if i take my engine(2000 ln2) up to 10:1-10.5:1 cr, with a full performance build, how much boost do you guys think it could take while still trying to keep the engine around for a little more than a few months, lol.

any advice on where to go on valve springs, valve guides, and other valvetrain parts other than the valves themselves? you guys seem to know of lots of websites that i don't.

thanks in advance

Dave

http://www.j-body.org/forums/read.php?f=2&i=338325&t=338325

unfortunately thats a question we could never give an accurate answer too. Tune, Sizing of turbo/Supercharger and other variant information would be needed even to make a wild guess...

Only way to find the answer is to do it



LE61T PTE6262 Powered

hmmm...i volunteer myself for this, haha

i'm gonna use the turbo kit from turbo specialties(28bb)

Depends on the octane tolerance of the engine design. This is where the matter of dynamic-compression comes into play, which is a very complicated thing to deduce. To save you a possible headache, I'd say 4.5psi max while running 100-octane. If you can't get that commonly where you are, and you've been considering converting to E85 (The only thing I'd ever run in daring to try such a combo), then I'd definitely go that way. The octane rating of E85 is 103pts, plus running it has a cooling effect provided by latent-heat of vaporization, would afford a boatload of power produced. This would be quite a contrast to the roughly 33% increase of BSFC seen, because E85 has 33% less energy content than gasoline.


Go beyond the "bolt-on".

hmmm...how hard is it to convert to e85?(i actually don't think there's too much of that near me either, haha!). i would probably just go with fuel additives...it'll just really be for fun...cuz i'm bored, haha. once i figure out how much this engine can take, i'll rebuild it to a more every day driver engine, and keep the turbo.

yay another ohv thread

lets see how far this one goes

nvm, i don't wanna do it anymore.

lmao, kidding.

i'm not getting another car till i'm happy with this one and it completely modded to my liking first, and it is far from it, so, there is only one way to go!(i won't have this done anytime soon...i'm helping family out financially, and in june i'm going to uti, so after i'm done with school in a little over a year, i will begin workin on the cav!)

Atta-boy, Dave. Hey... You going for ASE-Cert? I did, and if my one best prospect of a job didn't end so soon... not to mention showing-up the senior shop-mechanic, who hated me because I "paid" for my automotive education... I'd have mine right now instead of worrying about my father's health so much. Still, an education that you can apply is a good thing to have. As Ceaser (Planet of the Apes IV) said: All knowledge is good... Only how it's used can be determined if for good or for evil.


Go beyond the "bolt-on".

Who ever said you need a 100 octane for 10.1 or 10.5 with only 4 pounds of boost needs get there info right. There is a few cars on here mainly 2.4's that i know of running the gm charger and 10.5 compression on pump gas. There's no need for race gas unless you want to advance the timing for those measly 5 maybe even 10 extra horses.

And as for the static compression ratio that does play a role but only a few really follow. Also i know turbo's and chargers are all different but if you honestly think of it you take a turbo and charger. Put the same psi through the motor. Which one is going to be harder on the motor? The charger due to the fact it is building boost all the time putting stress on the motor even if you aren't in it to close the bypass valve.

Just to put this in a little prospective as for running high compression. When i bought my 95 trans am it was bone stock. Got the heads p&p with cosmetic head gaskets to keep the compression at the factory 10.7.1. Some head studs, pacesetter long-tube race headers, and a custom ground cam with 1.6 roller rockers. This was 4 years ago almost. The motor had 60,000miles at the time. I bought a p1sc procharger kit on top of that in which i switched out the 9lb pulley for a 14lb. In which i just a hair above 12 psi and on a real cold night it would spike to 13. It was tuned for 93 and then a tune for a 100 octane. On pump gas i put down 443hp at 5100rpm and right at 400 ft lb's. On the 100 octane tune. i only gained a little bit more than 15 horses across the board and at little less than 10ft lb's. I took it to the track every weekend i could for 2 years and it was street raced plenty( I don't want to hear flaming either). Plus was my daily driver. I put 80,3xx miles on it before i did my 391 build only because i threw the stock pressed balancer off about 3 times and it ate the crank bearings up a good bit to where warm it would only carry 15 psi at idle and if i would push in the clutch coming to a stop it would drop to zero.

The only problem though with running high compression is it's harder to tune. That is why some tuners say you can't run that much boost or were gonna have to run race gas or turn the boost down. Mainly due the fact they don't know what there really doing or don't want to take the time to get it right. Which is the biggest problem in the j-body scene. Also the sharp edges on pistons & combustion chambers will cause you detonation problems sometimes. Best bet is if wanting to run high compression is get the combustion chambers smoothed out.

So anything can be done with a good dyno tune and not a half aXXed one. And yea i know a 2.4 isn't a 2200 and neither is a lt1. But look at the lt1 everyone says 6lb's is pushing it on a stock motor let alone 9lb's what everyone usually runs. Also the 2200 and been proven time and time again to be a good little motor on boost stock. Kind of like the d series honda's.

And as for e-85 don't get me wrong on a boosted car it will work great. But do you have the money to change everything and go stand alone? You might get it to run half way decent with hp-tuners but is very limited for j-bodys unlike other platforms. And the other problem is it's been proven that there is less energy in a gallon of e-85 compared to gasoline. Although being boosted you will net some gains that you would with gasoline. Which is a cooler combustion temps to reduce detonation. So it's honestly some what of a gamble.

hmmm...well, like i said, i'm not doing this till i graduate uti next summer, and by then i'll know a hell of a lot more, and i'll be able to get a job making some decent pay, so i can fiddle around with this little engine and see what it has. i'm really excited for all of this...uti, and my car. can't wait!

Waddaya know... Phoniex got one right on the right on the nose! Yes, it's very true... Sometimes the limiting factor in a tune is the octane used, and it is very hard to tune for a low amount. This has been known for years, as as far back in the late-'50s it was shown in a old article on engine tuning what all results from dialing back the timing (Even in just the initial) just to run a lower octane fuel. The results were disappointing, to say the least.

But still... when you find yourself in a "high-wire" situation, it's best to have a good safety net. And if it's your first time tuning, trust me... you want it. Then... once you have everything dialed-in... then you can play with lower levels of octane. But keep a good ear to it, as knock may occur under odd situations of operation. Then adjust the mapping accordingly to prevent the dreaded internal-combustion inside-only parts blowout. This will take time, but be so wroth it in the end.


Go beyond the "bolt-on".