I recently installed the JR filter, and really like the sound with the cover off.....Does anyone really see any negative effects of leaving the cover off?

 

leaving the cover off may reduce performance. This is a "tuned" system. Youl'd have to run some dyno tests for sure.....but I'm sure the Honda engineers put the cover there for a purpose.

 

There have been several dynos run on this board with the air box off. Each one shows a loss of 2-3 hp.

 

I had my car dyno'd this weekend. First 2 pulls were with the airbox cover off, the third was with the cover on:

1st: 194.1
2nd: 194.9
3rd: 194.4

I too like the sound with the cover off. It doesn't seem like I'm losing power with it off either.

 

Hmmmmmm.....Interesting. Other people on this board have dynoed their car at around 200 hp....a difference of about 6 hp.

Do you think with the cover off you could be sucking in more warm air?

 

I think down here in Florida we're sucking hot air
most of the time

 

So you may have not lost peak power.. but what about the curves.. Theres more to making power than just peak power.

 

All three lines on the printout are just about on top of each other.

**interesting note: Even though the power starts to drop off after 8300rpm, there seems to be about a 5hp jump right at redline

 

I have seen dyno runs on three different S2000's on the same day and on the same dyno. All runs were done several times and done as 3rd and 4th gear pulls. One of the cars was completely stock, one car had a V-AFC and one car had a V-AFC and a cone style intake filter. The stock car pulled consistent 199-200's, the car w/ just the V-AFC (mine) pulled consistent 207-209's and the car with V-AFC and intake pulled consistent 205-206's. The V-AFC is good for at least 5 or 6 hp when tuned properly, many times it gives more than that. One of the most noticable differences in the dyno charts were above 8,000 RPM's. Both of the other two cars dropped off after about 8,200-8,300 RPM's. Mine continued to pull hard until about 9,000 RPM's. No point to this, just some more useless info.

 

While the car does sound much better with the airbox cover off, it does hurt performance.

1. On the dyno, the readings with the airbox cover off can vary widely, even on back to back runs. That's because blowing fans (the car's own or shop fans), etc. can cause fluctuations in air temp.

2. Your intake air temp, particularly with the hood closed and the car at rest will go up (20-30 degrees according to my tests and those of a friend using a scantool and an independent thermocouple). This can cause the car to be harder to launch off idle.

3. Your throttle response will diminish slightly because the stock system is tuned.

4. At speed the stock intake aystem receives a mild ram air effect from the front bumper area. Its nothing spectacular, but try running acceleration tests at hgih speed and you'll find the car does not pull as hard without the cover. That's something you can't simulate on teh dyno.

UL