Nocturn

Well the 2.0 is the Supercharged version to 205 HP, my question is why is GM using the 2.0L instead of the 2.4L to get the most performance.

All head designs being equal, the 2.4 would make more power using the SC, so ...what am I overlooking that made them choose the 2.0 L?

wesmanw02

Good question - but GM chose to use the 2.0 as the performance engine in the SS S/C for a lot of reasons:

As you said, the 2.4 is a bigger motor, makes more power N/A, and has more torque N/A, plus it has VVT - so why not use that engine instead of the 2.0?

Basically GM went with the 2.0 because it is a much better match for the supercharger. If the Cobalt SS was originally designed to be N/A (like the RSX-S or Spec-V) theres no doubt that they would have went with the larger motor, that would be a given.

However, the Ecotec 2.4 does not match the rev and power curve characteristics of the Eaton M62 Supercharger. The 2.0 Ecotec has the advantage of being able to rev quickly and rev relatively high - something that the 2.4 doesn't do as well seeing as it has a very long stroke and is a relatively large engine (for an Inline 4)

The 2.0 is the perfect match for the S/C, whereas the 2.4 is a better engine N/A. Hope that helps answer your question

Nocturn

Yes it does a bit, but it still seems that using the 2.4 would be a better match against the SRT4 as isn't it also a 2.4L? They could always get a SC made that better matched the 2.4....

Dman

^ that, and it was an easily adaptable paltform for the cobalt since the same motor ( -supercharger, + turbo) was already in GMs hands...they talk money

Nocturn

Ah, I had forgotten they had already had FI version in Saabs lineup...That makes more sence.

MikeSS

One of the main reasons not discussed here as to why GM used a 2.0 instead of a 2.4L is reliability. When you boost an engine, there is tremendous pressure on the engine and a small displacement engine creates less pressure from the same engine block.

If you look, you will see several eninges that get turbo or S/C will be slightly smaller then their N/A siblings. Volvo does this, Saab, and others.

Nocturn

Cadillac also now...

BlueVillain

Head designs aren't what make engines equal, and the 2.4 and 2.0 are different in many other ways.

If the only reason to build an SS/SC were to "beat" the SRT, then don't you think they would have dropped the 3.5L 200 hp V6 from the Malibu and Uplander and supercharged it?

Nearly everybody out there has a vehicle option with more horsepower than 205. So what?!?

The point of the vehicle is that 1) it is a much better vehicle in the class than the Cavalier, 2) it has options of doing all sorts of things discussed in this forum and 3) it fits GM's scheme to sell vehicles.

Price lines and value leaders and cost measure analysis make up much more of the decision process than "does it go faster than the SRT?"

Do you want a race? Then pit the Vette and the Viper.

Do you want a race-type car with a great value, then I believe the Cobalt wins hands down.

Just my 2 cents.

Villain

MikeSS

I still feel it is the interior that makes all the difference. A cobalt SS S/C can be made faster with a few performance upgrades.

A SRT-4 will still be a 4 door neon (opposed to our coupes), won't have awesome two-tone leather seats, and all the other interior goodies.

Plus, you can tell those SRT-4 guys, "my little 2.0 just beat your 2.4L"

If there engine was a 2.0L, it would only make 192HP

raptors_67

shortened stroke is much easier to boost as said above , just check out the stroke numbers for both engines , you will see the difference. Faster revs are achieved with a shorter stroke and you can get away with that short stroke since the engine no longer needs to worry about drawing in air on it's own, the supercharger is supplying this.

zinner

I would actually like to see GM produce a RWD 4.2L inline 6 *car*. I might even settle for a RWD car with the 3.5L I5.

As for the 205 HP LSJ I can only hope that GM left some room to grow in that engine. That way the tuner people can have the pleasure of getting more power out of the engine for all of us

GM has so many different engine configurations.

Tooleman

There are 2 reasons they went with the smaller engine.


First reason would be cost. Its a lot cheaper to make a built 2.0 then it would be to make a built 2.4. Car company will do anything to save some cash..

And the second reason is that they went the route of installing a roots blower, and roots blowers make full boost at a really low RPM which makes for a nice torque curve and making the need for a larger engine not needed..

But if you wanted a car with a huge engine, the cobalt isnt for you. Go get a used LS1..