Put on LS 3 stock head and intake

for

A stock LS2 head and stock LS2 intake.


Torque gain est=

cost installed with parts est=


(clic on my profile for current setup )

-cow Cow COW -

no cam swap at this time



this combo with 390's is my goal btw

 

Their is no Fast intake availbe for the LS3`s. If you use the LS3 heads, you have to use their intake also.

 

True, the LS3 heads (aka: L92 heads) require the use of the LS3 (or the L76) intake manifold. A FAST intake made for those heads might be available in the distant future though, last I read it wouldn't be until after the SEMA show at the end of the year.
But there's plenty of power to be gained by porting the LS2 heads and matching them with a properly chosen cam and topping it all off with the current FAST intake.

 

thanks-- edited out fast

 

You'd have mismatched heads and cam. If your tearing the motor apart, I'd do it right and put a cam in that matches the heads. The ports are night and day different, no one cam would match both those heads.

 

True, one should gain more power from doing a well executed cam swap while keeping stock/factory heads then they would from simply swapping out the heads (be they LS3/L92 heads or even ported LS2 heads) and intake and keeping the stock cam.
Ideally, one would do both of course.

 

100% false.

Slp has done this swap and the car will dyno within 8-10rwhp of a stock LS3. The LS3 comes with those heads stock and the only difference in the cams is that the intake side lift is .550 instead of .525. There will be nearly identicle performance. The last 8-10rwhp is from the size of the bore which is the ony remaining variable. The heads typically give 25-30rwhp and 30rwtq without a cam swap. SLP proved it.

Also "tearing into a motor" by putting heads on has a 10% overlap of work with a cam swap. Coil packs, valve covers, rockers, pushrods, water pump with draining coolant are the only overlap items and that is 1 1/2 hours of a 15hr cam swap. I have my fourth cam in my C6 all of which I did myself. I also have the LS3 heads on my LS2.

I'm sorry for the aggressiveness of this reply but I hate myths being perpetuated that spread non-sense.

An LS3 car with LG headers, cold-air intake, and a tune will do 425/425 to the wheels and an LS2 with the LS3 heads and the same supporting mods is 415/415. I've seen it 3 times now. Craigster05 is next in line for the stock cam with these heads. Gaining 30/30 isnt a bad gain for any mod.

 

While peak HP would support your claim, the area under the curve especially on the TQ, shows the opposite to be true with these heads and the stock cam. If you use a cam big enough to make the peak HP claim, the TQ will fall, especialy at 2500-4k. Cams make a big difference from 4500 and up. These heads bring you nearly to LS3 levels. The bore being the last part that cant be duplicated.

 

You will likely hit 380/385 for HP and TQ with no mods tot he car and headers, tune, and CAI will be 415/415.

Cost for parts is 1800:

Heads 175 each (350)
L76 Intkae manifold:525 w/ injectors, fuel rail, new TB, all gaskets
springs 450-600 depending on brand. (I used crane 833's that are fine to 7100 as per cartek's dyno.)
Valves 260
gaskets: 140...you cant use stock..cometic .040's needed to get decent compression
Head bolts:45-130 for stock or ARP

Install is 800-1000 or so.

 

since I am mostly a 0-90 mph'er I can't justify the cam (at least for now) and thought I could just do an LS3 swap job for now.

I was thinking that the ls2- to ls3 head and intake swap would likely get me into 11's on streets--without the cam and adding a 3:90 tail.

It seems like a more viable option than a cam and I could cam later if I want.


am I right?

 

A cam will definitely help 0-90 since you have to wind out almost 3 gears. The cam is a 4500+ rpm mod. Typical gains down low arent common. The mod you really want for 0-90 is 4.10 gears.

 

thanks, I understand and agree with the 410

however the wife likes to drive the lil vert too and i think the 410 is a bit much for her on the sunday drives

would I get into 11's with the ls3 swap and my current mods? (and the 390)

chuck will retune me n/c

 

Another myth. Your wife wont notice anything with the gears. Its 20% not 300%. You need to drive a car with some of these mods before you make decisions on them. When I got 4.10's on my first vette, I didnt notice anything at part throttle and had to convince myself that there was a difference to justify the 1600 bucks. When they were broken in after a few hundred miles and i did some WOT blasts, I said, "Oh,ok". 4.10's is the most exaggerated mod and misjudged by the purchaser before they get it.

 

Spin, I like your comments about the L92/L76 setup and I can see that in my future. I also like the comments about 4.10 gears I've read but am more skeptical about them. I'm a big fan of rasing the 1/4 trap mph, that is how I would rather measure gains then just SOTP type stuff.

In your opinion, what gives the best improvment in acceleration/trap speed. A 4.10 rear or L92/L76 setup. I see myself doing about 1 major mod per year on the car (last year headers/intake/tune) and just wondering what would give me a bigger grin out of the 2.

 

Gears first

 

Silver05 and I are on same page.

I am progressing 1-2 mod per year and have been heading for a finished product in my minds eye since I bought the car. 3 years ago.

Thanks for the input, I was planning to do the 390 (and now 410?) in 08before the heads and or cam in 09. I can't help but chuckle after having read the 390/410 battle in another thread some time back.


With this little vert, I'm not so sure I'll end up with the Cam /and or/heads.

Thanks for the advice, it's a new rear gear for me in 08 then I'll revisit the top side in 09.

 

haha, yeah looks like gears might be going on this spring/summer for me too.

 

How does this result compare (hp/tq and cost) to ported 243 heads (e.g., $895 from RPM Motors) and a ported FAST (e.g., $1200 from Vengeance)?

 

Well from my understanding ported L92's would be better (more potential) then ported 243's. The L76 manifold is also much better then the LS2, probably close to a FAST intake and that is before porting an L76. Pricewise seems much cheaper to add the L92/L76 compared to ported 243/FAST and the potential is greater with L92/L76.

 

The LS2 with L92 heads in stock form (not ported) and a 23x's cam has done 495rwhp and 457 TQ and as far as I know the same numbes have been done by those 243's and the FAST.

At this time it would make sense to switch to what you dont have but just to clarify siomething: The LS3 heads are here to stay and will be on all GM performance cars from now on. The 3 year stint of the 243 heads from 2005 to 2007 isnt of much consequence and the 243 cores are 1000 bucks while the LS3's are 350 for the pair. In other words the LS3 crowd isnt going to spend all that money on the cost to switch laterally.

The biggest part I left for last. FAST has released the info at SEMA that the AFST manifold for the LS3/L92 heads is comleted in beta from and is currently being tested. I was originally due out by Christmas as was told to Craigster05 at SEMA but it has been pushed back to the spring. A few things to note about the LS3 and its FAST manifold. I noticed unreal gains from porting the L76 (stock) manifold. The stocker is holding back what the heads can due and all porters of the new platform heads all say the same thing. The FAST will only build on those strengths. The prelininary numbers are 20rwhp and no loss in low end TQ. The best H/C combos for the L92s are actually better in the TQ than any cathedral head combo now so the FAST will obviously better the total gains.

Also, If you do a search for FAST manifolds you will find that I am the last person that would pay 1200 bucks to vengeance or any tuner for one. I have installed so many of them that I ported and modified that I lost count. The new FAST L92 will fit the C6 without needing a mod, will have a front mounting MAP sensro and will have the latest shape negating much port work needed in the initial offering so the L92 heads at 350, valves at 260, srpings at 450 and the manifold at 850 will also be less cost.

here is what I put together for 765 total installed for Welcome2try:

http://forums.corvetteforum.com/show....php?t=1799958