Ok so Ive been heavily considering this car, Ive read up on it as much as I can. I'm interested in knowing some of the thresholds of the motor, I have currently a supercharged ecotec in my cavalier with almost 100k on it, I know pretty much everything I need to on that motor, the info is out there its all proven. The LSJ is a bit foreign to me.

My plans for the SS when I get it is intake, exhaust and the intense stage 5 kit, from thier claims thats around 275whp, I know on an L61 thats past the safe margin and the rods go, in the L61s we all know the rods are the first thing to go, and in the cases where rods dont bust ppl bust ring lands

Now with the LSJ being all forged stuff whats the first thing that ppl have consistantly broken on this motor, if indeed it has forged pistons and rods factory, I know on the L61s the next thing was the head maxed out at 350whp, I would think the LSJ head flows better and also has stronger valves, how high can this sucker be revved? I run 7000 with no problem on my L61 eco. Beyond the valves next thing to go is the head gasket and or head seperating itself from the block, anyone have issues with this?

I doubt Ill run much more than 290whp, I know the blower maxes out, speaking of which has anyone done or made a kit with an M90 it seems like short of a turbo thats the only this motor can be pushed beyond 300whp.

Looking beyond the engine itself Ive heard alot of ppl breaking axles and clutches, are they just weak? Any crazy PCM stuff I can deal with , I have HP tuners

One last thing, what sizes are the speakers in this thing, im an audio nut and id prob want to replace them

 

The rods are good for 500-600 hp, pistons are good for 300-350 hp. Rev wise, the stock valve springs kinda dampen any REALLY high reving but the motor can handle 7300-7400 RPM and with valve springs over 8000 rpm. Its a stout motor

 

Rodimus, welcome to the SS.net I remember you from the the j-body.org The motor is fairly stout, with the headgasket being the first weak point on high boost. I already replaced mine with a Cometic one and Eagle headstuds as I blew the stock one. The axles and stock clutch on these cars just plain suck period. HPTuners will work great on our PCM for tuning too. I don't know of anybody that has an M90 adapter released as of yet, and people are starting to work on Twincharging and Turbo Kits. There is actually a Redline who successfully runs the twincharged setup. The stock audio system is pretty decent with the Pioneer 10" sub, but for someone like you, you'll probably change it. Not quite sure on the size, but a quick search in the audio forum will probably help.

I have a question for you as well. Who makes a decent ecotec turbo manifold now? They will work on the LSJ as the bolts and ports are the same. I'm trying to get an estimate together so I can fab my own turbo kit. Thanks.

 

welcome dude, the LSJ engine is a strong one!

 

I would worry about our axles and clutch before I worry about the engine. Seems commonplace around here anyway.

 

Hahn is about the only one I know that makes a quality manifold that doesnt crack and is ceramic coated (like they all should be) right out the box, with thier stuff you are of course limited to Mitsu turbos for these cars prob a 20G would work best

Whats the weak point on the head gasket if thats the first thing to go the L61 one was good to aboot 350ish

 

I blew my head gasket at 15psi, but I am the sole oddball out on this one. Usually it takes 22-23psi to blow it, so 300-330whp is the guestimate.

 

I don't know what size the speakers are, but they are better than many customs systems I have heard. Very clear and powerful.

 

I'd be worried about clutch/axles before anything on the engine goes...