Never even thought of that! I will try it tomorrow, as I'm still thinking its bleeding air a bit around the TB neck. But I was so happy it ran properly I didn't give it too much thought. That and the torqued off mani bolt was still freshly fixed so i wasn't in a huge hurry to go looking for trouble LOL Hey Cat! Every bar and restaraunt within twenty miles of Martinsburg is packed to the gills when the Mountaineers are playing, nevermind in the final four!

 

Double checked with WD40 today and then took it for another thrashing (this time up to highway speeds, and a little higher LOL) NO LEAKS! Wooot!! The louder aspect of the intake I can now quantify. The sound I'm hearing is the engine making its "all business" intake growl sooner due to the decrease in flow restriction and the fact that the upper manifold now also acts as an intake resonator. So my L15 now sounds an awful lot like a B series inhaling through a short ram. Too bad about the fact that it doesn't make Bseries power LOL

 

I just love the hell out of crazy people.... I am starting to wonder about how this would work and sound on a supercharged Fit being that there is an intake tube to the S/C and the boost tube crosses over and back to the throttle body...

 

I would think that as long as your manifold was strongly reassembled it shouldn't pose any problems. If I were to do this all over I would get a good quality plastic welder and reassemble the manifold that way, instead of vast quantities of glue. And I wouldn't grind through the roof of the manifold either LOL. Bernardi Honda sells just the upper manifold for around 90 bucks brand new (nudge nudge) I am far from done with this though, as happy as I am that it works I plan on messing with it until i have some useful gains to show for my efforts. My commute includes a mountain pass that has traditionally stymied the Fit without a fourth gear downshift or a " start the climb at 70 to finsh at 65ish" section. Today she climbed it at 70 no sweat and was actually gaining a few MPH at the top. Same routine on the trip home, with intake temps in the 125 range (88 degree ambient) I may try a TB coolant bypass next, just for the summer months... Oh and Tex, the words "shock and awe" spring to mind when I think of how a SC Fit would sound with this intake on it!

 

More good news! I figured I might as well clean and oil the filter on my A-spec CAI since i have done all this work on the manifold. Well guess what, that filter ain't no K&N thats for sure! The mesh was rusted almost clean away and filter media had eroded away to nearly paper thin. And the filter had a hole burned in it where it was making contact with the tranny! Sooooo I went and got a REAL K&N filter and installed it. Wow, what a difference. The throttle response that was soggy before is suddenly more crisp (for a long ass CAI anyway) and the mid RPM power is much more noticeable than before. Also the intake noise has been attenuated somewhat by the fact that the filter no longer has a big ol hole in one side. Did I mention that I finally popped a fuel light on the way home this afternoon (with the AC on) at 419 miles? It would appear that messing with the OE intake was worth it after all LOL

 

I can tell that this is going to be a much copied modification for people that prefer to hot rod rather than pay extra for shiny stuff that may or may not work as well.... I will eventually be copying this winner.

 

My problem now is that I'm looking at my CAI and trying to figure out a better way to get cool air into my engine. Wonder of wonders SHG Mike was involved in a ram air box that used a Rogue Fit-like cowl scoop as an entry point. And here it seems I have an OE airbox that isn't doing anything in my basement! To the bat-cave!!!

 

I haven't found a satisfactory way to duct air into the intake but have gotten very positive results in lowering the under the hood temperature with hood louvers. RunCool Hood Louvers/Hood Vents For Your Vehicle - Cool Your Engine - RaceAce These have also lowered the intake temperatures enough that I have a noticeable power increase.

 

I attacked my poor defenseless OE airbox with my grinder last night and a more pitiful sight i can't imagine. As soon as I charge up my trusty camera I'll take some pics of it. I'm still in the prototype/design stage right now, but I'm thinking of a larger than OE box with a snorkle/tube connected to the cowl scoop. I have fiberglass cloth and resin at the ready, as soon as I figure out and mock up how to shape the bottom of the new box. And for the one person who is still reading this thread, I chucked a CEL this afternoon after five days and 675 miles. Turns out it was the new K&N I installed a couple of days ago NOT the intake! Go figure.....
PIXOS

Shot with KODAK C360 ZOOM DIGITAL CAMERA at 2010-04-09

Shot with KODAK C360 ZOOM DIGITAL CAMERA at 2010-04-09

Shot with KODAK C360 ZOOM DIGITAL CAMERA at 2010-04-09

Shot with KODAK C360 ZOOM DIGITAL CAMERA at 2010-04-09

 

Was there a code thrown? Might be running lean.... You never mentioned what grade of fuel you are using.

 

It threw a P0507 Idle control RPM higher than expected. Since I changed out the mani when you clutch in at a traffic light idle RPM is slow to drop below 1000-850 to a normal static idle. It takes maybe two to three seconds to return to a normal 500 RPM idle. It hasn't gotten worse or affected driveability so I wasn't really paying it any mind. I suppose maybe now i should... I roll 87 Octane baby! Nothing but the cheap swill for my pride and joy! LOL

 

Search the "Idle relearn procedure" here on fitfreak

 

I'm thinking of the very same approach, only downside it is immediately detectable when looking into the engine bay...

Did you cut the whole lower part of the airbox? Aren't you worried of sucking hot air?

Thanks for sharing.

Stefano

 

Yes, I did cut off the whole lower airbox, along with the entire side closest to the engine, which is a big ol resonator. The photos are only step one of many! The snorkle and cowl scoop connection have yet to be built. I will put up more pics of the Franken-box as I make progress, just be aware that it may take awhile. Tex, i haven't got around to the idle relearn just yet. The damned thing is running so strong I really don't want to mess success!

 

Hi there! How's the Franken-box going on?

Is there much more noise?

TIA

 

No progress on the new box just yet, sorry. I'm thinking that it will be loud as hell, especially drawing air from the base of the windshield. That and the fact that half of the OE airbox served no purpose other than to quiet intake roar! The removal of the flow equalizer in the intake manifold gives the Fit an engine note very similar to a hopped up B-series, quiet at part throttle but has a valkyrie-like war cry when you stomp it. I found a newer K&N intake called the Cyclone on their website that may work for my purposes also. I'm just not sure if I should give K&N another shot given how terrible the short ram was....

 

Another minor update. The P0507 has struck again, seems like every three days or 450 miles (whichever comes first LOL) It pops on again. I reset with the SGII but it won't stay gone. The erratic idle has subsided to a simply annoying rev hang when you clutch in at a dead stop. Whenever I clutch in the RPM rise to 1500 and hang there for about three seconds before settling in at 1000. Other than that the car runs like a raped ape! Gas mileage has improved to 40-42 consistently from my usual 39-40, this is with four tanks on the modded manifold now. I'm gonna bite the bullet and do a complete idle learn procedure this weekend, so I can swap back to stock in case the ECU goes China Syndrome on me LOL

 

Hmm, going to exchange my bog standard filter with a panel one (pipercross for who cares), so having not any Honda device to reset ECU, I would be interested to apply the very same procedure you're doing!
TIA

 

You may only need to clean the IAT sensor the fix the idle problem..... Check the ohms reading of the sensor, they read between 40 and 80 ohms. I guess that your scangauge would show if it wasn't working if the temperature readings were off.

 

Hummm... seems like i'm gonna check the upper plenum when i'm gonna adjust my valves!! If you really do more miles with your fuel, pumping losses were reduced... Maybe it's leaner a little...

Marko!!