I don't know if Josh still has the spare head taking up space in his garage or not. He might be willing to take some pics for me....

 

Great,
thank you Marko!, indeed it doesn't seem such exotic a work... hmmm, really interesting!

 

Read this also!!

Boundary layer - Wikipedia, the free encyclopedia

MArko!!

 

I am trying like hell to absorb and make since of this stuff but my wife has out of the blue started doing and saying distracting and annoying things so I guess I will have to try later... I remember discussing this in class but it was many years and women ago.

 

Right, too bad I almost forgot everything of my engineering studies... time to refresh "a bit"...

Thank you!

 

I feel stupid now! Remember I'm a "building" engineer not a rocket scientist LOL

 

I had to drop my physics course because of terms and formulas like those on boundary layer.... That was 40 years ago and it is even more out of grasp for me now.... I am feeling better knowing that someone else is baffled also.... I do remember it being mentioned that intake and exhaust ports that were highly polished wouldn't flow as well as ones with a course finish and it somehow related to the boundary layer thingamajig chingadera whatchamacallit.

 

Something along the lines of a slightly coarse finish is beneficial in that it creates a boundary layer of low pressure over which the intake/exhaust gases can flow. And I'm sure that is true, but I see the rough textures inherent in most of the Fits inner workings being a cost cutting measure, not a study in boundary layer physics. Now the inside of the Lexus LFA or the NSX-R, those probably have boundary layers all up the whazoo! LOL

 

I tried to find a used plenum online and left my email address and phone number with a place called Quality Auto Parts in Chicago... These crazy people have called me 3 times telling me the part is $500.00 new and they can let me have one for no less than $ 182.00..... I gave them the part number, the retail and what I could get it for for online new for and those fools would not let up and even emailed me twice with the same deal with a 30 day money back guaranty saying the online Honda dealership was selling inferior copies of real parts....Man I was cussing and yelling at them and they just wouldn't stop.... It was hilariously insane even saying the dealer would charge me over $100.00 for shipping and handling.

 

WOW just WOW Thats nuts! Did you tell them you were born in the dark, but it wasn't last night? Bernardi Honda was where I looked when I thought of buying a new one, and I think they wanted 80 bux. Of course I'm sure thats naked with no sensors or gaskets and such, but still.....

 

I really wish you could have been listening in on the conversation... I was thinking , wow the gypsies have found the internet..... I suppose someone that was less informed than I am might fall for there BS but hopefully not.

 

...i'm definitely gonna make my upper plenum sightly rough on the inside when i'm gonna adjust my valves... Matching the opening of the throttle body and Upper plenum would be kool also if it's not allready done!!

Marko!!

 

A sand blaster would be capable of giving a uniform finish if you are careful to not remove too much material.... I have one that is ready to go but it has been a long time since I used it. It would be also be possible use on the bell shaped openings to the runners and maybe a little beyond.... You would have to get after everything with a lot of soap, water and a brush to make sure there was no sand that could be embedded and work loose.

 

Well I performed the PCM/idle learn procedure this evening while I was installing my HIDs. We'll see how it turns out, although on my test drive it was still taching up whenever you punch in the clutch. I'll give it few hundred miles to sort itself out and then we'll see.

 

i want to mod my intake too, but im scared to make a mistake or something bad. :\

 

I had the procedure done some miles ago and I seem car is smoother and a tiny bit less thirsty. But "she" keeps sporting a horribly high idle (about 1.5K) when powered on and for some tenths seconds later, even if with quite warm outside temperature which seriously impairs fuel economy...

 

Hey jazzista, have you gotten into the intake plenum or did your idle increase start occurring from the intake box being modified?? What is causing this to happen in your opinion?

 

Mine seems to be settling back to a normal idle more quickly than before i did the relearn. But it still isn't like before i messed with the intake mani. And though the car runs perfectly, the check engine light pops on roughly once every three or four days now. This happens after the idle seems to experience a spike, like I'll be sitting at a light with the clutch in the RPM starts at 1000 spikes to 1500 or 1750 then settles back to 1000 for no reason. The the CEL comes on. The car has never run rough, stalled, hesitated, missed, backfired, or lost any fuel mileage, its just the damned idle won't straighten out! I figure it is some kind of hiccup in the ECU due to the change in air volume at idle. I see it almost as the computer putting a feeler out to figure whats going on with the motor. I no longer think it has anything to due with a leak in my plenum, those have all been sealed. And she passes the WD40 test with flying colors. I may shell out some dough and haul her off to a dyno day to see what the hell is going on in there....

 

I can't see why the idle would be normal and then go sky high for no apparent reasons as it's controlled by Throttle opening by the PCM... What code are being thrown!! I've had one throttle body go bad on my Fit a year ago, it would idle fine a while and then go at 3 - 4k RPM for no reasons!! If you unplugged the Throttle Body i think there is a procedure that is needed to be done but i don't know if it's the idle relearn procedure or some other one... Try to call Honda!!

Marko!!

 

I didn't - yet - messed with anything, so I don't know...