well im bored as **** and i was thinking...after i finish up with my turbo and a new clutch im gonna start saving for internals...i was wondering:

1. whats a good company for pistons
2. whats a good company for rods
3. will i need a certain type of piston rings or a new rings?
4. what compression should a run? (my biggest issue-keep boost in mind)
5. i think i should probably go with new head studs

thats all i can think of for right now...if you all have any other suggestions feel free to comment

 

i dont know but im interested

 

we need posters

 

Diamond is the best imho. Go low compression for higher boost gain. Turbotechracing.com ARP headstuds, strongest and best out there.

 

1. wiseco
2. eagle
3. steel is tried and true, moly sometimes have issues seating
4. compression doesn't matter, tuning ability/availability and horsepower goals are what matter. your compression should be a product of the answers to those questions.
5. defiantly. cheap insurance.


You should also add head work, our valves, springs and most other things are exactly the same as the LSJ/2.2, just not advertised as such. Also, head gaskets are the same except you'll need to tap and fill two small oil holes next to the chain guide... its easy to understand, harder to explain. if you ever get to this point i'll explain further..

 

maybe see what the 2.4 liter srt-4's are running as optimal compression for a street car since we share displacement and turbo with them it might be worth a look.

 

SRT-4s run somewhere in the range of 8:1 - 9:1 compression out of the box IIRC

If you plan on running large amounts of boost I would go with LSJ compression of 9.5:1...they seem to be able to handle boost well at that compression. Say goodbye to that low end torque though if you're currently boosted at stock 10.4:1

keep in mind though alot of the parts you'll be getting will be custom AFAIK there aren't any companies that make drop in internals for the 2.4

 

If you alter the pistons heights youll change your compression.

 

While your at it do springs and retianers as well as I high flow oil pump and fuel pressure regulator. Although I would do all these things including the turbo at the same time. Be patient and you will get better results. I waited 2 years to put together my GTR and did everything at once. Now I have a 700hp beast that can actually utilize the potential of the turbos I put on the car. I would hate to have a turbo that I could only run at 6psi safely due to crappy internals

 

well i am working ona turbo setup....and i will probably want to run more boost...so im thinking maybe lowering the compression to 9"1 or something since ours is so high

 

you dont need to lower the compression substatially, just make sure you have the suporting mods and are very careful about the trim of the compressor/turbine wheels as well as the housing size for the turbo you use. Since the eco tec is a floating block setup it can be dangerous so definatly consider sleeving the block and reinforcing the head gasket using proper studs.

 

But lower compression does help turbo'ing

err boosting in general actually*

 

it allows you to run a higher psi rate through the turbo without fear of blowing the block. If the motor is built right that wont happen. I have 10.5:1 compression and am boosting twin GT28RS turbos at 23psi with little to no surge.

 

1. Wiseco, they offer a forged 8.8;1 designed specifically for boosted LE5's, Diamond makes decent stuff as well.

2. Carillo is the only rod I actually know that is easy to get. Not sure who else even makes an "off the shelf" rod for the LE5, I believe the Eagle only has 2.2 rods.

3. New rings definitely, consult with ring maker with your goals. I like Total Seal.

4. for serious boost drop down under 9.5:1. for single digit pressures stock CR is fine.

5. Absolutely, no question.



You should also invest in some LSJ or quality(Ferrea, DelWest) aftermarket valves, and matching springs.

 

I'm probably going to go stock compression forged rods/pistons/new rings/headgasket when I hit 75-85k (miles) on this setup. I just hit 40,000miles (15k boosted).

 

would stock forged compression be safe?

 

from what i collected yes...im wondering if i would benefit more to drop compression and raise boost or keep compression with forged equipment and raise boost

 

well the higher compression you have the better for low end power, you don't wanna scarifice more than you have to, if we could keep stock compression with stronger parts and up the boost away then that would be great!

 

sure would....if we were to do that though i would probably pick up a set of the best pistons/rods i could find....as well as maybe some new sleeves

 

if someone could list up some good names of good piston/rod companies ill send out some emails

 

weisco should be able to get you pistons for the 2.4 i know i saw them listed on a website a little while ago. But they do take custom orders if you want a certain cr.

 

https://www.cobaltss.net/forums/show...CO#post2167256

 

Wiseco doesnt manufacture "shelf stock" pistons for the 2.4L ecotec, just the 1996-2002 2.4L found in the J-Bodies (Cavalier/Sunfire)

 

http://www.importperformanceparts.ne...-cavalier.html

here's the site that listed the 2.4 pistons from weisco. They have them listed under the cavalier section but it has them listed as 2007 2.4 ecotec for the sostice/sky/cobalt.

 

thanks mave...i got that but i mean give me names of all the best and ill see what i can do...maybe get some new products...who knows