Anyone know what kind of power increase you gain when putting a aftermarket intake on a KFX450R I am looking at the FCI let me know if you have ran this and how it works thanks!!

 

if your talking about a stock bike and your just modifying the air box then the gains will be small... one to two horse. the reason being is the exhaust will still be restricted its like a hose it does no good to make one end larger if you dont also do the same to the other end air will be restricted lowering your volumetric efficiency of the engine meaning your not getting the best amount of air through the cylinder also meaning your not going to be able to get the most power out the engine throw a pipe on.... a slip on is better than nothing

 

Not in the case of the KFX450R... it breathes through a dang pancaked intake tube.

Gains from a full intake will vary... but with a good intake and tune you are talking about a gain of 4-5 hp... and that is no joke.

You can get about the same amount of gain out of a Jardine RT99 full exhaust also.

But that's not to say that doing both will get you a gain of a full 10 hp together.
It might, but it's hard to say for sure... 4-5 out of one and 7-10 out of both is a safe bet.

If you buy from KB Motorsports, the exhaust is more bang for the buck.
Just bolt it on and done... $365 (smoking hot deal!!!).

With an intake you WILL have to buy something to tune with also... $6-700 total.

Choices for fuel control range from the many "carb logic" type controllers... most of which are the same make with different stickers (Dobeck, Dynatek, etc). These are good for simple adjustment and tuning on the fly.

Then you have the Power Commander controllers... PC3 and PC5... same concept with both, PC5 just the latest and greatest. This uses mapping and requires a computer.

Then you have what I went with... The Procom fully reprogrammable ECU... totally replaces the stock ECU (a good thing) and comes with 10 good preset maps for the simple guy to try and choose from... with better timing and fuel curves... But it also comes with a USB connector and software... and you can completely reprogram every detail if you want... more adjustability and control than anything else on fuel... and also allows you to program your own ignition timing curves, which is a big plus.

 

so your saying just with a air box exhaust and a programmer a 450 will gain ten horse? that is a lot most 450s are around 45-48 stock you can mess with the tune a little bit but if the exhaust cant flow air out of it then there will be less of a pressure difference in the cylinder for the weight of atmospheric pressure to push it in its simple physics ya you can advance the timing a little bit in order to optimize the amount of fuel to get into the combustion chamber but you need air with it and with a stock exhaust when the exhaust valve opens wont be able to flow enough. i would agree the programmer gets you a little more power but i highly doubt with all three it gets you horsepower gains. My friend priced out the alba top end for his honda 700xx and with ported head cam and piston with k@n and exhaust it projected at highest 60 horse power and that is about a twelve horse jump of stock according to your lodgic with airbox exhaust cams pistons and head work you think it would be in the 20s for horsepower gain? i know for a fact on my yfz i havent gain that much and the kfx isnt going to be that much different in terms of gains

 

Nah... the 450's are more like in the 30's stock, and in the 40's with bolt-ons.
It just feels like 10 more than that because of how quick they make it.

Yours was probably in the high 40's before the piston...
No idea now though because I don't do the high compression thing anymore...

The KFX is real corked up on intake and exhaust and running rich from the factory.
It picks up 10 horses from exhaust, intake, and fuel control... and another 11 or more from a bore and stroke.

 

Thanks for all the info guys I am currently running a Lexx slip on exhaust and a Lexx Fuel controller I just have not done the intake yet and was curious how much more it would give me on top of what I have? I would say the exhaust and fuel controller added about 5 horse so hopefully I can get another 3-5 out of a intake.

 

Yes, you can get that much more out of an intake if you go with one that actually replaces the intake tube... The problem is the part of the stock tube that is plastic and molds around the rear shock.

Here is a picture looking inside of the section of the intake tube I found on the internet.

 

Cool thanks for the help again I think I am going to go with the FCI intake system will keep you posted on what kind of difference it makes.