Hello All! My ‘11 FE390 is stock including the factory Husaberg exhaust. I’ve been told by a couple of tuners that the stock exhaust is one of the first things I should swap out to let her breathe better. I can no longer find a new Akropovic and FMF doesn’t list my bike specifically. I’d like something on the quieter side and must have a spark arrestor. With that in mind - what do you folks recommend? Is there an FMF that fits but is not listed? How important would a new header be? Thanks for any input!
2011 FE390 Exhaust Choices
- Thread starter sanluissound
- Start date
I have this exhaust pipe and muffler on mine (version 570)
https://www.domaracing.fr/shop/fr/450-fx-fe/369-collecteur-bomb-husa-450-fx-fe-10-10.html
https://www.domaracing.fr/shop/fr/450-fx-fe/628-silencieux-alu-car-cpl-husa-450-fx-fe-10-10.html
I have not yet been bored in the sound test while the lilmites are hardened
https://www.domaracing.fr/shop/fr/450-fx-fe/369-collecteur-bomb-husa-450-fx-fe-10-10.html
https://www.domaracing.fr/shop/fr/450-fx-fe/628-silencieux-alu-car-cpl-husa-450-fx-fe-10-10.html
I have not yet been bored in the sound test while the lilmites are hardened
Thanks Noubazor! That site does not reference the FE390 or my year (2011) but I’ll reach out to them and see if the 450 fits.
Thanks Rainerio! This may be a very good option. I don’t think my ECU has been flashed and besides the add on fan I think the bike is stock. I called some tuners I know and they all said there’s no more option to flash the ECU but a big pinch point in the whole affair is the exhaust and that a muffler change would help a lot. I ride at 8000’ - 12000’ regularly so want to her to breathe well. I’d like to add an EJK fuel controller as well.
Factory re-flashes are very limited if not impossible to obtain here in the USA after some changes in policy from KTM. I believe it was primarily related to increased pressure from the EPA in terms of emissions from small gas engines. You best bet it one of the aftermarket tunable ECUs, JD Tuner, or adjusting the TPS a bit.
Mufflers from 450cc KTMs of the same era will fit. I had the KTM 4.1 RCT on mine and found it pretty cheap used.
Mufflers from 450cc KTMs of the same era will fit. I had the KTM 4.1 RCT on mine and found it pretty cheap used.
Every dealer/tuner I’ve spoke with has said “No way!” to flashing now. It’s a legal issue of some sort. I don’t need huge gains, just want to uncork her a little and so much of my research has pointed to the muffler. I’m also interested in the EJK fuel controller - it gets good reviews and appears pretty basic re installation.
Good to know the 450 is essentially the same exhaust. My understanding is that at least the header is different on the 570 though it’s hard to believe that would effect the muffler.
Good tip re the KTM 450’s of the same era, I’ll be looking into that soon!
Thanks folks, I really appreciate the intel!
Good to know the 450 is essentially the same exhaust. My understanding is that at least the header is different on the 570 though it’s hard to believe that would effect the muffler.
Good tip re the KTM 450’s of the same era, I’ll be looking into that soon!
Thanks folks, I really appreciate the intel!
Front pipe :
type 1 : 390/450
type 2 : 570
central pipe :
390/450/570FE : pipe on the 570, the front pipe and central pipe change
type 1: lambda senror : 81205008000
type 2 : not lambda : 81205108000
pour la 570 FS :
type 1 lambda sensor : 81205208000
type 2 not lambda : 81205308000
silencer / muffler : identical I think
type 1 : 390/450
type 2 : 570
central pipe :
390/450/570FE : pipe on the 570, the front pipe and central pipe change
type 1: lambda senror : 81205008000
type 2 : not lambda : 81205108000
pour la 570 FS :
type 1 lambda sensor : 81205208000
type 2 not lambda : 81205308000
silencer / muffler : identical I think
Thanks for the info so far!
I had been interested in the Akrapovic system, was a complete exhaust with an expansion chamber on the mid pipe. I don’t see them available online anymore but am wondering if anyone has experience with them and in particular wether or not the expansion pipe made a noticeable difference.
I had been interested in the Akrapovic system, was a complete exhaust with an expansion chamber on the mid pipe. I don’t see them available online anymore but am wondering if anyone has experience with them and in particular wether or not the expansion pipe made a noticeable difference.
Joined Nov 2001
17K Posts | 773+
Ely, England
the reflash is what you need. so chase that aftermarket OK? the dealers are connected to the factory. when they re-flash they have to put in the chassis number etc and as yours is already a street plated bike its a bit late to say "MX use only".
so you'll have to do it away from KTM/Husky dealers.
as far as pipes go, the pipe on the 570 is the pipe on the 390/450 I think. the only reason they are different part numbers is because the barrel on the 570 is longer so it needs a different shape. nothing to do with power.
there's nothing wrong with the original exhaust and if Rainiero knows a trick with the inside of the silencer then get it done.
fuelling and igninition.
the valves are huge, the exhaust is huge, the injector is huge. look at a belmouth.
look for another cam. maybe rainiero knows but, I have never seen a performance cam for these off the shelf have you?
that stuff about the exhaust...its bollocks, absolute phuqing tosh.
Taffy
so you'll have to do it away from KTM/Husky dealers.
as far as pipes go, the pipe on the 570 is the pipe on the 390/450 I think. the only reason they are different part numbers is because the barrel on the 570 is longer so it needs a different shape. nothing to do with power.
there's nothing wrong with the original exhaust and if Rainiero knows a trick with the inside of the silencer then get it done.
fuelling and igninition.
the valves are huge, the exhaust is huge, the injector is huge. look at a belmouth.
look for another cam. maybe rainiero knows but, I have never seen a performance cam for these off the shelf have you?
that stuff about the exhaust...its bollocks, absolute phuqing tosh.
Taffy
Fully agree with Taffy. That is what I understand from talking to people here and there.
One source I trust is Ljunggrens motor in Sweden where I bought my 570. He had put an acra header on the bench and it showed no more HP than stock, it had however 2dB less.
He told me that one could have a different, more open, silencer to remove some heat and it could benefit top end. But it wasn't much of a difference.
I have heard from a different source that the HP benefit compared to stock is negligible, that it even might be a loss. But then people talk about engine characteristics, loose top HP and gain in curve. I will not touch that as there is so much psychology with sounds
Tomtom has found out, amongst other tuners, that the bottle neck is to get air into the engine. But that is for 570s as they are based on the 390/450 using the same throttle body.
Imho a 390 is very good as it is. Just make sure your injector and air filter are clean. You could try to tune it following Alans advice if you like to make it a bit richer, and maybe even open up the silencer as Rainero says.
What make people believe these bikes are tamed, that they have more to give, is the very nice mapping curve. They deliver in a very linear fashion. Accelerate next to a "wilder" machine and I'm quite sure you will keep up with it
One source I trust is Ljunggrens motor in Sweden where I bought my 570. He had put an acra header on the bench and it showed no more HP than stock, it had however 2dB less.
He told me that one could have a different, more open, silencer to remove some heat and it could benefit top end. But it wasn't much of a difference.
I have heard from a different source that the HP benefit compared to stock is negligible, that it even might be a loss. But then people talk about engine characteristics, loose top HP and gain in curve. I will not touch that as there is so much psychology with sounds
Tomtom has found out, amongst other tuners, that the bottle neck is to get air into the engine. But that is for 570s as they are based on the 390/450 using the same throttle body.
Imho a 390 is very good as it is. Just make sure your injector and air filter are clean. You could try to tune it following Alans advice if you like to make it a bit richer, and maybe even open up the silencer as Rainero says.
What make people believe these bikes are tamed, that they have more to give, is the very nice mapping curve. They deliver in a very linear fashion. Accelerate next to a "wilder" machine and I'm quite sure you will keep up with it
You guys are so smart!
Funny thing is that this is the nicest bike I’ve ever had and I love it! I’m 155 lbs with all my gear during riding season, my power to weight ration on this thing is just fine. There’s nothing wrong with my 390, just thought a couple tweaks might open things up.
FWIW it was more than one tuner who told me the muffler is a bottle neck. As I understand it heat buildup has been a big issue with these bikes and the muffler is a known culprit. Mine has the fan (installed by the dealer as I understand it) which kicks in when I’m working hard, technical, uphill stuff but otherwise doesn’t seem to be on too often. I pulled the fuel pump and double checked the tank for the notorious white goo but all is fine. My bike runs great!
I may try the EJK fuel controller as an experiment regarding running richer and to see how it changes things at altitude - I’m riding at 8000’ - 12000’ routinely out here in Colorado.
Thank you all for keeping me in check
Funny thing is that this is the nicest bike I’ve ever had and I love it! I’m 155 lbs with all my gear during riding season, my power to weight ration on this thing is just fine. There’s nothing wrong with my 390, just thought a couple tweaks might open things up.
FWIW it was more than one tuner who told me the muffler is a bottle neck. As I understand it heat buildup has been a big issue with these bikes and the muffler is a known culprit. Mine has the fan (installed by the dealer as I understand it) which kicks in when I’m working hard, technical, uphill stuff but otherwise doesn’t seem to be on too often. I pulled the fuel pump and double checked the tank for the notorious white goo but all is fine. My bike runs great!
I may try the EJK fuel controller as an experiment regarding running richer and to see how it changes things at altitude - I’m riding at 8000’ - 12000’ routinely out here in Colorado.
Thank you all for keeping me in check
Regarding pipes and mufflers - I’ve got other bikes that gained HP from a straighter muffler flow but lost torque. Almost everything I really press this bike for requires torque/grunt. Just another reason to STFU and ride as is.
The perceived need for exhaust back pressure is largely a myth. The air needs to get in and out of the engine (air pump) as efficiently as possible.
I find it very hard to believe that with proper tuning a straight through design muffler is not going to provide benefit over the stock part. I have had both OEM versions taken apart and each has massive impediments to flow even if you cut down the rear outlet tube on the "better" version.
I find it very hard to believe that with proper tuning a straight through design muffler is not going to provide benefit over the stock part. I have had both OEM versions taken apart and each has massive impediments to flow even if you cut down the rear outlet tube on the "better" version.
Part of that flow/pump is a harmonic pulse which helps with scavenging. My understanding is that a “straight” flow is relative.
I’ll hunt around for an FMF or similar that will replace the factory muffler and add the EJK fuel programmer. If I can find a local dyno will do a before and after, no harm in learning for all of us. Oh, the rabbit holes...
I’ll hunt around for an FMF or similar that will replace the factory muffler and add the EJK fuel programmer. If I can find a local dyno will do a before and after, no harm in learning for all of us. Oh, the rabbit holes...
I could be wrong but feel like tuning for pressure wave scavenging on a small displacement single cylinder likely provides negligible gains. I think there is far more benefit to removing restriction and hopefully keeping some heat out of the exhaust given the issues the 70 degree bikes have with fuel temperature.
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