okay, im making this thread for two reasons, personal experience and hopefully lack of PM's

if you want to run over 12psi on your setup (reguarldless turbo/sc)

you need to check out zzp for two items

https://www.zzperformance.com/cobalt...s1.php?id=1015

and

https://www.zzperformance.com/cobalt...1112&catid=143

retainers are not required with the stock cams, which is great I would suggest getting the EVAP fittings for the $25 bucks tho

If you really want technical info, just call em up!

 

BRFPS is a good idea, valve springs are a necessity for 15+ psi

 

just an FYI, wanted to help some guys out, i have both and will be using them when doing the build in January

 

oh yea i know man like i said both are pretty much a necessity 15+ psi.. but not a bad idea at 12+

i'll be picking up at least the valve springs in the next months hopefully

 

...stock valve springs are fine.
people have been using stock springs for applications over 20psi..
BRFP system is nice, and allows you to get more out of your inectors, but its far from impossible to tune a setup without them. I wasnt going to get it untl i hit 20psi myself.

 

ok.. you do that.. have fun with the valve float..

 

you DO know 2.2 valves are the same as 2.0 valves right?

LSJs run high PSI all the time with TVS builds or even just small pulley'd M62s.

 

were not talking 2.2's here, thanks

 

Ok, noob question here: I thought valve springs were really only used on our applications to let us up the rev limiter allowing the valves to reseat faster. Is that not the case? Are our valve springs so borderline/sensitive that they come unseated due to 15 psi of boost on the intake side?

I ask this because the Auto transmission isn't rated to shift above 6900 RPMs, so I didn't plan on raising the rev limiter at all and, thus, thought I was also dodging the valve spring bullet...

 

omg... LSJs, LNFs, L61s, LE5s, and LAPs all use the EXACT SAME VALVETRAIN PARTS. There are different valves in the 2.0 motors, and different cams, but its all the same springs/retainers/valve guides, etc. So again, stock 2.4 valves have been pushed to 20psi MANY MANY MANY TIMES

stop being so argumentitive...im trying to save you money

 

bump

 

hunter sorry but on this one ... there are a bunch of companies who've pushed the 2.4 past 15 psi and all of them have recommended new valve springs because they can experience float...

it's not just the springs that matter in this case it's alot of other factors as well

 

glen229,
Do you have any of the dyno graphs from your testing of smaller pulleys? I think I saw your 3.0/258whp graph posted, but maybe the others would be beneficial to the community as well. This would also help to back up your statements in this post. I don't think anyone else has really ventured below 3.0 on the 2.4 to see what happens, so if you have them, please post it up!

 

there down at the shop, i picked up 1whp on the 2.7

 

Prob getting this for mine. At 16psi I start to lean out a bit. Vince says it's the pump not supplying enough pressure at that psi. So the fuel pressure thing I'll prob pick up sometime soon.

 

makes perfect sense, its nice, ive had it for a while, just havent installed it yet

 

#1 i dont recall mentioning anything about valves other than its one of the few components that does change, so yea, everything i said was relevant
#2 i HAVE pullied the car, thank you. maybe you should find out if i actually did something before making claims
#3 reasoning behind the bhp comment?

If im wrong, all it takes is a simple explanation. I know 100% that the valve springs in all ecotecs have run 20psi before. I know it is also the first part to fail in the valvetrain and is often switched out at lower-than-20PSI levels.

If they really dont work, then give a reason, teach me (and anyone else reading) why, and ill gladly admit im wrong. Here, let me take a guess at it: The higher CR increases pressure on the valve (and thus the valve spring) so even though you aren't making as much boost, you're still causing the same pressures necessary to induce valve float.
^that is a complete guess, BUT if you would have given something like this as a reason then I would have agreed that that makes sense.

example of a better argument. Thank you for not being a dick

 

I was just going to ask that same question, the CR theory makes sense to me

 

This thread was kind of fun until glen started being a dick.

My car starts to get too fast over like 12psi that I don't even need it. I get like 15.5 or so max. It is amazing how fast these engines pick up speed with the boost. I just got a ticket two days ago for 18 over the speed limit and I wasn't even messing around. Oh well.

 

yeah that was kinda uncalled for, sorry, anyways back on track, tickets suck, Ive had my fair share

 

I understand, you're a passionate guy. Casey has done a lot for me and answered a ton of my stupid questions in the beginning and he still answers stupid questions for many other people and to me, that is the true meaning of what these boards are supposed to be about. Sort of like this thread you've started... very informative, etc.

Casey is very respected here and for you to attack him, and in such a demeaning manner, doesn't give yourself a gold star for the day, lol.

Let's just all be cool, share information with each other and drive our sleepers another day!

 

not trying to start a flame war. but as you may have seen he has an AUTO, making dyno'ing our 4 speeds damn near impossible and a very big pita. so that's his reasoning for using BHP instead of whp, the BHP incidentally coming from his interceptor if i'm not mistaken so it's as damn near accurate as you're going to get with flywheel numbers seeing that the interceptors data comes directly from the PCM through utilization of the OBD2 port.

and second of all, 265 bhp turns into around 212 whp using a 20% drivetrain loss just for the sake of loss percentages.

now i don't know what makes 212whp such a hard number to believe on a supercharged 2.2 but i just wanted to see what you meant with that statement.

 

I got my first ever ever ever lol ticket back in August. I accidently got up to 109mph passing up some cars on the way to work. I didn't see the white undercover tahoe entering the highway.... He let me go with just a ticket for 298 since I USE to have a clean record.

officer-"why did you get up to 109? and you have a reason for speeding?"
me- "to be honest with you sir I didn't even know I was passed 100mph... and no sir I don't have a good reason at all...just that the people wouldn't let me in so I decided to speed up and pass them."
officer-"laughing.... you know I can impound your car, and take you downtown right?"
me-" yes sir"
officer- "I'll be back"
....
..
...
..
.
officer- " alright since you had a clean record I'll let ya go with a ticket"

 

LE5 cams have more lift than LSJ cams. This causes valve control issues at a lower psi and/or RPM. We couldn't get past 315whp on the stock springs. At 12psi/7200 RPM, the valve float was so bad that it sounded like a rev limiter. With 78lb springs installed, we dyno'd up to 15psi/7800 RPM and 356whp without issue.

 

interesting to know. I was under the impression the L61/LE5/LSJ all share a cam grind, and just utilize different timing. I know this is the case at least for the L61/LSJ.

The stock valves would be able to take more boost at lower RPMs though right? Im just thinking if you keep a stock redline (or maybe 7000rpm) and run higher boost (SC boost, since turbo boost will yield higher combustion pressures, working against the valve), you can pull it off. I know a few local guys running some small pulley'd M62's on a stock motor making abut 18-19psi daily with no issues.

Anyway, thanks for a technical reason

Thanks Gene for backing me by the way. You make me happy to help everyone
And a note to the people in this thread...i got my new car, and holy ****, RWD is SOOOO much more fun. I didnt think the differences in traction would be THAT huge.. 350hp with no wheelspin whatsoever even with super short gearing.
/offtopic