Ambient Temperature Research with Force Induction
 

After doing much research on ways to cool my TT 370z I thought I might share some findings. For starters I have the app Torque and have set it up to monitor several things on my car and one of them being the air intake temperature. My car is a touring with the sport package and a GTM Stage II TT. After logging and monitoring many trips in my car I noticed the ambient temperature and the air intake temps were right at 10% meaning what ever the outside air was the air intake temp would run 10% hotter. That being said I had an idea of trimming the plastic piece of the front bumper which is about 4 inches total in height so more air could be more effective of the intercooler. Doing that alone made a 5% difference from the ambient temps and the air intake temps. No biggie right..!! Recently I just went went a Vented carbon hood and did more logging and believe it or not my ambient temps are now the exact same is my air intake temps. I started this thread in hopes to helping others that might be looking at ways to cooling their FI z. Will post up pics today of the oem bumper trimming..:tup:

id be curious to see your pictures.

under what circumstances are you comparing temp? i would expect you to find drastically different percentages pending airflow (speed) and heat soak.

Good question obviously when you come to a stop light or stuck in traffic it will rise due to not getting any air flow. My test were done on the interstate cruising between 65-85. Loook its not rocket science but by opening up the stock bumper and or buying an aftermarket bumper with decent flow to the intercooler goes a long way. I couldn't be more happier with the results in my forced induction z...

Will post up some pics tomorrow.....

I'm glad you're logging this, since I'm always looking for more ways to keep my car cool. Another thing that may be helpful is tracking how long it takes for the IAT to come back down to ambient after sitting still- ie traffic conditions. It's a little late for a baseline though, since you've already cut the bumper and got a vented hood.

Now install a nitrous spray bar in front of the intercooler and let us know the results
:tup:

The problem with that is the location of the air filters on a GTM kit makes it too easy to suck in some NO2 you're not tuned for.

Good point, didn't even think about that.

Great info. I figured that the vented hood and a larger opening in the bumper would definitely help. The problem for me is finding a hood that is not heavier than stock and finding the right shop to do the bodywork (and it look good instead of hacked up).

Pretty happy with my VIS after having it painted to match the car. Pics will come Today!!!!

Yes, because of this, I am considering having vents cut into my stock hood backed by black mesh or something. I also do not like the necessity of hood pins with CF hoods.

I have been tracking my intake temps lately but never did prior so nothing to compare to.
Once I get a vented hood I am curious to see how it changes, if at all.

Nix, most 370z aftermarket hoods have the 3 lock slots like your OEM hood, so you just transfer them over. Most cars needed them in the past because they just came with a single lock and you needed to add 2 for racing.

As promised a few pics...

Looks really nice, Cosmo.

@theDreamer - do you know if the Seibon hoods come that way? I feel like I always see people saying (internet experts?) that you still should run hood pins.

I wouldn't be all that concerned about IAT's at cruise, and would pay a lot more attention to them at WOT. If the system is efficient, you should not be seeing IAT's more than 15% over ambient (at about 10psi of boost). Also, my experience shows that turbine housing flow has a lot more to do with IAT's than the size of the intercooler.

I think a lot of the need for hood pins comes from the fact that its a lot easier for the latching hardware to pull out of a fiberglass or CF hood than a metal one.

The seibon hoods have the slots for the OEM 3 hood latches.
A couple people in Houston have tracked their cars with seibon hoods with no problems YET, but if you are getting into heavy track days I would highly suggest looking into proper hood pins. Mainly because they will be stronger than the factory units and safer for track use.

I have had a Seibon vented "TS" hood for about 3 years and probably 40,000 miles. No hood pins, frequently visit 150+ mph. It feels real sturdy when shut, so I havent felt any need for pins.

Actually the VIS carbon hood I bought come ready so you can just move the oem hardware over to the hood and after making a few adjustments it closes nice and tight with No wiggle or play. Like I said in my first post my IAT's were about 10% more than my ambient temps so trimming the 4 inches of plastic on the stock bumper exposing more air to the intercooler and also going with a vented hood Iam down to 0 difference. And yes that is just cruising normally. I will do some more logging of stop and go to see how fast the temps rise and how long it takes for it to go back down next.... Forgot to mention the oil temps seemed to have dropped a few degrees as well with that formulation...:tup::tup:

All you CF hood guys park in a garage I assume right?

Or just paint the hood.

Mines is ALWAYS in the garage...

What about getting caught in the rain? Does water get thru?

Under these conditions, what really matters is post IC temps -- that will tell you how efficiently your IC is working.

IAT's are good to know too, but the really critical detail is the temps after cooling.

Interesting -- although that may also be due in part to the kinds of coolers being run. Are these air to air or air to water coolers?

The only FI setup I've seen here running an air to water intercooler is the Stillen kit.

Iam not too concerned with the rain because the hood has a fiberglass channel under the slots in hood so the water actually stay in the channel until it is diverted to the front lower section of the hood...

water just pours right on through my seibon TS hood vents... a few years of daily driving, and its never caused a problem. when i wash the car, soapy water just runs straight down those vents. <shrug> i see no problem with it. gotta wipe off the engine later if you care about water spots on the pipes and etc. i dont.

The IAT sensor is after the intercooler...

Thankfully I've never had any heating issues and I live in South Florida. Oil cooler and that's it.

Oh.

Then, never mind :p

Sounds like a very efficient set-up if that's at full boost.

you could do what the EVO guys have, hook up some intercooler sprayers, that should help bring down temps a bit, especially at speed

Excuse my ignorance here but what does the turbine housing have to do with Intake air temperature, maybe the compressor housing sure i could see some effect there, but that wouldn't make much sense to me either because one would think that so long as the chosen turbo runs through it's best path through the adiabatic efficiency islands when mapped to the flow of the motor, considering that adiabatic efficiency is the percentage of wasted energy due to the act of compressing a gas compared to the ideal amount of energy it takes to compress that gas if you are traveling through the 73% island that means that 27% of the turbo's energy is being converted into friction and heat instead of pumping air so basically what i'm trying to say there is to my understanding it doesn't so much matter what the flow of the housing is so long is the turbo is correctly mapped for the application you will see the lowest possible resulting iat's from the turbo. The next question i would have regarding this is that i would agree with you in that the intercooler size does not particularly matter so long as it is more efficient than any intercooler known at shedding heat, being that we are stuck with aluminum i would say that a larger intercooler is always a better thing because even if your turbo(of course matched to the motor) was belting out charge temps near 500 degrees(i dunno like a pro turbo drag car) if your intercooler has enough surface area and an appropriate temperature delta from the cooling media (be it air in cosmo's case or a very large chest of salty-icewater in the case of our dragster)than it would be entirely possible to reduce the temps solely through intercooling down to almost ambient (or below in the case of a monster chilled turbo[or supercharged] dragster). Also 15% is a common number but there is always improvement, by my math (calculating the density of air with the pressure held constant) for every 10% increase in air temps around the 100degF mark the air will get 3% less dense so going from 15% to 5% could net you a 3% gain in power(or just prevent a 3% loss). And while checking before and after iat temps while cruising won't tell him if his intercooler will keep up at wot it is a perfectly accurate way to check to see if his modifications have had a positive or negligible effect on the efficiency of his intercooler at speed. I would think that he has done some good work and found some valuable information that will help members of the forum out, but again I'm not the expert here and i'm always wiling to learn.

I often wonder if our intakes were Plastic (since metal acts as a bad heat soak) how much that would effect the IAT's.? Referring to the entire tube from the throttle body passing through the engine area to the intercooler.. It is possible because most cars now have plastic intake runners just for the heat soak..

The problem I think might be plastic can expand and with forced induction you do not want that.
If you want to counter any heat soak you can do thermal coating, intake pipe wrapping, or even do the gold wrapping stuff.

Yea I didn't think about it expanding but do you really think it would at a low to medium boost? Considering the plastic would have a decent thickness too. I would think a heat wrap would hold the heat in considering isn't that what its made to do?

The expanding part wouldn't be that big of a deal..

Schedule 40 PVC (the white, cheap stuff) @ 3 inches is rated @ 158 PSI operating pressure...

So if you had some piping made that was maybe half that thickness, you'd theoretically be in the 78-80 PSI range for operating pressure. That's @ 73 degrees f.

PVC wouldn't be a good choice for this application, it can't really handle the temps for any length of time, but I just wanted to use it as an example of good thermoplastics' pressure handling characteristics.

At the very least, plastic cold pipes could be used, but the tooling to manufacture them would likely be prohibitively expensive. Same goes for a composite design.

You are focusing too much on the compressor side. Remember, everything that flows out of the compressor goes in to the cobustion chamber, fuel is added and ignited. The volume of exhaust gas going out and through the turbine will be much larger than that of the compressor. If the turbine is too small, you have high back pressures, and efficiency goes down the turbe. As a result IAT's sky rocket.

If I was to use a T3 .82 a/r housing for example on the VQ37 (compressor side stays the same), there is no way any of my customers would be able to get to 500whp due flow restrictions of the turbine, increased heat (IAT's) and back pressure. Instead I use the much larger T4 1.15 a/r housings, and IAT's are never an issue because the system flows so well.