Has anyone been able to compare these kits? HPD claims over 85hp from the 416. I know the 470 has to put out a lot of power. Does anyone have any numbers or comparisons?

Colin

 

In my opinion the HPD would be the way to go, but you are looking at lots more money there. Usually there can be more power gained with a close to stock cylinder more so than one that is overbored or sleeved bigger. I have all Aaen stuff, well most of it, but If I had the money I would definitely go with the HPD powervalve set-up. These are new products for both companies, haven't heard anything about the Aaen yet, but I have heard many good things about the HPD kit. Modquad is at HPD alot(I think) so I would get his opinion. Just my 2 cents!

 

The HPD 416 rips. They spent last summer, all summer testing it. It is a lot of money, but as for the 400, it's the top of the line. You can gain tons just getting a trail mod from them also. If you are going with the race mod area, the 416 has it's own pipe, so you can't switch back and forth between a regular non-powervalved cylinder, and a powervalved cylinder. For all around grin factor the non-valved race mod with the ATV8 pipe, has instant throttle response, and can be a fun all around machine. Starting out, the two best things to do are a clutch kit, and a trail pipe. Make sure to purchase them from the same business, because they are matched to each other. The 400 can be a lot of fun, there are many areas to gain performance.