An Intake Temp Cooling Idea

[Guest]

  mickq said:

  fordboy1981 said:

I think you would find that the current drawn would put such a load on the alternator that the extra couple of horsepower you would gain would be sapped up by the alternator...

Dave.

<{POST_SNAPBACK}>

The alternators run at a fixed load, do they not? The alternator is "tuned" to put out xxxx watts at 12v across a certain rev range.

I fail to see how a higher current draw results in the alternator chewing up more engine power. This would only apply if the alternator somehow puts more load on the engine (which is via the pulley - ie the pulley becomes harder to turn as the load increases on the alternator) just because you put more electrical load on the alternator. An alternator is pretty much a reverse electric motor - the load is electrical - the physical part is just spinning things to generate the current. There isnt even a real physical link between the pulley-driven part and the electrical output part. (Other than perhaps brushes). I am reasonably sure (but not 100%) that there is no intelligence in it - ie it doesnt change something if it suddenly needs to produce more power. I guess they could have a clutch though - so that as load increases the clutch eases out which would put more load on the engine and makes the alternator spin faster and produce more power - but even if it does have that I certainly havent ever felt a noticeable drop in power from it.

Its not like aircon, which physically attaches another thing that has to be driven the the engine. The alternator's behavior doesnt change when you up the load. (To a point).

Happy to be corrected, but Im pretty sure alternators are dumb devices, and they suck (say 1hp) regardless of whether the electrical load on them is 10% or 100%.

<{POST_SNAPBACK}>

that's what a generator was like in the old days,my old man bought a HQ when they came out,that went from generator to alternator and from what I understood it would work harder under differnt loads

things might have changed now,I remember this cos we had nothing but trouble with the bloody thing.

The Expensive Daewoo mobb even showed us what to do when the ALT light used to come on,

Pop the bonnet,then with the handle of a screwdriver,tap the sides of the alt,so the brushes would slide down to make contact again

vik...bloody holdens

[F6_Tornado]

I think the massive volumes of air that travel through the intercooler is that great that you would need that many of these things that 240volts would be required.

Good in theory but in today’s world not even close enough to cope with the volume of air that it would have to deal with.

[PozzE]

  mickq said:

  fordboy1981 said:

I think you would find that the current drawn would put such a load on the alternator that the extra couple of horsepower you would gain would be sapped up by the alternator...

Dave.

<{POST_SNAPBACK}>

The alternators run at a fixed load, do they not? The alternator is "tuned" to put out xxxx watts at 12v across a certain rev range....

<{POST_SNAPBACK}>

First of all Hi all, this is my first post and I'm new to the forums but not new to electronics ;p

The Alternator in your car without getting to much into it produces a fixed (regulated) voltage and a varying amount of current. That is as you turn more stuff on the current draw goes up and the alternator has to produce more power (in Watts) to cope. It does this by converting the mechanical energy from the engine into electrical energy. Easiest way to demonstrate this is find a mate who’s spent more on the stereo for his car than the car is worth. Get him to turn the thing up while the car is at idle and watch the revs load up...

Long story short whatever power you draw from the alternator you lose from the engine…

Having said that intercoolers and turbos’ don’t really make an engine produce more power they just make it more efficient so you can get more usable power from them ( I know that’s confusing). For instance the turbo sucks the energy out of exhaust gas that would normally be wasted and uses it to compress air, thus making the engine more efficient and you go faster…

By using engine power through Peltier’s or an adapted Air Con to make the intercooler work better you MAY make it more efficient overall and get extra rwkw...

Remember you can’t get out more than you put in you can just use it better…

[F6 UTE]

Best use I can think of would be for a water to air intercooler like CAPA sell. The Peltier can be used to then cool the water down once it circulates back to the storage unit, or to cool water down before being used in a water spray kit.. That might be feasable.

But for now, I'm off to overclock the daylights out of my cpu!

Edited 04/12/05 11:15 PM by F6 UTE

[shockF6]

  PozzE said:

  mickq said:

  fordboy1981 said:

I think you would find that the current drawn would put such a load on the alternator that the extra couple of horsepower you would gain would be sapped up by the alternator...

Dave.

The alternators run at a fixed load, do they not? The alternator is "tuned" to put out xxxx watts at 12v across a certain rev range....

First of all Hi all, this is my first post and I'm new to the forums but not new to electronics ;p

The Alternator in your car without getting to much into it produces a fixed (regulated) voltage and a varying amount of current. That is as you turn more stuff on the current draw goes up and the alternator has to produce more power (in Watts) to cope. It does this by converting the mechanical energy from the engine into electrical energy. Easiest way to demonstrate this is find a mate who’s spent more on the stereo for his car than the car is worth. Get him to turn the thing up while the car is at idle and watch the revs load up...

Long story short whatever power you draw from the alternator you lose from the engine…

Having said that intercoolers and turbos’ don’t really make an engine produce more power they just make it more efficient so you can get more usable power from them ( I know that’s confusing). For instance the turbo sucks the energy out of exhaust gas that would normally be wasted and uses it to compress air, thus making the engine more efficient and you go faster…

By using engine power through Peltier’s or an adapted Air Con to make the intercooler work better you MAY make it more efficient overall and get extra rwkw...

Remember you can’t get out more than you put in you can just use it better…

Good first post

Welcome to the forum

[Cro]

Would it make the air flowing through the intercooler colder, or will it just make the actual intercooler colder.

I don't know if anyone else has tried this, but after about 15 laps at Wakefield Park, the intercooler was cool enough to touch.

Being a front mount, the air hitting it cools the intercooler enough.

I'm interested in this from a different perspective though. Would it be worth encasing the cold air intake snorkel with this stuff, therefore "icing" the air as it comes into the engine?

[Xtreme F6]

  mickq said:

Ok, so here is how it goes.

Ages ago I used to play with these things. Forgot about them for a decade or two, and then I was sussing out a photo of a rally car's dash, saw the keyword, and then thought "holy sh1t, I cant believe I didnt think of doing that....".

They are called peltier coolers. If you have a portable fridge (like for camping) that uses 12v power, then chances are there is one in there.

In effect they are a flat sheet with two wires connected. You generally feed in 12v DC to the wires so they are perfectly matched to most cars electrical systems.

Technically they are heat pumps not coolers - they actually pump heat from the cold side to the hot side. To the point that things can freeze on the cold side.

When you connect the power, they tend to do the following

1) Connect it up and one side turns very hot, while the other gets icy cold - and I do mean icy. It will freeze stuff and you will get ice forming pretty quickly. (At room temp)

2) You can swap the voltage around (reverse polarity) and the opposite side gets cold while the other side gets hot.

So imagine this: its a hot day. Your intercooler is struggling and intake temps are rising, and it all results in power-sapping results.

So you flick a switch on your dash. One or more peltiers are then turned on. They are mounted on your intercooler in the right places (Not blocking airflow).Within minutes they are producing a freezing cold - literally icy - effect right on your intercooler. Intake temps drop, power increases, and everyone is happy.

This is why the rally car dash I saw had a switch mounted on it labelled "peltier". The rally car was an STi Spec C Group N, and you can see the same photo I saw on page 94 of the December Wheels magazine.

I just checked and they are easily available on ebay. You can buy them locally but they are more expensive. Only about US$16 for a large one (62mm square, 350w draw - not sure how the car will like 350w so smaller may be better). They may even be too strong as a 55w one will form ice in a few mins. 1-4 of them (I havent gone and specced out my intercooler to ensure they will fit somewhere nice as its night time) and you should be able to very quickly be able to just about freeze your intercooler if you wanted to.

So as long as the hot side is facing forward to have the air take away the heat, your intercooler will be getting very cold.

Now this is where it can get interesting. Peltiers have a temperature differential - the difference between the hot and the cold side. The more you can "cool" the hot side, the colder the cold side will be. You can do this a few ways: you can mount heat sinks (metal fin type things) to the hot side to help draw out the heat, or you can run pipes which cart away hot (water or similar) and circulate cooler water onto the peltier. Sort of like a pump to a mini reservoir of coolant or similar to keep circulating the hot coolant away and replacing it with cooler stuff. Both of them would assist the air rushing past in taking heat away from the hot side - and thus make the cold side colder.

If you do this, and for example (on a cool day) drop the hot side to just 10 degrees, the cold side will be around -60 degrees - now that is cold! And that's just with one. You could go even lower with several in one area. Even on the hottest of days Id imagine your intake would still be nice and cool. 

Even on a 30 degree day they should get pretty cold when the car is moving.

So there you go....Im amazed I didnt think of this sooner, but something for people to explore. I know I would LOVE to get rid of the heat drain I get when summer temps come around - and this may just be the way.

Thought there may be a few people interested here....make a nice summer experiment to see if it can be made to work ok.

I have used peltiers on computers for years and as you may know they are a heat pump. The problem is the amount of heat that you are talking about is not realistic for peltiers. I tested this about 4 months ago. The area you are looking at is just not do able. Also take into consideration, if you dont cool the peltier correctly it wont work correctly, on computers I used water cooling over top of the peltier that we hook upto a small fridge with water located inside of it with a water pimp.

This keeps the water at around 15 'c as the peltier gets hotter the hotter the CPU runs. Imagine the size of the peltiers you would need to cool the car .

[Xtreme F6]

  F6_Tornado said:

I think the massive volumes of air that travel through the intercooler is that great that you would need that many of these things that 240volts would be required.

Good in theory but in today’s world not even close enough to cope with the volume of air that it would have to deal with.

that would be correct, the are moves that fast that just doing the end tank would do nuthing, hence why cores are so big and also why the core that flowes the best isnt always the best, the air passes through to quick and doesnt get cooled enough.

[Benny]

I think this sort of thing would be good to have someone with a little time and money to experiment with and see exactly what the current draw would be and what effects this cooling would make. I'd be thinking more along the lines of Cro and encasing the intake piping where there isn't a great deal of air flow past the outside of the Peltier to effect it's cooling operation.

Another quick fix that I've seen used to cool the intercooler is spraying it with nitrous for a few seconds before a run. I'm not sure how expensive this process would be though.

[iTec]

  Benny said:

Another quick fix that I've seen used to cool the intercooler is spraying it with nitrous for a few seconds before a run. I'm not sure how expensive this process would be though.

you can use almost any compressed gas to do this

cro, the problem I would see with using the peltiers on the cold air intakes is that the air is still going to pass thrue the turbo which is going to heat it up again alot more efficiently.