Air box mod save $$$

[TINK_imp]

Good call ferret.

So, the point of this exercise is to leave the air cleaner cover (snorkel?) off? Is that what we're doing here?

[The Spaceman_imp]

6 http://www.samurider.com/?p=1803

This the fancy-schmancy part cip57 replaced. He's created his own high-flow air intake system using only the materials available to the crew on board Apollo 13.

LMAO what the hell are those shoe horns

LMAO what the hell are those shoe horns
Oops, I meant to post a link to the TSR Air Funnel! I think that error created confusion about cip57's obviously ingenious mod, and perhaps some of the ensuing rhubarb.

"My bad," as the youngsters say.

[Greg_imp]

For those considering modifying their air intake:

I did dynometer runs comparing various intake and exhaust configurations.
1) Stock everything
2) Unrestricted exhaust (Yoshimura full) with TSR air intake
3) Unrestricted exhaust with stock air intake (stock air filter)

While the air-fuel ratios changed, the HP curves for each of these configurations was exactly the same.

I am unwilling to compromise intake air filtration, but before you conclude that the stock air filter is holding the performance back, another member ran butt dynos comparing unrestricted air intake (no snorkel or air filter) to stock and could not detect a difference.

[DAC]

Uh-oh. Someone resurrected the dreaded air box mod thread!

Before I get banned, please let me express my undying love for all on this forum, including our very industrious moderators/admins.

[Ridem32_imp]

DAC: I say this with tears running down my face! Will miss you ! I hope the kick in the ole bootie don't hurt to bad as you fly out the forum door !! Lol lol.

[Greg_imp]

Ha, DAC.

I got spanked for my part in this kerfuffle but it occurred to me that even though this is an old thread, new members are coming in and reading what is old stuff for us.

I did the controlled testing after this dust-up and think my results are repeatable. After all we're talking real time and dollars and people should be informed.

If the mods are being done for aesthetic reasons or simply because it's there, then that's fine, but facts is facts.

(Don't taze me dude!)

[CB4ME_imp]

Ha, DAC.

I got spanked for my part in this kerfuffle but it occurred to me that even though this is an old thread, new members are coming in and reading what is old stuff for us.

I did the controlled testing after this dust-up and think my results are repeatable. After all we're talking real time and dollars and people should be informed.

If the mods are being done for aesthetic reasons or simply because it's there, then that's fine, but facts is facts.

(Don't taze me dude!)

Air box mods are very popular with the Bonneville crowd. Often referred to desnorkling the air box, this mod, combined with a less restrictive exhaust supposedly lets the engine breathe easier and produce more power.

Greg did dyno testing of various intake and exhaust configurations. I find the results interesting and worthy of follow-up. But the results seem to contradict the claims of aftermarket manufacturers and the experience of other riders.

I haven't done any dyno testing and can only go by seat-of-the-pants "testing". My first mod was a Staintune. I did not notice any increase in power. When I opened the intake with a TSR air funnel, the bike seemed a lot more lively.

Several other members have done intake and exhaust mods and seen significant HP gains, verified by dyno testing.

Greg, I’m not disputing your results, but I remain unconvinced that opened up air boxes and CAT free exhausts will only affect A/F ratios while HP numbers remain unchanged.

Now I've done it

[rboe]

You should see a good ten percent gain, but that is only if you use pre-filtered spring air sold under the Honda brand. Don t try it with recycled air, oxygen molecules can only be reused just so many times before they get tired and simply don't perform as expected.

[Ridem32_imp]

All I can say is this ! I got a friend with a gsxr1000 he put a new exhaust on it sounded great! But his drag strip times dropped. Put his stock pipe back on and his drag strip times went back up! Dyno don't lie. Lots of guys buy pipes, K&N filters thinking more power more speed when most bikes lose performance FACT

[Greg_imp]

In spite of my own numbers, something changed when I modified the exhaust. Throttle response seemed more lively, as I've said elsewhere, I felt less vibration, and of course it sounded much better. The aesthetic experience of riding was enhanced.

Since my ECU / ECM is stock, my bike is limited in rear wheel speed and rpms. My rough calculation is that at 7,500 rpm my motor is sucking in about 140 cubic feet of air per minute, which is in the range of a medium sized shop vac. Obviously, the intake plumbing creates some resistance which results in some reduction of air mass in the air box. Air mass sensing is the biggest factor in EFI, since it has to accommodate quite a large range of atmospheric pressures. Ferret was recently at 14,000 feet and it would be interesting to hear if he noticed any difference in performance given since at that altitude atmospheric pressure is about 15% of what it is at sea level.

My point is that adjusting for air mass is the main thing the ECM does, so small changes in intake resistance are not going to make any difference in performance, at least below 7,500 rpms. However, if the rpm limiters are removed, a much higher air flow is possible and then intake air resistance might be a factor.

I don't know how to explain the feeling of increased liveliness without a measured change in the hp curve, but again, in my experience, this resulted from exhaust changes, not air intake.

I believe CIP57 reported faster speed trials with the stock air intake than with "opened up" intake. I've read in other places that there's some serious mojo put into air box design, what with resonance and all that but that is all way above me.

edit: with ECM limiters in place, peak dyno hp results vary depending on what gear is used. In 5th gear, rear wheel speed limits hp below 80, in 4th gear you might see 80. I got 85 by running in 3rd gear and it appears that rpm limiters are what sets the peak reading. YMMV.

edit: edit: In 1st, 2nd, 3rd rpm limits dyno peak hp. In 4th and 5th the stock rear wheel speed limit caps the peak hp.