Water to air intercooler location..

[[email protected] 0]

Mmm kay, so in an unrelated project to my E36, Im working on an old style roots supercharger setup on a V8.

The roots blower is top mounted, and needs to be as low as possible in the valley, so the manifold I have designed has no room for an internal water to air intercooler inside of it, though if height was not an issue I could easily run a good sized WTA intercooler between the supercharger and the intake manifold... but sadly that can't be a practical solution

Not long ago I was thinking perhaps a small water to air intercooler would work build into the throttle body adapter between the TB & supercharger unit so the ambient air temperature going into the supercharger was colder - obviously makes sense to cool the compressor discharge temperature (CDT) but as said in the previous paragraph I can't do that.

Would there be a benefit cooling the intake temp before the supercharger, or is this a complete was of time?

I'm only running 6 PSI so I almost don't need an intercooler but I still feel it would be a good idea to try incorporate something to reduce the air temp.

Any advise would be great.

Edited June 3, 2010 by Mike-E36

[[email protected] 0]

Hmmm I was just thinking about a bit further, I think Ive answered my own question...

Say for instance if the ambient temperature was 20 degrees c, the temperature of the water in the water to air setup would have to be less than that of the air going in which is unlikely, as its going to get heated up by the coolant lines being near the hot engine and other radiators... so all it would do is heat up the air going into the supercharger...

Certainly not a solution.

Otherwise, I was thinking maybe I could fit in an inline coolant pipe with heat sink fins in the middle of the intake manifold under the supercharger as theres a small amount of space in there where it could fit and not block anything, but its around 50x40x350mm max, similar to one of these in the picture bellow... though I think that would be too thick and need some fins removed...

How much effect it would have is the question though.. not much surface area compared to a proper intercooler.

Then again, maybe at my boost level I am over working it, not really needing to cool it..

Edited June 3, 2010 by Mike-E36

[*Glenn* 854]

An intercooler would be a good idea... however with the restrictions you have its not practical. SC's, unlike TC's are not subjected to the same amount of temperature from the exhaust and manifold. SC's cool the air down by compressing it and the SC's run quite cool. The Holden V8's fitted with a SC just have a front mounted induction housing with a slim air filter in them, maybe you could adapt something like that ?

[*Glenn* 854]

A bit OT, but I've always wondered why someone has never invented a small intercooler running off a AC compressor with an evaporator plate built into the induction system so that it acts in the same way as a aircon unit in a car. You could also control the degree of cooling as well.

[[email protected] 0]

A bit OT, but I've always wondered why someone has never invented a small intercooler running off a AC compressor with an evaporator plate built into the induction system so that it acts in the same way as a aircon unit in a car. You could also control the degree of cooling as well.

I was just thinking that too while laying in bed last night.

Powering a smaller compressor would be the question though... would you have something hooked up to run off the serpentine belt or some sort of quet electric motor.

I am sure 12v electric a/c compressors exist in in some form... but they could be noisy and expensive.

That would be at least the best solution, somewhat of an active cooling system rather than a passive one.

Hmmm

[Mike 1]

An intercooler would be a good idea... however with the restrictions you have its not practical. SC's, unlike TC's are not subjected to the same amount of temperature from the exhaust and manifold.

you were right up to this point...

SC's cool the air down by compressing it

opposite glenn - air is heated when it is compressed, whether is turbo, supercharger, or compressor

Mike - At only 6psi from a supercharger I wouldnt be so concerned about running and IC. You're definately wasting your time running one before any compression has taken place. If you can fit one though go for it, as its easy horsepower.

[thorburn 121]

what about water injection?

will most definately fit in the space

[[email protected] 0]

what about water injection?

will most definately fit in the space

Yeah, an methanol-water injection system is another alternative. A guy running the same system did it and said it worked very well & suggested it. Didn't get much detail from him however.

Though the biggest factor with that is the corrosion that can take place on the aluminum.

Are there ways around that though? A corrosion inhibitor of some sort? I haven't really looked in to the fine details.

Edited June 3, 2010 by Mike-E36

[dirtydoogle 383]

Yeah, an methanol-water injection system is another alternative. A guy running the same system did it and said it worked very well & suggested it. Didn't get much detail from him however.

Though the biggest factor with that is the corrosion that can take place on the aluminum.

Are there ways around that though? A corrosion inhibitor of some sort? I haven't really looked in to the fine details.

Methanol/water injection through the top of the blower. Keeps everything a bit cooler, the problem with this is the restrictions on how long you can run the engine for without topping the supply up, and the cost of doing so. I have seen this idea utilized multiple times.

The heat sink idea is practical and cost effective.

A strange idea, that works in my mind is a water cooled intake pipe before the blower? There shouldn't be a huge amount of heat generated by a low stressed and low speed rootes type anyway, so you could always tune around that by running a wee bit richer to keep the intake valves cooler.

[MLM 57]

A bit OT, but I've always wondered why someone has never invented a small intercooler running off a AC compressor with an evaporator plate built into the induction system so that it acts in the same way as a aircon unit in a car. You could also control the degree of cooling as well.

There would be a couple of reasons for this i can think of,

1) The compressor required to provide sufficient cooling for a large airflow at a high temp would need to be quite large itself and you would use the extra power you created just driving it. If it were a electric compressor it also would need a fair bit of grunt to run so upgraded alternators/batteries would be required which would be weighty again probably offsetting the performance gains.

2) Not an obvious one but an evap plat would build ice over time( they run at down to -34C), particularly on a humid day dispite having a hot air charge blown onto it. A way of shedding this water without it going through the engine would be an extra cpomplication

3) The heat exchanger in the inlet manifold would need to have sufficient surface area to cool the air effectivly so if a water to air heat exchanger dosnt fit a evaporator version probably wouldnt either.

I think the weight, power requirement and complication is why we havnt seen it before.

Another theory may be if the compressed gas came from a pre charged cylinder, good for drag racing ? maybe but the power gain would need to be sufficient to overcome additional weight etc

But hey where there is a will there is a way...

[*Glenn* 854]

What about a pre MAF pre SC front mounted watercooled IC ??

[dirtydoogle 383]

What about a pre MAF pre SC front mounted watercooled IC ??

Would help wouldn't it?

[Mike 1]

^ That was considered, i think?

Reason that wont work is that the air hasnt under gone compression yet so will be at ambient temperature, or the same as the air cooling the intercooler.

[MLM 57]

Reason that wont work is that the air hasnt under gone compression yet so will be at ambient temperature, or the same as the air cooling the intercooler.

+1

An intercooler can only "cool" down to ambient temperature (assuming 100% efficient thermal transfer)

IIRC as a rule of thumb arround 10 degrees C = 1 Hp in air charge density, though i think real world gains are more due to the ability to tune closer to the edge ie more advance etc.

[No name user 379]

An intercooler would be a good idea... however with the restrictions you have its not practical. SC's, unlike TC's are not subjected to the same amount of temperature from the exhaust and manifold. SC's cool the air down by compressing it and the SC's run quite cool. The Holden V8's fitted with a SC just have a front mounted induction housing with a slim air filter in them, maybe you could adapt something like that ?

superchargers are the one of the worst things as far as heat goes to which is there biggest down fall, yes turbos are exhaust driven and they too generate heat but alot easier to cool the charge air down over a sc.

sc's take 33% of the crank to make them work turbo's are 5-7%, sc's are around 50-60% efficent verus a turbo at 85-95%.

[tibbs.james 1]

Water/Meth Injection sounds idealfor your setup, but 6psi isn't really enough to matter, many oem turbo setups on jap cars run 5-8 psi with no intercooler with no problems at all.

I have heard of 12 psi + on some jap turbos running ok with no intercoolers.

[[email protected] 0]

^ yeah I have heard of quite a number of low setups running with out intercoolers.

I guess really I'm being pedantic. (Typical)

I found some M90 Supercharger tech specs, according to those I would be increasing the air temperature by 35-45 degrees at peak RPM, otherwise at lower RPM more around 25-35, so the air going into the engine would be that + whatever the ambient temperature is.

With colder spark plugs, a proper WMI kit I should be in the green.

[No name user 379]

Water/Meth Injection sounds idealfor your setup, but 6psi isn't really enough to matter, many oem turbo setups on jap cars run 5-8 psi with no intercooler with no problems at all.

I have heard of 12 psi + on some jap turbos running ok with no intercoolers.

They will run without coolers but it does nothing for performance and anti detonation,charge air temps can raise well past 150 degrees c and when running on crap fuel thats not a good look.

Yes you can retard timing but cly temps go up and again performance drops, a cooler is cheap insurance and low maintance.

Water/alky works great but remember unless you have safety features built into it when the water runs out your back to square one and could cost you and engine if you have increased timing to go with it.

[EdifGee 0]

They will run without coolers but it does nothing for performance and anti detonation,charge air temps can raise well past 150 degrees c and when running on crap fuel thats not a good look.

Yes you can retard timing but cly temps go up and again performance drops, a cooler is cheap insurance and low maintance.

.

I have a mate (completly OT) that has a 70's lancer that was running a 1600 motor he bolted a supercharger up to it and that was run on a motor that should never had been forced inductedbut did anyways. That motor seemed to last for atleast a month or so without any cooling other than standard and that was daily driven. It went pretty nuts to. But yeah. it was completely off topic. Just thought i might share it.