RotaMan99

I was looking at the Prelude intakes and all the ones I find are 3" in diameter which is small for almost 400CFM. According to a graph I have been using for airflow restriction, that would cause .32in H20 of restriction per foot. How restricted is this really?

From doing the math, the TB bores equal out ot be 3.076" ID without the shafts. With the shaft it would be around 2.616" ID. 2.75" is around .40in H20 of restriction per foot.

The intake tubing im going with is 3.25 ID, 3.50 OD which is the same ID as the elbow. Which would have about .18in H20 per foot

Once I can eliminate the AFM the largest restriction will be eliminated. Im just wondering how small is to small.

phoenix7

well, smaller than stock is too small. If you go with the same diameter as the elbow you should be ok but this is now beyond my scope of knowledge ( this is the reason I have not replaced my NA intake with the 3" pipes I used for My turbo TID.)

RotaMan99

I know smaller the stock is to small. That last pic looks like 3" OD piping which would be around 2 7/8" or smaller ID. I wouldn't go smaller then 3.25" ID.

phoenix7

are you going to make a CAI or just make a replacement pipe?

RotaMan99

Im making a CAI. Moving te AFM closer to the TB and putting the filter behind the front bumper. It would be better to have the filter closer to the TB. Unfortunatly I can't do that unless I found a way to seal the filter some how and have it ducted to outside.

I looked at that last pic and it actually looks like 2.5" OD piping since the output side of the AFM is a little less then 3" OD.

86inthe530

heres mine

cozmosland

iTrader: (1)

any more?
i'd like to see some custom shrowds

kanuk93gt

dat1kid

iTrader: (4)

do carb intakes count?

magus2222

iTrader: (22)

here ya go

peace

mali_FC

here's mine.....

phoenix7

pic?^^^

mali_FC

^_^......

phoenix7

cool. Will the AFM function properly if it's not mounted flat? I know this is not an issue with S5's but I thought S4's were more sensitive to these changes.

RotaMan99

This thread has a lot of examples of how NOT to build an intake. Placing a cone filter in the engine bay with no shielding will make you LOOSE power. Do it right or keep the stock intake system.

I read some where that every 10 degrees of IAT is about 10hp loose?

phoenix7

sounds right. If you make a nice box you will see the hp increase. Or you can route the pipes to a fresh air area like the guy who JUST posted (mali FC).

My question is: will the restrictions of the bends nullify the gains made by the cold air intake ?

mali_FC

you are right, we would loose power do to the heat.

....but if you install your air filter to be under the right front panel (away from the heat from the engine) it will be the same as having the heat shield installed.

mali_FC

no, no problems here

mali_FC

if you take out the long rubber piece under your hood (the long one that's near front windshield).
you'll get better air flow in your engine bay.

Noel Caraballo

iTrader: (2)

why is it all non turbo custom intakes are using home depot couplers looks retarded. when i do this in the winter time i am taking my sweet old time making it. All that custom work and the filter exposed to the heat equals no gain. I did that on my gxl for a while and felt like crap.

RotaMan99

Right front panel? You mean having it near the corner of the engine bay where 90% of the intakes are? Then you are still sucking in the hot engine bay air. The air in the engine bay is not going to cool off enough to give you that cooler by the time it gets to the corner of the bay and sucked up by the filter.

Run a filter in the corner of the bay for a year, then put the filter out of the engine bay. Notice I didn't say make a cold air box because its hard to get them to seal 100% so the still leak hot engine bay air.

If you are talking about where you have the filter, then yes you are right.

We would be talking fractions of a hp. Nothing to measure. This also depends on how hard the bends are and how they are designed internally.

I spend about $70 on silicone couplers, bends, and t-bolt clamps for my intake. I do agree about the home depot crap though. I try to stay away from black piping or couplers, I used light blue couplers for mine to try to minimize the radiant heat soak.

mali_FC

....that’s personal preference,

CarzArKoo1

I have a stock air box, how much gain from doing a intake like this.

mali_FC

I was talking about the set-up I did on my car....lol

There was a thread a while back about this set-up. I don't remember who has posted it ....

not much, unless you've changed your exhaust including your headers -

cozmosland

iTrader: (1)

i like that little mini filter on the end of the tubing that would normally goto the stock box,
what is that tube for anyway??