Has any one used HFP Exhaust system on your sportsman? I have an 04 700 EFI any recomendations? And did you need an controler for your efi? just wondering

 

Did you mean HSP? If so, they are awesome sounding. Had the true duals on my 09 800. Shouldn't need a controller or remapping. Ran that exhaust and a single aaen pipe prior to that with no issues.

 

If you change the exhaust you will need an efi tuner, otherwise you will be running lean and you won`t get the full power gain from the exhaust.

 

I put an HSP on my 500 EFI and it sounds great. Gave me a little more low end thru mid range power and speedwerx claims it was not necessary to add a fuel controller since the EFI would compensate for it. I added one anyways and pipe with controller there's a noticeable difference!

 

Thank You I did mean Hsp. Ok so look like a controller any one in general I should use? do they just plug and play or do I have to tune it in with a computer

 

power commander makes a really good product and hsp will prolly tell u the same thing, they are a plug and play set up in a way, but if u want the best results you can put ur quad on a dyno and make ur own fuel mapping.

 

Thank you

 

From what ive read, the efi computer does not have the ability to compensate for engine mods, that`s why a tuner is needed. If the computer had an 02 sensor hooked up to it so it could read the air fuel ratio in the exhaust the computer would be able to compensate to a certain point for added engine mods, but our atv`s don`t use an 02 sensor. Maybe that will come in the next generation of ATV`s

 

Thank you much for all the input. I purchased a full HSP system couldnt pass up the price. They claim I dont need a controller but I'm going to put one on anyway.

 

You won't go wrong with adding the controller. It will make the most of your bikes potential with the exhaust. Don't forget a quality intake as well. With the exhaust and controller that baby's gonna want to breath.