It is Amazing

[Drak]

This is what i took out of my Rc390 One stock KTM air intake. Witch i will note is one of the worst air intake systems i have ever seen. Pulling air from the back of the bike all the way to the front. And replaced it with a K&N Rc 9630. I used a 2.25 to 2.5 reducer to go from the intake to the pipe. The pipe has a 45 degree bend to go over the rear shock and connects directly to the filter. then i had to get some 7/16 rubber hose to connect the old hoses to my new intake. after all this i took it out for a test run. It was amazing. i could drive in 6th gear at 3k RPM with no problem. it would fly through all the gears with ease. then i found a problem. driving up the side of a mountain instead of sifting down i decided to open it up full throttle just to find half way up the bike runs out of steam. so i shift down to find that that gear also dos'nt want to pull it. so i go down another and another. so i stop on the side of the hill to find nothing wrong with the bike. so i take off again and make 6th before i reach the top with no problem. so i did some test and every time i reach full throttle after a few seconds the bike would shut down. Not die but lose a lot of power. so i fount out the problem. my stock exhaust wasn't letting out enough air and it was killing my ponies. it was an interesting problem never had it before. Question though. Am i the only person to take out the stock system, and why wound someone want to pay 50 dollars to put in that little chocked air filter when 70 dollars will replace the whole thing?

 

[reenmachine]

This is what i took out of my Rc390View attachment 2180 One stock KTM air intake. Witch i will note is one of the worst air intake systems i have ever seen. Pulling air from the back of the bike all the way to the front. And replaced it withView attachment 2179 a K&N Rc 9630. I used a 2.25 to 2.5 reducer to go from the intake to the pipe. The pipe has a 45 degree bend to go over the rear shock and connects directly to the filter. then i had to get some 7/16 rubber hose to connect the old hoses to my new intake. after all this i took it out for a test run. It was amazing. i could drive in 6th gear at 3k RPM with no problem. it would fly through all the gears with ease. then i found a problem. driving up the side of a mountain instead of sifting down i decided to open it up full throttle just to find half way up the bike runs out of steam. so i shift down to find that that gear also dos'nt want to pull it. so i go down another and another. so i stop on the side of the hill to find nothing wrong with the bike. so i take off again and make 6th before i reach the top with no problem. so i did some test and every time i reach full throttle after a few seconds the bike would shut down. Not die but lose a lot of power. so i fount out the problem. my stock exhaust wasn't letting out enough air and it was killing my ponies. it was an interesting problem never had it before. Question though. Am i the only person to take out the stock system, and why wound someone want to pay 50 dollars to put in that little chocked air filter when 70 dollars will replace the whole thing?

Good heavens I don't know where to start. Your problem isn't that the exhaust "isn't letting enough air out". It's that your fuel injection calibration is now completely mismatched to the hardware. You're running massively lean and you're lucky you didn't do some serious damage (or maybe you have, depending on how and how much you've ridden that way). You need to do one of two things before riding again:

1) Go get a custom dyno tune

OR

2) Put everything back to stock

If you get the custom tune, that may or may not get things running as well as stock. Believe it or not, the shape and size of the airbox has an effect on how an engine runs. Also, intake air temperature makes a big difference, and you're now breathing significantly hotter (and thus less dense) air than before, compounding the problem.

Before you take the obvious next step, keep in mind that exhaust is the same way. Your intuition may be that the shortest, most direct exhaust will "let the air out easiest" and thus increase power and efficiency -- not so. Exhaust pipes are a certain length (or at least within a certain range) for a very specific reason. Also, you'll need to get that custom dyno tune done again after changing the exhaust or any other engine changes.

Good luck! It's fun to modify things, but be careful! There's more to it than you think. I'm not trying to sound condescending, I just don't want you to hurt your engine!

 

[Rexbo]

^^ this. Get the bike tuned. World of difference

 

[Old3]

Reason #1 to avoid used bikes.

dis guy is everywhere!

 

[NafizAliKhan]

Does anyone know how this type of cone filter intake would compare to stock intake with higher flow filter both with dyne tune and exhaust?

 

[Drak]

most of what your saying is true. It is running leaner and the soft reset of the ecu ( letting it idle to for 15 min's to let it august isnt enough ) so the next step would be to have it tuned. the part that your wrong about is the intake air being hotter. Its not. and no i would not opt to have the shortest exhaust. It is pointed behind you for a reason. currently I am rethinking my muffler. I dropped the old one off and built a new one in its place. After i got every thing welded and put in it worked well. but it is currently louder by some degree than my 1600 yamaha road star with strait pipes. Making it almost impossible to ride with out hearing protection.
About your comment about buying used bikes. I would not sell the bike. But you are right it needs tuned. I have one last upgrade to get worked out before i do so.

 

[Drak]

With out tuning and depending on exhaust it gives great low end torque while sacrificing some high end power. My top speed now is at 10` mph instead of 110 and i am still at the same 18 Miles per litter gas mileage, and the higher flowing exhaust doesnt help with mileage only low end power. Oh if it helps I did attend college for ME and EE. I stopped because i was bored.

 

[Drak]

If you get the custom tune, that may or may not get things running as well as stock.

This made my day thank you

 

[cjwell]

There is certain length velocity stack in the original air box for a reason among another handful or things relating to air box design, volume, res freq, etc. ..... Now that is gone. Can't wait to see dyno graph with a 5'' shorter v stack now. Did you data log pre and post modifications regarding intake air temp? Also even though you think air filter "placement" is good/better than OEM now, It could be in "dead" air (negative pressure area) on the bike. Sr500 syndrome....

Oh and because I can make over 50 rwhp on that 50 dollar choked air filter (and stock air box)

 

[Muckabucka]

I threw away my airbox ages ago. It weighed too much...

 

[psych0hans]

Oh and because I can make over 50 rwhp on that 50 dollar choked air filter (and stock air box)

1234567890

 

[reenmachine]

most of what your saying is true. It is running leaner and the soft reset of the ecu ( letting it idle to for 15 min's to let it august isnt enough ) so the next step would be to have it tuned. the part that your wrong about is the intake air being hotter. Its not. and no i would not opt to have the shortest exhaust. It is pointed behind you for a reason. currently I am rethinking my muffler. I dropped the old one off and built a new one in its place. After i got every thing welded and put in it worked well. but it is currently louder by some degree than my 1600 yamaha road star with strait pipes. Making it almost impossible to ride with out hearing protection.
About your comment about buying used bikes. I would not sell the bike. But you are right it needs tuned. I have one last upgrade to get worked out before i do so.

With out tuning and depending on exhaust it gives great low end torque while sacrificing some high end power. My top speed now is at 10` mph instead of 110 and i am still at the same 18 Miles per litter gas mileage, and the higher flowing exhaust doesnt help with mileage only low end power. Oh if it helps I did attend college for ME and EE. I stopped because i was bored.

This made my day thank you

Ok, best wishes then I guess. Sorry you were too bored to finish your engineering education -- I wasn't.

 

[psych0hans]

Guys, since we're on this topic, is it true that removing the snorkel will have the same effect as the airbox lid mod?

 

[Old3]

Leave this thread for further discussion about burned valves and melted pistons. Ill post mine over in engines.

 

[cjwell]

Guys, since we're on this topic, is it true that removing the snorkel will have the same effect as the airbox lid mod?

NO, just removing the snorkel is no where the same as removing the whole lid. Removing the snorkel does virtually nothing (just like having it intact).

 

[psych0hans]

NO, just removing the snorkel is no where the same as removing the whole lid. Removing the snorkel does virtually nothing (just like having it intact).

Cheers! Thank you for your reply

 

[Drak]

I didnt know it was so easy to make people mad. This is fun.
I am right now still working one my new muffler. I need to shorten it by 5 in'. It sounds great now that i made it a bit quieter.
The original design was to point it right out the bottom, but i had to narrow the end to make it quieter which now makes it to long.
Oh and i am happy for you mister 50 Hp. and that's not sarcasm.

 

[micahpearlman]

I didnt know it was so easy to make people mad. This is fun.
I am right now still working one my new muffler. I need to shorten it by 5 in'. It sounds great now that i made it a bit quieter.
The original design was to point it right out the bottom, but i had to narrow the end to make it quieter which now makes it to long.
Oh and i am happy for you mister 50 Hp. and that's not sarcasm.

I think the skepticism on this particular forum is that there is a general consensus here of prove it with a dyno run. There are some serious professional tuners here who have spent hundreds of hours researching and developing performance for this bike and have backed up their results on the dyno. "Cjwell" aka Mr. 50 horsepower, is one of the top tuners in the country as it getting amazing *proven* results from his genius and hard work.


Sent from my iPhone using Tapatalk

 

[Drak]

See the problem with Dino testing is I'm not finished. Besides why am i competing with the top tuners. i am doing this from my garage, not a shop. it is a low budget project that I am doing for fun. But after i get it finished i will take it to a Dino to test it out.

 

[Drak]

Does anyone know it they make a larger after market tank?