[QUOTE]Originally posted by ultimate lurker
[B]Gernby,

Here is something to consider:

Intake temps.

 

these dyno plots are great. I'm really interested on opinions why some of the slightly modded s2000 shows no gains or even less compared to some of the stock ones. I noticed some stockers are relatively new. I also noticed one with CAI and exhaust only putting down 180+ hp, which had OZ Superleggera's on it, which were probably 18" (couldn't really tell), and if I'm not mistaken these OZ's are significantly heavier than the stock rim.

That viper sure shows a nice broad curve Maybe I'll have to go FI after all. That SC'd s2000 looked really nice.

 

That's too bad they didn't let you supervise. Generally, it looks like most of the S2000s were run cold on their first runs - probably in the 165-175 F coolant temp range from past experience. You can deduce this by noting that the A/F ratios on the first runs are generally leaner (especially in the first few thousand rpms as the coolant temp comes up). The one abnormally low S2000 was much richer on the first run though - a symptom of whatever problem it has?

As the engine warms up (and the fluids thin out) power generally comes up, although you will note that in several cases, the peak power differentials between runs 2 and 3 were about the size of a small spike here or there. In the case of the RSX, it looks like it got hot and detonated near the VTEC transition. Note how dramatically the A/F ratios diverges at that point. That is a sure sign that the knock sensor pulled out timing at that point.

You can tell a lot from dyno charts, although its best if the operator will let you monitor conditions.

UL

 

There is a lot of discussion between dyno pulls. There are different types of dynos and they will all yield different results. The most important thing is consistency. Once you make a run and do a few mods, you should go back to the same dyno to get a relative improvement. There are too many variables to figure out which type of dyno is the best. For isntance, a Dynojet or Eddie Current dyno will give you a better look at what you're putting to the ground. A lot of that can be put down to the type of alignment you are running or the types of tires and tire pressures. They will all create different types of resistance on the dyno roller. A dynopack will bypass that because it doesn't take into consideration any of that. That's why it will generally give you a higher hp number. A Dynopack will give you a more accurate info about the engine without caring about alignment etc.

 

WOW very interesting results. It seems many of the modded cars S2000's didn't show much higher results over the stock ones. They did show some increase in torque over the stock one's though.

With all these dyno tests on cars with different mods, has anyone ever figured out which mods make for the best n/a setup for the s2000?

 

[QUOTE]Originally posted by wicky
[B]these dyno plots are great.

 

fperra - thanks. I was pulling that from memory. They're much lighter than I thought.... hmmmm..... the weight was always my issue with those wheels even though I like the looks. I may have to reconsider

I wonder if running rich above VTEC indicates detonation?

 

Wouldn't detonation show up on the dyno plot?

 

I seriously doubt that an S2000 with ONLY exhaust and header would detonate after cooling in the parking lot for hours on a cool day.

 

So what gear should u be using when doing pulls?....I dont think that question has really been answered yet

.....in any case i just got my car dyno'd on a dynapack and did several pulls in 3rd, 4th, and 5th.....yielding some somewhat weird results considering the temps...

3rd - 94F, 224hp, 133tq
4th - 108F, 219hp, 127tq
5th - 96F, 200hp, 118tq

several runs were done in each gear except for 3rd.....all yielding within 1-2 hp and tq, of one another.