# The best way to get 500+rwhp N/A from a LS1 or LS2?



## IcemanGTO (Mar 2, 2011)

I am purchasing a 04-06 GTO this year and I would like to know 
from the knowledgable people here what is the best or easy way
to get 500+ rwhp from a LS1 or LS2 engine N/A? Is a head/cam/
intake combo a must to achieve this goal? If so,what head/cam/
intake combo do you subjest? Links? Also what mods are the most 
affective N/A on the LS1 and LS2 engines?
I'm looking to give my friends 08 Roush 427R a run at the track 
that he will not forget once I get my GTO.
Thanks guys in advance!


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## dustyminpin (Jun 19, 2006)

You won't get 500 rwhp with H/C/I. Been there done that. I'm sitting on 481 and have every possible all motor/stock cube mod you can think of. You need a blower with standard bolt ons, or a turbo I guess, but I know nothing of turbos... By the way, 427R Mustangs suck. There's one that parades around town her in Daphne. They aren't much more then a Standard Rustang with a body kit in my book. Kind of sorry they have a blower and only make 427 crankshaft hp.


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## Poncho Dan (Jun 30, 2009)

You need to add displacement, either with a stroker crank, or an aftermarket stroked short/long block.


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## SirMarco (Nov 5, 2009)

You can hit 500 N/A on a LS1. I have seen it in person. That motor is actually being parted out now and a new fresh setup is getting done. 
You just need all the right parts, a donky **** size cam and the right tuner. The car I speak of had AFR heads on it also. 

It's not cheap by any means but very possible.


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## GM4life (Mar 18, 2007)

I'm not saying it can or can't be done. It's not going to be a streetable car I can say that for shure. You are going to need a cam that too big for the stock pistons and high dollar heads. An LS2 would be the best platform to start of with.

You are better off starting off with bolt ons first and work your way up. If your into nitrous do it, FI is also an option.


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## IcemanGTO (Mar 2, 2011)

I really appreicate your insight guys I forgot to mention that I will 
be using the stock pistons/displacement and I need it to be streetable though.I like the Trickflow heads and cams.I'm not sure what brand 
heads and cams to go with? Also I don't know what intake will flow the 
best either? links? I'm researching and trying to see what works best.
Longtubes will be a must probably and I would like to stay N/A 
but,it's going to be tough! What bigger cam do you guys recommend that
is streetable?
What's worse about this guy with the 08 Roush 427R is his huge ego and
the fact that he thinks his 08 Roush 427R is the fastest vehicle in the 
world.I really want to beat this guy at the track and know the combo to do it with.


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## 05GTO (Oct 6, 2004)

Go with a 402 (4.000" stroke/6.3L) or a 421 (4.125" stroke/6.8L) stroker kit with flat top pistons. With the right heads, cam and intake you'll easily exceed 500 rwhp with the 421.

Better start saving for drive train upgrades as well.


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## IcemanGTO (Mar 2, 2011)

05GTO said:


> Go with a 402 (4.000" stroke/6.3L) or a 421 (4.125" stroke/6.8L) stroker kit with flat top pistons. With the right heads, cam and intake you'll easily exceed 500 rwhp with the 421.
> 
> Better start saving for drive train upgrades as well.


Thanks do you have any links to stroker kits you would recommend?
What heads,cam and intake should I be looking into purchasing? 
Links please?


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## Poncho Dan (Jun 30, 2009)

IcemanGTO said:


> I really appreicate your insight guys I forgot to mention that I will
> be using the stock pistons/displacement and I need it to be streetable though.I like the Trickflow heads and cams.I'm not sure what brand
> heads and cams to go with? Also I don't know what intake will flow the
> best either? links? I'm researching and trying to see what works best.
> ...


With only 427 crank hp, you can probably beat on him with my humble mods and a good hook.


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## ROBSGTO (Jul 6, 2008)

05GTO said:


> Go with a 402 (4.000" stroke/6.3L) or a 421 (4.125" stroke/6.8L) stroker kit with flat top pistons. With the right heads, cam and intake you'll easily exceed 500 rwhp with the 421.
> 
> Better start saving for drive train upgrades as well.


What's the cost associated with stroking a motor?


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## 05GTO (Oct 6, 2004)

IcemanGTO said:


> Thanks do you have any links to stroker kits you would recommend?
> What heads,cam and intake should I be looking into purchasing?
> Links please?





ROBSGTO said:


> What's the cost associated with stroking a motor?


You can find the crank, rods and FT pistons for around $2K, The heads, cam, intake, headers and other bolt-ons could run between $4-$6 K, an auto transmission will need a stall converter along with new half shafts, stub axles and drive shaft whether auto or 6-speed. Then top it off with a pedders suspension package. The total for a N/A beast could run $12-18 K plus the cost of the car.

You can also find stroked 550hp crate motors and keep the original LS2 in storage. Here are a few google links with some options,

LS2 421 Stroker Kit

LS2 Head and Cam Package

LS2 Stroked Crate Engines


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## DementedSix0 (Oct 13, 2010)

The "recipe" to 500 rwhp with heads and cam. - LS1TECH

I think this will help


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## IcemanGTO (Mar 2, 2011)

Thanks guys this really helped!


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## motoristx (Apr 27, 2010)

i'm putting down 515 on an LS2 block and 243 heads i'm guessing 600 - 620 at the Flywheel? sound right? I'm not sure of the power loss in the DL.

Target compression for pump gas is around 11.4:1, depending on timeing and other facters. (correct me if I'm wrong please)
I shot for 11:1 compression to run on pump gas:
Dragonslayer 4.0 inch stroke crank, small Journals.
Callies H beam rods 6.125LS1SJ
Diamond 4.020 semi dished pistons

243 heads, ported 
double valve springs
bigger valves both sides
(I forgot the kinda valves, sorry...)

243 251 .624 .624 114 LSA cam from comp cams. (this cam made all the differance from my last build +30 HP from 244 244 .612 .612 112 LSA)
Short travel plunger lifters from comp cams (for the high end)

Fast intake
36LBS injectors
kooks Long tube headers
AEM Brute force CAI (although i think the filter is choking it up)
stock MAF (i could use a bigger one it might be choking it up)
ported Throttle Body (no hole in the blade and it idles fine)

The Absolute Most important thing is a good tuner! your tuner can blow up your perfect engine, or make it purr. A good tuner can get you running and staying safe with almost any setup.
i think thats the jest of it... i need to start a photo bucket or soething to get you some pics...


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## GM4life (Mar 18, 2007)

motoristx said:


> i'm putting down 515 on an LS2 block and 243 heads i'm guessing 600 - 620 at the Flywheel? sound right? I'm not sure of the power loss in the DL.
> 
> Target compression for pump gas is around 11.4:1, depending on timeing and other facters. (correct me if I'm wrong please)
> I shot for 11:1 compression to run on pump gas:
> ...


Nice numbers NA exp w/243 heads. Wonder what it would get with L92 style heads.


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## Poncho Dan (Jun 30, 2009)

I'd like to go the big cube route myself, but I'll probably just do the LS7 block stroked to 440. Seems like the biggest you can go in the aluminum castings, without taking an 80lb hit by moving up to the cast iron LSX... even then you're limited to 454 with the standard deck, or you could go tall deck, and supposedly go up to 482, but that seems like lots more headache than it's worth.

I was just going to do a 404/402, but if it's going to cost me like 6 G's, then what's difference of a few $1000? It's not like I have any of the funds to tackle that project right now anyways. And I want to do ITBs - a kit from Kinsler is a good $4k on top of that. Not to mention the P&P LS7 heads will be about $2800...

My goal is to be the first 6 speed IRS GTO to hit sub 10 seconds N/A. Because using boost or nawz through a stalled auto is so played the f*** out it's not even funny...


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## GM4life (Mar 18, 2007)

FYI: In my latest issue of GM High-Tech Performance magazine they done a artical about stuffing the biggest cam in a stock LS1 without modifications to the pistons and stock heads. Good read, bigger cams than what I thought you can put in there. The biggest cam with FAST 102R intake, open LT's on stock LS1 was 527hp and 443tq on *engine dyno*.


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## dustyminpin (Jun 19, 2006)

:agree

I worship Scott Parker.


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## scryfst (Sep 4, 2010)

500RW is a tall order on a stock cube LS1/2 I'm sure with ideal conditions it's possible, but why set a number in stone? I'm sure you can get 480+ with a M6 LS2 GTO. Especially dyno numbers through 3:46 gears. 

My last tune (August, 93* temps) showed 475 and I'm still using 243 heads. 

I just installed a EWP, am getting ready to increase compression to roughly 11.3:1, will be adding a GZ vacuum pump and am going to match port the FAST (since it will be off again) just to see how far I can push this LS2 with 243 heads. I'll be happy if I can pick up 6-10RWHP/RWTQ. With my new additions and maybe some worked over MAST or PI heads I think 500 is possible. 

If you're just looking for a number or to beat on other street cars why not just buy a used PD blower, take care of the fuel needs and be done with it? It sure would be A LOT cheaper!


I made 475/42X with:
*AI 243 heads with Manley valves (stock valve sizes) and Crane adjustable RR's
*Ed C. custom spec cam 
*Ported FAST (Rails, lines, injectors etc..)
*Ported TB
*Kooks Signature series
*Kooks catted mids
*X-Pipe
*Magnaflows welded in place of factory mufflers (stock rear 2.5" pipes)
*UDP
*Vararam
*SD tune
*3:73 gears and Eaton out back.

OP, that's close to 10K with NO labor  Looking back a TVS sure looks good!


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## GM4life (Mar 18, 2007)

FI has it advantages and disadvantages to N/A.
Pros: 
- More power/efficancy
- Cheaper or equal to the cost of N/A @ roughly the same power
- Easy to upgrade the power
- Some are emissions friendly
- Low, mid, high power, flat tq curve in PD blower

Cons:
- Weight. My S/C alone added 100lbs exactly to the nose of the car
- Heat soak
- Pluming
- Tuning has to be good, unlike N/A you have more of a tolerance
- Roots: alot of low end tq = harder to launch
- Centrifugals= more maintiance 5k oil changes, some lag
- Turbos more heat, lag


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## scryfst (Sep 4, 2010)

GM4life said:


> FI has it advantages and disadvantages to N/A.
> Pros:
> - More power/efficancy
> - Cheaper or equal to the cost of N/A @ roughly the same power
> ...


:agree And, we have a winner folks!

Unfortunately most people just chase a number and don't take any of that into consideration. 

IMO (and my dream), the ultimate street GTO set-up would be 600rw, mini-tubbed and ALL MOTOR  Screw the bottle or boost, there's nothing like a high HP all motor ride!


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## jpalamar (Jul 22, 2008)

scryfst said:


> :agree And, we have a winner folks!
> 
> Unfortunately most people just chase a number and don't take any of that into consideration.
> 
> IMO (and my dream), the ultimate street GTO set-up would be 600rw, mini-tubbed and ALL MOTOR  Screw the bottle or boost, there's nothing like a high HP all motor ride!


If you get 600HP NA out of a LS1/LS2 I can guarentee it will drive like complete **** on the street. Thats why FI is so great.


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## ThePrincipal (Jan 3, 2006)

I've got a 2004 GTO. Comp Cam, 85mm throttlebody, performance parts intake, headers, Magnaflow Catback exhaust and a Procharger. Dynotuned at 579 rwhp.

rx performance in Palmetto Fl does great work.


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## GM4life (Mar 18, 2007)

jpalamar said:


> If you get 600HP NA out of a LS1/LS2 I can guarentee it will drive like complete **** on the street. Thats why FI is so great.


Thats another thing that can be added to the pros list; driveability w/high hp.


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## 1fstGTO23 (Feb 18, 2011)

GM4life said:


> Thats another thing that can be added to the pros list; driveability w/high hp.


If you go with a rear mounted STS turbo kit you can take the heat under the hood con away too. Plus it weighs less than a supercharger. I have read about guys getting 550+ hp with stock internals on about 6-7 psi. If you buy their universal kit plus things you will need such as external wastegate, piping by a shop, intercooler, meth kit, and fuel induction upgrades your talking about 4 grand and that's a pretty high estimate considering the turbo kit is only 2 grand. :cheers


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## GM4life (Mar 18, 2007)

1fstGTO23 said:


> If you go with a rear mounted STS turbo kit you can take the heat under the hood con away too. Plus it weighs less than a supercharger. I have read about guys getting 550+ hp with stock internals on about 6-7 psi. If you buy their universal kit plus things you will need such as external wastegate, piping by a shop, intercooler, meth kit, and fuel induction upgrades your talking about 4 grand and that's a pretty high estimate considering the turbo kit is only 2 grand. :cheers


The STS kit has more cons to it than a normal turbocharging system. Its advertised to have low lag, but folks have said it has plenty of lag. Look how long the air has to traval. You need a *electric* oil pump to pump oil clear to the rear of the car and back to the front. The turbo hangs low and looks tacky, and alot more plumbing.


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## Poncho Dan (Jun 30, 2009)

If you want 500 at the wheel, N/A, you need to _begin_ with a stroker rotating assembly and work from there. Even so, a 383 LS1 might not have enough to do it and be streetable like a 404 LS2 would. A lot there too is going to depend on head & cam selection...


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## YellO5LS2 (Jan 9, 2011)

I don't know anything about this stuff, that's why I'm here to learn.

BUT PLEASE KICK THE CRAP OUT OF THAT MUSTANG. If they need a supercharger to produce only 27 more HP's than out motors do stock than it's not even worth racing. 

Maybe someone can explain to me why all cobra drivers are A&&holes. They're also always bald...I don't understand.


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## 1fstGTO23 (Feb 18, 2011)

GM4life said:


> The STS kit has more cons to it than a normal turbocharging system. Its advertised to have low lag, but folks have said it has plenty of lag. Look how long the air has to traval. You need a *electric* oil pump to pump oil clear to the rear of the car and back to the front. The turbo hangs low and looks tacky, and alot more plumbing.


You think it looks tacky? The ones I have seen look pretty nice I thought you couldn't even see the turbo unless you look underneath the car. The youtube videos of them I have seen the cars seem nasty fast. And idk about all that I hope it doesn't lag too bad considering that's the set up I plan to do! lol


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## GM4life (Mar 18, 2007)

1fstGTO23 said:


> You think it looks tacky? The ones I have seen look pretty nice I thought you couldn't even see the turbo unless you look underneath the car. The youtube videos of them I have seen the cars seem nasty fast. And idk about all that I hope it doesn't lag too bad considering that's the set up I plan to do! lol


Yup. I seen a 06 GTO with one. Seen the turbo from across the street. I'm more of a person that the install looks OEM/clean. I have people all the time ask me is my S/C stock. I've heard the they do lag and if you think about it the laws of physics will agree seeing that the air has to traval from one end of the car to the other thru the I/C before it gets to the engine They may come with a small A/R turbo so that the lag don't seem to bad. The thing with small turbos is the top end will suffer.

I liked the STS turbo when it first cam out on the T/A. After adding the prices up for it came out to around $8k for everything I wanted. Then after looking at it, it just too much stuff to go wrong.


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