Wildcat Forum banner

HMF Performance slip-on Do I need a tuner

12K views 20 replies 9 participants last post by  maverickmarc 
#1 ·
Hello guys, I've been around the forum since I got my trail 1 year and a half ago and learned a lot reading your posts. I went with a HMF performance slip-on as it was the best deal I could get (exchange rate US-CAD is killing me).
I read all your posts regarding the need of a fuel tuner when adding a slip-on muffler and still don't know if I need one or not. It's a pretty expensive mod for me right now and was wondering what you guys think I should do ?

Here is the note on the slip-on installation page :

Note: HMF recommends the Dobeck generation 4 AFR + closed loop fuel tuner tomanage fuel tuning. It is your responsibility to be sure your engine is tuned properlyafter silencer installation. Failure to tune your engine can cause poor drivability,accelerated wear on engine components, and damage to your exhaust system.Damage to your machine, or exhaust system caused by incorrect tuning will not becovered under warranty.

Thanks for your input and keep posting good informations about our ride !
 
#3 ·
Probably not, but just keep an eye on everything.
 
#4 ·
Ok I will keep an eye on it to be sure everything is ok ! I'm always using fresh gas DRock but do you think I should only use 91 octane with the slip on ?
Thanks a lot guys for getting back to me so quickly ! I'm also waiting on the new spring from speedwerx and the sway bars bushings from energy ! Happy with my trail since the beginning ans starting to do some modding on it !
 
#5 ·
I use 91 but nothing to do with how it runs. I just got use to putting it in my truck cause it was tuned and couldnt run anything else plus i found out that all 91 oct sold in the maritimes doesnt have any ethanol added. That alone is reason enough for me to run 91. Few cents extra per fill up wont kill me.

Just so you know i run the dobeck gen 4 and the afr with the stock tune and a slip on isnt lean. It looks a little lean at idle and light load but nothing too lean considering its a fuel injected set up. At WOT and high rpm where it will do damage running lean has the stock program richening it up pretty good. Aftermarket recommends tuners for two reasons, to cover their ass if something should go wrong and to sell more parts. Tuner is good insurance but not needed in you case.
 
#8 ·
Just so you know i run the dobeck gen 4 and the afr with the stock tune and a slip on isnt lean. It looks a little lean at idle and light load but nothing too lean considering its a fuel injected set up. At WOT and high rpm where it will do damage running lean has the stock program richening it up pretty good.
Do you remember what the AFR numbers were at idle, light cruise and WOT with the slip on and stock tune?? Was that with 91 or 87??
Have you ever done a check on how much the AFR changes from 87 to 91??
 
#10 ·
Hello guys, I've been around the forum since I got my trail 1 year and a half ago and learned a lot reading your posts. I went with a HMF performance slip-on as it was the best deal I could get (exchange rate US-CAD is killing me).
I read all your posts regarding the need of a fuel tuner when adding a slip-on muffler and still don't know if I need one or not. It's a pretty expensive mod for me right now and was wondering what you guys think I should do ?
Here is the note on the slip-on installation page :
Note: HMF recommends the Dobeck generation 4 AFR + closed loop fuel tuner tomanage fuel tuning. It is your responsibility to be sure your engine is tuned properlyafter silencer installation. Failure to tune your engine can cause poor drivability,accelerated wear on engine components, and damage to your exhaust system.Damage to your machine, or exhaust system caused by incorrect tuning will not becovered under warranty.
Thanks for your input and keep posting good informations about our ride !
just a quick shout out welcome to the forum stmoi14...great place to learn alot even though i can't/won't do what i read about here...i let our dealer do it...well, some of the real easy things maybe...haaaaa
 
#11 ·
Thanks Dean. I really enjoy reading you guys and learned a lot thanks to you ! I went buying my Trail after reading most of the posts on this forum and seems to me I made the right decision ! ITo date I only had the oil hose who blew up my first ride but I noticed it early and there was no damages whatsoever.
I have a lot of fun riding it and in Quebec we have a lot of trails which is plus !
I'm just starting to do some modding since my warranty is over. Still waiting for my speedwerx spring and my slip on to start with. Hope the HMF performance is a good choice as everything else was too expensive due to exchange rate and lack of performance parts here in Canada.
If someone has the HMF performance I'd like to have some feedback !
 
#13 ·
Don't remember exact numbers but they aren't much different than what I'm running now, mid 13 idle/lite cruise. Octane rating shouldn't affect afr, the added octane is an indication of its resistance to predetonation. Trail was designed to run on 87 so anything over that is fine unless you change compression of the engine. I run 91 cause 91 in my area doesn't have ethanol
 
#16 ·
Octane rating shouldn't affect afr, the added octane is an indication of its resistance to predetonation.
I understand what you are saying. I have thought the same thing. However, richening a mixture also adds resistance to predetonation. So, I was thinking a higher octane may have a similar effect and change the AFR but I have never seen anyone post actual numbers from 87 vs. 91 to see if there is in fact any difference.
 
#18 ·
Now I am confused for sure. ;) I was thinking it would take more 87 to equal the same AFR as 91. Lower octane (87) and exhaust/intake mods would increase the chance to run lean...right?? ;) A little 91 and life is good again (not lean)??
 
#21 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top