blackozvet

I measured it and it is squashed down 5mm (or 3/16") so it is hardly ovaled at all, move the join to clear the tight spot will avoid the hood brace coming down on the join but will still push down on the silicone hose instead when the hood is closed so maybe nothing to be gained there,
I have read a lot of stuff on this and other forums re using oiled filters on MAF engines and people in the know say No - dont use them, the oil contaminates the screens and the wires and upsets the MAF, you will see some counter arguments blaming "over oiling" but why take the risk ?
The cradle is made from an old road sign with sides rivetted on, and yes the hood will hold it down tight !
I just measured the stock air box, it has a thin flat area that squeezes into a 2" tube (at its narrowest point) before running into the MAF, so that would explain the 500 cfm flow. Even if you increase your flow with better filter and cut lid it still has to squeeze thru a 2" hole.

slickfx3

thanks for breaking it down, since the joiner is being compressed by the hood, wouldn't the "stiffness" chafe the hood with the hose clamps etc.?

I have had the existing hose clamps in the wrong spots and the underside of my hood get deep wear marks, so moving the joiner forward cushion the hood and allow it to bounce on the tube like a little shock absorber?

so if i did this will the hood still hold the tube on tight?
somebody mention the hose will collapse when you accelerate, did you ever see that happen, reving the car?

that's an easy fix... i'm using a budget $4.70 home depot home exhaust pipe 3 inches, for the joiners, i could shove one up inside the silicone, albeit a little tight

slickfx3

after seeing the turbo setup on tequilaboy and using your clearance measurements..

the outside dia of the silicone is about 3 5/16 or a tad over, so a 3" dia pipe like this..

http://www.ebay.com/itm/1-Aluminum-S...sories&vxp=mtr

would fit, so a short silicone at the MAF and the tube over the radiator and directly to the cut elbow might do the trick, or to save 20 bucks I could use the exhaust pipe and tape the seam...

blackozvet

show us a photo when your done !

I spoke to an engine guru friend about cfm requirements, he said it is a mathematical formula, cubic capacity (in cylinder measurement) x number of intake cylinders per revolution x volumetric effeciency x max rpm of engine (i have to admit i have the figures in front of me and still cant really understand it ! )
but anyway it works out to a 350 cubic inch engine needs about 557 cfm to rev to 5500 rpm, a 383 cubic inch engine requires about 609 cfm to rev to 5500 rpm.

TPI airbox (stock) 500 cfm
Bosch MAF (stock) 518 cfm
Bosch MAF (de-screened) 658 cfm
Stock 2 x 48mm throttle body 783 cfm

So if you have a stock or mild 350 the stock airbox and MAF will be ok, if its modified (and can rev to 5500) or you have a built 383 (and it can rev to 5500) you will need to modify the air intake.

Midnight 85

I still have reservations about removing the maf screens so at least at first I will leave mine in. Since I don't race the car it seems to be a good idea to leave them alone. I hope to get all my parts this week so I may have it all together later this week. However, the airbox is not my only glitch right now so results may be delayed until I get other engine problems taken care of.

slickfx3

my car revved pass 6300, with my other cam... all with the stock throttle body and airfilter..., but i don't know if it was optimal.

GREGGPENN

I think your conclusion is reasonable...though I looked at CFM requirements myself. The more I read/studied, the more confused I got. The basic point of "contention" is how much instantaneous flow you can get thru intake/heads. With constantly improvements in head flow, I found the numbers to be higher than what you posted above. I think a 350 can exceed 600cfm while 383's can get up into the 700cfm range.

I don't think the engine is really getting more air...it just ends up supplying "air needs" in a shorter period of time (percent of revolution) than calculations imply. The reason would be cam/valve opening events.

Just BOB

Squashing a circle into an oval does reduce cross sectional area. A 3 inch diameter circle has a cross section of 7.1 sq in. To demonstrate the extreme case (for clarity) if you squash a 3 inch diameter circle (circumference 9.4 inches) until it is 1 inch high, in round numbers you have a rectangle that is 1 inch high and 3.7 inches long. The cross sectional area of the resulting rectangle is 3.7 sq in, give or take.

GREGGPENN

Well stated! And, good point (that wasn't intuitive).

slickfx3

can't find a filter to fit in that spot for the life of me

slickfx3

my guess is if it's too extreme it could alter flow characteristics, for the worse, but in this case it's really nothing

i took a look at the screen... so that is restrictive huh?

Midnight 85

Check out K&N part number RU-1500. It's the one I am going to use whenever I get around to installing it. I'm about 99.9% sure it will fit right down in there. The inlet though is only 2.75 so I am going to use an exhaust reducer to make the thing fit. I never did find a filter of these dimensions with a 3" inlet. If you don't like K&N then I can't make any other suggestions because I didn't have any better luck searching than you did.

blackozvet

that is correct, the big variable in that equation is 'volumetric efficiency' - as it was explained to me, the results i gave are with a 98% volumetric efficiency, that would be achievable with a well selected cam and head combination, apparantly some race engines exceed 100 %
a stock or mildly modified engine would be around high 80%, climbing into the 90% zone with better mods,
so the results slide up and down with volumetric efficiency, cubic capacity and rpm required. The lower rpm levels of the TPI engine is actually a bonus to us due to the lower cfm requirements.

slickfx3

http://www.ebay.com/itm/200740099810...84.m1438.l2649

http://www.ebay.com/itm/330709721682...84.m1438.l2649

blackozvete gave me some sizes his is 5.5 at the base mine is 6" this is the only difference, i tried a 3" (height) and the 6" dia raised the unit too close to the hood as well, must return everything.

GREGGPENN

Because of the "pinch" going over the radiator, I find myself thinking about a dual "Y" intake with two pickups...merging into one before the MAF.

Look at the Camaro/Firebird TPI air box for an idea. But, they must hook into the hood scoop(s). Modifying one of those...or even creating a similar concept seems worth considering -- for modified motors.

I'm even wondering if a simple Y-pipe would work -- with two hoses coming off the front of it????

slickfx3

http://www.unifilter.com/clamp_on.html

slickfx3

i search the camaro set up, it's bigger in the area where we have the squeeze, corvette hood-line i suppose..

do your thing, you know a thing or two about meandering pipes...

I bought the uni filter,best price after shipping

http://www.ebay.com/itm/Universal-76...item45fcdd2089


i had those on my bike and they don't need oil for the street, dirt bikes different story, and they contort, since it's foam and a spring. waiting for ups yet again.

I even thought about an inter-cooler since my car loves the cold

slickfx3

total cost $57.73
had to return 2 filters and a hose

GREGGPENN

Don't you have software/ALDL to read the code?

Does it run any different?

slickfx3

I hate hooking up autoprom, yes my wide-band reads leaner, still within specs... runs harder, hits faster....

i forgot the po moved the stupid intake manifold air temp sensor to the air cleaner housing,

cold ambient = full spark advance, hot above the manifold= retard... all great but my spark table hase been optimized to negate this obsolete input.


I plugged the loose sensor onto the loose wiring and hope the next time i drive this goes away.

I don't know what happened to my stock sensor under the plenum, the last person to work on it was cusinartvette, I should ask him, it's no big deal, prolly he forgot or I forgot and there is a pipe plug in that spot....the sensor is long gone....

hmmm what to do???

btw, the UNI motorcycle filter is great, the space in there is smaller than it looks, i couldn't find my filter oil, so I poured a little power steering fluid on my gloves and wiped the filter, sure is easier than oiling a cotton mesh/kn clone.... and the oil gives me a little peace of mine, but looking through the filter I see no daylight, this puppy is dense, but it flows... now that's technology, it's made for the dirt and I could run it dry.... it's really dry now anyhow, didn't use enuff oil to make a difference.


it's a few pounds lighter to boot and not to mention a damn good-looking rig