sbnrx7

iTrader: (4)

So getting a Power FC has been good and bad. It has made my car run better, eliminated the 3k hesitation, deleted the emissions stuff and automatic warm-up system, and made it idle smoother. On the bad side, I can now see the coolant and intake temps. For this thread, I'm just going to cover the intake temps and what I did to bring it down.

So my set-up is basically stock except for a set of BNR Stage III's, Street port, Fighters Garage intake, and a PFC. Still using the stock intercooler.

So, again, the PFC allows you to see a lot of stuff but my intake temps are what set off the sleepless nights. Why so high? On a regular day just rolling along the temps seemed to stay at 73C (163F) which in my mind is detonation just waiting to happen. So I asked a few people on this site if this was normal and all said no..."That's really high". I decided to take a look up front to see just what the stock intercooler ducting looked like. I couldn't see it. So I got a towel and laid on the ground...there it was...way up there^^^. No way was any air getting to it especially with my aftermarket front clip. Time to fix the air flow. Here's what I did....


Stock duct which terminated behind the fiberglass crash-bar. In my car, this could not be seen with the front clip installed.





So fabrication of the ducting starts...



Fitment first then more rivets..



A top is added to complete the duct extension.


Next I have to trim the fiberglass crash-bar to accommodate the duct.



Cutting complete. This is the bottom of the crash bar.



Now close to the finished product with the crash-bar reinstalled..



Finally, the front clip reinstalled...(ignore the damage to the front. I know it's there).


Now for the top side hole...



Done.



So what is the result temp wise?

Before= 73C (163F)
After= 47C (117F)

Temps verified using the PFC before and after with the "fast acting" after-market temp sensor.

Hope this helps others in a quest for lower temps on a budget.

Steve.

theorie

iTrader: (31)

i've done the same thing with my stock mount custom IC, except i used some carbon fiber sheet to extend the duct.

oh and btw, lower temps or not, if you plan on pushing more boost don't even bother keeping the stock intercooler. the plastic end tanks are prone to crack/leak even if you're not pushing more boost.

modified pettit c.c. III duct:

sbnrx7

iTrader: (4)

I have the boost limited to 10psi via a Greddy controller. Higher PSI will, of course, require an after market intercooler. This thread is for those on a budget stuck with the stock intercooler.

theorie

iTrader: (31)

good call. i'm definitely about doing things on a budget

very clean install, i forgot to mention. looks great.

oppa637

iTrader: (6)

its hard to tell...but the real issue might be cause from not running an undertray. Ignore if you are running one

sbnrx7

iTrader: (4)

Absence of an under-tray will affect coolant temps more than intake temps. The under-tray is really necessary for proper air-flow to the radiator. Great observation though.

Steve.

Sgtblue

iTrader: (16)

Budget is a relative term. And I say this having stuck with the OEM IC for several years.
I appreciate what you've done. I also did something similar. I just didn't have a PFC at the time to see the results.

But it seems like your also reducing flow to the radiator by the same amount your increasing it to the IC. IMHO, one of them (radiator or IC) eventually has to become more efficient just to maintain status quo because the nose is still getting a finite amount of air.
Getting back to budget and intake temps, it might be easier to install a simple basic AI system to to compensate for the stock IC inefficiencies and bring IATs down... more than a duct extension, but less than a larger quality SMIC.

sbnrx7

iTrader: (4)

Sgtblue,
As an engineer I appreciate your input and the suggestion of an AI system which we all know the benefits of, however, this is a thread on a budget. I just wanted to report that with my mods I achieved a 46F temp difference for $11 worth of materials. Take it for what it’s worth.

Steve.

adam c

iTrader: (2)

I like it. I wonder how much the temps would have dropped by simply closing the opening on top (as you did), and keeping the duct unmodified?

MSilk

iTrader: (1)

Looks good and clean. It also looks like your rad is leaking

Mike

Double_J

iTrader: (28)

I did the exact same thing to my ebay SMIC last weekend. I was going to post some pics in hopes of being the first but apparently others are just as smart

Anyway my results were positive as well. I went from 25 degree above ambient to 15degree above ambient. These results were noticed on my pfc and also using a fast air intake sensor.

My next project is to get cool air to the filters instead of hot engine air.

DaleClark

iTrader: (55)

Good job, Steve!

This also goes to show how critical ducting is to a stock mount intercooler. I've seen PLENTY of Ebay stock mounts tossed in with no ducting, guys thinking "it'll be just fine". Nope, it won't.

Steve, did you have the stock duct that goes from the intercooler duct to the airbox installed previously? Or was that hole just open?

Dale

MrNizzles

iTrader: (5)

^ yah, if that hole was always open, then that alone might be the fix to lowering temps and not so much with the extended duct out front. still nice fab work

moconnor

iTrader: (14)

A comparison with just the hole closed would be interesting. I had the M2/ASP extension duct with my M2/ASP large and could not detect any intake temperature difference (though, this is obviously not a fully fair comparison since this IC is so large that there may have been little scope for improvement).

However, I did have to remove it during the summer because my coolant temperatures started climbing above what they used to because of the radiator obstruction. I would monitor these closely.

A better test of performance would be recording temperatures after driving the car very hard for 15 minutes. Though, I think that this could be risky. When my intake temperatures climb above 45C I stay off the boost. 73C would scare me silly.

As others have mentioned, I would go with water injection. With a little creativity, it is possible to put a simple system together for a few hundred bucks these days.

sbnrx7

iTrader: (4)

Dale....the man, the myth,

That stock duct was deleted before I got the car. The previous owner installed some type of aftermarket intake which I ditched for the Fighters Garage intake. Gotta say though, I'm pretty happy with the results of this little project. My wife started laughing when I told her I had to go to Home Depot for some car parts.

Steve

Double_J

iTrader: (28)

Just a bit more info. My car water temps has never climbed a degree with this mod. My fans come on at 85 and the pfc has not seen 86 once. This is just cruising around the streets, so highway, and stop and go.

I do have an aftermarket rad though so that too could help a bit.

MustangEater

iTrader: (4)

where can i order this fast air intake sensor you speak of -- thanks

Mahjik

iTrader: (1)

http://www.fighters-garage.com/rx7.html

gracer7-rx7

iTrader: (16)

This is an oldie but goodie mod. Has been around since I was first active on the forum back in 2001 or so.

Metan

haha, and I am thinking what a nice idea!

I made it yesterday for just my better feeling and wow... i don´t have a PFC but your numbers really makes me happy. this thing will work.

my modify

Sgtblue

iTrader: (16)

Good to see you posting Metan. Jak se mas?
But even though this is an oldie, low budget mod, I have doubts that the OP's results are repeatable. No mention of the conditions before and after intake temps were taken, engine temps, forward speed, boost conditions, ambient temps or anything else. Re-reading his reply on whether or not the hole at the top of the duct had previously been plugged and couldn't really tell what the answer was. If it was open previously I'm with moconnor, much of the temp drop might be due to just plugging that.

Metan

ahoj, mam se dobře, díky

I am with you about covering the hole in the top, (this is definitely the whole point of this mod, but still, extend ducting makes sense to me.)
I still use a stock airbox with K&N. So this is a bonus for airbox too. I think it is

On the other hand, it might be better to cover the top hole and let the airbox to suck in air without a transition piece of plastic.

without PFC, I am not able to test and measure: (

Sgtblue

iTrader: (16)

Dobre Metan.
But it won't be a bonus for the airbox if the hole is plugged. And to do that, you should do a "cheap bastard" style modification to the airbox and source air from underneath....so it doesn't scavange air from that intercooler duct.