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intercooler temps


Guest Anonymous

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Guest Anonymous

what kind of temps do you guys see after the ic. I am not running one and so far have only gone up to about 180 degrees F. I know this is a very broad spanning question just hoping to get some idea of average temp reductions with a ic.

Thanks

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I'm running a small Spearco, and I find that on the highway going aroun 70MPH, the intake temperature runs consitently 20deg F over ambient temperature (steady state). So on a day that is around 68 deg F, the air in the intake is approximately 88 deg F. My FI computer displays intake temperature, and also log min/max values. What I find interesting is that whan really step on it, the intake temp actually cools initially, because you are opening up the throttle plate and alowing more air to flow through the system. The temp will increase as the boost pressure increases. Also, if you open up the throttle, and then let off on it, you will see the temperature increase, because the throttle plate is closed, and very little are is flowing through the system.

 

Some interesting observations..... Got to keep my eyes on the road!! rolleyesg.gif

 

Pete

pete_sanders_driver_side.jpg

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Guest Anonymous

The cooling effect is caused by the additional gasoline. Aircraft engines are often additionally cooled that way, you make them fatter to reduce the temperature. I found a reduction of 5 degree's just changing my cruise jetting (no FI yet, and it DEFINITELY is going to be getting it, carbs are so bad at keeping a consistant fuel mixture that its rediculous).

 

Nice car BTW,

 

Lone

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In this case, the cooling is just the intercooler doing it's job, and you see temperature variations from the changing boost level and changing flow. No fuel is mixed with the air yet - the air temperature is measured before the fuel injectors.

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Ideally, what you want is an air to air core that is big enough to keep your intake temps at ambient, or just above under full boost. That would be its efficiency rating, and shoot for the highest you can get that will flow the cfm you are planning on reaching. In other words, you need to know what your turbo can flow in cfm, and the intercooler shuld be sized appropriately.

 

An air to liquid core can get you below ambient for short periods due to the ability to add ice or dry ice to the liquid resivoir. These are better for drag racing mainly.

 

There are options for air to air cores that help like having NOS sprayed on them, or a water and alcohol mixture that would cool them substantially as the stuff evaporates. You could also add an electric fan to the backside of the intercooler and that would help its efficiency in town and on hot days. Anything youy can do to help concentrate air and speed it up going across your core will help. Ducting for example, helps.

 

Your temp getting up to 180 degree's is costing you power. The cooler your intake charge, the more air you can get in there, and the more power you can make. Imagine what dropping your charge temp 100 degree's would do.

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Ideally, what you want is an air to air core that is big enough to keep your intake temps at ambient, or just above under full boost. That would be its efficiency rating, and shoot for the highest you can get that will flow the cfm you are planning on reaching. In other words, you need to know what your turbo can flow in cfm, and the intercooler shuld be sized appropriately.

 

If you can get your intake charge to ambient, that is the definition of 100% efficiency (for an intercooler), which is very difficult to do on an air/air IC. Typically the ICs from Spearco will get efficiencies in the 80% range within the flow specs. I think 20 degrees over ambient is very good.
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I would agree with you sleeper that 20 degree's over ambient is very good, but there are some very efficient units out there, or rather, claimed efficient units.

 

I mainly wanted to point out that the higher the efficiency, the better off he would be. I would get the most efficient core I could afford.

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Guest Tom Scala

Most guys seem to have the temp sensor on their SDS's mounted in the intake manifold but I put mine in the IC pipe near the TB. I thought putting it in the manifold would subject the sensor to heat soak and artificially high temps causing the engine to lean out. SDS said either way is correct you just have to program the fuel map differently depending on which method you choose. BTW I have a small Spearco rated at 660cfm,I don't remember the core part #. Before the IC was installed I had the sensor about a foot from the turbo (Buick GN hybrid) outlet. At 8-9psi it would get to as high as 130-140F on hot days after a burst through the gears.

Yesterday the temps were in the high 70's and cruising temps after the IC were in the low 80's. A 15psi burst only raised the temps to near 90F. I'm sure it would go alot higher if I were beating the car over a prolonged period of time like in road racing but I think it shows the IC is doing the job for my purposes. I can run 22 deg total timing at 15psi on 94 octane Sunoco Ultra with no hint of detonation. Can you say 20+psi on 110 Cam2? :cool:

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Actually, you want it in the intake. You want an accurate reading as close to the inake port as possible. Otherwise you will be giving your SDS false information for air temperature compensation. You want the computer to knwo about any heat soak so that it can compensate for it appropriately.

 

Pete

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Guest Tom Scala

Thats a good argument for mounting the sensor in the intake itself. But according to the tech person at SDS the alumium manifold absorbs heat from the exhaust manifold and gets considerably hotter than the inlet air. Some of this heat is absorbed by the metal in the sensor body and could cause it to read higher than the actual inlet air temps,especially at lower air flows and after a shutdown. He said it's ok though as long as you compensate for it in your programming. At least this is what was told to me by SDS. I know GM mounts theirs in the air cleaner duct on n/a cars too for this reason.

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James, weren't you selling that custom intercooler that you had made a while back? Did you end up selling it, or keeping it? If it's not on your car what are you running with now?

 

Not bad numbers, I hope I'll have a setup that efficient some day smile.gif

 

I dig this cross flow head on the 7m-gte, won't have that heat soak problem.

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On my Mustang I used to see sky high temps idling at a light and then see the IAT temp drop down to within 10degrees of ambient once I got moving :D

 

On th eSupra I'm also seeing temps VERY near ambient but th eprobe is in the intercooler ooutlet. What's been said about heat soak is VERY true! However, the IAT temp sensor isn't used to make big adjustments, mostly just fine tuning for when temps are different than when the base map was done. One Supra guy whodid put his IAT in the manifold is going to move it - heat soak is making his temps WAY high. My current intercooler is a GIANT 4core Greddy and while I've not been boosting very much (not tuned yet) the temps are VERY flat while driving. An entire 45min drive home will start out with temps at about 36 degrees before cranking, 32 degrees idling after cranking, and then has dropped as low as 28 while driving part throttle. This is very close to ambient lately.

 

Remember, an intercooler acts more like a heatsink than a radiator. It absorbs heat and radiates it over time - it doesn't constantly remove all of the heat. You have to be really flying before you can overcome heatsoak! Bigger and better the intercooler is the longer it'll be before temps begin to climb on a long pull.

 

Read this series - it's pretty interesting! http://www.autospeed.com/A_0527/page1.html

 

P.S. The ECU I'm using will allow me to log air coming in the intake, out of th eturbo, and of course out of the intercooler. I intend to FULLY instrument this sucker! :D

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Guest Anonymous

What do you guys think of the water spray module sold by that AU place Blkmgk posted? I've been considering ways to draw the best efficiency from whichever I/C I can finally get my hands on (which will hopefully be already efficient)

-James I wrote you a PM, did you sell the fmic?

Anyway, there's a moderate amount of space to work with, provided a 3" thick core or skinnier.. such as

ducting, to make it hardest for air to go around, easiest for it to flow through the core

a seperate puller fan for the i/c, module controlled to cool as heatsink effect

or a water-spray type module like that sold by the aussie place.

Of course, this mainly implies race-only usage, I certainly wouldn't be squirting water on my way to work :rolleyes:

however it would be nice to run progressively similar c/a temps while up in the 3-bar..... another precaution to keep from frying the stock pistons! 2thumbs.gif

well.. a good read, thanks for posting that site blkmgk

-980mak rockon.gif

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Guest Anonymous

Oh and another thing..

I plan on having ceramic jet hot coating on the exhaust manifold & (perhaps) turbine. Not exactly sheer heat soak prevention, but its the little things that count ;)

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Most I've seen is 130F after IC just before TB with 90F amb at road race track driving school running 15 psi. Any measurements probably not accurate due to failure to attain steady state and heat capacity of IC and sensor assy. OBTW max IC inlet was 280F. We usually figure 20F approach with air to air. My IC 160 in2 with 2 1/2" core. Heavier IC is better on street due to heat capacity, but once you approach steady state, area takes over.

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