There haven't been any dyno results published from either as far as I know. I have my exhaust designed, but won't be releasing it until such time as I can finish dyno testing and be able to publish performance data. Without dyno results, you are just crossing your fingers and hoping. From all accounts without remapping, any modifications to the intake or exhaust will result in a potentially dangerous lean condition. The Power Commander V will be out in about a months time, and my intent is to release my exhaust to coincide with that so that mappings for it will available concurrently. It's possible to have the dealer map your stock ECU with the Akrapovic mapping, which would be an improvement, but still not optimized for any modifications to intake or exhaust.
Backmarker
New Member
I am looking at the ghost line, I am more interested in power over sound, it's a track bike for me. But I am going to wait and see what formula390 comes up with. I would much rather buy this side of the ocean.
yeah thats true, mines only a street bike so I'm kind of looking at the sound. just want something a little louder than stock but not outrageously loud.
A1VW2NV
Member
Dean, weren't you the one selling the AHM exhaust? What exactly are you after? I think that system sounds amazing.
yeah its a great system, but its a little loud for my liking.
KTMGene390
New Member
Hey guys,
I received the Akrapovic slip-on exhaust (KTM PowerParts) recently and just noticed it says it's for a '14. I assume it will work with the '15 as well?
I received the Akrapovic slip-on exhaust (KTM PowerParts) recently and just noticed it says it's for a '14. I assume it will work with the '15 as well?
My understanding is the exhaust was initially designed for the Duke and was then mounted on the RC for the cup bikes. It was the only available slip-on at the time (tho Arrow and a few others followed soon after the RC was released). There is no difference for the RC as there is still only one model year, with the Cup and Street versions being virtually identical but for the upgrades the Cup bikes got with the WP suspension, exhaust, bodywork, ECU mapping, and the restriction plate.
DCmetro
New Member
When exactly is your exhaust going to be released?
Im new to this site, just bought my 2015 rc390 last week and want to upgrade to either of the grp options however I have seen many posts from you about your muffler that will match the stock exit. Do you have any pictures of the prototypes? I'd be interested in waiting if you can get something out soon. I'd be interested in getting my hands on one first.
Backmarker
New Member
Put me in the line, wish I had it now.
He is still in the production/test phase I think. Dyno time coming next weekend. I think there are a few of us in line when he is ready.
Correct. My "seat o pants" meter is showing what I think will be the winning design, but that's not scientific enough. The Dyno needs to prove it out. The dyno day is Saturday July 4th.
Once I have the dyno results and can publish that, I should be able to go into production. I'm also waiting for the site to turn on my sponsorship. I sent in the initial payment but it hasn't been announced on the site / or my vendor area setup yet... So to not run afoul of the sites rules I can't yet offer anything for sale anyway. The intent is to release my exhaust design to come out concurrently with when the Power Commander V becomes available for sale to the public in mid to late July tho. Without the ability to remap, any changes to the intake or exhaust is going to make things too lean. Chad has proven that out on the dyno with his graphs time and again with his engine kit testing.
I don't have photos yet as the test cones are actually sticking out the side of the frame. I've confirmed fit with heavy paper models, but when I was fabricating the test exhausts it's just too much work to make THAT many final designs, roll and bend the metal, and weld it all up for final fit when I can prototype the pieces in CAD, cut it all out on the laser cutter with paper, roll and tape it together, and test to make sure things fit... I've got a range of sizes of cones that'll fit, and the one I THINK will be the winner (Dyno will tell) fits in that range.
RoninJames
New Member
Yea im waiting for your exhaust as well Matt. i want something that keeps the stock position. since we have to wait for the PCV to release anyway before putting any exhaust on (besides the akra) i decided im just gonna live with stock for now. once the PCV is available i am assuming/hoping you will have a map for ur exhaust PLUS a K&N air filter with the billet airbox mod
Yea im waiting for your exhaust as well Matt. i want something that keeps the stock position. since we have to wait for the PCV to release anyway before putting any exhaust on (besides the akra) i decided im just gonna live with stock for now. once the PCV is available i am assuming/hoping you will have a map for ur exhaust PLUS a K&N air filter with the billet airbox mod
That is indeed The Plan™.
I've got the K&N filter already in hand for testing next Saturday.
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KTMGene390
New Member
Thanks, do you happen to know the stock exhaust weight?
Yeah... 3.79 metric tons!!! No actually 5.2kg / 11.5lbs. It's a SERIOUS chunk of steel and weight to be sure. The first time I pulled it off it shocked me with how much it weighed even with my EXPECTING it to weigh a lot.
A1VW2NV cut his open, and you can see why it weighs so much:
The routing in the can lengthens the total exhaust length and provides the dampening... but to total length doesn't need to be nearly this long. Of course, stock exhaust systems are all about noise mitigation with the hope it doesn't hurt power too much. That's 180 degree turn it has to make with the exhaust gasses however isn't doing the motor ANY good. That's just basic fluid dynamics theory!!! You just don't, or at least SHOULDN'T, do that!
KTMGene390
New Member
Yeah... 3.79 metric tons!!! No actually 5.2kg / 11.5lbs. It's a SERIOUS chunk of steel and weight to be sure. The first time I pulled it off it shocked me with how much it weighed even with my EXPECTING it to weigh a lot.
A1VW2NV cut his open, and you can see why it weighs so much:
The routing in the can lengthens the total exhaust length and provides the dampening... but to total length doesn't need to be nearly this long. Of course, stock exhaust systems are all about noise mitigation with the hope it doesn't hurt power too much. That's 180 degree turn it has to make with the exhaust gasses however isn't doing the motor ANY good. That's just basic fluid dynamics theory!!! You just don't, or at least SHOULDN'T, do that!
Thanks for that info. Very interesting to know as I weighed the Akrapovic slip-on exhaust and with all mounting hardware included plus the Akrapovic hanger eliminating the passenger peg (minus the Duke 390 bracket which isn't used on the RC 390) it comes out to 10 lbs, 12.6 oz. Or 9 lbs, 6.5 oz with just the exhaust system and no mounting hardware. $1,000 exhaust system and not much in weight savings. It's no big deal as I will be saving enough weight elsewhere on the bike, I just thought it would be more.
By EVERY calculation I've done, using every formula and research paper I could dig up, the results show time and time and time again that the total system length for the Akrapovic system is WAAAAAAAY to long. I honestly have no idea how the engineers that designed the system came up with the length they did, other than the bean counters tried to save some funds re-using exhaust components from other bikes or something. There's no ENGINEERING reason for it to be built the way it is tho. Or at least, none that I can fathom (or calculate).
DCmetro
New Member
He is still in the production/test phase I think. Dyno time coming next weekend. I think there are a few of us in line when he is ready.
Im really not looking to wait too long, there are plenty of good exhausts on the market and the ghost is product by a company with lots of resources, I thank its a great option. I'd be interested in a hard timeline and I'm sure im not the only one that would appreciate an eta on the exaust.
You must have not seen the post earlier today on how Dyno testing of the designs went:
http://www.rc390-forum.com/forum/en...95-exhaust-development-post5081.html#post5081
In short... not great. It seems that ANY design which utilizes the same location and exit won't be able to beat the stock street exhaust , other than possibly doing a CAT-ectomy on the stock exhaust. Maybe. We are trying to setup a dyno test of stock vs. stock with CAT removed to see if this proves out to be true.
Because GPR was looking like it would be my competition, I also tested a "PowerClone" (a copy I made of the Powercone without the CAT or DB-Killer/baffle, made to the dimensions of the PowerCone) as well, and it actually produced 3HP LESS than stock (where as my best design managed to "only" produce 0.5hp less). We don't have any dyno data for the GPR PowerCone exhaust on the RC390, so there's no way of saying definitively yet if this 3HP loss is exact (it seems to be based on feedback I'm seeing on the Duke forum from the guys in the UK however) or if the Ghost exhaust will suffer from that same performance loss (at this point based on the dyno testing I did yesterday, I'd be shocked if it didn't, but I welcome anyone who has one to put their bike on the dyno with stock vs a "real" Powercone or Ghost exhaust and prove me wrong) but I think it's fair to say that it almost certainly will. Before you or anyone else drops $250-350 on an exhaust from GPR, which currently is completely without any corroborating evidence for their "power gain" claims, I would try to get some dyno results data from someone who already has the system on their bike, or from the manufacturer, distributor, or reseller, to back up their claim. Currently, it appears however to just be an expensive noise maker which it turns out actually hinders performance.
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