nick_968

Having fitted my expensive new ninemeister intercooler radiator and finally getting rid of coolant leaks (old pipes) and other related probs such as getting the original 968 ducting in place to get the airflow right, I was hoping the intercooler would acheive the desired results. Unfortunately on driving WOT for periods of 20 seconds or more the intake temps are rising to 45 degrees plus and may climb more - I ran out of road and was going way too fast! As soon as I back off the temps drop down fairly fast but with an ambient temp of 9 - 10 degrees on the day in question I feel that the intercooler is not doing enough. Airflow is good so that isnt the prob. I feel the core too open (to allow air through easily for the rad) and needs to be more restrictive. I am only running 16psi and want to be able to run 18 - 20psi on the track without problems. What are other peoples experience with respect to air intake temps? Is the fact that my sensor is on the manifold changing the data? Will insulating the hotside and bottom of the intake manifold make any difference? Would really like to find a way to make this work without changing out the intercooler core, but I will if I have to.

CarbonRevo

45* in the intake? Isn't that like...pretty good?

blown 944

are you talking about 45 deg F or C ?

My experience is that the stock IC runs post IC temps of about 80 deg F under about 15 psi for 20 seconds on a 70 deg day.

nick_968

Sorry guys degrees C, should have said!

333pg333

Nick,
How is the fact that your i/c is coarse and allows plenty of flow to the rad hurting the cooling?? I don't see how having a finer core will help? Do you have any pics of your setup?

Diver944

45 degrees C is 113 degrees F which does sound way way hot for an ambient air temperature of 50 degrees F

blown 944

^^Agreed, this conversion stuff confuses me to the point where it is a pain to look at the results .

Again I observed about 80 deg F with about 170-180 out of the turbo on a 70 deg F day so I ould say you are no seeing an efficient IC.

nick_968

Thanks, I know its too hot, just wondering how much is to do with the location of the sensor in the intake manny and also some heat transfer from the turbo etc to the manny. Answer is its prob mainly down to the IC but just looking for ideas. I am going to look carefully at ways to improve the ducting and flow out of the IC before I look at redesigning the end tanks for better flow and swapping the core for a different one. Just one of the many joys of turbocharging a 968, suprised more turboed 968's are not having these problems.

blown 944

You make a good point about the temp sensor location.

For reference I was measuring just before the TB on the charge pipe. If you are measuring in the manifold I could see some exhaust heat causing excess heat.

TurboTommy

It's true that if the core is too coarse there won't be enough core material for the air to snuggle up to and exchange its' heat.
Is this a homemade unit?
And, how big is it compared to the stock unit?
I'm assuming this is a 3 liter? You'll have more volume/mass of charge air to cool than a 2.5L.

Also, I always wondered how much the hotside really heats up the intake manifold if the car is at highway speeds. If anybody has two temp readings; one after the IC and then one of the intake manifold; that would be good info.

A.Wayne

Could you post pics of your intercooler setup, showing front location and intake pipe sensor location. ALso turbo type and boost used when tested ....

nick_968

The location is right in front of the radiator using the standard ducting found on the 968 to direct airflow to the rad - and now the IC.

It is not a home made unit - far from it. The boost was 16psi.

Turbo is a Vitesse Stage V KKK Garrett Hybrid.

Sensor is mounted in the Intake manny just behind the throttle body. I dont have any pics right now but here is the link to the IC pics before I installed it. The first page has the IC/Rad installed in a ninemeister car and the 4th page has pics of the IC in my flat before I installed it.

I am thinking I need to have another look at the airflow and improve the ducting and the way it seals to the IC and reducing the entry area to stop air escaping back out. I cant believe this IC is not up to the job!

https://rennlist.com/forums/968-forum/352011-9m-968-supercharger-conversion-360-430-or-480hp.html

Duke

IMHO the core is very thin, but the temps you are seeing seems too high regardless!

A.Wayne

Coolers need 1 inch between them to work effectively , are you having water temp issues also ? What type of air temp sensor , plastic or metal tip .

Your intake temp should drop when the car goes into boost , then rise 10 -15 deg above ambient for optimum performance. how is the floor under the coolers done ?

95ONE

Lets do some math.

your avatar says your in London. Since the Thames River is in a Flood plain.
Lets say you're at exactly sea level, or 14.5lbs per square inch atmospheric pressure.

you're using a Vitesse turbo, so lets Go a little crazy and say it's at78% efficient.
(Not of course all the way through boost, but lets ignore those facts and not split hairs)

Now lets Use Corky Bell's book to come up with the temps your turbo should be blowing out without your intercooler. Math from Corky Bell's book states:

Your relative density is around 1.0% (14.5lbs/inch at 59deg F) your being a tad better because of colder ambient.
Pressure ratio assumed at a estimate of 2.1

(NO MATH, I used a Graph with a temp curve based Pressure ratio,
and different compressure efficiencies assuming sea level at 60deg F. VERY close to
actual conditions you described)

We get an compressor output temp of right around 250 degrees - Farenheit.


So to use Corky's actual math on your intercooler efficiency

Ambient = 40F
temp out turbo = 250
temp out intercooler = 113

So his math is

250-113
_______ = 65% efficient.
250-40


Engineer professionals, please feel free to correct this math. I did it fast.