Man I'd be pissed if I bought a full system for the 400ex.

The Big Gun and DG exhausts put out less peak HP than the stock exhaust!! Looks like Honda put some time into the stock exhaust. Maybe there would have been a bigger improvement if the exhaust was on a modified 400ex.

Mac

 

chrismac,
wo words if you are going to buy a full exhaust...
CURTIS SPARKS
ron

 

His Exhaust made 1.9hp increase in peak hp. $200+ per HP isn't very good.

Mac

 

By now it's no secret that an after market head pipe can actually hurt performance with the stock compression ratio. If the motor is internally stock, a slip on exaust is the way to go. Also, when you're talking about a motor that only puts out 27 hp, a 2 hp increase is quite noticeable.

As for the noise issue, this may come as a shock to those applying for their eco **** membership cards, but atving is a motorsport. While participating in this activity you will be sbjected to the melodious sounds of high performance enfinges and maybe even the sweet fragrance of two or four stroke exaust. If this type of thing seems "icky" to you, may I suggest a more sedate hobbie, like gardening or star gazing.

 

Well in case you didnt realize that loud exhausts on ATV's is a big concern. Alot of riding areas have been closed where due to excessive noise so 2hp and a twice as loud quad for $450 doesnt seem worth it.

Mac

 

To go fast you gotta spend the $$$. If speed is not your priority then keep it stock. No one is twisting your arm to make your 400 loud. Allen Greenspan once spoke of supply and demand. Interesting concept.

 

2hp is the gain on the top... in the mid range and low and u may gain 5 hp... now theres a difference.

 

I can tell you for a fact that putting on a Big Gun system does not make you lose topend power. You don't gain much at the top, but you don't lose it either. After I installed my full system, I raced my buddies bone stock 400. From lowend to Midrange I drove by him, time after time. Then from mid to topend I could just barely pull him. That is until we got to top speed where we had identical top speeds. By the way we weigh about the same. Don't always take the Dyno numbers as being the law, the real proof is at the track.

 

What is really frustrating is that these exhaust companies advertise much more power than they actually deliver....for all atv's.
Also, it seems there is very little effort to keep these expensive systems reasonably quiet. Noise just gives the tree-huggers another weapon to fight with.

 

On a stock motor the exhuast do not make much of a difference over the stock system. But once you build your motor up you will need the pipe very bad. Then you will notice a pretty big difference.