you can use windshield washer fuid and up your horse power by 10-15% that is pretty crazy!!


Don't believe every thing you read. It does two things. Raises your octane and cools the intake charge temps. Any car will benefit from higher octane, but you need to tune for it. The purpose of running higher octane is to be able to up the timing and that is how it makes more power. S/c and turbo cars will benefit greatly from reduced iat2's. This won't help iat's much on a n/a is they shouldn't be much over ambient anyways if you built your intake properly. As long as you get a tune you'll see gains. If you don't it'll run way worse and bog.


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## GM4life (Mar 18, 2007)

:agree
And don't run out of it nither. You'll end up building a new motor.


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## PBF Bioset (Apr 25, 2010)

Hi,
I've had a look in a few construction books and there is a security factor mentioned. For an engine in everytime full load stage, it is used a 2, what means 800 hp could be handled with the stock parts. But if GM thought of partial load stage construction the factor may fall to 1,25 what would cause a maximum (without damage) of 500 hp. This thought was not figured out in detail, but somewhere between this two it will be.
In terms of the crankshaft you can minimize the risk of "to low choosed factor", if you get one with a higher diameter, or got better surface materials and a lower tolerance of bearing clearance ( to reduce the pressure per square ) in combination with oil of a high viscosity...
If you don't want to change anything, you should have a look at the oil everytime your engine passed the 500 hp-border. If there are metall-strands in it, it is too much power for the stock engine.


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## danfigg (Sep 27, 2009)

*re*

[ya i agree that it is better to over build than half ass.. so what ill probably do is do the heads/cam first. then get drive line and half shafts. then save and do rods pistons and new barrings. then do procharger.. sound like a pretty safe plan?
__________________
QUOTE=danfigg;229945]This plan is back words as a mofo. To properly build an engine you need a well qualified Machine shop that specializes in LS Engines. Second You dont buy new heads and a new cam stuff it in a engine then do rods and pistons and then do a supercharger. This should all be done at one time. Have your engine build from the ground up Hot tanked honed new cam bearings new freeze out plugs align hone and bore deck the block measure measure measure. Rotating assemble measure measure measure. until the short block is complete. oil pump timing chain oil pan gaskets ETC upper end would be next heads intake and or supercharger. Do it right and do it once-------------Danfigg[/QUOTE]


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## goatpower420 (Apr 30, 2013)

Dallas Performance | Tuning For High-Performance Cars.... they state that they do ls2 corvettes but when i contacted them they said they would do gto's. they also said they use the stock motor but switch out all the internals b/c stock heads and rods would melt if you were to take it to the strip. check out their list of upgrades and the package also come with a 1 year / 10,000 mile warranty, meaning you blow the motor or the supercharger or whatever, they replace it.


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## svede1212 (Nov 1, 2005)

If you have the money you can throw a lot into the engine. The thing about a GTO is then prepare to spend another fortune getting the power from the engine to the ground. I would plan on an expensive double or triple clutch, stall if it's an auto, trans buildup of either kind, drive shaft, new IRS rear end, half shafts and stubs or a solid conversion, mini tubs, big tires and new wheels and all the suspension stuff to make everything work right. There is no bolting on $10 grand to an engine and you're done.


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## Sumfoo1 (Jun 18, 2013)

Your crank is fine I would replace rods and pistons, and since I would be doing that I would do it the right way with Carrillo or crower quality pieces because the labor will be the majority of the expense so why try to save a grand on Chineese eagle/scat parts that are sometimes good for 800 hp.... Sometime not... When Oliver/Carrillo/crower will be good for 1200hp all day every day.

Says the guy building a big block ford with all billet crower pieces.


Sent from AutoGuide.com App


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## LOWET (Oct 21, 2007)

740tank said:


> my car is the shop right now its going to have 650 whp with stock pistons, lifters, rocker arms, push rods Ill let you know how it goes:rofl: its a ls1



650 HP at the wheels with a motor stuffed with stock parts and a LS1 at that. That is really easy, just tell the tuner to get your Dyno numbers and multiply it by 2 and you just might get 650. EASY,,,,,,very ,,,,,,EASY


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