i recently bought my 05 m6. it has 86,000 miles on it, so i know in the next year or so i will rebuild the engine in it.(i dont like running on an engine that has over 100.000 miles on it) my question is.... should i rebuild or replace the ls2 with a different one (LS3, LS7, etc) i would like more hp/tq. i am an old school guy as far as engines go. i have rebuilt an ls engine but dont have the experience to know which LS motor is the better one to build. i have thought about adding f.i. or nitrous and will welcome adding this to the engine afterwards. i daily drive my car and am not going for anything that is not pump gas friendly or be a pain to drive in stop and go. let me know what your suggestions are. they will be much appreciated. as i was saying i can build an LS motor i just dont know which one is the better choice to go with. thanks in advance

 

Lots of C6 LS2's on the forum with well over 100k miles, and I read recently of an LS engine (2/3) that had over 200k miles approaching 300k.

If taken care of properly, that LS2 of your will go well past 100k and still be a great performing engine. Save the money you would use on the rebuild and add some performance mods like long tube headers and a FAST 102 intake! Then, drive it like you stole it!

 

Down the road, will have higher resale value if the block number matches the car number.

As for HP, you do have the weaker 05 diff in the car, so that will limit you on the amount of hp that the diff will hold before snapping.

As for the motor right now, has around 411hp, and with just port/polishing with fresh OEM parts if needed (low on compression), can push that number up around 440HP. And in some long tube headers and high flow cats, and that number is 460 HP+.

But lets just get back to the stock 411HP that LS2 has now, and with nothing more than a tune, that number jumps to around 425hp, and better yet, the tune de-hobbles the amount of HP that the TM is holding back to the ground as well. Throw in a little throttle table rework in HP tuner (tables percentages are way down on the 05 model, while on the later models, the tables are maxes out instead), and the car will feel HP increase night and day instead.

As for figuring out crank to rear wheel HP, with a M6, subtract 60 hp. so right now, you should be at 350rwhp/350rwt dyno numbers, but as stated, the TM is holding back a lot of HP so you don't do something stupid and blow the drive line. So the tune will get you a few more HP, but the greater part of the tune is gaining back what the TM is holding back now. Get this far alone with a tune, then you can figure out if you want to add more HP, hence have the back end breaking out all over the place as you are trying to put all the extra HP to use instead.

 

thanks for the input, like you suggested Dano523 i have already tweaked the ecu with hp tuners (throttle, afr, tm, etc) i just cant leave well enough alone, lol. i thought about just doing a refresh on the bottom end but having the heads reworked and a port n polish done on them and a fast intake with throttle body. i didnt know the rear-end was a weak link on the 05 though. is there a fix for this without replacing it? the previous owner put a differnt exhaust on it already. dont know what kind it is. have not had the chance to get the car on a lift to give the underside a good looking over yet.
i have read about the gm hot cam and was thinking about doing that as well but didnt like that some were saying it gave it a rough idle. anymore input i would appreciate. it would be a while before i did anything like a was suggesting, but wanted to make an informed decision before i did anything that i would waste my money on if it wasnt needed. i forgot to mention and i am not sure if it has a factor in the rear diff issue, but it does have the Z51 package on it.

 

In the next two months I'll be pulling the stock LS3 from my 2014 Chevy SS; decided on a high displacement/high compression LSX build versus a heads/cam swap.

Engine will have about 5K miles on it when it comes out. Long-block, Oil pan to intake manifold.

I also have a BNIB Lingenfelter cam that I was going to use.

LMK if interested.

KW

 

On a stock motor, you will pick up around 10HP with either the fast, or the OEM intake ported by themself (lot cheaper to just port the stock). Where the Fast shines, is where you are hopping up the motor, and need to pull more air in that the ported OEM can handle.

Also, might want to post your HP tune file so we can give it a once over for any glaring problems.


There are couple of internal upgrades on the diff on later stronger diffs, but the stem on the problem on the 2005 diff is the case it self, with the cases stronger on latter models as well (even on the z51 option cars). So with the dif case as the base problem, just cheaper to upgrade the entire diff to a stronger diff is needed. But, as long as you are not getting stupid with wheel hoop, too much upgraded power, or trying to hard launch with drag slicks on the car, should not have a problem with the 05 diff on a stock motor.


Cam is a tricky $2K road to go down, since with gaining power on the top end via the cam, you can have some problems on the bottom end instead (surging and slow traffic drive-ability). Add in a cam with high enough lift (pistons would need to be valve relief milled, so forget that $2.K value price), and you can get into having to replace valve springs every 35K as well.

To be blunt, Super charging it the best value per dollar when adding HP, and the stock motor is good for 650HP when supercharged ( a meth kit as this level of HP on the stock motor is mandatory).

 

thank you very much. been doing a little researching and have came to the same conclusions. price per hp is way cheaper with a sc. thanks again for you responce

 

Stock LS2-LS3's can live fine in the 700-800hp area and I have. Literally hundreds of guys doing it. Not need to swap blocks on your car. If you want piece of mind, do a leak down on the car. I've seen plenty of LS motors making big power with lots of miles. Saw an LS6 making 700+rwhp with 175,000 miles. My buddy on here, Turbo Geist ran his stock LS1 at 800rwhp with hundreds of track passes in his FRC for 20-30,000 miles at that power level. Stock differential and all and beat the snot out of it. (You basically have a C5 diff being an 05 car).

Good luck!

 

I never heard of a stock ls2 being rated for 411hp. I had an 06 a6 with a fast 92, ported tb, vararam, lt's, and corsa sports. The car ran great! Much improved over stock. It put down 385rwhp on Cartek's Dynojet.
As far as the mileage, don't worry about it. As long as it was well maintained, no noise or smoke and good oil pressure, leave it. It would be a waste of energy and money to rebuild the bottom end.

 

thanks to everyone with there responses. been doing a lot of researching and have decided that i will go with A&A sc kit and after i do a leak check on the bottom i might rebuild it if it shows any signs that it needs it. again thanks for all your responses on this. it has helped me make a decision that i can live with. again thanks.

 

Do the math,
Stock LS-2 with M-6 will put down around 350/350 RWHP/RWT on a dyno with stock tune. You have a lose of around 60'ish hp through the m-6 drive line (higher lose with a auto trans), which puts you around 411 on the stock tune (stock with a tune is around 425HP instead).

The reason that the LS-2 was GM listed at 400hp only, GM did not want to let on that the 2005 C6 LS-2 C6 corvette, was making more HP and torque than the 2004 older C5 LS-6 Z06 vet instead ( specs where released in 2004 for the new C6 model, and would have killed sales on the remaining stock of the C5's z06's that the dealer where still sitting on).

Also, consider that the 2005 C-6 z51 option cars (which was cheaper in when release than a 2004 C5 z06 at same time) was running the same brakes, was around the same weight, and handled sharper/better than the C5 Z06 due to the new geomitry, plus newer upgraded interior/functions, GM would had to given out some very, very heavy rebates to unload the new C5 z06 out of the dealers inventory, even in 2004 before the C6 hit the dealers floors.

 

You guys are really splitting hairs that don't mean anything. Bench racing is entertaining to participate in or read, but go put a MPH down at the track if you really want to know how fast your car is.

 

Car will need to be tuned for the supercharger, so make sure to add on the meth kit when you install the super charger kit, so it can be tuned at the same time it being tuned for the supercharger (so you are not having to pay for another tune).

As for the fuel pump booster with the AA kit , one way to go, but wire from the battery to the booster with in line fuse (use the stock wiring as the control wire only, not the power feed), then to the fuel pump so you are not burning up the OEM wiring harnesses.
Note, ZR-1 fuel pump would be a better way to go, but you have to drop the tank to change that out.

Also, the harmonic balancer will need to be pinned, so when you are that deep into the engine bay to pin the HB, change it out with a ATI HB and pin it instead to the crank (read OEM HB is just a problem waiting to happen).

 

i did read the threads about the hb and decided to change it to the ATI hb during the process, i didn't know about using the ZR-1 pump instead of the boost a pump. i did some research on it and never seen anything about them overcoming the issue with the base and Z06's ecu not being able to control it. any info on if anyone has a work around for it. Again thanks for you knowledge.

 

If you are only making around 600HP, Z06 fuel pump should be more than enough, and no needed extra controls. But, check with A&A, since your kit may include a secondary fuel pump, instead of just a Boost a pump module to increase the output of the LS-2 fuel pump.

http://www.aacorvette.com/pdf/aa_c6_instructions.pdf

And install a meth kit at the same time. The meth kit is used to prevent detonation that can destroy a boosted motor in a heart beat.
If you are just street driving, a full tank of meth mix will last you are while.
Also, check with the local chemical suppliers. Should be able to pick up meth for less than $7 a gallon, so it mixed 50/50 with distilled water has you at 2 gallon on meth mix for less than $8 (lot cheaper than boost juice at $34 a gallon instead).

 

i will check in to it. thanks a lot for the info.