I think adding a slip-on exhaust will be the only engine mod I'll do, at least for now. I'd like something that will give me a little more power with a throatier sound but not louder then the stock pipe. Price is also an issue, I'd like to get the most inexpensive one I can find that meets my needs.

The only ones I've looked at so far are the FMF Powercore 4 and Q4. However, it's hard to understand the differences from the limited info on the FMF site. Can someone tell me the real differences between these two? Is there any difference in gas mileage after adding a muffler?

Also, is installation as simple as unbolting the stock exhaust and bolting a new one on? Will re-jetting be required?

 

No after market pipe will be as quiet as stock. The Q4 is not overly loud. The powercore 4 is loud and no spark arrestor. Cheapest slip on is the DG O Series. It is $209 msrp, and has a spark arrestor. Jetting is always a good idea with a slip on. Install is easy as unbolt, bend the passenger peg guard and bolt on the new pipe. Mileage is best with a totally stock bike and seems to get lower with the amount of mods you do as well as how you ride. With just a slip on your mileage should not change much.

 

Sound Comparison FMF Q4 vs. FMF Powercore 4 - YouTube

I installed the quite core insert on the Powercore 4 and it reduced the sound level almost equivalent to the Q4. On the video the sound on both pipes sound similar, in person the Powercore 4 is REAL loud without the insert.

 

How much of a difference do you think the Quiet insert makes? Any idea on cost? Thanks!

 

My Powercore 4 came stock with the spark arrestor inside it. It's loud but less than some of the other choices.

 

In my opinion it makes a big difference. On my decibel app it lowered it to around 98 or 99 from 105. Just 1 or 2 decibels over the Q4. I forgot what I paid for the pipe, I ordered it from Dennis Kirk. I'm thinking it was around $300 or so. The insert I ordered from FMF directly. The one Dennis Kirk sent was the wrong part number. I believe the quiet core insert was around $25.

 

From what i saw on the DG site the O series comes with a quiet core insert. If the O series was out a year ago I may have given it a go.

 

Nothing wrong with Dennis Kirk; great variety of parts and accessories, but I think they are usually on the high side (no pun intended) of cost. Might try Motorcycle Accessory Warehouse, Ron Ayre, Competition Accessories. It saves to price shop.
(Do we have any site sponsors who could help??)

 

Amazon.com

 

Thanks for the info. I ordered the Q4 off Amazon for $291 with free shipping. Too good of a deal to pass up.