Pmorgan

I have a 2011 Grand Sport, automatic trans. I want to do some performance modifications, I love the car just like it is, but who doesn’t like more horsepower. Been reading on the net, saw somewhere,, where ported heads, cam swap, headers and cold air intake and tune after, can get me close to 600 horsepower, is this true? Trying to find the exact place that read this, when I do I’ll post it. Does anyone have any experience with these modifications and the results from them?

z288uup

From what I have seen. A good heads and cam setup can get you near 500 at the wheels on M6 cars. If you want more go FI.

mikeCsix

In your quest for more power, just remember the more power you try to extract from the engine, the shorter it's lifespan. To get to 600, you'd probably have to increase compression too (ala forced air or high compression pistons). Realistically (IMHO), for long time performance, headers and a tune, ported heads and intake will give you the best bang for you buck.

I know Lingenfelter cars have a lot of horsepower and are forced air and are in the 200k range, but their mods and engineering expertise are well above average.

jaybee924

If you want 600 horsepower you're going to have to go with a supercharger. It's not possible to get that N/A and if it were you're going to spend money out the butt and I'm sure you won't like it on the street. Just sayin

Patriot Six

An A&A or ECS supercharger kit with no other mods will get you over 500rwhp or about 600 at the crank, and it will drive like stock until you step on it. You can do it NA, but it will cost about the same, if not more, and driveability will suffer.

LSX228R

The A&A kit will do 550-600rwhp on pump gas and 700rwhp + with meth/e85. The car will drive stock, get the same gas millage and can easily be reversed if you go to sell..

JeremyAZ

I have a 2010 GS manual. Heads, Cam, Kooks long tubes, intake and a good tune on 91 gets you around 475whp. 154mph 1/2 mile with passanger.
LS9 injectors and flex kit on E60ish gets you just at 500whp with a good safe tune. Could get a bit more or less depending on dyno.
No way to get 600 NA. Need spray or blower/boost.

Purple92

The LS3 in your 2011 GS is a great motor - BUT remember - it's a 376 cubic inch motor !!! 600 HP is asking for about 1.6 HP/cubic inch - that's pretty rarified air in the Normally aspirated world.

Since you have an automatic, and since you didn't say that you plan to change the converter - you simply won't like what happens if you go with too wild a cam. If you go with good heads, a set of long tube headers, and a somewhat better cam (and a GOOD custom tune - done by someone who knows what they're doing) - you are probably going to be up 75 - 100 HP. If you want more than that - I'd say to go with Forced Induction.

If you do decide to go with Forced Induction - remember those are stock Hypereutectic pistons in there - and they were not designed to deal with the loads and temperatures that come with boost. Most all reputable engine builders will recommend forged pistons when Forced Induction is going to be part of the equation. I'm not saying that the stock pistons won't live - there are hundreds of people on this forum that are running boost with stock pistons every day - I'm saying that you have significantly reduced your safety margin, and the more boost pressure you run - the smaller that margin gets. Abuse things too much and there is real potential for cracking a piston... I'm not saying this to drive you one way or another - but you need to understand the cons of your potential choices as well as the pros.


GOOD LUCK !!!

Dano523

The vet already has more horsepower then its handing abilities, so by increasing the HP, your just tipping the scales even more, and can actually make the car have slower lap times around a high speed road race course instead.


My suggestion, before you do anything to car, a few laps around a high speed road course to figure out where the extra money would be best spent instead. If your like 90% of the vet owners, it's not the car that needs anything, but HPDE driving lesson needed for you to get the most out of the stock vet instead.

S.C. vette

and you will realize the same level of reliability you have come to know, count on...

xBoostx

'11 grand sport here heads llsr cam cold air intake and headers A6 car 3.42 gears 3400 converter made 575/560 wheels on e85 still factory intake and throttle body.

Power with the 3.42 gears was reduced to 500 wheels from 560 sense higher numerical will reduce resistance on the dyno.

Against a 10 cyldr dual throttle body 8.6 liter 513Ci.

60 to 150 roll

CMY SIX

where did you get that from? I know of a NA 1200 HP LS6, if you got the $ anythings possible. I just love guys like you completely clueless, take a look at an ARCA motor 600 and some out of a 350CI and there cheap enuff to buy and go racing all year. Guys just like you in 2007, "oh you'll never get 400 rwhp out of an LS2" I'm running near 455 with very little mods

JeremyAZ

Pretty sure OP was talking about his stock block and mods to get his specific goal.....

jaybee924

The OP never said anything about changing out the block or going with a bigger cubed motor which is what I was taking the post for (Stock block). Maybe I'm wrong or read something wrong and didn't say anything about internals besides a camshaft. Yes you can make any type of power you want with money that's true unless the the OP want a race car. It seem the OP was doing a budget build without getting in to deep but they will have to answer what they are willing to do and what they aren't that's why I said what I said. Plus the OP said he seen somewhere on the net about it but haven't cam back to post it or where they seen it. Just sayin

Pmorgan

xBoostx

600 hp where crank or wheel

Purple92

As other posters have suggested - before you go the ported head route - price what a good cylinder head porter will charge, and compare that against a new set of High performance aluminum LS3 heads. I'd suggest that you look at BOTH price and airflow (look more at intake airflow than exhaust - both are important - but intake airflow is "more" important). As far as price goes - also look at things like the cost of the valve springs that the new cam may require etc. Then make your decision.

A decent "benchmark" is the flow numbers that a set of the GM Performance LS3 heads provide. These certainly aren't the "best" LS3 heads out there - but it gives you a good solid data point. If I remember correctly - the GMPP LS3 heads flow about 10% better than the stock LS3 heads.

The other thing is that you shouldn't only look at flow with the valves at max lift. The valve spends very little time at max lift - so compare the flow at mid-lift (e.g. 0.400 lift). And if you're running a cam that will only have 0.540 lift - a head that flows great at 0.700 lift is kind of pointless....

SteveDoten

Don't do it.

Sell the GS for 28-35k (typical market)

Buy a C7 for 35-40k with a warranty.

-----------------

Or....

The best hp/$$ mod is a cam/tune, PERIOD.

No other single mod sub $2000 is going to net >40whp

(Before someone posts a 50 shot of dope, have fun filling bottles if that's for you)

0Daniel@Vengeance

Take a look at our performance packages to get an idea of CRANK horsepower ratings and the modifications it takes to get there. The best way for you to achieve 600RWHP is to go with a blower setup. If you have any questions or would like to discuss any of our packages please feel free to contact me or Robert. Our phone number is 678-513-7105 or you can email us at Sales@vengeanceracing.net

https://vengeanceracing.net/packages-c6-2008-2013.html

David @ Vengeance Racing

Chiselchst

...I dare you to go in to the FI section and ask this...

Schepnxl has ~700rwhp, on an LS2 at 200k miles. Check out the FI reliability thread here

Calloway has >250k on their blown C6 LS3...

Go blower, IMO