they have a 300 hp build book... which is part of the reason i find it so funny that so many people are saying that you can't hit 300 hp... but i've never seen a 400hp build

 

Stock head you mean. I am not sure but the did build the 300hp engine with the a non ported head although they had to up compression and almost completely upgraded the valvetrain. I am not sure that it would be possible to build a 400hp lsj with the stock head.

 

with nitrous in the time attack car.

 

That setup is for racing only and will not work on the street.

 

Theres lots of people that have hit 300 bhp . The GM 300 build is bhp , not whp .

Thanx for all these flow #'s Jcm007 . Ive wondered for a while what a stock LSJ head is worth cfm wise ...I can now justify buying a spare head to play with

Once youve moved on from the heaton its possible .

 

100 shot

 

huh I didn't realize it was BHP, since they say take it from 200 hp to 300 hp i guess that was my fault assuming considering the lsj's are underrated

and shawn how was it "for racing"? yea they nixed a few things that would compromise ride comfort but i didn't think they had anything in there that wasn't streetable

 

Not disagreeing with ya there , hehehehe

 

http://www.compcams.com/Information/...ECOTECCams.pdf

http://www.compcams.com/technical/Ca...12-117_226.pdf

 

They don't work with the LSJ

 

It's probably WHP ...

https://www.cobaltss.net/gallery/sho...imageuser=2736

I need porting !!!

 

sadly at this time theres not an affordable aftermarket cylinder head all thats out there is the jbp which is way over priced, too bad theres not a patriot head out there

 

Sorry for a silyl question guys, but:

Okay, are P&P head and ported head the same thing? P&P=Ported Polished?

The head is everything above the pistons (cams, valve springs, crank shaft, etc?)?

And is the GM head just as good as getting a race ported head at a shop?

I've heard nothing but bad about JBP, but they are the only ones with race proted heads? And what about their wild crate engines? Don't those do it for you already?

 

I was almost banned the last time i talked bad about a sponsor so i will just say this....

OVERPRICED!!!!!!!!!!!!!!!!!!

 

I just looked at it. It is extremely expensive.

http://www.jbodyperformance.com/new/...catName=JP0940

It seems REALLY good, but that is more than the TS Swap is. that should be cut at least $600+

 

I'll agree with you..

 

the 10.0:1 Piston thing, are those Ceramic Toped (Cer top?)? And why 10.0:1?

 

you lose some compression due to overlap from the aftermarket cams and the ceramic coating is for protection against heat i believe

 

Ah, alright. I was looking at the 2.0LSJ WILD build on JBP as well. For the wild build they only use 8.5:1 or 8.0:1.

http://www.jbodyperformance.com/new/...catName=JP0912

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But I see it now with the MILD build. They offer the 10.0:1 comrpessions.

http://www.jbodyperformance.com/new/...catName=JP0916

Hm. Mild Crate Engine + Stage 3 Cylinder head = Big HP? (Also an empty wallet)

http://www.jbodyperformance.com/new/...catName=JP0916 -(MILD Crate Engine)

http://www.jbodyperformance.com/new/...catName=JP0940 -(Stage 3 Cylidner Build)

 

One of the things about this forum is that so many members are young and inexperienced with basic performance concepts and don't yet know how all the pieces fit together to make a big power motor.

With this thread I'm sure there are some young kids out there with stock 2.2 Balts that are now convinved that they need a $1000 port & polish job done on their head!

We must keep perspective, the more experienced guys know that. There is a whole list of things that should be done to their engine before someone needs to worry about the flow rate of their head because the stock head flows pretty well, compared to older designs.
For example, lets say I've got stage 2, CAI, headers and 2.5" exhaust, what, maybe 260HP, how much HP would I get from a $1000 head job? I bet it wouldn't be very much, maybe 10 HP, and by slowing the velocity of the intake air it would probably move my torque curve farther up the rpm band so I'd lose some low end. Some people who have paid to get their heads ported have gotten no advantage, no more power.

I always advise people to leave the head alone until you have to open it up. In other words, when you've bolted on enough external power equipment that the head is holding back your performance, then it is time for a P&P.

So what do you experts think? You probably need a ported head when you approach what, maybe 300WHP? Seems to me that any less than that and the money would be wasted.
But of course the guys going for absolute max HP need the head work, and the cams, and the springs for your high RPM monsters!

You know, I just had an idea for a spreadsheet. I wish we could put together a sheet listing the power increases people are getting compared to the money spent. We all want the most for our money, right?
For example:
Part: Price: HP Gain:
Stage 2 Kit $550 XX.X HP at XXX RPM

Oops, hit the submit button.
Again, I wonder if we can make a spreadsheet like that, especially showing how different parts add up to increase gains.

Just my opinion
Randy
'05 Yellow SS/SC

 

Good post. Just FYI, I wasn't thinking of doing this. I am just trying to learn about engines in general, specifically the LSJ. I'm not going to P&P my head. Of course if you por and polish the head too early when you don't need it, your powerband is going to get all freaked up. And yes, I am a young guy who is inexperienced with the basic concepts, and the only way I can learn is to ask, and post.

The problem I see with the spread sheet though is every car is different. Some people stock dyno between 210-220whp. Some people slap on mods and get different numbers.

 

You show wisdon beyond your age! You're right, hog out the ports before you need it and all you do is really screw up the low end performance of the engine. Guys with carbs can really cause problems with uneven fuel atomization and things like that. Cams are like that, too, BTW. I've known guys over the years that thought "bigger must be better" and threw high lift cams in their motors and then couldn't get it to idle at less than 3000rpm. Useless on the street.

As far as the spreadsheet, I would just try to get an idea of average gains for the parts. Each engine and part are different but if enough people donated data we could get a good idea of what each part would do. Now that I think about it more, maybe tomorrow I will start making up a sheet just using the manufacturer's claims. Wouldn't be very accurate but would get newbies an idea of where to put their money into mods.
Something like: Stage 2 Kit, $550, 25HP, = $22 per HP gained.

But again, the more I think about it the less probable the sheet would be. I know that when I build my Balt over the winter I will most likely just install and mod everything at once before putting it on the dyno for a tune.

Randy
'05 Yellow SS/SC

 

Good info. This goes with what I have said all along, one of these cars can make good power if done right, I think low 300s on the stock blower without running a 2.6 or smaller pulley is very possible, but you have to deal with the restrictions as you come to them. I will have to do a head eventually, my goal is to be at a solid 350 to the wheels, with a strong enough engine to spray and additonal 100hp shot on top of that, for emergency use only. I think with a proper build it can be done with the Eaton. I still may end up with a twinscrew though, depending on what people get outta some of these new kits.

 

Here is one ;

http://www.m2race.com/product_specs.asp?ID=5#

 

Important : Post Number 1 edited.

Also read this :

http://www.year2032.com/ecotec.pdf

Question : What am I ?

https://www.cobaltss.net/gallery/sho...=3&userid=2736

Answer : The absolute biggest bottleneck ever on the LSJ ...