I checked the FAQ but didn't see this listed...

What's the threshold for a stock bottom ended Ecotec in the Cobalt SS? Has anyone made 400/400 or in that area and drove it daily?

 

They say the bottom end can hold about 300 whp. It has not been proven yet that you can go over that. And it is all over this site. I hope no one flames you

 

300whp? Holy crap... what a joke. haha Well they can flame. What can I say. I thought it would be easier to ask... so I did.

 

so 300 HP is a JOKE for a Fourbanger???

Wow man, I know it is Supercharged and all, but 300 seems a little high already for a stock fourbanger.

Hell even V8s need some work to get the power to size ratio we have.

so your wanting 100HP a Cylinder and stock internals, GOOD LUCK! If that was plausible for the V8s then we'd be seeing GM's 6.0 LS7 making 800hp...It starts needing work at about 650.

 

yeah my buddy riceeater has a redline with about 460whp all he did was replace the pistons not rods his car held up fine till a few months ago when he snapped his crank

 

The weak link in the LSJ bottom end is the pistons. Replace those and you get to over 400 without a problem.

You know a guy that broke a forged LSJ crank at under 500 HP? That's very odd.

 

yeah rice eater from the redline forums

 

not to be a jerk but the 4g63t can hold 500AWHP completly stock. it was used in 1st and 2nd gen eclips's and i think its even in the evos

 

rice broke the stock crank...and its mainly due to the fact that he revved it above 8k IIRC and he had the stock balance shafts in as well.

 

agreed piston is the major limitation on the lsj block. in the build book for the lsj it specifically states that the pistons need to be changed when wanting to achieve 300hp. the crank and rods can handle it at least that is what the book is stating.

 

With proper tuning the pistons will only survive to just over 300 hp, but not for too long. Blown 4-banger is proof.

Rods are rumored to last to 400, but I have yet to have confirmation.

Crank is good to 600 according to GM Racing, but they change theirs at 550.

 

x1000000, that book is a very good key to a very fast cobalt. When my warnity goes, I'm going to shoot for a 325 whp SS/SC. Would not mind a forged lower end to handle a good 50-100 shot every once in awhile.

 

yeah doc i know him personally he did drive like an ass but idk if he changed his rev limiter to 8k but still it should have held up

 

If that is all you're looking to do you will be fine just getting forged pistons. Everything else is strong enough to handle it.

 

LMFAO
no.

i have built many many many dsm's in my time. nope.
sorry.

 

Thank You! At least someone knows something on motor strength.


The guy Asked STOCK bottom end holding that much...bottom end is anything below the cylinder head. So PISTONS are bottom end.

And I doubt the stock crank can handle above 400 without some modifications somewhere along the lines or around it.

 

Umm... I know a few guys making up around 500whp on a bone stock 4g63. They don't run it all the time... but whenever they use race gas they do. A real good friend of mine made 400whp everyday for 7k miles. Engine was fine... just put it back to stock and sold it. And for the record... stock 4g63 cranks are good for over 1k whp. Oh yea... so are LS1 cranks. Just polish those bitches up... OEM cranks holding over 1k hp. I think it's a bit more then 400.

Stock SRT4s hold 400whp no problem.

LS1s hold 550whp no problem... There's even a guy making 700whp on stock bottom and did it for over 2 years.

The Cobalt Ecotec is by the far the worst built bottom end in the 4 banger market if 300whp is the max output before snappage.

Hell... even B series Hondas can make 350-400whp before something goes wrong.

This is all things considered of course... good tuning on a well maintained engine.

And just so you know... when I say stock. I mean bone stock bottom end.

 

Actually, the stock L61 nodular iron crank is good to well over 400. So the LSJ forged crank is even better.

But if you spin the thing at 8K, well, thats your own stupid mistake.

I have been on this board for over 2 years now, and I have yet to hear about an LSJ rod getting broken.

 

i also know a few dsms makeing 400+ whp and im helping my friend build his up this summer

 

And how many of them are run EVERY day Hard in and out of traffic and stop and go driving. I have yet to see a high horse power 4 banger with stock bottom ends in these parts last more than 2k miles without throwing something apart.

It may be possible in the race world where everything is taken care of on a daily race basis, but I just can't see something that was meant for 200 some horsepower accomplishing 400+ with stock internals.

And the Crank MAY be rated at those numbers, but that isn't The ONLY piece to a bottom end. You also have rods and Cylinders/Pistons and bearings that need to be beefed up. As I remember in the Ecotec right up from GM the rods and pistons had to be changed out at 350 HP, meaning NEW BOTTOM END!

 

03/04 Cobras can support 800+ on the stock bottom end. they need a bigger blower or turbo conversion to get there, but they can handle it.

I realize that has very little relevance to this thread. Sorry.

 

Cobra? As in Cobra Mustang? so a V8 can handle 800? your also talking about a specific Performance engine that was made by Ford's SVT group...I DOUBT the left the Stock internals from their Stock V8s ford gives them inside the block, I bet they changed out stuff to make it work.

Try again buddy. They are talking Completely stock, not sent off to a secondary group to have performance parts added in.

LS2, basically GM's 5.7L Vortec V8 sent off to the Performance devision to be turned into an LS2, before it was mass produced. So, I'd like to see the 5.7L Vortec V8 handle the 800hp thresh hold with NO problems in FULL ON STOCK FORM with just POWER ADDERS. IE NOS, F/I

 

we had a grand prix in the 9s... 9.01 to be exact on the stock bottom end... over 700whp easily.

 

LS2=6.0
LS7=7.0

the LSJ shows piston failure first then nothing else till like 450 hp range...reference buildbook for strengths also GM buildup only changes pistons to smoke the skyline on street tuner challenge

 

There's a difference between longevity DD and a track car. Hell the 2.4 has dynoed 348whp and 380 wtq, stock bottom end, but for how long will that old up.....not very.