I was looking at the stock intake system and they clearly emphasized managing NVH. But it looks like the fresh air is "leakage" from the area in front of the rad; for example around the hood latch.

Am I reading it right? There is a little plastic duct under the big intake duct that goes across the rad but it looks like it just pulls air from around the bank of relays.

I was thinking about building something to cover the area in front of the rad, hiding the overflow tanks , relays, etc. and didnt want to disrupt the balance between combustion vs cooling-destined air.

Thx

 

yep. you're reading it right.

Bad idea. If it's an NA, you really can't do much better (many have tried) than the stock intake. Putting a "cooling panel" in that location would aid in cooling flow to the radiator, but restrict air to the intake.

 

I disagree.
You don't need to do "much better" than the stock arrangement, you need to do "just as well" as the original with a configuration that allows for adequate ambient air to the filter AND the best possible ducting for the radiator.
This doesn't seem to be a very difficult proposition given the relatively small and convoluted pre-filter OEM ducting.

 

Hmmm... The oem rad plastic end cap split a couple of weeks ago and since I saw that Clokker seemed happy with his we put a Godspeed in. The Godspeed is thicker and prevents the use of the stock prefilter air duct. We built a new filter box since the plastic oem one was falling apart and we are looking now at the best ways to route air into that box. Inspite of being a turbovert with a BNR Stage1 the oem system didnt seem to have any trouble keeping up with 12 psi of boost.

I saw Clokker's air intake system but being in TX the a/c is sacred so we cant emulate that design. I saw another writeup by dwb(?) showing how he cut the "floor" under the stock filter box just behind the fuel relays. He put a three inch adapter with a metal screen.

So we are looking at better routing air into our air box from in front of the radiator between the passenger side headlight and the top of the rad and maybe from below like dwb.

The Godspeed rad seems like a very nice piece but being thicker has set off a chain of domino mods. We are going to write-up what we've done but it wont be as epic as the Descent into Switchgear Madness!

 

if you really look at the stock setup, you will see that there is a seal between the bumper and the 1st crossmember, so that the place where the OEM duct goes doesn't have a fresh air feed. then there is also a seal between the duct and the hood, so you have to look at where the OEM setup is really pulling its air from.

it does work fine, but i wouldn't say that its "cold air" its just not hot air

 

I haven't had a look at the S5 setup in person, but on my S4, there's a path over to the passenger headlight (over top / against the hood) that would allow air to be pulled up from the lower bumper area. On my driver-side, there's a plastic piece blocking the same area, so I'm not sure if any previous owner messed with things.

This is the intake setup I'm using instead of stock: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/diy-cold-air-box-830116/. The stock TID would choke my stock turbo at high RPM, and simplifying things greatly improved flow.

 

Oh, it's turbo... that changes things a little. I still stick by my guns that the NA intake really doesn't have a lot to improve on. On my S4 convertible, there was an area where the intake could draw in ambient air from in front of the bumper. It works well, and I never noticed any power difference from changing the intake to a "cold air" vs stock. The only thing the "cold air intake" I made for it afforded me was a bad AFM after I sucked up a little water, then a subsequent hot day caused the aluminum inside corroded so badly it would get hung up.

The stock TID though, that little guy is pretty restrictive. I made one essentially just like RR88's, from a 3", 45° aluminum pipe and a K&N filter. I didn't use any shielding though, that's next.

 

Thanks, guys.

Here is a picture of the area behind the bumper and in front of the rad. It's an S5 vert. While the car seemed unmolested when we bought it, I can't be sure if it was as shipped from the factory.



We have a Vis CF hood with aerocatch latches so pulled the oem hood latch. The rectangular "duct" on the right is where the oem intake duct draws air. Interestingly, there is a plastic shield of sorts by the driver side's headlight but none on the passenger side.

On the passenger side you can see that there is a gap between the passengerside headlight and the aerocatch pin (annodized red). We pulled the 3" bit of weatherstripping from the hood that purported to seal that gap. But the weatherstripping on the hood is pretty hard and warped.

The new airbox is almost completely sealed so the bulk of the incoming air is coming thru that gap. The car is boosting over 13psi now with no dramatic drop to redline.

So we'll probably seal that mess up with a port twice as big as the rectangular duct thing and more centered. Then we'll improve the sealing along the front of the rad and by the driver's side headlight to guide the air to the airbox. It probably won't significantly improve performance but it'll look clean and tidy.

Should be fun.