Hey,
I was wondering if anyone knows the safe amount of psi that can be put on a Stock 99 cavalier 2.4l engine.
Thanks
Read the Stickies on the top of the BOOST FORUM (on this page)!!!!!!! IT WILL HELP YOU A LOT
And looking at how much PSI you can run, depends how much miles and how well you take care your motor.
How much boost can I run without sacrificing reliability?
---- Boost is so much more than PSI. Imagine for a moment that you have a box, its 1 cubic foot big (1 foot x 1 foot x 1 foot). One turbo can take 10lbs of air (it's a lot of air), and compress it to 5 PSI, and stick it in that box. Another turbo can take 20lbs of air, compress it to 5 PSI, and also stick it into that box. Obviously the 20lbs of air will make more power than the 10lbs of air of the smaller turbo charger (provided you have the right fuel mixture).
If you are worried about reliability and how much downtime your car will have, then your best bet is to stay away from turbochargers and aftermarket superchargers that weren't designed for your vehicle. The problem with people who add boost to their vehicle is that they are looking to add boost, but don't want to spend the money to do it right. They add the boost, but forget about the fuel, hoping that their stock injectors will hold up. Depending on the turbo or supercharger, the injectors might hold up for a little while, but don't count on it.
Long story short, there is no magic number to tell anybody. There are too many variables from type of turbo or supercharger, to the long term previous maintenance of the engine. Every motor has different breaking points. It is generally accepted that you should be able to run the following:
Assuming a T3 Style turbo
2.4 / 2.2 Ecotec
6-8 PSI Non-Intercooled with proper fuel and timing mods
8-12 PSI Intercooled with proper fuel and timing mods
2.2 / 2200 SFI
4-5 PSI Non-Intercooled with proper fuel and timing mods
6-10 PSI Intercooled with proper fuel and timing mods
Another thing people seem to forget when running boost is the transmission. If you have a 5 speed I would suggest a clutch at the very minimum. ACT or SPEC are great clutches, don't buy cheapo E-Bay clutches. Auto transmissions hold up to boost better than manual transmissions. Especially the Isuzu, they seem to have a tendency for the differential to self destruct. Your axles and CV's are also weak points.
Good Luck!
The stock oiling system wouldnt be able to hold up with what your putting the motor through at higher boost levels, so having the fuel wouldnt matter at that point. Thats where most rod/bearing failure comes from, the stock ld9 oiling system sucks which is why the 2.3 pump swap is soo popular.
icemike89 wrote:The stock oiling system wouldnt be able to hold up with what your putting the motor through at higher boost levels, so having the fuel wouldnt matter at that point. Thats where most rod/bearing failure comes from, the stock ld9 oiling system sucks which is why the 2.3 pump swap is soo popular.
Oil pressure has nothing to do with boost pressure or power levels. You could have 19598175981745 psi of boost pressure and it wouldn't change the oil pressure. A mechanically driven oil pump is entirely rpm based. So, on a stock cam'd LD9, he should be fine with whatever he wants out of it. When you start building power at a higher rpm, then I would certainly recomend an oil pump change (i.e. 94-earlier 2.3 pump, dry sump, etc.). Oh, and this is coming from someone who has the 2.3L oil pump swap.
I have no signiture
your right but the more power the engine puts out the stronger the force trying to drive the rod bearing into the crank (they are not supposed to touch) this is ware you need better oiling. (also psi in not everything you have to b concerned with the shear strength of the oil as well as the volume of oil that you are flowing)
^^^ Correct, but without modifications to the oil passages, oil pressure does dictate the mass flow of oil, because the cross sectional surface area of the passage remains constant. The 2.3L pump would therefore deliver no more mass of oil as the 2.4L pump until the 2.4L pump pressure drops off...and the pressure doesn't start to drop off until around 5500 RPM with the balance shaft driven LD9 pump. So my point is, the 2.3L pump isn't necessary on a boosted LD9 with a stock rev-limiter. Would it hurt to upgrade to the 2.3L? Absolutely not...but it's not required.
I have no signiture
ok looks like were in agreement just looking at it from diff sides
Keep going till it blows and then back off 2 PSI.
auto will hold up more ?? really?
wantboost wrote:auto will hold up more ?? really?
That was a very bad statement. That guy should just be ignored. I put down 214whp for over 20,000 miles on my stock clutch. It never slipped once and still some life left in it. It had 77,000 miles when I replaced it. The only reason I replaced it was because I was rebuilding the engine so I figured I would just do it while I was in there.
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
but manuals are better are they not
manuals are FUNNER... not 'better'.
ld9's can barely keep rods in one piece n/a... why the hell would you want to throw boost onto a stock engine? i sure would not...
Needing 2.3 oil pump stuff? PM me...
z yaaaa wrote:manuals are FUNNER... not 'better'.
ld9's can barely keep rods in one piece n/a... why the hell would you want to throw boost onto a stock engine? i sure would not...
Really???? Never heard of that.
There is no safe amount of boost for a 2.4. If ti has boost it is built!!!
FU Tuning
^^^ what?
Needing 2.3 oil pump stuff? PM me...
wantboost wrote:but manuals are better are they not
oh yeah. its really fun when you doulbe clutch
Im a Xbox 360 fanboy...and damn proud of it!!
z yaaaa wrote:manuals are FUNNER... not 'better'.
ld9's can barely keep rods in one piece n/a... why the hell would you want to throw boost onto a stock engine? i sure would not...
The problem is not the engine but the operator. If you look at the ratio of LD9 compared to the #3 bearing failure, you'll see that it's not as bad as you think. The engine must not be so bad if GM was willing to come out with a supercharger and giving a waranty on the engine with the SC on.
Boost + stupid owner = desaster
Boost + good car + intelligent owner = no problem
You easily seem to forget that you beat on a DD engine, not a race engine, and you wonder why things go wrong. It's like using a microwave to dry the cat after his bath. It can work but disaster will happen.
I'd say that 90% of the problems on this site is ignorant owner. "I was beating on my car and it blew up. The 2.4 s.....!" No, YOU s....
Also, unexperience kids plays a big role in this.
Gilles
2.3 Ho
Mfk-223 wrote:z yaaaa wrote:manuals are FUNNER... not 'better'.
ld9's can barely keep rods in one piece n/a... why the hell would you want to throw boost onto a stock engine? i sure would not...
The problem is not the engine but the operator. If you look at the ratio of LD9 compared to the #3 bearing failure, you'll see that it's not as bad as you think. The engine must not be so bad if GM was willing to come out with a supercharger and giving a waranty on the engine with the SC on.
Boost + stupid owner = desaster
Boost + good car + intelligent owner = no problem
You easily seem to forget that you beat on a DD engine, not a race engine, and you wonder why things go wrong. It's like using a microwave to dry the cat after his bath. It can work but disaster will happen.
I'd say that 90% of the problems on this site is ignorant owner. "I was beating on my car and it blew up. The 2.4 s.....!" No, YOU s....
Also, unexperience kids plays a big role in this.
Well Put. Th 2.4 is a great motor but like any engine you can't beat on it all of the time and expect it to last forever. Especially if it's boosted.
Well Put.
Mines boosted and I beat on it all the time. I too thought it was only a matter of time til she blew. Boosted at 114xxx and pushing 150xxx. I don't agree with the above.
Labrat
Didn't you hear?
The LD9 can't handle boost. That's why they built the economy-tec engine. It's good to 7 psi intercooled, but if you add meth it'll go to 7.2 psi.
Unfortunately the best platform for boost on earth is the Kia Rondo. Those are hard to come by unfortunately due to their ability to hold up to 8 psi of boost.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
