modified exhaust # - potential motor damage?

I wish there were such a simple answer to this such as a yes or no but there isn't. Hopefully NCB will correct me if I'm wrong here but I'm taking a stab at this due to all the research I've done on the VFR and exhaust systems and the PCIII.

A PCIII on a stock VFR will bring some gains. It seems that there is some shitty air/fuel ratio's at certain RPM ranges on the VFR as well as a rather abrupt throttle response especially at low RPM. Adding the PCIII with dyno tuning can work most of this out to remove some of the dip in HP/torque immediately before hitting VTEC and can add a little bit of power. If you have problems with how it acts and don't plan on throwing different headers on later down the road then you could probably say that a PCIII and dyno tune will give you all the gains to be had at this point.

However unless you replace the stock headers on the VFR you will never see the full potential of the PCIII. This is due to the catalytic converter in the stock headers and how restrictive it is. This is why you can get away with just doing a slip on and not having to worry about tuning it. The slip on just changes so little since the catalytic converter does so much in terms of restricting air flow and keeping up the back pressure. Once the stock headers are replaced then some dyno tuning really needs to be done so that the changes are compensated for correctly and thats where the dyno tune and PCIII comes in.

With all that being said, there are still gains to be had with installing a PCIII now with just your slip on and NOT doing a dyno tune albeit not nearly as much with the dyno tune. There are many maps available for download via many websites that could prove to be useful for you such as the stock ones put out by DynoJet or even the famous Cozey's map.

The really sad thing of all of this is just how little of gains there are to be had with full exhaust modifications and proper tuning. Without going inside the engine, most can expect to see somewhere around 110 RWHP after tuning. Before modifications, most will be seeing somewhere between 95RWHP to 100RWHP. Depending on what slip on and what headers you go with, you are looking at spending somewhere between $1000 and $1800 for all the parts and tuning required. All this works out to cost somewhere between $67 to $180 per RWHP. Pretty darn expensive for such little gains and mildly disheartening.

 

One of the benefits of the modern box-stock motorcycle is that they are pretty well developed as-is. There are always gains to be had, but like Meatloaf points out (and NCB is more aware of than all of us), it costs a lot. I used to spend a bunch of money on all of my vehicles adding aftermarket performance parts. The VFR has been limited to a few windscreens, as it does what I got it for reasonably well. If I could spend about 2K and get a lot of bang for the buck on engine output, it would be tempting. I'd probably spend it on the suspension instead.

I went out into left field a bit. Sorry about that.

 

well, I bought it - woo hoo!

It sure does sound awesome with the short pipe, I will have to see how it is at highway speeds.

pics to follow in the daylight.

 

I disagree. I have seen drivers turn their heads to look, when I have come up behind them. That is a GOOD thing. - It means they know I'm there.

There is a difference between having an exhaust that is sufficiently loud that people can hear you, and an exhaust that is "wanker-loud", which is what Harley owners have.

The recent South Park episode about Harley riders summed it up quite accurately:



The average Harley owner does not ride for the pleasure of riding. He rides to show everyone else that he has a Harley. (Much like the typical Ducati owner.) I hate them.

 

Bra ...bra brab brab brab...braa

 

"Look at me!!! Look at MEEEEE!!! I own a Harley!!!! GIVE ME YOUR ATTENTION!!!!!!!!!"

YouTube - Harley Davidson Crash

 

..... lol

 

Want to know the Harley guys can't ride. Check this out and listen towards the end.

"DON'T HIT THAT FRONT BRAKE" Oh yea ride like a Pro!

YouTube - Ride Like a Pro Don't be a Footdragger!

 

Threadjack, VFR World style. The classiness of the VFR owner never ceases to dissappoint.

 

slip on

Where do you get one of those?

 

I think the PO made it. I looks like a section of the midpipe cut off with a saw and a short section of baffle and some packing shoved in. It is pretty quiet at idle and not obnoxious until you wind the rpms up some.

Here are a few more pics: