A Lot of Bang for Your Buck

[rcamp]

Just installed MNNTHBX's intake cover along with a K&N (KT-1211) air cleaner filter, and what a difference in sound of engine, throttle response, and seat of the pants hp increase.

Have Akra pipe and download installed, and from looking at the dyno specs it appeared to be rich enough that increased air flow could be a plus. 30 mile run and engine temps stayed n the normal range without help from the fan.

If you don't like a loud engine, this may not be for you, but I'm a can't be too loud type of a person. Really gives a 50% louder, and a much deeper sound.

The opening in the air box to the engine is a least twice a large as the snorkel and the top of the air box that you get rid of.

Throttle response was definitely increased and it may just be me but it feels like a 3-4 hp increase.

All this for a total cost of $113. I'd say that's a lot of bang for your buck!

 

[cjwell]

Just installed MNNTHBX's intake cover along with a K&N (KT-1211) air cleaner filter, and what a difference in sound of engine, throttle response, and seat of the pants hp increase.

Have Akra pipe and download installed, and from looking at the dyno specs it appeared to be rich enough that increased air flow could be a plus. 30 mile run and engine temps stayed n the normal range without help from the fan.

If you don't like a loud engine, this may not be for you, but I'm a can't be too loud type of a person. Really gives a 50% louder, and a much deeper sound.

The opening in the air box to the engine is a least twice a large as the snorkel and the top of the air box that you get rid of.

Throttle response was definitely increased and it may just be me but it feels like a 3-4 hp increase.

All this for a total cost of $113. I'd say that's a lot of bang for your buck!

Its rich enough to support in open loop areas but everywhere else not so much by my dyno data. Yes it makes big gains but needs serious tuning for those mods. See below

Same set up as yours stock filter, lid pipe and akra map vs my lid mod with K&N.

Then that modified set up vs tuned with PCV.

And you can do the same thing to stock lid for free.... Even more bang for buck!

 

[DCMoney]

Since my photo was removed from MNNTHBX's thread about the intake cover Ill post it here since they can't edit my post here.

Remove the 4 screws under the lid, apply a little heat around the base and pull apart, only took a few minutes. Yes its "unrefined", but I like money more than shiny parts that never see the light of day anyway.



Put it back to stock in the meantime waiting for the PCV to be released.

 

[JKBC]

I was wondering if the stock air filter is paper and if so then a K&N would be a good change for any vehicle.
I'm planning on keeping the stock exhaust and need to keep it close to stock noise-wise where I live so any air-box modifications beyond just changing the filter aren't really needed by me.
I see K&N also is making an oil filter for the RC 390's. You can buy them both at Amazon.com which is likely what I'll do although straight from K&N they offer free shipping to Canada which might be cheaper depending on what shipping from Amazon would be.

 

[rcamp]

Good info about the air cleaner box. I had ordered the intake cover before I took the air box cover off. Didn't even notice that it came apart.
Thanks cjwell, for posting the dyno data. I don't know what I had looked at before but, but it sure does look like I would be pretty lean below 7000rpms.
Carbs I'm pretty good at tuning, but no experience tuning fuel injection.
Do you guys think I should put it back stock until a good tuning system is available?

 

[MNNTHBX]

Since my photo was removed from MNNTHBX's thread about the intake cover Ill post it here since they can't edit my post here.

Remove the 4 screws under the lid, apply a little heat around the base and pull apart, only took a few minutes. Yes its "unrefined", but I like money more than shiny parts that never see the light of day anyway.
Put it back to stock in the meantime waiting for the PCV to be released.

DC, it's very rare that we edit anything in our forum, but when we do, we typically send a PM giving notice and explanation. If I failed to do so, my apologies. The reason behind it is we spend advertising dollars on that particular section for the sole purpose of MNNTHBX product information. When they get a little far off base, we clean them up. Hopefully that's understandable to most.

As for our cover vs. DIYS, there's nothing at all wrong with garage mods and saving money. I get that. The differences, while small, are that our plate provides a better seal, and it has a smoother radius rolling into the filter. There's plusses to going either way on this, but it's always a good thing to have options, regardless of the product or manufacturer.

 

[cjwell]

Good info about the air cleaner box. I had ordered the intake cover before I took the air box cover off. Didn't even notice that it came apart.
Thanks cjwell, for posting the dyno data. I don't know what I had looked at before but, but it sure does look like I would be pretty lean below 7000rpms.
Carbs I'm pretty good at tuning, but no experience tuning fuel injection.
Do you guys think I should put it back stock until a good tuning system is available?

It's "probably" ok but should definitely be tuned when the Pcv's are available... It's up to you if you think it's not surging and you can "deal" with it then run it. Obviously there's a huge difference and gains to be had with tuning.

 

[DCMoney]

DC, it's very rare that we edit anything in our forum, but when we do, we typically send a PM giving notice and explanation. If I failed to do so, my apologies. The reason behind it is we spend advertising dollars on that particular section for the sole purpose of MNNTHBX product information. When they get a little far off base, we clean them up. Hopefully that's understandable to most.

As for our cover vs. DIYS, there's nothing at all wrong with garage mods and saving money. I get that. The differences, while small, are that our plate provides a better seal, and it has a smoother radius rolling into the filter. There's plusses to going either way on this, but it's always a good thing to have options, regardless of the product or manufacturer.

I get it, when you did the CFD on the modified lid flow vs your lid what percent differences did you see in the velocities of the fluid (air) just before the throttle bodie? What kind of deflection did you see in the modified lid under pressure in your CFD model?

 

[micahpearlman]

It's "probably" ok but should definitely be tuned when the Pcv's are available... It's up to you if you think it's not surging and you can "deal" with it then run it. Obviously there's a huge difference and gains to be had with tuning.

I did the airbox lid mod and I am guessing that it will help my race setup. Last race, with the stock setup, it felt lacking up top and not wanting to rev out when the temps went above 75F. My assumption is that its running rich up top and looking at the A/F for Chads dyno runs seems to confirm that. I'm too cheap todo a dyno run with my current setup -- waiting to get the PCV and just get that dialed -- so it will be old school feel. Realize, racing this bike on this particular track (Thunderhill) I'm either no throttle or WFO and I doubt I ever get below 7K RPM. Would not do this mod for a street bike without a PCV.

 

[rcamp]

Thanks for the replies guys.
Since I'm not racing the bike and see a good bit of time below 7K, I think I'll put it back stock till a PCV is available just to be safe.

 

[Formula390]

I did the airbox lid mod and I am guessing that it will help my race setup. Last race, with the stock setup, it felt lacking up top and not wanting to rev out when the temps went above 75F. My assumption is that its running rich up top and looking at the A/F for Chads dyno runs seems to confirm that. I'm too cheap todo a dyno run with my current setup -- waiting to get the PCV and just get that dialed -- so it will be old school feel. Realize, racing this bike on this particular track (Thunderhill) I'm either no throttle or WFO and I doubt I ever get below 7K RPM. Would not do this mod for a street bike without a PCV.

Not sure why you have having to guess/assume you are running rich. You've got the ODB2 readout from the O2 Sensor... you should be able to see your A/F mixture..

Anyway, yeah... I think most of us are chomping at the bit waiting on mid-July when Chad / CJWell gets the PCV ready to ship...

Is it July YET?!?!!!!

 

[micahpearlman]

Not sure why you have having to guess/assume you are running rich. You've got the ODB2 readout from the O2 Sensor... you should be able to see your A/F mixture..

Anyway, yeah... I think most of us are chomping at the bit waiting on mid-July when Chad / CJWell gets the PCV ready to ship...

Is it July YET?!?!!!!

I did not run the OBD last race. I will this race (June 20-21) and log the O2 sensor and TPS ( Still cannot get RPM out of the OBD :-/ ). I have slight doubts about completely trusting the narrow band O2 sensor, but I guess it is better then nothing, ie. "seat of the pants" tuning.

 

[reenmachine]

I get it, when you did the CFD on the modified lid flow vs your lid what percent differences did you see in the velocities of the fluid (air) just before the throttle bodie? What kind of deflection did you see in the modified lid under pressure in your CFD model?

C'mon, you don't need to be that way. He gave a perfectly good explanation and it was in their thread about their business after all.

Besides, CFD wouldn't tell you anything about deflections of physical parts under load. That would be FEA

 

[Fasteddy]

I'll take empirical data over model any day... ;^)