Luis

Before installing the Mugen header and exhaust I did some measurements to gauge the change I was going to get.

As I do not have access to a dyno, I basically measured the time it took to go from 2-5Krpm, 4-7Krpm and 6-9Krpm, in a certain set of given conditions, that is, basically a stretch of road and a gear. 2-5Krpm I did in 6th, 4-7 and 6-9 in 4th.

The results were reproduceable within a 10th of a second, for instance in 6th from 2krpm to 5krpm one run took 22.80 secs the other 22.74. I averaged the results.

After installing the Mugen stuff I did the same runs and got the following:

range*before*after*%improvement
2-5___22.77___22.46___1.4%
4-7___13.93___13.10___6%
6-9___10.92___10.27___6%

This is basically equivalent to 14HP, which I find very good. Do not compare these numbers with yours, as they were not obtained on a flat surface. In fact 2-5 and 6-9 was on a slight downhill and 4-7 on a slight uphill. Mugen claims 10PS (on the Japanese version (250PS)) which should be about right as some of the improvements could be attributed to the weight saving.

The pieces are very beautiful and well made with one exception: the tips of the exhaust are welded and the finish is far from smooth.

It sounds louder, but not a lot. At idle it has a nice rumble to it. From then on I wouldn't say it sounds better. There is more whistling and rasping and I'm short for other words. You can see that the target was not refinement but power. The header is lighter, the walls most probably thinner, and less noise filtering is the result.
In summary, if you want more of a race car, go for it, if not stay away.

The dealer complained bittely about the header install. They had to unscrew one of the engine mounts to squeeze the header through. I mentioned Pepe's from Puerto Rico solution (jingle the engine!) but he said if he did that he would risk damaging the header so he went the other way.

I will post a few pictures as soon as I get around to Photopoint.

Luis

... and here are the pictures:

Sideways

Luis, very nice. Do you know the weight difference between stock and mugen? Again, very nice!

cdelena

I have to admit to a bit of envy.. that without a doubt is a great looking quality exhaust.

BTW, Is that another new set of PP

Luis

The OEM header is 10.2 kgs, the Mugen 6.4kgs.
The OEM exhaust is 23kgs and the Mugen 11.9Kgs. Overall I saved 13kgs that's close to 30lb.

Yep, Chris, that is now my 3rd set. I've clocked around 16,000 miles so far. I'd like to try a different set of tyres next time. Maybe Michelin MXM or Pirelli P-Zero.

Pinky

Luis: Did you get the new Mugen header? The one with 4 mounting bolts on the heat shield? There have been some problems with the old style one. I just put it in my car after taking out the old one.

Luis

Better get some memory pills... you were the first to identify my header as a newer version . How hard was your re-install?

A few additional comments after another day of driving:

This was never a quiet car. But you could still drift down the highway at 3Krpm in 6th and enjoy a resonably calm and silent environment. This is now lost. The "boominess" of the new exhaust is particularly evident at low rpm where some silence could previously be found. It is definitely louder than before but especially so down low.

I can't imagine being able to live peacefully with an exhaust louder than this, unless all you do is racing. I understand now why elnetti sold his amuse exhaust.

Luis

Further update:

I'm now considering re-installing the stock exhaust.

The boominess in the 2-5Krpm range ressonates inside the cabin in a most annoying fashion. At least to my ears.

It is no problem when you're racing. And it's a wonderful throaty sound when you stab the throttle from idle, but get going, and you're soon into rolling drums terrain.

It is not that this exhaust is loud, it is only slightly more so than stock, but the ressonance is killing me. I wonder if the inner cover makes it worse. Top down it's ok.

I also wonder about that closed side pipe in the stock exhaust. And whether that is not the solution that Honda found for this kind of problem.

I know that several members have the Mugen header, what about the exhaust? Does this match your experience?

Anyway. Keep tuned. An exhaust may be coming up for sale

Prolene

Thanks for the truthful evaluation of the Mugen exhaust. I was considering trading the intransit HKS for a Mugen because of the weight savings. We'll see how the HKS sounds.

Pepe

Regarding the issue of the header not going through because of clearance with the engine mount, the needed space to make it go through is so small that a simple push on the engine is all that is needed.

No damage wil occur if it gets stuck. Anyway you dealer went the hard way but this also works.