nemo1

iTrader: (1)

im doin some research on air o water intercoolers. i know they can be useful on the straight away because you can add ice which will give extremely good temp. how are these just on the steet tho, are they worth the extra equipment.

thanks

zeeman

iTrader: (1)

regular air to air intercoolers work great in our cars.

Air to water IC's are good when you don't have a lot of space for a FMIC or the necessary charge piping.....or on a high WHP race car.

MPR

Perfect example: Look at my sig.

We threw out the old air to air intercooler (interwarmer we called it) in our mr2 supercharged and installed a water to air intercooler because of the location of the engine (it's mid engine rwd) and to keep the intake piping short as possible. It works awsome.

zeeman

iTrader: (1)

cobalts have water to air IC's or heat exchangers as they call them.

I'm working on one now, thats turbo'd (not supercharged) and its using the stock heat exchanger. It works well below 15psi or so, but over that the logs are showing the IAT/IVT's increasing rapidly.

MPR

Which cobalt are you talking about?

The new SS turbo cobalts have fmic's. My friend has an HHR SS turbo (same car) and it uses a fmic as well.

If the IAT's are going up rapidly with a water to air ic, the water heat exchanger may be too small or the water pump may not be flowing enough water to keep up. On our MR2 we are using the a/c exchanger from my 86 volvo 740 as our water cooler/exchanger and dyno run after dyno run the IAT's are very consistant and do not increase quickly at all. Mind you, we are only running 11-12psi. Our IAT's were hitting a max of 90 degree's F durring dyno runs.

zeeman

iTrader: (1)

I'm working on a 06 cobalt SS that used to be supercharged.

The heat exchanger is definately too small on these engines, as its built into the intake manifold after where the supercharger would be.

90 degree's F isn't really what I'd call a cool charge.

This cobalt i'm doing is logging IAT's in the 60-70 degree F range....my car logs IAT's in boost around 60-75 dergrees F as well at 12psi with the smallest PT&E FMIC they make.

MPR

Ok I see. Probably be better off swapping to an NA manifold or newer cobalt ss turbo manifold and fmic.

90 degrees was that hottest it ever got during a dyno run after repeated runs on a hot summer day. It would drop down to between 50-60 degrees between runs.

90 degrees is very cool considering when we were using the air to air ic, the IAT's were hitting 260 degrees F at 14psi. Hence why we called it the 'interwarmer'.

zeeman

iTrader: (1)

interesting.

Usually the IAT's increase between runs due to the lack of air flowing through the engine, so the IAT sensor gets heatsoaked and reads high values.

The cobalt today, after a few back to back runs was logging IAT's in the 130F area....yikes!

MPR

Never heard of that happening. The IAT sensor that came with the megasquirt must be a good one. The IAT sensor shouldn't hold heat like that since it needs to read accurately. Ours shows the IAT going down the moment you lift off the throttle. Yeah, there's less air flow, but it's not hot compressed air.

Where is the IAT located on that cobalt?

zeeman

iTrader: (1)

I beleive its in the manifold (like with hondas).

The reason the reading will go up during runs (with the engine off) is b/c the sensor isn't seeing the air pass by it, instead its getting hot from being attached to a hot intake manifold.

I have tonnes of logs (from hondas and GM's) of the IAT's going sky high between runs (with the engine off). As soon as you start the car the IAT's drop back down and once you start driving the car the IAT's will drop futher.

The cobalts have a IVT (intake valve temperature) reading too, which is nice.

MPR

Ok I see.

On our MR2 I put the IAT sensor in the plastic charge pipe after the SC and before the manifold. Not really close to any strong source of heat.

zeeman

iTrader: (1)

after the IC?

We had the cobalt up on the hoist today (Crank sensor problem) and I was checking out the heat exchanger system closely, I should have taken pictures, I had my camera there and everything. Its pretty cool the setup, but uses a small pump and is a completely separate system from the engines coolant system. It has lines running to the heat exchanger and to a condensor tucked up behind the rad and a/c condensor. The pump is pretty small and the heat exchanger inside the manifold only so efficient, but its better than no boost charge cooling at all.

MPR

Yeah, sorry, the IAT sensor on our MR2 is between the IC and the intake mani.

We're using the AC exchanger from my 86 volvo 740 turbo with a fan, mounted flat under the rear of the car. It's so big you can see it hanging out the back. lol. Also using a fairly strong impeller type water pump (yay princess auto! lol) that seems to flow quite well. Use clear hoses to see the water flow while running as well.

We may switch to use the AC exchanger and fan I just took out of my em1 the other day, since it's smaller and more robust than the volvo unit and would fit under the car better.

We also run a seperate water cycle through the IC from the engine's cooling system.

Sounds like they need to spend a little more coin on that cobalt and put in a proper fmic or a better water pump.

I'd like to see pics of the setup tho...