GM or Honda Engine, which has worked best in the atom?

**planters49** · August 21, 2015, 07:41 AM

For people who have either owned or driven both a GM and Honda powered atom, which seems to be the best engine for the car? I was watching a Jay Leno's garage web episode where he is driving his atom 2 and he says that the GM ecotec is "more balanced" What exactly does that mean?

**MadMaxAtom** · August 21, 2015, 08:07 AM

Hondas rev higher and Ecotecs have a stronger torque curve (compared to NA Honda) In my opinion,it's a wash…you learn to drive each one a bit differently. Life of the motors is about the same (pretty much forever, taken care of) but I will give the nod to Honda powered Atoms for a better resale,warranted or not.

That said,if you own a Honda,it's better.If you own an Ecotec..it's better: They both are great.

What powers the Atom is not as important as the whole package.

**Sagen** · August 21, 2015, 10:32 PM

I haven't driven both of them, but I will make a couple of quick points. Leno's comment might have been speaking about the fact that the GM Ecotec vibrates less due to having balance shafts while the Honda's in the Atom 2 didn't.

One thing that I noticed at the big gathering at Laguna Seca was that the Honda powered Atoms didn't seem to have issue meeting the sound requirements while I think all the Ecotecs struggled. I was running a Supertrapp and made it through ok, but ended up with a clogged trap that eventually had me limping off the track.

**McFred** · August 22, 2015, 04:29 AM

Run the Hp/Tq numbers relative to gearing and the Atom 2s are virtually the same.

Excluding the '300 hp' models:
High torque, low red line supercharged Ecotec through a tall-geared 5-speed is the same as a low torque, high red line, Honda through a low-geared 6-speed (you'll just be a gear lower than the Ecotec)

Now that the K24 comes with the newer models the comparison may be skewed, but I'd say it doesn't really matter a few Hp/Tqs here and there, an Atom is an Atom.

*edit*
FWIW the K24 comes with balance shafts now too. When TMI took over the construction they changed the engine mounts. A Honda K20 Atom 3 I rode in felt completely different than my Honda Atom 2 from the engine mounts alone.

**MadMaxAtom** · August 22, 2015, 05:06 AM

The stock brammo mufflers were junk.Nothing more than a hollow shell. I run Flowmaster Hushpower mufflers (they make a bolt on unit for the brammo ecotec) with Supertrapps secondary and have no problems passing sound levels of 88db at Limerock,and no loss of power. I run the large 3.5" unit with 20 discs and they have never clogged..matter of fact,I have never even seen any accumulation of anything on them.If yours is clogging,maybe the packing is coming out of your main muffler and into the Supertrapp, or something is wrong with your engine. I eliminated my balance shafts and had the engine dynamically balanced and it is smoother than stock,especially above 4k rpms.