Breathe Easier

CB4ME_imp

Road warrior
Thread starter
Check out the latest accessories from Samurider.

The first one, an air intake funnel, looks like a big intake port that fits into a hole in the side of the air cleaner box. It also seems like you are looking at a filter from the inside.

Apparently it needs a corresponding high flow silencer to work. Staintune anyone?

The second is a set of 4 air funnels that apparently go between the "intake manifold" ?? and the throttle bodies. These are 10mm wider than stock and are the same diameter as the throttle bodies.

So would it be something like this: 1)air intake funnel, 2)stock or K&N filter, 3) the 4 air funnels into the throttle bodies, then out via TSR headers and a hi-flow slip-on like the Staintune? I'm surely no expert and have never even seen my air filter.

Will these accessories, combined with an aftermarket full exhaust, turn the mild mannered CB into a beast?

88138da3eda08c35c56ea969f524f96c.jpg


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Wow, if this dyno chart is to be believed, combining the intake funnel kit, the air funnel kit, a pipe and a power commander will add 20 horsepower! That's how you make this motor breath.
I have a performance exhaust already (Power Box Two-Tail) so I need to blow a grand to get the other stuff (wrong time of year!).
2 0 extra hp on top will be a real kick in the pants and worth every dime.

[url=http://imageshack.us/photo/my-images/24/ldoh.jpg/]
 
If they gave us the fuel map that went with that dyno run I might think about it.

also I don't think its a lot of fun getting that front air box out of the way to get access for the injector "funnels".
 
Thanks for an interesting post. I've always believed the CB engine is capable of 100 hp with intake, fueling, and exhaust mods, based on experience with similar engines from the Kawi Z bikes. The trick is to get there without ruining either the asthetics of the bike or its rideability. Not voiding the warranty might be a consideration as well.

A free-flow exhaust, PCV, and K&N with a good dyno tune alone should get really close to 100 hp.
 
I don't think a slip-on will get you there. You need a full exhaust to get the full benefit. That Cat has to go to let the engine breath.
 
The Spaceman_imp said:
Thanks for an interesting post. I've always believed the CB engine is capable of 100 hp with intake, fueling, and exhaust mods, based on experience with similar engines from the Kawi Z bikes. The trick is to get there without ruining either the asthetics of the bike or its rideability. Not voiding the warranty might be a consideration as well.

A free-flow exhaust, PCV, and K&N with a good dyno tune alone should get really close to 100 hp.
At the wheel, or net? If the former, I'm gonna call BS.

That dyno chart shows a mostly 2-3hp gain under 5.5k rpm, which is where most people spend their time meaning, you wouldn't really notice anything unless you go full-throttle a lot. For those times that I do, the extra breathing would be helpful, but enough for the cost, IMO.
 
The dyno chart I've seen shows 88 hp at the rear wheel stock. The same chart shows 6-8 more hp with just the 2 Bros exhaust, depending on the RPM. So you're only 5 or so hp away from 100 hp with no other mods. If you can't get 15% more hp from an EPA-strangled 1100cc engine, I'd be pretty surprised. We could do that with a Stage II kit on a primitive HD EVO for crissakes.

I've never been all that worried about the CB's power, but I'm willing to use it as a test mule. I'll need about $1k to get started, so lets start donations to the experimental fund right away!
 
The Spaceman_imp said:
The dyno chart I've seen shows 88 hp at the rear wheel stock. The same chart shows 6-8 more hp with just the 2 Bros exhaust, depending on the RPM. So you're only 5 or so hp away from 100 hp with no other mods. If you can't get 15% more hp from an EPA-strangled 1100cc engine, I'd be pretty surprised. We could do that with a Stage II kit on a primitive HD EVO for crissakes.

I've never been all that worried about the CB's power, but I'm willing to use it as a test mule. I'll need about $1k to get started, so lets start donations to the experimental fund right away!
If that's true, then yes, I agree. However, the bike is rated at 88hp net, and the dyno chart in this thread shows ~76hp to the rear tire. Working with that data, you're looking at 24hp to get to 100, which is more than a 30% increase in power. That's unlikely with just intake and exhaust mods, even with a proper tune, IMO. Would certainly love to be proven wrong, however.
 
The chart I saw can be found by searching "MASSIVE HORSEPOWER GAINS WITH TWO BROTHERS" etc. etc. Be sure to use ALL CAPS.

Since most dyno runs I've seen are done with the rear wheel on a drum, I've always assumed they're indicating rear wheel hp. Maybe that's wrong.
 
Most of the dyno charts I've seen for the stock bike have shown RWHP around 83-84 hp. Factory measurements are usually taken at the crank and you can expect a the loss of a few horses in the drive line.

Given that, low to mid 80s at the rear wheel are about what I would have expected to see with a factory claim of 88 at the crank.

The other thing that I've noticed while looking at the various charts that have been posted on the 'net is that opening up the exhaust and adding a PC shows pretty good gains across the powerband, with about 10 hp total at the top.
 
The K 'n N filter arrived, and I'm disappointed. Its been a couple years since I had one of these; the last one I had was in the S&S carb teardrop filter on my Shovelhead. I remember that being a pretty heavy-duty unit.

This new one seems cheezy, especially compared to the OEM unit. I'm wondering if these guys have pulled a Briggs and Stratton and turned a once great product into Chinese junk (pun intended).

The Honda part has gasket on both ends, it has a mesh screen surrounding the paper, and when you install it, you can feel it seating on both ends to make a seal. The new one doesn't have any of that.

Oh, one more thing: does anybody know if these ship ready to use, or do I need a kit? I reckon its worth seeing how it performs.
 
Thread starter
The Spaceman_imp said:
The K 'n N filter arrived, and I'm disappointed. Its been a couple years since I had one of these; the last one I had was in the S&S carb teardrop filter on my Shovelhead. I remember that being a pretty heavy-duty unit.

This new one seems cheezy, especially compared to the OEM unit. I'm wondering if these guys have pulled a Briggs and Stratton and turned a once great product into Chinese junk (pun intended).

The Honda part has gasket on both ends, it has a mesh screen surrounding the paper, and when you install it, you can feel it seating on both ends to make a seal. The new one doesn't have any of that.

Oh, one more thing: does anybody know if these ship ready to use, or do I need a kit? I reckon its worth seeing how it performs.
Well that's a bummer. I'm expecting one before Thanksgiving. Let us know how it performs.
 
736cc_imp said:
Wow, if this dyno chart is to be believed, combining the intake funnel kit, the air funnel kit, a pipe and a power commander will add 20 horsepower! That's how you make this motor breath.
I have a performance exhaust already (Power Box Two-Tail) so I need to blow a grand to get the other stuff (wrong time of year!).
2 0 extra hp on top will be a real kick in the pants and worth every dime.

[url=http://imageshack.us/photo/my-images/24/ldoh.jpg/]

Isn't a proper Dyno curve supposed to have the h.p. line and
torque line intersect at 5250 rpm.Meaning the bike has to at least
be revved in each gear to 5250 RPM then higher.
 
_imp said:
736cc_imp said:
Wow, if this dyno chart is to be believed, combining the intake funnel kit, the air funnel kit, a pipe and a power commander will add 20 horsepower! That's how you make this motor breath.
I have a performance exhaust already (Power Box Two-Tail) so I need to blow a grand to get the other stuff (wrong time of year!).
2 0 extra hp on top will be a real kick in the pants and worth every dime.

[url=http://imageshack.us/photo/my-images/24/ldoh.jpg/]

Isn't a proper Dyno curve supposed to have the h.p. line and
torque line intersect at 5250 rpm.Meaning the bike has to at least
be revved in each gear to 5250 RPM then higher.

Depends on how you want want to plot it. If you want to compare just hp, as in the chart above, you can leave out the torque plot altogether. It's usually done to reduce clutter.
 
_imp said:
736cc_imp said:
Wow, if this dyno chart is to be believed, combining the intake funnel kit, the air funnel kit, a pipe and a power commander will add 20 horsepower! That's how you make this motor breath.
I have a performance exhaust already (Power Box Two-Tail) so I need to blow a grand to get the other stuff (wrong time of year!).
2 0 extra hp on top will be a real kick in the pants and worth every dime.

[url=http://imageshack.us/photo/my-images/24/ldoh.jpg/]

Isn't a proper Dyno curve supposed to have the h.p. line and
torque line intersect at 5250 rpm.Meaning the bike has to at least
be revved in each gear to 5250 RPM then higher.

I think you can get 100 hp out of this engine without even messing with the intake system. But you most surely could if you added that to the mix.

And yes, the hp and torque lines always intersect at the same place, because the formula for hp is a function of torque and rpm. There's a really good write up on wiki about it.
 
For every engine. It's all about how horsepower is calculated. An engine produces torque (rotational energy) and horsepower is calculated using that force and the speed and which the engine is spinning (RPM). So because of that horsepower and torque ALWAYS intersect at 5250 RPM for ANY engine. Anyone that says otherwise doesn't understand how horsepower is actually calculated.
 
Kazowee!

I went out west into "the countryside" today on some roads that cross the sugar fields between the city and Lake Okeechobee. Lots of wide open stretches with few rogues coppairs. My mission: test the performance on the K 'n N air filter combined with the Two Bros exhaust.

There's a modest but noticable bump on the lower RPM range. But holy crap, from 4,500 and up, its frikin amazing! I was rolling along at 70 and whacked the throttle and the bike lunged forward. The acceleration was so hard it literally pushed me back on the saddle and stretched my arms.

I realize this isn't a 140 hp Tuono, but damn thassa lotta meatballs for a filter and pipe swap. I can't wait to get a bigger header pipe kit and a PCV. If that engine can't dyno 100 hp with that setup, I will be damned surprised.
 
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