Intercooler temperature gauge??

[dsmperformance]

I think it would make perfect sense to have an intercooler temperature gauge in this car. Mine came with the $300 boost guage that just sits there to look at! Since we have the I/C spray system, keeping an eye on the I/C temps would be way more useful than a boost gauge. I'm not saying the boost gauge is not needed, its just not really that useful on a unmodded factory STi. I have noticed the I/C get very hot after you come to a stop or leave the car sit for a prolonged time. Heat soak would be a big issue along with fuel detonation if you run your car hard after a brief parking session. Anyone have plans for a I/C temp gauge?

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[rallykeith]

I'm thinking about the same thing. Here is what I would have done if mine didn't come with the factory boost gauge. Find the temp sensors for the factory outside temp gauge, and relocate it to the intercooler. Then it looks factory and is easily readable at night.

Keith

[dsmperformance]

Originally posted by rallykeith
I'm thinking about the same thing. Here is what I would have done if mine didn't come with the factory boost gauge. Find the temp sensors for the factory outside temp gauge, and relocate it to the intercooler. Then it looks factory and is easily readable at night.

Keith

That sounds like an excellent idea. Its not going to be as accurate as the probe design, but will give you a good idea on the temperature range differences. Do you know what the sensor looks like? The idea sounds very feasible.

[johnfelstead]

its charge air temp you want to measure after the intercooler, there is no point measuring the temp of the intercooler itself. Dont use an external temp probe for this.

[Janq]

Originally posted by johnfelstead
its charge air temp you want to measure after the intercooler, there is no point measuring the temp of the intercooler itself. Dont use an external temp probe for this.

John is 100% correct.

But measuring the external air flow temp at/near the core surface is a passable if not ghetto alternative for 'relative' figures and assesment.

The following details some notable examples/ideas toward such a project; http://www.autospeed.com/cms/article.html?&A=0589

I hope this helps...

- Janq

[Turbobug]

just get a dual egt gauge, one to measure the charge temp and one to measure the exhaust temp....ive found one before but i dont remember where. Ill post if I find it again.

[hampster]

Does the automatic IC water spray setup use a thermocouple on the intake to determine when to spray? You could easily set up a control strategy to spray the intercooler when the difference in intake temperature and ambient air temperature reaches some threshold.

On another related topic, has anyone outfitted an electric fan to the top of their intercooler? You could run the fan whenever the car drops below a certain speed/throttle condition or all the time. It requires no refills, and doesn't mess up your engine bay as much as water (even distilled water attracts dust).

[Janq]

As for the automatic IC water spray setup there are several options detailed but you'll need to review the entire article for all the specifics (parts 1-5) as I've forgotten off hand.

In regard to installing a fan onto the IC I thought the same thing but I'll bet the under hood clearances aren't good. How about as an alternate idea setting up A/C service for the IC?!

Build up a duct off of the interior ducting that directs on to the IC (some custom plastic fabrication required). You close out all the interior vents and run the A/C at the mid position (manual mode) resulting in a constant blast of chilled air onto the IC.

Although the A/C compressor will induce some losses the resulting temp drop and HP gain may make up the difference. Its cheap, plentiful and possibly 'instant on' power without all that much work required.

What do ya think?

- Janq

[hampster]

Well, lost the first message, so here's the short of what I wrote:

The a/c system has the problem of using an engine driven compressor. Cooling the IC results in higher engine efficiency. If this efficiency gain does not result in a large enough horsepower gain, then you may actually have a net loss in horsepower.

A fan is driven off the battery, which, in turn acts like a big reservoir. The battery is charged slowly all the time, so you can actually draw large amounts of instantaneous power from it on demand.

I agree, though, there isn't much room for a fan under the hood...but you may be able to mount a slim radiator fan under the intercooler to pull air through it.

Another way to cool the IC is with liquid nitrogen. It's expensive, but draws no engine power.

There are all kinds of ways to boost the efficiency of an engine. One way that I would love to try is with an air compressor. You run an air compressor to pressurize an air cylinder while idling. When you accelerate, the air cylinder discharges into the intake. The result is just like a turbo but with absolutely no lag....but also no top end. It's like an anti-turbo: no top end, but fills that boost void before the turbo can spool up.

...we should start a whole thread on new ways to boost the performance of the STi....

[redrexx]

Originally posted by rallykeith
I'm thinking about the same thing. Here is what I would have done if mine didn't come with the factory boost gauge. Find the temp sensors for the factory outside temp gauge, and relocate it to the intercooler. Then it looks factory and is easily readable at night.

Keith

That would be nice in theory, but the the stock outside temp gauge will only read to 122 degrees. That's a lot higher than you want your intake charge to be, but still, if the outside of the intercooler is hotter than, you won't know how hot it is.

[J-rod]

In regard to installing a fan onto the IC I thought the same thing but I'll bet the under hood clearances aren't good. How about as an alternate idea setting up A/C service for the IC?!

Build up a duct off of the interior ducting that directs on to the IC (some custom plastic fabrication required). You close out all the interior vents and run the A/C at the mid position (manual mode) resulting in a constant blast of chilled air onto the IC.

Although the A/C compressor will induce some losses the resulting temp drop and HP gain may make up the difference. Its cheap, plentiful and possibly 'instant on' power without all that much work required.

What do ya think?

As far as that goes the compressor will cause much bigger losses than what would be seen from the temperature drop in the intake charge.

It also seems pretty futile to spend a lot of time and energy to cool the intercooler better since the gains are minimal. ie 5hp quote from the guy who was doing all the dyno tests. I'm sure the engineers at Subaru already went through this and decided the best solution was spraying water.

J-rod

[johnfelstead]

the IC compressor disengages on WOT.

[Janq]

You know, the whole idea was dumb...yeah, I'll say it dumb as in 'boneheaded'. I know better too.

You guys are right as the HP losses for an A/C compressor are much more than any hope of air cooling HP gains I might hope for.

I was at work when I posted that idea and quite possibly suffering from pre-mature symptoms of 'old timers' disease.

Please disregard...

Thanks,

- A totally embarrased Janq

[J-rod]

This brings up something else I've been meaning to ask.
Why does the WRC car have a hood vent right in front of the hood scoop? Wouldn't this dump the hot air coming from the radiator into the intercooler?

J-rod

[me109]

Originally posted by J-rod
This brings up something else I've been meaning to ask.
Why does the WRC car have a hood vent right in front of the hood scoop? Wouldn't this dump the hot air coming from the radiator into the intercooler?

J-rod

The WRC car uses a front mount intercooler. That vent removes heat. I guess they leave the "normal" IC scoop on to make it look like the street car.

[J-rod]

Really! I guess a FMIC gives more power which is always the end goal. But that brings up another point, I have noticed a lot of people talking about moving to a FMIC but never heard any discussion about the pro's and con's of such a move. With the IC mounted where it is on the STi, on top, doesn't that shorten the distance of the charged air thus giving you a faster response time (less turbo lag). So by moving the IC to the front, and increasing the path length, wouldn't you increase the turbo lag.

J-rod

[me109]

I would think an FMIC would not heat soak as bad as the TMIC, this would be very important to rally cars. As for street cars I think the TMIC is sized sufficiently, but there are many aftermarket FMIC available for the WRX so there may be some performance improvement on cars with big mods.

[banman]

Didn't some Ford concept pickup truck have an intercooler that was cooled using some sort of A/C-like system?

[reks]

The Ford SVT products use a supercharger with a water-to-air intercooler system. So, in a sense it's a/c like yes. I don't know too much about the systems though. I don't think they nec. compress anything, I thought they just used a circulator pump like your radiator.

[me109]

The supercool system expands refrigerant through an evaporator core to cool the compressed charge for short bursts of power. It’s like taking the evap core out of your a/c and letting your compressed charge airflow through it (like outside air accross the core's face). Maybe a better way to explain it is the evap core is the opposite of an intercooler - the cold stuff is on the inside - the stuff your cooling is on the outside.

This compressed charge would be at about 50°F (reasonable guesstimate) on a 90°F day - big punch (gotta be like nitrous)! Robs about 5 -7 HP to run the a/c compressor though. Hey but why not, you’re already robbing Peter to pay Paul with the supercharger. Sounds like a mega expensive setup to me.

[Janq]

Ok, following the wacky sub-thread I inadvertantly started (while suffering from empty stomach syndrome)...what if one were to run an electricly powered refrigeration unit ala the '04 Toyota 'Prius' A/C system and use it to cool intake air?

There is only a weight penalty (nominal) with zero HP losses.
Win - Win situation...?

- Janq

[me109]

No free rides. Power comes from somewhere. The only two power sources on the car are the engine and the battery (ok maybe some capacitors and springs and the like but they don't count).

To run an electric compressor you need to generate a lot of electricity through the alternator - big drag on the engine. Then convert it to mechanical energy to the compressor (losses). Plus put some huge wire and alt in there - more weight / cost.

No flame intended so don't take it that way. One of the first things they teach us engineers is: There is no free lunch.

[Janq]

Originally posted by me109
No free rides. Power comes from somewhere. The only two power sources on the car are the engine and the battery (ok maybe some capacitors and springs and the like but they don't count).

To run an electric compressor you need to generate a lot of electricity through the alternator - big drag on the engine. Then convert it to mechanical energy to the compressor (losses). Plus put some huge wire and alt in there - more weight / cost.

No flame intended so don't take it that way. One of the first things they teach us engineers is: There is no free lunch.

No flame taken.

Seeing as everyone and their 83 yr/old 'Soggy Bottom Boys' listening grandpappy are packing some level of ICE...I'm thinking that with a stock e-system if not moderate upgrades an electric A/C based intake cooling system might just be feasible for short term power boosts.

The Prius electric A/C system runs on 12 volts though I'm not versed (yet) on the specifics of its wiring & systems. But seeing as its a prodcution car for general Ma & Pa Kettle consumption I would imagiune that its not running a system thats too exotic (read expensive or hard to maintain).

Were just talking a quick & dirty reroute of cool air ducting into the intake pathway.

But maybe its a bit too avant garde...

- Janq a non-practicing ME & one time machinist

[me109]

Ok, I hope this doesn’t bore anyone but here goes:

P=VI @ V = 12V and P = 5 hp =3728.5 W so I = 310.7 A ---> Lots of I (current) - big wire / big alt / big engine drag. Maybe with a 48V system?

Now to cool the charge quick a dirty - let’s try chilling the IC spray water. Sure it's lots of energy to get it cold but water has a wonderful heat capacity and we can leave it in the fridge overnight. You could insulate the bottle (maybe use dry ice under the insulation?) Ah - wet ice and insulate the bottle like a cooler - insulate the lines. Ya, that may do the trick. A nice 32°F slurry could last a whole day and insulation is cheap and light. Just a thought.

I think an electric a/c would be on every car if it were more efficient than the current mechanical - better gas mileage.

[RichQY]

oh..... IC cooling thread.

some one mentioned Liquid Nitrous

there is the CO 2 alternative.

or the ultimate water / alcohol injection