The beautiful powerband of the Si

[snubnose]

As I look at the Si brochure I am especially studying the powerband graph on the centerfold page.

Our Si reaches very close to its torque peak at 3,000 rpm and builds until 5,000 rpm and stays there until 6,000 rpm.

This is an extremely wide sweet spot.

I feel that this makes for a beautiful driving experience.

Compare this to the RSX:

The base RSX reaches its peak at 4,000, then it drops off a cliff.

The Type S doesn't reach its peak until 6,000. Before that, it stays too low.

I think we may have one of the most underestimated cars of the year.

[MadMax]

The base RSX reaches its peak at 4,000, then it drops off a cliff.

Okay... whatever. Note that both cars are rated 160 hp @ 6500 rpm therefore they are both making ~129 lbs-ft at 6500 rpm. Just because the base rsx makes more torque between idle and 4700 doesnt make it a worse torque curve.

Also, you are assuming that the type-S is gutless below 6000 rpm, which it is NOT. In fact, it makes torque close to the Si's peak from 3000 to 5500.

[punkdork]

The VW/AUDI 1.8t and the AUDI 2.7t. Their "curves" climb quickly and level off at about 2500-3000 and they're basicly flat from there until redline. Then you put in a chip and they just get sweeter.

[JSIR]

it looks good on paper,but this car needs more top end power. Easily attainable with a few bolt-ons though. Yeah actaully the RSX motor is probably a bit better with the two stage manifold, it builds more bottom end power and still has the same top end power as the Si, despite the appearance of the torque curves. So I don't understand why Honda used the Type S manifold on the Si. It may lend itself to more top end power with modifications but that is just a guess, not totally sure about that.

One saving grace is that Honda used the electric steering gizmo on the Si and not the RSX models, so the Si torque that actually makes it to the pavement is raised to a level that is close to the base RSX despite the difference in numbers at the crank. When you compare dyno numbers of both cars from a chasis dyno they are very similar in both torque and hp. That is due to the lower % of power loss in the Si using an electric power steering system. Still makes me wonder what could have been if Honda used the two stage manifold on the Si ?.

[MagusDC5]

Originally posted by MadMax


Okay... whatever. Note that both cars are rated 160 hp @ 6500 rpm therefore they are both making ~129 lbs-ft at 6500 rpm. Just because the base rsx makes more torque between idle and 4700 doesnt make it a worse torque curve.

Also, you are assuming that the type-S is gutless below 6000 rpm, which it is NOT. In fact, it makes torque close to the Si's peak from 3000 to 5500.

best way to put it....and after 6000rpm's the Type S is definitely not gutless :p

[MadMax]

How flat a dyno curve LOOKS also depends on the scale. Sometimes they start at 0 (like above) and sometimes they start at like 100 ft-lbs. This exaggerates bumps and dips in the curve.

[chunky]

the si is making 90% of peak torque from 3000rpm on up. I'm not even gonna bother comparing to the rsx motors b/c they're so similar.

here's my dyno sheet just for giggles, this is bone stock btw. Peak #'s aside, it's a healthy torque curve. With an air/fuel controller, I could smooth out that camel's back in the torque curve to improve acceleration w/o much change in the peak #'s

http://personal.atl.bellsouth.net/at...selinedyno.jpg

oh, I might add, those are uncorrected numbers, so note the temp, pressure, and humidity of the runs. If i wanted to be a dyno queen, I could go back at night to pull a much better #

the main things that differ between the si and the base rsx are 1) the 2nd order harmonic balancer that the base rsx doesn't have, 2) the dual plane intake manifold, 3) the electrical power steering (which gives us a 4ft advantage in turning radius!).

The si has to turn that 2nd harmonic balancer, and lacks the dual plane manifold, and only has the EPS to balance things out. And it's a heavier car by a small margin. But somehow the si is just as fast.

i've always found that to be curious.

[JSIR]

the Si also has a higher final drive gear of 4.764 which helps with the acceleration a bit. In bone stock condition my 2002 SiR put down 126 ft lbs torque and 138.7 hp at the wheels, corrected numbers, running 5w-30 weight oil after break in period. Although these numbers aren't really comparable to those above that were done on a Dynapack dyno, mine were from a Dynojet Chasis Dyno so they will read slightly differently. My numbers were alomst similar to those of Miamijdm's who also used a Dynojet dyno. I wish we had Dynopack Dyno's in my area they seem to be better for tuning purposes.